All the patents obtained from the database were filtered to find out the most relevant patents, this process included going through the full text of the patent. Relevant patents related to stimulation technique for tight gas formations were found. This was followed by a detailed analysis of the relevant records. All the patents were analyzed to capture the focus of the patent, stimulation technique described in the invention and the fracturing ingredients used in the invention. The analyses of the patents lead to following observations:
====Top Assigneesand Inventors====Schlumberger, Exxonmobil and Halliburton feature in this listamong the top assignees.
[[Image:doc1.jpeg|center|500px]]
[[Image:IP activity pub year.jpg|center|500px]]
The publications of patents in the last were nearly stagnant till 2007 after which one can witness a sudden surge in publication related to tight gas stimulation. For the years 1997 and 2001 there was no publication of patents related to tight gas stimulation. The last 3 years (2008-2011) has witnessed a sudden growth of publication activity, the highest being in 2011.
[[Image:IP activity prio year.jpg|center|500px]]
The IP activity by priority year saw a sudden surge in activity in the year 1994 and thereafter from 2005 onwards, where a significant IP activity was observed. The numbers are more likely to change when patents claiming priority over the last 20 years are published. There was no IP activity observed in the year 1996.
====Geographical Distribution of patents====
b) Total patent families filed across the globe
[[Image:doc4Patentfamilies.jpeg|center|500px]] As shown in the above figure, United States has the highest filing of patent families filed across the globe. The filing spread is seen across North and South America, Europe, Russia and Australia. PCT filing also remains an important choice of assignees when it comes to filing patent globally.
==Technology and Scientific Information Search Strategy==
<mm>[[Tight Gas Recovery Analysis Taxonomy1.mm|800px|Interactive Mindmap|center|title Taxonomy for patent analysis]]</mm>
=Stimulation Techniques=
===Graphical representation of Assignee vs Stimulation techniques===
[[Image:Assignee vs Stimulation Technique.jpg|center|600px]]
Different types of fracturing techniques are used for stimulation of tight gas reservoir. Here we have covered the patents and articles which are focusing on the application of fracturing technique for the development of the tight gas reservoir.
==Hydraulic Fracturing==
'''Table: Hydraulic fracturing patent of different Companies.'''
{|border="2" cellspacing="0" cellpadding="4" width="80%" align = "center"
|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Hydraulic Fracturing'''
|-
===Halliburton===
[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110209868%22.PGNR.&OS=DN/20110209868&RS=DN/20110209868 US20110209868A1] titled "Fracturing a '''stress-altered subterranean formation'''" by Halliburton. Fracturing of a stress- altered subterranean formation is difficult to perform. Fracturing of stress altered formation using signaling subsystem communicably coupled with injection tools installed in the well bore.'''Signaling subsystem''' adapted to transmit control signals from a well bore surface to each injection tool to change the state of the injection tool according to stress condition....[Contd]
'''Signaling subsystem''' adapted to transmit control signals [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220090288833%22.PGNR.&OS=DN/20090288833&RS=DN/20090288833 US20090288833A1] titled "System and methods for constructing and fracture stimulating multiple ultra-short radius laterals from a parent well bore surface to each injection tool to change " by Halliburton. Hydrocarbons are often dispersed in a stacked sequence in the state reservoir. The reservoir also contains water bearing zones. Conventional equipment cannot be used for drilling and stimulation of the injection tool according to stress conditionmulti lateral well as they are very time consuming, and expensive in nature....[Contd]
It can modified stresses, thus fracture network can be created along a substantial portion of a horizontal well bore===Schlumberger===.....[Contd]
===Information from the Article=== Many authors have talked about massive hydraulic fracturing <u>Ahmed et al</u>. in 1979, <u>Hanson, in 1981 </u>and <u>Schubarth et al. in 2006</u>. '''Massive hydraulic fracturing '''(MHF) is a primary candidate for stimulating production from the tight gas reservoirs in the U.S. MHF is a more recent application that differs from hydraulic fracturing in that more fluid and proppant are pumped to create more extensive fractures in the reservoir.... [Contd] ===Summary of Hydraulic fracturing=== Various companies are using or developing different techniques for performing hydraulic fracturing in different operating condition and reservoirs. ==Multi Stage Fracturing=='''Table: Multi Stage Fracturing patent of different Companies.''' {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Multi Stage Fracturing'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59"|1|align = "center"|'''Schlumberger'''|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%22200902888332220110024121%22.PGNR.&OS=DN/2009028883320110024121&RS=DN/20090288833 US20090288833A120110024121 US20110024121A1] titled "System and methods for constructing and fracture stimulating multiple ultra-short radius laterals from a parent well" by Halliburton. Hydrocarbons are often dispersed </u></font>||Fracturing multilateral wellbores in a stacked sequence in the reservoir. The reservoir also contains water bearing zones. Conventional equipment cannot be used for drilling and stimulation single mobilization of multi lateral well as they are very time consuming, and expensive in naturefracturing unit. It provide a systems and methods for constructing |-|align = "center" bgcolor = "#9BBB59"|2|align = "center"|'''multiple ultra-shot radius laterals####''' from a parent well and stimulating the subterranean zones intersected by multiple lateral wellbores extending outwardly from one or more parent wellbores by injecting a stimulation fluid into the lateral wellbores; and stimulating the zones intersected by the lateral wellbores.|align = "center"|****|align = "center"|****|-|}
These sections now concentrate on the work done by the companies or institutes.
===Schlumberger===
<font color="#0000FF"><u>[http://wwwappft1.wipouspto.intgov/pctdbnetacgi/en/wo.jspnph-Parser?WOSect1=2011143053 WO2011143053A1PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110024121%22.PGNR.&OS=DN/20110024121&RS=DN/20110024121 US20110024121A1] </u></font> titled "Methods Method and apparatus for unconventional gas reservoir multilateral multistage stimulation with stress unloading for enhancing fracture network connectivityof a well" by Schlumberger. Conventional method shows decrease in hydrocarbon production due to damage It employs a '''continuous multistage fracturing of surface regions of the fractures, leading to decrease lateral wells by wellbore isolation and focused fracturing placement'''. Fracturing multilateral wellbores in the permeability a single mobilization of the formation. Improved method of hydraulic fracturing to initiate a fracture in the shale unit(s) by injecting sequentially connecting a treatment fracturing tubing string to each lateral wellbore, directing a fracturing fluid at that specific lateral wellbore in the fracture a manner to partially destabilize and remove achieve the shale and then repeating the step of desired fracturing in the shaleand isolating those lateral wellbore after it is fractured. It helps in minimizing the damage of the fracture surface...[Contd]
[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&pInformation from the Articles=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6508307.PN.&OS=PN/6508307&RS=PN/6508307 US6508307B1] titled "Techniques for hydraulic fracturing combining oriented perforating and low viscosity fluids" by Schlumberger. Conventional method for fracturing very tight gas formation by using perforation in combination of high viscosity fluid shows-
-Unoriented perforationsSaldungary et. al., results 2008 of '''Schlumberger''', studied on Efficient Multifractured Horizontal Completion change the economic equation in Latin America; they have discussed the effect of '''Effective Multistage Fracturing System (EMFS). '''The system consists of mechanical open hole packers, are capable of withstanding high differential pressures at high operating temperatures, with specially designed fracturing fluid does not take ports (FracPorts), are located between the most direct route into the fracture and leads to fracture the formation directly opposite to the perforationpackers... This effect often known as near-wellbore tortuosity is highly undesirable for well completion.[Contd]
-Use ===Summary of high viscosity fluids results in higher pumping cost, damaging to the newly propped fracture. And requires additional breakers, thus further increasing the cost of the treatment.Multi Stage Fracturing===
New method is a combination of From the steps of patents, it'''properly orienting perforations''' and creating s observed that Schlumberger employs a propped fracture by means continuous multistage fracturing of a '''low viscosity lateral wells and focused fracturing fluid'''placement....[Contd]From the articles, it can be concluded Schlumberger, is focused on effective multistage fracturing system (EMFS)....[Contd]
-Advantage of using oriented perforating are performing fracturing in pay zone area, minimizing sand production in weak formations, prevent damage to the equipment, such as electrical cables, fiber optic lines, submersible pump cables, adjacent production tubing or injection pipe.==Slickwater Fracturing==
-Low viscosity fluid leads to lower pumping and treatment cost===Graphical representation of Assignee's holding patents of Slickwater fracturing ===[[Image:Assignee Slickwater.jpg|center|500px]]
[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5295393.PN.&OS=PN/5295393&RS=PN/5295393 US5295393A] titled "Fracturing method and apparatus" by Schlumberger. Conventional method such as micro hydraulic fracturing technique for fracturing an underground formation, suffer from certain problems such as unwanted fracturing of the non pay zone area due to
-Pumping excessively at higher rates where control '''Table: Slickwater Fracturing patent of the pressure development in the test interval might be less accuratedifferent Companies.'''
