CA2086594A1 - Selective placement of a permeability-reducing material to inhibit fluid communication between a near well bore interval and an underlying aquifer - Google Patents
Selective placement of a permeability-reducing material to inhibit fluid communication between a near well bore interval and an underlying aquiferInfo
- Publication number
- CA2086594A1 CA2086594A1 CA002086594A CA2086594A CA2086594A1 CA 2086594 A1 CA2086594 A1 CA 2086594A1 CA 002086594 A CA002086594 A CA 002086594A CA 2086594 A CA2086594 A CA 2086594A CA 2086594 A1 CA2086594 A1 CA 2086594A1
- Authority
- CA
- Canada
- Prior art keywords
- interval
- gel
- permeability
- immature
- well bore
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/60—Compositions for stimulating production by acting on the underground formation
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
- C09K8/504—Compositions based on water or polar solvents
- C09K8/506—Compositions based on water or polar solvents containing organic compounds
- C09K8/508—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
- C09K8/512—Compositions based on water or polar solvents containing organic compounds macromolecular compounds containing cross-linking agents
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/10—Sealing or packing boreholes or wells in the borehole
- E21B33/13—Methods or devices for cementing, for plugging holes, crevices, or the like
- E21B33/138—Plastering the borehole wall; Injecting into the formation
Abstract
Undesirable fluid flow is inhibited between a near well bore interval and an underlying aquifer in fluid communication therewith.
A permeability-reducing material is injected into the near well bore interval and a portion of the material is selectively overdisplaced out into the formation by means of a low density gas subsequently injected into the interval. The gas desirably restores hydrocarbon productivity or fluid injectivity to the interval while the permeability-reducing material remaining in the interval inhibits fluid communication between the interval and the aquifer.
A permeability-reducing material is injected into the near well bore interval and a portion of the material is selectively overdisplaced out into the formation by means of a low density gas subsequently injected into the interval. The gas desirably restores hydrocarbon productivity or fluid injectivity to the interval while the permeability-reducing material remaining in the interval inhibits fluid communication between the interval and the aquifer.
Description
WO9~/071~ ù )J~1 P~r/l)S91/047~i SFLIE~CTIVE IPLAC:E~ NT OF A PEP~MEAE31LITY
F2EDUelNG MATERIAL TQ IINH~BI~ FLUII:~
C:C)MR~UNICATION BETWEEI\I A NEAR WELL BORE
INTIEIRVAL AND AN lJl~ ERLYll~lG AQIJIFER
BACKG;MOllND ClF THE INV NTICIN
Technical Field:
Th~ invPn~ion relates to a proc~ss tor recovering hydrocarbons from a subterranQan hydrocarbon-bearing formation and mor4 particularly to a hydrocarbon recovery proeess utilizing a permeabili~y-reduoing material.
10 Background Information:
Fluid communication in th~ near well bore b~tween a hydrocarbon production interval or a driv0 fluid injaction in~erval and an underlying aquifer oan diminish hydrocarbon r~cov~ rom ~hQ associated hydrocarbon-bearing forrnation. Fluid communication c~n occur ~ithar al::7055 parmeable 15 matrix separating the int~rval from tha aquifar or via onc or mor~ vertical fractures or a frac~ure networ~ connacting the interval anc~ the aquifer.
When hydrocarbons are produc~d from a formation across a near well bore production i~tarval into the well bore pene~rating the formation, wa~er from an underlying aquifer tends to migrat~ upward into ths production 2a intcrval if there is fluid eommùnication between the int~rval and the aquifer.
Migration of water into the production intorvai is termed watQr coning. There are two n~gativ~ cons~quence5 of wat~r coning. The first is that water residing in th8 p~duction in~rval can block or signific~ntly diminish the flow of hydrocar~ons from th~ outlying ~ormation into the well bore. Th~ s~cond 25 consequence is tha~ wat~r producti~n can comp~te with and diminish hydrocarbon produc~ion. As a result, ~he ratio of wa~er to hydrocarbons - produced from the well bore can becom0 unacceptably high when water coning occurs.
