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/* Taxonomy for patent analysis for tight gas recovery */
<mm>[[Tight Gas Recovery Analysis Taxonomy1.mm|800px|Interactive Mindmap|center|title Taxonomy for patent analysis]]</mm>
==Hydraulic Fracturing==
===Graphical Representation of Assignee's holding patents of Hydraulic fracturing===
[[Image:Ass Hydraulic.jpg|center|500px]]
Schlumberger holds the maximum no. of patents 27 whereas the least no. of patents 3 are held by Chevron.
'''Table: Hydraulic fracturing patent of different Companies.'''
{|border="2" cellspacing="0" cellpadding="4" width="100%"
|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"|'''Comment'''
|-
|align = "center" bgcolor = "#9BBB59" rowspan = "5"|'''1'''
|align = "center" rowspan = "5"|'''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=%2220090288833%22.PGNR.&OS=DN/20090288833&RS=DN/20090288833 US20090288833A1]</u></font>
|align = "center"|Fracturing of multiple ultra-shot radius laterals from a parent well
|-
|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=7278486.PN.&OS=PN/7278486&RS=PN/7278486 US7278486B2]</u></font>
|align = "center"|Method of fracturing a multi-zone subterranean formation utilizing bottom hole assembly.
|-
|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=6119776.PN.&OS=PN/6119776&RS=PN/6119776 US6119776A]</u></font>
|align = "center"|Stimulating and producing multiple stratified reservoirs
|-
|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=7001872.PN.&OS=PN/7001872&RS=PN/7001872 US7001872B2]</u></font>
|align = "center"|Treating subterranean well formations by using treating fluid.
|-
|align = "center" bgcolor = "#9BBB59" rowspan = "7"|'''2'''
|align = "center" rowspan = "7"|'''Schlumberger'''
|align = "center"|<font color="#0000FF"><u>[http://www.wipo.int/pctdb/en/wo.jsp?WO=2011143053 WO2011143053A1]</u></font>
|align = "center"|Treatment fluid in the fracture to partially destabilize and remove the shale from the reservoir.
|-
|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=6508307.PN.&OS=PN/6508307&RS=PN/6508307 US6508307B1]</u></font>
|align = "center"|Techniques for hydraulic fracturing combining oriented perforating and low viscosity fluids
|-
|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=5295393.PN.&OS=PN/5295393&RS=PN/5295393 US5295393A]</u></font>
|align = "center"|Fracture an underground formation that is traversed by a borehole.
|-
|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=%2220090065253%22.PGNR.&OS=DN/20090065253&RS=DN/20090065253 US20090065253A1]</u></font>
|align = "center"|Optimize production of a reservoir
|-
|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=%2220090065198%22.PGNR.&OS=DN/20090065198&RS=DN/20090065198 US20090065198A1]</u></font>
|align = "center"|For increasing production of a reservoir using lateral wells
|-
|align = "center"|<font color="#0000FF"><u>[http://www.wipo.int/pctdb/en/wo.jsp?WO=2011070453 WO2011070453A2]</u></font>
|align = "center"|Method for increasing fracture area
|-
|align = "center"|<font color="#0000FF"><u>[http://www.wipo.int/pctdb/en/wo.jsp?WO=2011081550 WO2011081550A1]</u></font>
|align = "center"|Inexpensive proppant materials for hydraulic fracturing of tight gas reservoir having crushable properties
|-
|align = "center" bgcolor = "#9BBB59"|'''3'''
|align = "center"|'''Integrated Petroleum Technologies'''
|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=7032671.PN.&OS=PN/7032671&RS=PN/7032671 US7032671B2]</u></font>
|align = "center"|Reliable method of propagating a fracture farther from the well-bore into a target formation.
|-
|align = "center" bgcolor = "#9BBB59"|'''4'''
|align = "center"|'''Phillips Petroleum Company'''
|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=5054554.PN.&OS=PN/5054554&RS=PN/5054554 US5054554A]</u></font>
|align = "center"|Recovery of hydrocarbon fluids by controlling the rate of injection to form the desired fracture length and width in the reservoir.
|-
|align = "center" bgcolor = "#9BBB59"|'''5'''
|align = "center"|'''Union Oil Company'''
|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=5472050.PN.&OS=PN/5472050&RS=PN/5472050 US5472050A]</u></font>
|align = "center"|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.
|-
|}
These sections now concentrate on the work done by the companies or institutes.