{|border="2" cellspacing="0" cellpadding="4" width="85%" |align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Slickwater Fracturing'''|-Use of packers also leads to unwanted |align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "2"|'''1'''|align = "center" rowspan = "2"|'''Baker Hughes'''|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100089580%22.PGNR.&OS=DN/20100089580&RS=DN/20100089580 US20100089580A1]</u></font>|Performing fracturing of the formation method by combining proppant free stage and proppant ladden stage in two stages helps in reducing the conductivity damage of packers was also observed.|-|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7699106.PN.&OS=PN/7699106&RS=PN/7699106 US7699106B2]</u></font>|Hydraulic fracturing treatment by using ULW (Ultra lightweight) proppant and low viscosity slick water fracturing fluid.|-|align = "center" bgcolor = "#9BBB59" rowspan = "2"|'''2'''|align = "center" rowspan = "2"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''3'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|}
Method and apparatus used to fracture an underground formation that is '''traversed by a borehole'''. Traversing a borehole helps in
-Proper orientation of These sections now concentrate on the fracture,work done by the companies or institutes.
-Reducing the breakdown pressure for the hydraulic fracturing operation and also reducing the damage occurring at the straddle packers,===Baker Hughes===
[http://appft1.uspto.gov/netacgi/nph-Low energy storage in the Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100089580%22.PGNR.&OS=DN/20100089580&RS=DN/20100089580 US20100089580A1] titled "Method of enhancing fracture conductivity" by Baker Hughes. In hydraulic fracturing, fracturing fluid in containing gelled fluid, viscosifying polymers and surfactants used to provide fluid viscosity for proppant packing but often leads to the system so allowing better controlformation of filter cake which causes conductivity damage....[Contd]
[http://appft1patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htmlhtm&r=1&f=G&l=50&s1=%2220090065253%227699106.PGNRPN.&OS=DNPN/200900652537699106&RS=DNPN/20090065253 US20090065253A17699106 US7699106B2] titled "Method and system for increasing production of a reservoirreducing fluid loss during hydraulic fracturing or sand control treatment" by SchlumbergerBaker Hughes. Complex fractures Hydraulic fracturing treatment using high ASG (Apparent Specific Gravity) proppant and proper fracture geometry generally give improved production rateshigh viscous fracturing fluid often leads to....[Contd]
Complex fractures increases ===Information from the tortuosity of the flow paths, proppant may not be sufficient to prop the fractures developed by them as proppants may not be adequately delivered to all of the branches of the fracture, or the density of the proppant delivered might be insufficient to maintain conductivity. Those portions of the fracture might then close, thereby reducing fracture conductivity.Articles===
Pearce et. al., 2002 of The '''Houston Exploration Co '''studied on successfully pushing the limits in tight gas fracturing. A South Texas tight gas field was fractured using '''LPF (Lower-So, a need exists for a method, apparatus and polymer fluid) system '''. LPF system avoided the proppant damage due to promote the self-propping of complex fractures less polymer residue, and complex fractured regions,improved well productivity through increased fracture conductivity....[Contd]
'''Generating proper fracture geometry''', the conditions affecting the treatment ===Summary of the individual reservoir (e.g., near-wellbore effects, reservoir heterogeneity and textural complexity, in-situ stress setting, rock-fluid interactions) should be determined before generating a fracture.Slickwater fracturing===
-So, a need exists for a method, apparatus Baker Hughes focused on hydraulic fracturing treatment by using ULW (Ultra lightweight) proppant and system to detect the conditions required for generating induced fracture complexity, high fracture density, large surface area during low viscosity slick water fracturing, identify unique conditions of reservoir properties, fluid. And performing fracturing method in-situ stress, and completion settings to determine a design of fracture treatments that specifically adapt to these conditionstwo stages helps in reducing the conductivity damage....[Contd]
The method to increase and/or optimize production ==Acid Fracturing=====Graphical representation of a reservoir involves first the determination Assignee's holding patents of the textural and induced fracture complexity of the reservoir, then follows performing the first operation based on the complexities wherein the first operation introduces shear stress into the formation which can be either fracturing wellbores with cement slurries or proppant, multilateral drilling, inducing thermal stresses and then creating fractures. Also, performing the second operation which can again be either Acid fracturing or multilateral drilling till the satisfied production rate is reached.===
[http[Image://appft1Assignee acid.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220090065198%22.PGNR.&OS=DN/20090065198&RS=DN/20090065198 US20090065198A1jpg|center|500px]] titled "Method and system for increasing production of a reservoir using lateral wells" by Schlumberger.
Complex fractures and proper fracture geometry generally give improved production rates.
Complex fractures increases the tortuosity '''Table: Acid Fracturing patent of the flow paths, proppant may not be sufficient to prop the fractures developed by them as proppants may not be adequately delivered to all of the branches of the fracture, or the density of the proppant delivered might be insufficient to maintain conductivity. Those portions of the fracture might then close, thereby reducing fracture conductivitydifferent Companies.'''
{|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Acid Fracturing'''|-So, |align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "2"|'''1'''|align = "center" rowspan = "2"|'''Schlumberger'''|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7380602.PN.&OS=PN/7380602&RS=PN/7380602 US7380602B2]</u></font>|Treating a need exists for subterranean carbonate with a methodfluid comprising of an acid, apparatus and system to promote the selfchelating agent, or betaine surfactant.|-propping |<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6828280.PN.&OS=PN/6828280&RS=PN/6828280 US6828280B2]</u></font>|Stimulation of complex fractures and complex fractured regionshydrocarbon production from low permeability formations by hydraulic fracturing,acid fracturing, and hydraulic fracturing followed by gravel packing in a single operation|-|align = "center" bgcolor = "#9BBB59"|'''2'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''3'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|}
Generating proper fracture geometry, These sections now concentrate on the conditions affecting work done by the treatment of the individual reservoir (e.g., near-wellbore effects, reservoir heterogeneity and textural complexity, in-situ stress setting, rock-fluid interactions) should be determined before generating a fracturecompanies or institutes.