Wat~r coning is ~xtramely difficuit to remedy wh~ther fluid 3 0 communication between tha interval and aqwi~r is across vettical fractures or matrix. A traditional method of tr~ating wat0r c3nin~ is to csment ~he well bore ovar th~ lower portion of ths production interval. Unfortunately, well bore cem~nting at best only slightly r3duc~s water coning and subsequent water production. Water coning usually r~eurs at the uncemented upper 3 5 portion of the production interval shortly after ths c~men~ treatment, negating th~ ~ff~ctiveness o~ th~ treatm~nt.
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WO 9~/071fi8 ~ PCr/llS91/04706 J~ 3 2 Another means of treating watar coning is to inject gels into the fractures or matrix provi~ing fluid communication witll the production interval A gel treatment can block migration of aquif~r water into the production interval, but the treatment also unacceptably damag0s the produclion interval because of the presence of 9~l in the interval~ Even attempts at selPctive gel placement, such as mechanical zon~ isolation, are not entirely satisfactory because the gel tends to migrate into the production intervai. Since it is difficult to plac~ a gel using present technology to effsctively pr~vent water coning without excessiva damage to th~ production interval, known gel 1 0 treatments have limited practical utility for tha prev~ntion of water coning.
The inverse problem to water coning ~xists whcr~ there is fluid eommunication between an undsrlying aquif~r and a drive fluid injection interval. Hydrocarbon drive fluids are commonly inject~d into a hydrocarbon-bearing formation via th~ injection intsrval of an injection well bore to displace the hydrocarbons into an adjnining production well bore. Where fluid communication exists between the inJecticn interval and the underlying aquifer, particularly in the near w~ll bore, the drivc fluid is undesirably divertad away from the outlying hydrocarbon-bearing zones of tha formation into ~he underlying aquifer.
F2EDUelNG MATERIAL TQ IINH~BI~ FLUII:~
C:C)MR~UNICATION BETWEEI\I A NEAR WELL BORE
INTIEIRVAL AND AN lJl~ ERLYll~lG AQIJIFER
BACKG;MOllND ClF THE INV NTICIN
Technical Field:
Th~ invPn~ion relates to a proc~ss tor recovering hydrocarbons from a subterranQan hydrocarbon-bearing formation and mor4 particularly to a hydrocarbon recovery proeess utilizing a permeabili~y-reduoing material.
10 Background Information:
Fluid communication in th~ near well bore b~tween a hydrocarbon production interval or a driv0 fluid injaction in~erval and an underlying aquifer oan diminish hydrocarbon r~cov~ rom ~hQ associated hydrocarbon-bearing forrnation. Fluid communication c~n occur ~ithar al::7055 parmeable 15 matrix separating the int~rval from tha aquifar or via onc or mor~ vertical fractures or a frac~ure networ~ connacting the interval anc~ the aquifer.
When hydrocarbons are produc~d from a formation across a near well bore production i~tarval into the well bore pene~rating the formation, wa~er from an underlying aquifer tends to migrat~ upward into ths production 2a intcrval if there is fluid eommùnication between the int~rval and the aquifer.
Migration of water into the production intorvai is termed watQr coning. There are two n~gativ~ cons~quence5 of wat~r coning. The first is that water residing in th8 p~duction in~rval can block or signific~ntly diminish the flow of hydrocar~ons from th~ outlying ~ormation into the well bore. Th~ s~cond 25 consequence is tha~ wat~r producti~n can comp~te with and diminish hydrocarbon produc~ion. As a result, ~he ratio of wa~er to hydrocarbons - produced from the well bore can becom0 unacceptably high when water coning occurs.
Wat~r coning is ~xtramely difficuit to remedy wh~ther fluid 3 0 communication between tha interval and aqwi~r is across vettical fractures or matrix. A traditional method of tr~ating wat0r c3nin~ is to csment ~he well bore ovar th~ lower portion of ths production interval. Unfortunately, well bore cem~nting at best only slightly r3duc~s water coning and subsequent water production. Water coning usually r~eurs at the uncemented upper 3 5 portion of the production interval shortly after ths c~men~ treatment, negating th~ ~ff~ctiveness o~ th~ treatm~nt.