===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.
It can modified stresses, thus fracture network can be created along a substantial portion of a horizontal well bore.
[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" by Halliburton. Hydrocarbons are often dispersed in a stacked sequence in the reservoir. The reservoir also contains water bearing zones. Conventional equipment cannot be used for drilling and stimulation of multi lateral well as they are very time consuming, and expensive in nature. It provide a systems and methods for constructing '''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.
[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=7278486.PN.&OS=PN/7278486&RS=PN/7278486 US7278486B2] titled "Fracturing method providing simultaneous flow back" by Halliburton. The top down completion method has several drawbacks:
-a larger ID tubing is required for the fracturing fluid to be pumped down the tubing which is difficult to handle in the wellbore compared to smaller pipe sizes (1.5-2.0 inch diameter) and is more expensive.
-previously placed fracturing fluid is produced up the annulus, which impinges against the tubing string and therefore can cause damage to the tubing string.
- the previously fractured zones are above the packer and flowing these zones back may result in proppant building up on the top of the packer.
Method of fracturing a multi-zone subterranean formation utilizes bottom up approach comprising, the steps of first perforating the pay zone by injecting a hydraulic fluid into the subterranean formation through the jet ports of the hydra jetting sub and isolating this pay zone from the adjacent pay zone using packers by moving the having a bottom-hole assembly ("BHA") downhole below the zone, second is fracturing by pumping the fracturing fluid down an annulus formed between the wellbore and a tubing string and then flowing back the fracturing fluid to the surface through the BHA and tubing string. The second zone to be treated next is above this treated zone.
[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=6119776.PN.&OS=PN/6119776&RS=PN/6119776 US6119776A] titled "Methods of stimulating and producing multiple stratified reservoirs" by Halliburton. The production of hydrocarbons from multiple stratified hydrocarbon reservoirs has been a low economic return venture for oil and gas exploitation companies because
-the hydrocarbons are contained in numerous relatively small reservoir compartments, many of which cannot be practically or economically penetrated by well bores.
-the reservoir formations containing the hydrocarbons have relatively low permeabilities.
Methods of stimulating and producing multiple stratified hydrocarbon reservoirs having '''numerous separate reservoir compartments''' are provided.
-It comprise steps for the drilling a first well bore into a lower part of the reservoir having a horizontal portion which intersects a previously drilled second well bore therein. Fracture is formed extending into two or more reservoir compartments from the horizontal portion of the third well bore for conducted hydrocarbons in the reservoir into the horizontal portion of the first well bore from where the hydrocarbons flow into the second well bore and are withdrawn.
[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=7001872.PN.&OS=PN/7001872&RS=PN/7001872 US7001872B2] titled "Subterranean formation treating fluid and methods of fracturing subterranean formations" by Halliburton. Use of high viscous fluids as a fracturing fluid, containing gelling and crosslinked agent, show some serious problem such as
-For maintaining the viscosity of fluid, the concentration of the gelling agent may be increased, which results in, increased costs and pumping of the fracturing fluids more difficult.
- Sometimes, the filter cake produced from the fluid on the walls of well bores shows difficulty in cleanup.
- Higher operating and fixed cost as they required expensive metering devices and other similar equipment.
Improved method for treating subterranean well formations, by using treating fluid concentrates which comprise of water, '''fully hydrated depolymerized polymer''' and a crosslinking agent.
-gelling agent are replaced by depolymerized polymer and these fluid are less viscous in nature.