-So, a need exists for a method, apparatus and system to detect the conditions required for generating induced fracture complexity, high fracture density, large surface area during fracturing, identify unique conditions of reservoir properties, in-situ stress, and completion settings to determine a design of fracture treatments that specifically adapt to these conditions.===Schlumberger===
Method comprises knowing the textural [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7380602.PN.&OS=PN/7380602&RS=PN/7380602 US7380602B2] titled "Composition and induced fracture complexity through software<nowiki>’</nowiki>s, drilling the first wellbore comprising method for treating a lateral well in the subterranean formation based on " by Schlumberger. Matrix acidizing treatment leads to the complexity data, drill a second wellbore and fracture the second wellbore, inject a material problem of (cement1) that fills inadequate radial penetration (portions of the fractures, pressurizing formation away from the fracturing fluid in the second wellbore, the fracture in the second wellbore penetrates in radial direction is untouched by the first wellbore to induce a fracture in acid because all of the first wellboreacid reacts before it can get there); (2)....[Contd]
The plan [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6828280.PN.&OS=PN/6828280&RS=PN/6828280 US6828280B2] titled "Methods for introducing shear stress into the formation include stimulating hydrocarbon production" by Schlumberger. In hydraulic and acid fracturing wellbores with cement slurries or proppant, preventing closurea first, to alter viscous fluid called a "pad" is typically injected into the stress conditions prior formation to a subsequent initiate and propagate the fractureand often to contribute to fluid loss control and mainly consist of polymers. Methods are provided for stimulation of hydrocarbon production from low permeability formations by hydraulic fracturing, '''acid fracturing'''....[Contd]
[http://www.wipo.int/pctdb/en/wo.jsp?WO=2011070453 WO2011070453A2] titled "Method for increasing fracture area" by Schlumberger. Existing fracture techniques are limited in providing an optimal effective fracture area. A method of improving the fracture area by a fracturing treatment, comprises the steps of first performing an evaluation of textural heterogeneity of a formation; Creating step over<nowiki>’</nowiki>s by delivering a fracture treatment material downhole at high pressure, propogating a fracture ==Information from step over<nowiki>’</nowiki>s and closing (isolating) the respective step over and re-pressurizing the fracturing material to create more step over<nowiki>’</nowiki>s and thus the fracture complexity and formation conductivity.Articles===
[http://www.wipoAl-Ghurairi et.int/pctdb/en/woal.jsp?WO=2011081550 WO2011081550A1] titled "Hydraulic fracturing system" by Schlumberger. Need , 2003 of an inexpensive proppant materials for hydraulic fracturing of tight gas reservoir having crushable properties. '''Hydraulic fracturing utilizing crushable particulatesSaudi Aramco''', which provide sufficient and cost effective fracture conductivity dependent studied on closure stressSuccessful Fracturing through optimizations steps for high rate deep gas wells in carbonate reservoirs of Saudi Arabia where acid fracturing treatments was applied at Khuff reservoir, has been presentedgelled HCl acid system, emulsified acid (consisting of HCl acid and diesel) was tested for tight reservoirs to achieve deeper penetration....[Contd]
Crushable proppant produces more than about 20 percent fines in a crush test using hydraulic pressure, crushing can be controlled by changing rate ===Summary of injection of proppant slurry.Acid fracturing===
Fine particulates are used to deliver proppant far-field (deep into the reservoir away from the wellbore) into Schlumberger is using acid fracturing technique for subterranean carbonate with a complex fracture networkfluid comprising of an acid, where no high strength proppants can be placed via current practiceschelating agent, or betaine surfactant. And similarly along with hydraulic fracturing also acid fracturing was tried....[Contd]
==Carbon dioxide Fracturing=Integrated Petroleum Technologies='''Table: Carbon dioxide Fracturing patent of different Companies.'''{|border="2" cellspacing="0" cellpadding="4" width="70%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Carbon dioxide Fracturing'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59"|'''1'''|align = "center"|'''Schlumberger'''|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7726404.PN.&OS=PN/7726404&RS=PN/7726404 US7726404B2]</u></font>|Use of carbon-dioxide-based fracturing fluids|-|align = "center" bgcolor = "#9BBB59"|'''2'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''3'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|}
[http://patftThese sections now concentrate on the work done by the companies or institutes.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&pSchlumberger=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7032671.PN.&OS=PN/7032671&RS=PN/7032671 US7032671B2] titled "Method for increasing fracture penetration into target formation" by Integrated Petroleum Technologies. Reliable method of propagating a fracture farther from the well-bore into a target formation and inhibiting the growth of the fracture in the non-pay zones (water bearing zones) is required. The geometry of the fractures is increased by creating a zone of increased in-situ stress at a vertical distance from the target zones and hydraulically fracturing the target zones. The fracture in the target zone then propogates vertically in the stress induced zone till the limit set by the zone of increased stress is reached after which the additional fracturing fluid which is pumped propagates the main fracture more laterally and farther from the well.
[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=Phillips Petroleum CompanyPALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7726404.PN.&OS=PN/7726404&RS=PN/7726404 US7726404B2] titled "Use of carbon-dioxide-based fracturing fluids" by Schlumberger. Conventional hydraulic and slickwater fracturing leads to the problem of fluid leak off, well damage and water blocks. Treatment of shale-containing subterranean formation is carried out by forming a '''carbon dioxide treatment fluid''' having a viscosity of less than about 10 mPa-s at a shear rate of about 100 s.sup.-1. and comprising of 90% by weight carbon dioxide and a surfactant....[Contd]
[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&pSummary of Carbon dioxide Fracturing=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5054554.PN.&OS=PN/5054554&RS=PN/5054554 US5054554A] titled "Rate control method for hydraulic fracturing" by Phillips Petroleum Company. Production of fluids from the fractured zone or area is more a function of fracture conductivity in high permeability reservoir, hence increased fracture length is not as important as increased fracture width. Therefore a need exist to provide a fracture which will maximize the production of hydrocarbon fluids from earth formations having moderate to high permeability by increasing the fracture width. It provides an improved method of hydraulic fracturing of formations to produce hydrocarbon fluids by controlling the rate of injection to form the desired fracture length and width in moderate permeability and high permeability formations.
===Union Oil Company===Schlumberger has developed carbon-dioxide-based fracturing fluids and shows CO<sub>2</sub> has ability to displace methane from the shale-containing formations....[Contd]<br>Articles say Schlumberger has developed new CO<sub>2</sub> viscoelastic surfactant (VES) system, which is known as ClearFRAC....[Contd]
[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&dFoam Fracturing=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&lGraphical representation of assignee’s holding patents of foam fracturing=50&s1=5472050=[[Image:Ass foam.PN.&OS=PN/5472050&RS=PN/5472050 US5472050Ajpg|center|500px]] titled "Use of sequential fracturing and controlled release of pressure to enhance production of oil from low permeability formations" by Union Oil Company. Under current economic conditions, there is a need for a more efficient process for producing oil from low permeability formations. Recovery of hydrocarbon from a low permeability formation is increased by fracturing the formation and avoiding the release of pressure from the fracture to lengthen the time so that the reservoir pressure remains above the fracture collapse pressure.
A method for producing hydrocarbon from a hydrocarbon'''Table: Foam Fracturing patent of different Companies.'''{|border="2" cellspacing="0" cellpadding="4" width="102%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Foam Fracturing'''|-containing subterranean formation, includes |align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "2"|'''1'''|align = "center" rowspan = "2"|Halliburton|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5990052.PN.&OS=PN/5990052&RS=PN/5990052 US5990052A]</u></font>|Foamed fracturing fluid|-|align = "center"|<font color="#0000FF"><u>US5310002A</u></font>|Microemulsion generating component and foaming agent component function to enhance the steps ability ofthe compositions to remove any blocks of fluids interlocked with gas in formations|-|align = "center" bgcolor = "#9BBB59"|'''2'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''3'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|}
- drilling and casing a wellbore which penetrates the subterranean formation, perforating the casing to form set of perforations, fracturing the subterranean formation with water, steam or gas through the set of perforations; producing the hydrocarbon from the formation through the set of perforations while restricting the release of pressure from the fractured formation to lengthen the time that the reservoir pressure remains above the fracture collapse pressure; and repeating the steps till satisfactory results are produced.===Halliburton===
[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5990052.PN.&OS=PN/5990052&RS=PN/5990052 US5990052A] titled "Foamed fracturing fluid" by Halliburton. Fracturing fluids must provide an optimal balance between minimizing fluid leakage, filtercake buildup thickness and filtercake removal as it impairs the permeability and conductivity of the formation. Need of a foamed fracturing fluid that has the performance advantages of crosslinked gel foams but which deposits a filtercake which can be substantially completely removed after the fracturing operation is completed....[Contd] <font color="#0000FF"><u>US5310002A </u></font>titled "Gas well treatment compositions and methods" by Halliburton <font color="#FF0000">(Also in foam)</font>. Treatment fluids or fracturing fluids remaining in the pores of the formation and water blocks leads to kind of damage that impairs subsequent hydrocarbon production from the formation. The release microemulsion generating component and foaming agent component function to enhance the ability of pressure the compositions to remove any blocks....[Contd] ===Information from the Articles===Walser et. al., 2001 of '''BJ Services Company '''USA, studied on Production response from Southeastern New Mexico Morrow wells stimulated with binary foam. Stimulation and fracturing of Morrow formation in south eastern New Mexico was performed with binary foam fracturing fluid. Stimulation fluid contains liquid CO<sub>2</sub>, gaseous nitrogen, gelled 2% KCl water, methanol and hydrated polymer are added in the base gelled water....[Contd] ===Summary of Foam Fracturing=== Halliburton disclosed a new crosslinked foamed fracturing fluids and also using foam agent in combination with microemulsion to remove any blocks of fluids in the reservoir....[Contd] ==Explosive Fracturing=='''Table: Explosive Fracturing patent of different Companies.'''{|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Explosive Fracturing'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59"|1|'''ExxonMobil'''|align = "center"|<font color="#0000FF"><u>[http://www.wipo.int/pctdb/en/wo.jsp?WO=2011115723 WO2011115723A1]</u></font>|System and method for fracturing rock in tight reservoirs by regulating explosive fracturing|-|align = "center" bgcolor = "#9BBB59"|2|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} These sections now concentrate on the rate at work done by the companies or institutes. ===ExxonMobil=== [http://www.wipo.int/pctdb/en/wo.jsp?WO=2011115723 WO2011115723A1] titled "System and method for fracturing rock in tight reservoirs" by ExxonMobil. A conventional hydraulic and explosive fracturing lead to pervasive, isotropic permeability increase in the rock of the formation but does not create a spatially extensive network of fractures.'''Explosion fracturing is done in the lateral wells by using a squash head charge'''....[Contd] ===Information from the Articles=== Cui et. al., 2006 PetroChina studied In-fracture Explosive Hydraulic fracturing fluid and its rheological study. An experimental test was performed using In Fracture Explosive Hydraulic Fracturing Fluid (IFEHFF) which oil is pumped a combination of hydraulic fracturing fluid properties and an explosion fluid (TNT). According to simulator calculation, the system can generate fractures with desired geometry and suspend explosive evenly in the fractures. ===Summary of Explosive Fracturing=== Both Exxonmobil has worked on increasing the permeability of the formation by inducing explosive fracturing. Exxonmobil has adopted a technique of drilling lateral wells and placing the squash head charge in the wells....[Contd] ==Sleeve fracturing== {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Sleeve fracturing'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59"|1|align = "center"|'''Coiled Tubing Specialties'''|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110290561%22.PGNR.&OS=DN/20110290561&RS=DN/20110290561 US20110290561A1 ]</u></font>||Downhole Hydraulic Jetting Assembly, and Method for Stimulating a Production Wellbore|-|} ===Coiled Tubing Specialties=== [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110290561%22.PGNR.&OS=DN/20110290561&RS=DN/20110290561 US20110290561A1] titled "Downhole Hydraulic Jetting Assembly, and Method for Stimulating a Production Wellbore" by Coiled Tubing Specialties. Need of a method for forming lateral boreholes from a parent wellbore for hydrocarbon recovery from the formation. It provides a new stimulation technique for hydrocarbon-producing formation....[Contd] ===Information from the Articles=== Rahim et. al., 2011 of '''Saudi Aramco '''studied on success criteria for Multistage Fracturing of tight gas in Saudi Arabia. Open Hole Multi Stage (OHMS) fracturing was used to improve hydrocarbon production from the deep gas carbonate sandstone wells in Saudi Arabia. Here authors talk about dual sleeve hydraulic fracturing device....[Contd] ===Summary of Sleeve Fracturing===....[Contd] ==Hydrocarbon recovery by using control valves biogenic materials combined with Pneumatic fracturing== {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Hydrocarbon recovery by using biogenic materials combined with pneumatic fracturing'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59"|1|align = "center"|'''Groundwater Services Inc'''|align = "center"|<font color="#0000FF"><u>[http://www.wipo.int/pctdb/en/wo.jsp?WO=2008041990 WO2008041990A1]</u></font>||Stimulating anaerobic biologic production of methane from non-liquid hydrocarbon-bearing subsurface formations|-|} These sections now concentrate on the work done by the companies or institutes. ===Groundwater Services Inc.===[http://www.wipo.int/pctdb/en/wo.jsp?WO=2008041990 WO2008041990A1] titled "Methods and systems for '''stimulating biogenic''' production of natural gas in a subterranean formation" by Groundwater Services Inc. A new method and systems for stimulating anaerobic biologic production of methane from non-liquid hydrocarbon-bearing subsurface formations. It comprises of subsurface formation comprising a hydrocarbon;....[Contd]
===Information from the Article===
Many authors have talked about massive hydraulic fracturing <u>Ahmed '''Lan et . al</u>. in 1979, <u>Hanson2010 '''of '''Drilling Research Institute of Shengli Oilfield''', in 1981 </u>and <u>Schubarth et al. in 2006</u>. Dongying, Shandong studied on application of '''Massive hydraulic fracturing bio-enzymatic '''(MHF) is a primary candidate for stimulating production from completion fluid in the tight sand gas reservoirs in the Uof ordos Daniudi Gas field.S. MHF is a more recent application that differs from hydraulic fracturing in that more Solid free brine completion fluid and proppant are pumped to create more extensive fractures in shows a little effect on the reservoirformation damage, water blocking and solid slugging with small particle. Application of MHF to increase production from the tight reservoirs has provided mixed An environment acceptable and, nontoxic bio-enzymatic completion fluid was prepared and tested in many cases, disappointing results especially in lenticular reservoirs (<u>Hanson,1981</u>)15 horizontal wells of Ordos Dainiudi gas field.... [Contd]
===Summary of Hydrocarbon recovery by using biogenic materials combined with Pneumatic fracturing===
....[Contd]
==Chemical reaction induced pressure pulses fracturing==
{|border="2" cellspacing="0" cellpadding=Summary of Hydraulic "4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Chemical reaction induced pressure pulses fracturing'''|-|align ="center" bgcolor ="#9BBB59"|'''S.No'''|align ="center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59"|1|align = "center"|'''Univ Louisiana State'''|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5083615.PN.&OS=PN/5083615&RS=PN/5083615 US5083615A]</u></font>||The pressure pulses are generated by the reaction of aluminum alkyl with either water, or alcohol, or acid.|-|}
Various These sections now concentrate on the work done by the companies or institutes. ===Univ Louisiana State=== [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5083615.PN.&OS=PN/5083615&RS=PN/5083615 US5083615A] titled "Aluminum alkyls used to create multiple fractures" by Univ Louisiana State. The pressure rise after fracturing is the important parameter in determining the fracture pattern. The time required for the pressure rise is found to be longest in hydraulic fracturing. So to control the fracture pattern the pressure rise time has to be controlled....[Contd] ==Propellant Fracturing== {|border="2" cellspacing="0" cellpadding="4" width="100%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Propellant Fracturing'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Inventor'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Comment'''|-|align = "center" bgcolor = "#9BBB59"|1|align = "center"|'''Carter E. E'''|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5083615.PN.&OS=PN/5083615&RS=PN/5083615 US20110247816A1]</u></font>||Method and apparatus for increasing well productivity by using solid rocket propellant in the slots.|-|} '''Carter E. E'''[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110247816%22.PGNR.&OS=DN/20110247816&RS=DN/20110247816 US20110247816A1] titled "Method and Apparatus for Increasing Well Productivity" by Carter E. E.,Method and apparatus for increasing well productivity by using explosives such as '''solid rocket propellant''' are typically a mixture of ammonium perchlorate and....[Contd] ==High pressure & high temperature (HPHT) fracturing== '''Information from the Articles''' Bartko et.al., 2009 of '''Saudi Aramco '''studied first application of high density fracturing fluid to stimulate a high pressure & high temperature tight gas producer sandstone formation of Saudi Arabia. High pressure and High Temperature fracturing was performed by using or developing a new fluid system containing '''sodium bromide (Nabr brine), carboxymethylhydroxypropyl guar (CMHPG) gelling agent, zirconium cross linker and gel stabilizer'''. The new high density fracturing fluid can be used for high temperature fracturing as it can be stable upto 350 oF. Positive results obtained on field application of this new fluid system in Sarah and Qusaiba formation basin like lower injection rates, delay crosslinking time, good proppant transport capabilities, lower horsepower requirements and a safer work environment....[Contd] Table shows the comparison made by the author between different techniques fracturing fluids. High density weighted fracs (Sodium bromide frac fluid <nowiki>+</nowiki> special cross linker) shows higher conductivity and lower fracture complex growth as compared to other fluids while high rate water frac shows lower fracture conductivity and higher fracture complex growth.