===Schlumberger===
[http://www.wipo.int/pctdb/en/wo.jsp?WO=2011143053 WO2011143053A1] titled "Methods for unconventional gas reservoir stimulation with stress unloading for enhancing fracture network connectivity" by Schlumberger. Conventional method shows decrease in hydrocarbon production due to damage of surface regions of the fractures, leading to decrease in the permeability of the formation. Improved method of hydraulic fracturing to initiate a fracture in the shale by injecting a treatment fluid in the fracture to partially destabilize and remove the shale and then repeating the step of fracturing in the shale. It helps in minimizing the damage of the fracture surface.
[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=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 perforations, results in fracturing fluid does not take the most direct route into the fracture and leads to fracture the formation directly opposite to the perforation. This effect often known as near-wellbore tortuosity is highly undesirable for well completion.
-Use 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.
New method is a combination of the steps of '''properly orienting perforations''' and creating a propped fracture by means of a '''low viscosity fracturing fluid'''.
-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.
-Low viscosity fluid leads to lower pumping and treatment cost.
[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 of the pressure development in the test interval might be less accurate.
-Use of packers also leads to unwanted fracturing of the formation and the damage of packers was also observed.
Method and apparatus used to fracture an underground formation that is '''traversed by a borehole'''. Traversing a borehole helps in
-Proper orientation of the fracture,
-Reducing the breakdown pressure for the hydraulic fracturing operation and also reducing the damage occurring at the straddle packers,
-Low energy storage in the fluid in the system so allowing better control.
[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=%2220090065253%22.PGNR.&OS=DN/20090065253&RS=DN/20090065253 US20090065253A1] titled "Method and system for increasing production of a reservoir" by Schlumberger. Complex fractures and proper fracture geometry generally give improved production rates.
Complex fractures increases 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.
-So, a need exists for a method, apparatus and system to promote the self-propping of complex fractures and complex fractured regions,
'''Generating proper fracture geometry''', the conditions affecting 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 fracture.
-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.
The method to increase and/or optimize production of a reservoir involves first the determination 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 fracturing or multilateral drilling till the satisfied production rate is reached.
[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=%2220090065198%22.PGNR.&OS=DN/20090065198&RS=DN/20090065198 US20090065198A1] 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 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.
-So, a need exists for a method, apparatus and system to promote the self-propping of complex fractures and complex fractured regions,
Generating proper fracture geometry, the conditions affecting 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 fracture.
-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.
Method comprises knowing the textural and induced fracture complexity through software<nowiki>’</nowiki>s, drilling the first wellbore comprising a lateral well in the formation based on the complexity data, drill a second wellbore and fracture the second wellbore, inject a material (cement) that fills the fractures, pressurizing the fracturing fluid in the second wellbore, the fracture in the second wellbore penetrates in the first wellbore to induce a fracture in the first wellbore.
The plan for introducing shear stress into the formation include fracturing wellbores with cement slurries or proppant, preventing closure, to alter the stress conditions prior to a subsequent fracture.
[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 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.
[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.
Crushable proppant produces more than about 20 percent fines in a crush test using hydraulic pressure, crushing can be controlled by changing rate of injection of proppant slurry.
Fine particulates are used to deliver proppant far-field (deep into the reservoir away from the wellbore) into a complex fracture network, where no high strength proppants can be placed via current practices.
===Integrated Petroleum Technologies===
[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=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.
===Phillips Petroleum Company===
[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=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===
[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=5472050.PN.&OS=PN/5472050&RS=PN/5472050 US5472050A] 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-containing subterranean formation, includes the steps of
- 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.
The release of pressure from the formation by regulating the rate at which oil is pumped using control valves from the formation.
===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. Application of MHF to increase production from the tight reservoirs has provided mixed and, in many cases, disappointing results especially in lenticular reservoirs (<u>Hanson,1981</u>)... [Contd]
===Summary of Hydraulic fracturing===
Various companies are using or developing different techniques for performing hydraulic fracturing in different operating condition and reservoirs.