[[Image:Comparison between different fracturing fluids.jpg|centre|thumb|800px|Comparison between different fracturing fluids]] '''Summary of High pressure & high temperature (HPHT) fracturing''' Saudi Aramco in 2009 used sodium bromide (Nabr brine)for fracturing wells....[Contd] =Fracturing Fluids and Additives used= '''Fracturing Fluid''' Water based fracturing fluids has been widely used whereas hydrofluoric acids and hydrochloric acids are also commonly employed to dissolve some types of rock, wherein hydrochloric acids are very effective in carbonates. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#C5BE97" colspan = "5"|'''Fracturing fluid'''|-|align = "center" bgcolor = "#C5BE97"|'''Acid'''|align = "center" bgcolor = "#C5BE97"|'''Hydrocarbon fluid'''|align = "center" bgcolor = "#C5BE97"|'''Gas'''|align = "center" bgcolor = "#C5BE97"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#C5BE97"|'''<nowiki>### </nowiki>'''|-|align = "center"|15% Hydrochloric acid|align = "center"|Metal associated-phosphate ester gelled oils, oil, frac oils, gelled oil|align = "center"|Carbon dioxode|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>| |align = "center"|<nowiki>****</nowiki>| |align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| | |align = "center"| |-|align = "center"|<nowiki>****</nowiki>| | | | |-|} ===Graphical representation of Fracturing fluids used for corresponding stimulation methods=== [[Image:Fracturing fluids.jpg|center|800px]] The combination of various fluids used for performing fracturing of reservoirs satisfactorily is shown in the above graph. ==Proppant== '''Proppant''': Allows the fractures to remain open so the gas can escape. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#B2A1C7" colspan = "6"|'''Proppants'''|-|align = "center" bgcolor = "#B2A1C7"|'''Sand'''|align = "center" bgcolor = "#B2A1C7"|'''Resin-coated'''|align = "center" bgcolor = "#B2A1C7"|'''Man-made ceramics'''|align = "center" bgcolor = "#B2A1C7"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#B2A1C7"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#B2A1C7"|'''<nowiki>### </nowiki>'''|-|align = "center"|Sand grains|align = "center"|Resin-coated sand,resin-coated sintered bauxite, resin coated ceramics|align = "center"|Ceramic beads|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| | |align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| | |align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| | |align = "center"| |align = "center"|<nowiki>****</nowiki>|-|} The proppant materials have greatly improved and the technology for specially engineered proppants continues to advance. The most widely used proppant so far is naturally occurring sand for eg. white and brown sands(Ottawa, Brady respectively), quartz sand grains. To increase the strength of the proppants resin coated proppants has been come up which are Resin-coated sand, resin-coated sintered bauxite, resin coated ceramics. Ultralight weight proppants which can easily be transported by slickwater is used currently. '''Ultra lightweight proppant preparation-'''Below are the additives employed by '''Baker Hughes Incorporated''' to prepare porous particulate material for use as lightweight material in liquid carbon dioxide-based well treatment systems. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#C2D69A"|'''Additives'''|align = "center" bgcolor = "#C2D69A"|'''Role'''|align = "center" bgcolor = "#C2D69A"|'''<nowiki>### </nowiki>'''|-|align = "center"|Chemical treatment|align = "center"|Nylon, polyethylene, polystyrene chemicals|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} ===Graphical representation of Additives used for corresponding stimulation techniques===[[Image:Additive used.jpg|800px|center]] Hydraulic and slickwater fracturing employs viscosifiers for thickening the fracturing fluid which helps in proppant placement but the amount used in slickwater is less as compared to hydraulic as seen in the graph. The highest amount of breakers are used in hydraulic and slickwater fracturing as it degrades the polymers present in the well after fracturing. Friction reducers are mainly employed in slickwater fracturing. The Role of the different operating condition additives used and the compounds employed for the corresponding additives are mentioned below. ==Acid== '''Acid:''' Helps dissolve minerals and initiate cracks in the rock. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "3"|'''Acid'''|-|align = "center" bgcolor = "#EAF1DD"|'''Inorganic /mineral acid'''|align = "center" bgcolor = "#EAF1DD"|'''Simple organic acid'''|align = "center" bgcolor = "#EAF1DD"|'''Organic aromatic acid'''|-|align = "center"|HCl|align = "center"|Carboxylic acid|align = "center"|Chlorobenzoic acid|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|} ==Biocides== '''Biocides''' are added to the mixing tanks with the gelling agents to kill bacteria which otherwise can cause problems of plugging (inhibiting the flow of gas), corrosion failures of downhole equipment, solid deposition (or scale), break down the gelling agent reducing its viscosity and ability to carry proppant. Multifunctional material comprising aldehydes; formaldehyde; dialdehydes; glutaraldehyde; hemiacetals;....[Contd] ==Breaker=='''Breaker''': It allows a delayed break down of the frac gel. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "6"|'''Breaker'''|-|align = "center" bgcolor = "#EAF1DD" colspan = "4"|'''Oxidative'''|align = "center" bgcolor = "#EAF1DD" rowspan = "2"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD" rowspan = "2"|'''<nowiki>### </nowiki>'''|-|align = "center" bgcolor = "#EAF1DD"|'''Sulfate group'''|align = "center" bgcolor = "#EAF1DD"|'''Chromate group'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|-|align = "center"|Ammonium persulfate – GBW 5|align = "center"|Potassium dichromate|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|} The proper breaker selection for a given gel system is very important to the success of the fracturing treatment. The high viscosity frac fluid must sufficiently degrade with time to allow for high fracture fluid recovery rates on the flowback and cause minimal damage to the formation. Widely used oxidative breakers are sulfates, chromates, borates,....[Contd] ==Corrosion inhibitor=='''Corrosion inhibitor''': It prevents corrosion of equipment (pipe, pump etc) Compounds for performing the function of corrosion inhibitors employed in fracturing treatments are Azoles, quaternary amines, formic acid....[Contd] ==Crosslinker=='''Crosslinker''': It helps in maintain the viscosity of frac fluids. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "6"|'''Crosslinker'''|-|align = "center" bgcolor = "#EAF1DD"|'''Borates'''|align = "center" bgcolor = "#EAF1DD"|'''Zirconium'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|-|align = "center"|Borate crosslinked polymer, borate crosslinked guar|align = "center"|Zirconium lactate, zirconium lactate triethanolamine and zirconium diisopropylamine lactate|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"| |align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"| |align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"| |-|} Widely used crosslinkers are boron based and zirconium based compounds such as borate crosslinked polymer....[Contd] ==Friction Reducers== '''Friction Reducers''': It helps in reducing the friction of the frac fluid. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "4"|'''Friction reducer'''|-|align = "center" bgcolor = "#EAF1DD"|'''Polyacrylamide'''|align = "center" bgcolor = "#EAF1DD"|'''Other acrylate based compound'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|-|align = "center"|Hydrolyzed polyacrylamide|align = "center"|Polyacrylates|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |-|} Amongst various friction reducers like acrylate based compounds (polyisobutyl methacrylate, polymethyl methacrylate),....[Contd] ==Gel=='''Gel''': It helps to suspend proppant/sand in the frac. fluids {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "5"|'''Gel'''|-|align = "center" bgcolor = "#EAF1DD"|'''Guar/Guar gum'''|align = "center" bgcolor = "#EAF1DD"|'''Cellulose and its derivatives'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|-|align = "center"|Borate crosslinked guar|align = "center"|Hydroxyethyl cellulose (HEC), Carboxymethyl hydroxyethyl cellulose (CMHEC), Carboxymethyl cellulose (CMC)|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |align = "center"| |-|} Crosslinked Gel Fluids consisting of Guar and its derivatives such as borate cross-linked guar gel,....[Contd] ==Viscosifiers== '''Viscosifiers''': Helps in maintaining the viscosity of frac. fluids. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "3"|'''Viscosifiers'''|-|align = "center" bgcolor = "#EAF1DD"|'''Synthetic polymers'''|align = "center" bgcolor = "#EAF1DD"|'''Polysaccharides'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|-|align = "center"|Polyvinyl polymers, substituted polyvinyl polymers, polyvinyl acetate|align = "center"|Cellulose ethers, galactomannans|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |-|} Most widely used viscosifiers are polysachharides such as guar based compounds (hydroxypropyl guar (HPG),....[Contd] ==Clay stabilizer=='''Clay stabilizer''': Prevents formation clays from swelling''' '''and includes''' '''compounds like''' '''sodium salicylate''', '''potassium chloride, sodium chloride, ....[Contd] ==Surfactant=='''Surfactant''': Used to increase the viscosity of the fracture fluid {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "5"|'''Surfactant'''|-|align = "center" bgcolor = "#EAF1DD"|'''Viscoelastic'''|align = "center" bgcolor = "#EAF1DD"|'''Cationic/Anionic'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|-|align = "center"|Erucylamidopropyl betaine|align = "center"|Erucylamidopropyl betaine and oleylamidopropyl betaine, oleylamidopropyl betaine|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|-|} Various surfactants used so far have been presented in the table of which viscoelastic and zwitterionic surfactants are mainly used....[Contd] ==Iron control=='''Iron control''': It prevents precipitation of metal oxides. For eg''': '''Citric acid has been widely used by Schlumberger and Halliburton in treatment of formation. ==pH adjusting agent=='''pH adjusting agent''': Maintains the effectiveness of other components, such as crosslinkers. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "7"|'''pH adjusting agent'''|-|align = "center" bgcolor = "#EAF1DD"|'''Carbonates'''|align = "center" bgcolor = "#EAF1DD"|'''Phosphates'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|-|align = "center"|Sodium sesquicarbonate, sodium carbonate|align = "center"|Sodium phosphate, sodium hydrogen phosphate|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |-|align = "center"| |align = "center"| |align = "center"| |align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"| |-|} '''pH control agents''' includes Carbonates(sodium carbonate, potassium carbonate), Phosphates(sodium or potassium phosphate, sodium or potassium hydrogen phosphate, sodium or potassium dihydrogen phosphate),....[Contd] ==Scale inhibitor=='''Scale inhibitor''': It prevents scale deposits in the pipe. It includes compounds like methylene phosphonic acid, 1-hydroxy ethylidene-1,1-diphosphonic acid; 2-hydroxyphosphonocarboxylic acid;....[Contd] ==Fibrous material=='''Fibrous material''': Fibres are used to prevent proppant flowback and also enhance proppant transport. Polylactic acid fibers and polyglycolic acid fibres are mainly used by Schlumberger. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "4"|'''Fibrous material'''|-|align = "center" bgcolor = "#EAF1DD" colspan = "3"|'''Organic'''|align = "center" bgcolor = "#EAF1DD" rowspan = "2"|'''<nowiki>### </nowiki>'''|-|align = "center" bgcolor = "#EAF1DD"|'''Lactide/polylactic acid'''|align = "center" bgcolor = "#EAF1DD"|'''Glycolide/polyglycolic acid'''|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|-|align = "center"|Polymer of monomer- polymers and copolymers of lactide|align = "center"|Polymer of monomer- polymers and copolymers of glycolide|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>| |-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|align = "center"|<nowiki>****</nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|align = "center"| |-|} ==Solvents=='''Solvents''' {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#EAF1DD" colspan = "2"|'''Solvent'''|-|align = "center" bgcolor = "#EAF1DD"|'''Alcohol based'''|align = "center" bgcolor = "#EAF1DD"|'''Other organic solvents'''|-|align = "center"|Polyol or polyol ether, polyglycols|align = "center"|Carbon dioxide, nitrogen,toluene, diesel, heptane, octane, or condensate, methane- ("ISANE" ,ISOPAR), cetone or 2-butanone|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} Mostly used solvents are polyol or polyol ether based compounds (2-butoxyethanol, ethylene glycol, propylene glycol,....[Contd] ==Salts=='''Salts''': NaCO<sub>3</sub>, Graded calcium carbonate, Potassium Chloride, Calcium chloride, Magnesium chloride,....[Contd] ==Emulsions=='''Emulsions''': Various patents have talked about emulsion system based fracturing fluid (Emulsified carbon dioxide fracture fluids)<sub> </sub>as emulsion enhances the ability of the compositions to remove any blocks of fluids interlocked with gas in formations after the desired treatment is achieved. This technique has been majorly adopted by Schlumberger. ===Graphical representation of Additives used for corresponding Fracturing fluids=== [[Image:Additives used alongwith Fracturi fluids.jpg|left|500px]][[Image:Additives used alongwith Fractu fluids2.jpg|center|500px]] ==Miscellaneous compounds== Table below list out the miscellaneous compounds used for well treatments with their role based on the conditions prevailing in the reservoir. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#C2D69A"|'''Additives'''|align = "center" bgcolor = "#C2D69A"|'''Role'''|align = "center" bgcolor = "#C2D69A"|'''Chemical compounds'''|-|align = "center" bgcolor = "#EAF1DD"|'''Embrittlement modification agent'''|align = "center"|Embrittled fracture face to prevent formation intrusion|align = "center"|An amine; lithium hydroxide; sodium hydroxide; potassium hydroxide; rubidium hydroxide; calcium hydroxide; strontium hydroxide; barium hydroxide; sodium carbonate; lime|-|align = "center" bgcolor = "#EAF1DD"|'''Plasticity modification fluids'''|align = "center"|Prevent the extrusion mechanism (e.g., through embrittling the rock) and proppant embedment or fracture closure.|align = "center"|Hydroxy aluminum and zirconium oxychloride|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#EAF1DD"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} ==Trade names additives used for fracturing fluids== Various compounds with their Trade names and roles have been tabulated below. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#C2D69A"|'''Trade names'''|align = "center" bgcolor = "#C2D69A"|'''Generic name'''|align = "center" bgcolor = "#C2D69A"|'''Role'''|-|align = "center"|Daxad.RTM. 31|align = "center"|Maleic anhydride copolymer|align = "center" rowspan = "3"|Polymeric drag reducing units|-|align = "center"|Daxad.RTM. 32|align = "center"|Ammonium methacrylate polymers and copolymers|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center" rowspan = "2"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center" rowspan = "2"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center" rowspan = "2"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" rowspan = "2"|<nowiki>### </nowiki>|align = "center" rowspan = "2"|<nowiki>****</nowiki>|align = "center" rowspan = "4"|<nowiki>****</nowiki>|-||-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center" rowspan = "4"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center" rowspan = "2"|<nowiki>****</nowiki>|align = "center" rowspan = "2"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center" rowspan = "2"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center" rowspan = "4"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"| |align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center" rowspan = "2"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|-|} =Heat Treatment===Heat treatment of wells== Few geological formations contain an organic matter known as "'''kerogen'''". When kerogen is imbedded in rock formations, the mixture is referred to as oil shale. In the United States, oil shale is most notably found in Wyoming, Colorado, and Utah. Decomposition of kerogen leads to the formation of hydrocarbons wherein the decomposition is temperature dependent. Temperatures of higher than 270°C are required for their conversion. Many attempts have been made to extract oil from oil shale. Conventional process and method have been made for extraction of hydrocarbon from kerogen rocks formation. Near surface oil mining has been widely conducted in this formation for recovery of hydrocarbon fluids in earlier days. But this technique has proved to be uneconomical and also shows environmental constraints due to the disposal of spent shale. ===Graphical representation of assignee's holding patents of Thermal fracturing===[[Image:Assignee thermal.jpg|center|500px]] ===ExxonMobil=== [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220080271885%22.PGNR.&OS=DN/20080271885&RS=DN/20080271885 US20080271885A1] titled "'''Granular electrical connections for in situ formation heating'''" by ExxonMobil. Provide method for heating a subsurface formation by using an electrically conductive granular material. It also includes passage in the subsurface between a wellbore located within the subsurface formation for injection of electrically conductive granular material. This technique is particularly advantageous in oil shale development areas initially having very limited or effectively no fluid permeability....[Contd] The various means for providing heat is tabulated below.{|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59"|'''Electric means'''|align = "center" bgcolor = "#9BBB59"|'''Thermal-energy carrier fluid'''|align = "center" bgcolor = "#9BBB59"|'''Electrically conductive material'''|-|align = "center" rowspan = "2"|Radio-frequency (RF) electrical energy|align = "center"|Hot fluids- methane gas or naphtha|align = "center" rowspan = "2"|Granular metal, metal coated particles, coke, graphite, metal coated particles, coke, graphite, silica, quartz, cement chips, sandstone|-|align = "center"|Water, Steam|-|align = "center"|Heater|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} In situ heating of the subsurface was also accomplished by combustible fuel, burning a fuel, cooling fluid, surface burner, flameless distributed combustors, flameless distributed combustor, natural distributed combustor. ===Summary of Heating treatment==='''ExxonMobil '''is working in recovering hydrocarbon through heat treatment of shale formation comprising kerogen or organic-rich rock formation since 1995 till today, by using conductive granular material,....[Contd] =Challenges in Tight Gas= We have analyzed patents and scientific articles and found different challenges that are faced in the process of recovery of tight gas. We have used all the relevant records obtained from the search conducted to list out different problems and challenges. All the similar challenges are taken together and analyzed for different solutions. The main heads under which these challenges lie are: 1. Water blocking/damage problem 2. Fracturing Fluid 3. Proppant 4. Geology problem 5. Environmental impact 6. Fracturing 7. Drilling 8. Fracturing and stimulation in high temperature and high pressure formations ==Water blocking/damage problem== There are several patents which talks about problem associated with presence of water in these tight reservoirs. {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Water blocking/Damage'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Solution'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "3"|'''1'''|align = "center" rowspan = "3"|'''3M/Univ of Texas'''|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100224361%22.PGNR.&OS=DN/20100224361&RS=DN/20100224361 US20100224361A1]</u></font>|Treatment fluid comprising wettability modifier and solvents.|-|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100167964%22.PGNR.&OS=DN/20100167964&RS=DN/20100167964 US20100167964A1]</u></font>|Stepwise treatment with the first and second wettability modifers.|-|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8043998.PN.&OS=PN/8043998&RS=PN/8043998 US8043998B2]</u></font>|Treatment fluids comprising of solvent and a nonionic fluorinated polymeric surfactant.|-|align = "center" bgcolor = "#9BBB59"|'''2'''|align = "center"|'''Schlumberger'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''3'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''4'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''5'''|align = "center"|<nowiki>### </nowiki>|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} These sections now concentrate on the work done by the companies or institutes.<br/>===3M/Univ Of Texas=== [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100224361%22.PGNR.&OS=DN/20100224361&RS=DN/20100224361 US20100224361A1] titled "Compositions and Methods for Treating a Water Blocked Well" by 3M/Univ Of Texas. Fracturing of hydrocarbon-bearing subterranean formation containing non-connate water often leads to well damaged and decreases in the production after a time period. The major source of water in the well can be from natural (water from the adjacent water bodies) or manmade artificial (drilling mud and other water-based drill-in-fluids and fracturing fluids) sources. Treatment of hydrocarbon-bearing subterranean formation containing non-connate water by treatment fluid comprises of '''wettability modifier and solvents'''....[Contd] [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100167964%22.PGNR.&OS=DN/20100167964&RS=DN/20100167964 US20100167964A1] titled "Compositions and Methods for Treating a Water Blocked Well" by 3M/Univ Of Texas. Fracturing of hydrocarbon-bearing subterranean formation containing non-connate water often leads to well damaged and decreases in the production after a time period....[Contd] <font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8043998.PN.&OS=PN/8043998&RS=PN/8043998 US8043998B2] </u></font>titled "Method for treating a fractured formation with a non-ionic fluorinated polymeric surfactant" by 3M/Univ Of Texas. Though clean up of water for their removal from the reservoir helps in increasing the hydrocarbon production, need exist to increase the conductivity of the propped fracture, when brine or condensate is used in the fracturing treatments....[Contd] ===Information from the Article=== Wheeler S. R et. al., 2010 studied on "A Study of High-Quality Foamed Fracturing Fluid Properties" of BJ Services Company. High rate slickwater stimulation uses a large quantity of water which leads to reservoir damage. Objective is to examine the rheological properties of high quality foamed fracturing fluids and compare it with other fracturing techniques....[Contd] ===Summary of Water damage=== Water damage is a serious problem which if not overcome, renders a productive well unproductive. Schlumberger and 3M/Univ Of Texas are the major companies working in this area as seen from the above graphs....[Contd] ==Fracturing Fluid=={|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Fracturing Fluid'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Solution'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "3"|1|align = "center" rowspan = "3"|'''Schlumberger'''|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6929069.PN.&OS=PN/6929069&RS=PN/6929069 US6929069B2]</u></font>|Aqueous based fracturing fluid is used for reducing the leak off of fracturing fluid|-|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220090318313%22.PGNR.&OS=DN/20090318313&RS=DN/20090318313 US20090318313A1]</u></font>|Slickwater treatment fluid by polyacrylamide and stabilized peroxide breaker fluid.|-|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8066073.PN.&OS=PN/8066073&RS=PN/8066073 US8066073B2]</u></font>|Stabilized aqueous dispersions of water inert polymers in treatment fluids|-|align = "center" bgcolor = "#9BBB59"|2|align = "center"|'''Halliburton'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|3|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|4|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|5|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} These sections now concentrate on the work done by the companies or institutes. ===Schlumberger=== [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6929069.PN.&OS=PN/6929069&RS=PN/6929069 US6929069B2] titled "Fracturing fluid and method of use" by Schlumberger. Need of improved fracturing fluids which reduce the leak off of fracturing fluid and aid in clean up of the well. '''Aqueous based fracturing fluid''' consist blend of an amine oxide having aliphatic and alkyl or alkenyl group and viscosifying amount of a solvatable polysaccharide....[Contd] ===Information from the Articles=== King, S. R., 1983 of American Fracmaster Inc studied the effects of residual fluid in the stimulation of low permeability reservoirs liquid. Carbon dioxide (CO<sub>2</sub>) as a fracturing fluid was developed to combat the problems of fluid imbibitions. Advantage of the CO<sub>2</sub> is it can easily returned to the surface under controlled rates as a gas, thus more rapid cleanup can be performed easily....[Contd] ===Summary of Fracturing Fluid=== Fracturing fluids faces problem due its viscous nature, leaking off ability and getting trapped in the area surrounding the fractures. Various companies have worked on different categories to prevent damage due to fracturing fluid.'''Schlumberger''' is the first company to have utilized delayed and non delayed breakers in the viscous fracturing fluids in 1992, they also used polyacrylamide and stabilized peroxide breaker fluid as an additive....[Contd] ==Proppant=={|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Proppant problem'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Solution'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "2"|'''1'''|align = "center" rowspan = "2"|'''Schlumberger'''|align = "center"|<font color="#0000FF"><u>[http://www.wipo.int/pctdb/en/wo.jsp?WO=2011081550 WO2011081550A1]</u></font>|Inexpensive proppant materials for hydraulic fracturing of tight gas reservoir having crushable properties.|-|align = "center"|<font color="#0000FF"><u>WO2011145965A1</u></font>|Providing proppant slugs in fracturing treatments|-|align = "center" bgcolor = "#9BBB59"|'''2'''|align = "center"|'''Baker Hughes'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''3'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''4'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} These sections now concentrate on the work done by the companies or institutes. ===Schlumberger=== [http://www.wipo.int/pctdb/en/wo.jsp?WO=2011081550 WO2011081550A1] titled "Hydraulic fracturing system" by Schlumberger. Need of an inexpensive proppant materials for hydraulic fracturing of tight gas reservoir having crushable properties. '''Hydraulic fracturing utilizing crushable particulates''', which provide sufficient and cost effective fracture conductivity dependent on closure stress, has been presented....[Contd] ===Information from the Articles=== Ingram, S.R., et al 2007 of Halliburton, XTO Energy studied the production loss due to proppant flowback through Coiled-Tubing Intervention.A combination of coiled tubing, pressure pulsing tool, and low-viscosity consolidating agent (liquid curable resin) provides a reliable and economical remedial treatment to overcome proppant flowback problems, without mechanical isolation, to eliminate subsequent cleanouts and improve the operator<nowiki>’</nowiki>s return on investment by saving costs....[Contd] ===Summary of Proppant challenges=== Proppant placement being a serious problem many companies has explored this area which includes Baker Hughes, etc. in 2011. Schlumberger performed Hydraulic fracturing utilizing crushable particulates; heterogeneous proppant placement was done by metering proppant slurry through control valves and then placing it into the fracture in 2011....[Contd] ==Geology=={|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Geology problem'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Solution'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "3"|1|align = "center" rowspan = "3"|'''Halliburton'''|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110209868%22.PGNR.&OS=DN/20110209868&RS=DN/20110209868 US20110209868A1]</u></font>|align = "center"|Fracturing of stress altered formation using signaling subsystem communicably coupled with injection tools installed in the well bore.|-|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110120713%22.PGNR.&OS=DN/20110120713&RS=DN/20110120713 US20110120713A1]</u></font>|align = "center"|Increasing fracture complexity in ultra-low permeable subterranean formation using degradable particulate.|-|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110136703%22.PGNR.&OS=DN/20110136703&RS=DN/20110136703 US20110136703A1]</u></font>|align = "center"|CO<sub>2</sub> fluids for stimulating liquid-sensitive subterranean formations|-|align = "center" bgcolor = "#9BBB59"|2|align = "center"|####|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|3|align = "center"|####|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|4|align = "center"|####|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} ===Halliburton=== [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110209868%22.PGNR.&OS=DN/20110209868&RS=DN/20110209868 US20110209868A1] titled "Fracturing a stress-altered subterranean formation" by Halliburton. Fracturing of a stress- altered subterranean formation is difficult to perform. Fracturing of stress altered formation using signaling subsystem communicably coupled with injection tools installed in the well bore....[Contd] [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110120713%22.PGNR.&OS=DN/20110120713&RS=DN/20110120713 US20110120713A1] titled "Increasing fracture complexity in ultra-low permeable subterranean formation using degradable particulate" by Halliburton. Need for increasing the fracture complexity of the ultra low permeability for recovery of hydrocarbon. It include a method for pumping one or more fracturing fluids into a far-field region of the treatment zone....[Contd] [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110136703%22.PGNR.&OS=DN/20110136703&RS=DN/20110136703 US20110136703A1] titled "Compositions for stimulating liquid-sensitive subterranean formations" by Halliburton. Stimulation of liquid sensitive formation often shows the migration of fines particle and rock slippage which can plug any pathways of hydrocarbon productivity and thus reduced the permeability of the hydraulically fractured zone. ===Information from the Articles=== Zillur R. et. al., 2010 studied on "Selection of Completion Strategy for Sand Control and Optimal Production Rate - Field Examples from Saudi Arabia<nowiki>’</nowiki>s "Unayzah Sandstone Reservoir" of Saudi Aramco. Completing wells in high sanding environments raises major risks that are not faced in more competent formations....[Contd] ===Summary of Geology damage=== Different geology challenges are there in tight gas reservoir such as stress altered, ultra low permeability, diatomaceous reservoir and liquid-sensitive subterranean formations. Halliburton has worked on signal subsystem, slickwater and CO<sub>2</sub> fracturing to overcome these challenges. ExxonMobil is using acid fracturing and steam for hydrocarbon recovery. Similarly Chevron is also using cyclic steaming for hydrocarbon recovery from diatomite formations. ==Environmental impact=={|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Environmental Impact'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Solution'''|-|align = "center"|'''1'''|align = "center"|'''Baker Hughes'''|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5424285.PN.&OS=PN/5424285&RS=PN/5424285 US5424285A]</u></font>|align = "center"|Reducing deleterious environmental impact of fracturing fluid by using foam fracturing fluid|-|} ===Baker Hughes=== [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5424285.PN.&OS=PN/5424285&RS=PN/5424285 US5424285A] titled "Method for reducing deleterious environmental impact of subterranean fracturing processes" by Baker Hughes. Fracturing fluid generally shows deleterious environmental impact such as -Fracturing fluid containing carbon dioxide shows contamination of well products, this cannot be easily removed from the well products. And for removal of CO<sub>2</sub> flaring of the well products was performed which releases combustion products, and other gases from incomplete combustion which had a green house impact on environment....[Contd] ==Fracturing== ===Hydraulic Fracturing=== {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Hydraulic Fracturing'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Solution'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "2"|'''1'''|align = "center" rowspan = "2"|'''ExxonMobil'''|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5890536.PN.&OS=PN/5890536&RS=PN/5890536 US5890536A]</u></font>|align = "center"|Multi stage fracturing method is used for overcome the challenges of massive hydrauli fracturing(MHF).|-|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220110272153%22.PGNR.&OS=DN/20110272153&RS=DN/20110272153 US20110272153A1]</u></font>|align = "center"|Horizontal wellbores to facilitate vertical movement of flow able materials|-|align = "center" bgcolor = "#9BBB59"|'''2'''|align = "center"|'''Schlumberger'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''3'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''4'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} These sections now concentrate on the work done by the companies or institutes. ====ExxonMobil==== [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=5890536.PN.&OS=PN/5890536&RS=PN/5890536 US5890536A] titled "Method for stimulation of lenticular natural gas formations" by ExxonMobil. Need exists of a well stimulation method for substantially enhancing production from reservoirs characterized by tight gas, lenticular deposits such that they become commercially exploitable gas fields as,-Conventional Massive Hydraulic Fracturing technique applied for lenticular sand, tight gas reservoirs resulted in very long MHF fractures which failed to achieve desired results....[Contd] ===Explosive Fracturing==={|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Explosive Fracturing'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Company/University'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Solution'''|-|align = "center"|1|align = "center"|'''Gas Technology Inst'''|align = "center"|<font color="#0000FF"><u>[http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6880646.PN.&OS=PN/6880646&RS=PN/6880646 US6880646B2]</u></font>|align = "center"|Perforate well casings by application of laser energy|-|} ====Gas Technology Inst==== [http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6880646.PN.&OS=PN/6880646&RS=PN/6880646 US6880646B2] titled "Laser wellbore completion apparatus and method" by Gas Technology Inst. Conventional method for perforating a well casing shows following problems: <br/>Perforation by bullet impact usually reduces the permeability of the producing formations resulting in a reduction in production rate....[Contd] ===Summary of fracturing problem=== To overcome the challenges involved in hydraulic fracturing new techniques have been developed according to the situation. ExxonMobil is working on multi stage fracturing method in lenticular sand and they are also working on horizontal wellbores to facilitate vertical movement of flow able materials....[Contd] ==Drilling=={|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#9BBB59" colspan = "4"|'''Drilling'''|-|align = "center" bgcolor = "#9BBB59"|'''S.No'''|align = "center" bgcolor = "#9BBB59"|'''Assignee'''|align = "center" bgcolor = "#9BBB59"|'''Patent'''|align = "center" bgcolor = "#9BBB59"|'''Solution'''|-|align = "center" bgcolor = "#9BBB59" rowspan = "2"|'''1'''|align = "center" rowspan = "2"|'''Schlumberger'''|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100243242%22.PGNR.&OS=DN/20100243242&RS=DN/20100243242 US20100243242A1]</u></font>|align = "center"|Performing fracturing by the drilling string.|-|align = "center"|<font color="#0000FF"><u>[http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220090151938%22.PGNR.&OS=DN/20090151938&RS=DN/20090151938 US20090151938A1]</u></font>|align = "center"|Simultaneously drilling a wellbore and fracturing a formation|-|align = "center" bgcolor = "#9BBB59"|'''2'''|align = "center"|'''Halliburton'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''3'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''4'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''5'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''6'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|align = "center" bgcolor = "#9BBB59"|'''7'''|align = "center"|'''<nowiki>### </nowiki>'''|align = "center"|<nowiki>****</nowiki>|align = "center"|<nowiki>****</nowiki>|-|} These sections now concentrate on the work done by the companies or institutes. ===Schlumberger=== [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220100243242%22.PGNR.&OS=DN/20100243242&RS=DN/20100243242 US20100243242A1] titled "Method for completing tight oil and gas reservoirs" by Schlumberger. Conventional well treatment procedure involves time consuming process steps viz., drilling the well, removing the drilling assembly and then fracturing the well....[Contd] [http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PG01&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.html&r=1&f=G&l=50&s1=%2220090151938%22.PGNR.&OS=DN/20090151938&RS=DN/20090151938 US20090151938A1] titled "Stimulation through fracturing while drilling" by Schlumberger. The conventional method of drilling, completion and stimulation are expensive and time consuming, as it comprises the steps of drilling a well, removing the drilling assembly and then fracturing the well....[Contd] ===Summary of drilling problem=== Drilling is very important and essential step for recovery of tight gas from the reservoir. Schlumberger is focusing to develop assembly for simultaneously performing drilling and fracturing a wellbore....[Contd] ==Fracturing and stimulation in high temperature and high pressure formations== ===Information from the articles===Curtino et. al., 2011 of Petroleum Development Oman (PDO) studied on Challenges for recovering gas in fracturing a deep, high- pressure, and high- temperature formation of Oman. <br/> Challenges with respect to high temp and pressure overcame by creating high bottom hole pressure inside the deep well by using a high density crosslinked fracturing fluid (sodium bromide- base fluid) and Hybrid fracturing techniques....[Contd] ===Summary of high pressure and high temperature problem=== Articles say fracturing of high pressure and high temperature tight gas reservoir requires specially developed compounds for performing successfully fracturing of these reservoirs....[Contd] ==Miscellaneous=====Information from the articles===Eller. G. J., et. al. 2002 studied on "A Case History: Use of a Casing-Conveyed Perforating System to Improve Life of Well Economics in Tight Gas Sands" of Marathon Oil Company. Problem with a conventional approach is "cherry picking" the best sands in a well for stimulation, which leaves a large percentage of pay unstimulated and it also prohibited evaluation of low-quality Beluga sands to determine whether they could be commercially developed and added to the reserve base....[Contd] =Appendix===Technical Analysis== {|border="2" cellspacing="0" cellpadding="4" width="80%"|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''S.No'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Author'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Company/University'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Testing Area'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Fracturing'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Fluid/Proppant'''</font>|align = "center" bgcolor = "#4F81BD"|<font color="#FFFFFF">'''Result'''</font> |-|align = "center" bgcolor = "#DBE5F1"|'''1'''|bgcolor = "#DBE5F1"|Nasr-El-Din et.al., (2007)|bgcolor = "#DBE5F1"|Saudi Aramco|bgcolor = "#DBE5F1"|Carbonate formation of Saudi Arabia|bgcolor = "#DBE5F1"|Acid Fracturing|bgcolor = "#DBE5F1"|28wt % HCl, Pickling acid treatments|bgcolor = "#DBE5F1"|Large amount of iron and traces of Manganese, Zinc was found during the treatment of sour well |-|align = "center"|'''2'''|Nasr-El-Din et.al., (2007)|Saudi Aramco|Carbonate formation of Saudi Arabia|Acid Fracturing|15 wt% HCl and 9wt% formic acid, Borate gel, Viscoelastic surfactant based acid, gelled acid systems and surfactant-based acid system|Surfactant-based acid showed better cumulative production. |-|} =References= *[[Website references]]