.. : -. . , .
:
WO 9~/071fi8 ~ PCr/llS91/04706 J~ 3 2 Another means of treating watar coning is to inject gels into the fractures or matrix provi~ing fluid communication witll the production interval A gel treatment can block migration of aquif~r water into the production interval, but the treatment also unacceptably damag0s the produclion interval because of the presence of 9~l in the interval~ Even attempts at selPctive gel placement, such as mechanical zon~ isolation, are not entirely satisfactory because the gel tends to migrate into the production intervai. Since it is difficult to plac~ a gel using present technology to effsctively pr~vent water coning without excessiva damage to th~ production interval, known gel 1 0 treatments have limited practical utility for tha prev~ntion of water coning.
The inverse problem to water coning ~xists whcr~ there is fluid eommunication between an undsrlying aquif~r and a drive fluid injection interval. Hydrocarbon drive fluids are commonly inject~d into a hydrocarbon-bearing formation via th~ injection intsrval of an injection well bore to displace the hydrocarbons into an adjnining production well bore. Where fluid communication exists between the inJecticn interval and the underlying aquifer, particularly in the near w~ll bore, the drivc fluid is undesirably divertad away from the outlying hydrocarbon-bearing zones of tha formation into ~he underlying aquifer.
2 û For the sams types of reasons that gels are not suited for the treatment of water coning in a production intervai, gels are unsuitable for treating the loss of drive fluid from an inj~ction interval. When gels are used to plug fluidpathways betw0en an injection int0rval and an aquifer, corresponding plugging of the injection intarYal is virtually unavoidabl~, even with zone isolation. As such, gel treatments unacceptably reduce injectivity into the injection well bore and reduc~ hydrocarbon production from the adjacent production well bore.
A treatment process is need~d for s~l~ctiv01y placing a permeability-reducing matarial in ths lower portion of a near well bore production or injection interval in fluid communication with an undorlying aquifer via permeable matrix or v0rtical fractures. A treatment process is further needed which does not significantly dir~inish fluid communioation b~tween the upper portion of the near well bore interval and an outlying hydrocarbon-bearing formation when the permeability~r~ducing matorial is placed in the lower 3 5 pbrtion of the interval.
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wo 92/07168 ~ ) J 3 ~ Pcr~us9~
The presont invention is a process for inhibiting fluid flow between a near well boro int~irvai and an aquifer und~rlying the int0rval. The interval ispenetrat~d by a weJI bore which is either an inj~ction well bore or a production well bore in fluid communication with a hydrocarbon-bearing r~s~rvoir.
In tha case of a production w~ll bore, th~ pres~nt process inhibits water coning and its attendant consequences includiny the reduction of the relative pern eability of oil in the near well bore production interval and the 1 0 production of aquifer water into the well bore. In thc case of an injection well bore, ths pres~nt process inhibits the flow of drive fluid from the near w~ll bore injection int~rval into the underlying aquifer.
The proc~ss comprises injsction of a flowing porm~ability-reducins material across the entiro vertical interval of the near well bore. Injection oftha permeability-reducin~ matarial is followed by the controlled injection of a Iess danse gas into the upper portion of t~e intorval. The gas overdisplaces the permeability-reducing material from the upper portion of th~ interval out into the formation where it dissipates without substantially altering the injection or production capacity of the wcll. The p~rmeability-reducing material inj0ctsd into the lower portion 9f the in~erval, which encompasses permeable matrix or fractures in fluid communication with tho underlying - aquifer, remains th~rein and transforms ~rorn a flowing state to a nonflowing state to ~ffect penn~ability r~duction.
Th~ pres~nt proc~s enabl~s ~elective placement of tha permeability-reducing mat~rial in th0 low~r pwtion of th~ production in~sNal a suffici~nt distance from the well bore to ~ff~cUvely inhibit undesirable water coning or drive fluid dissipation, without excessively damaging ~he upper portion of the intemal. The overdisplacing gas obviates the n~ed for selective injec~ion of the permeabili~y-reducing material into the interval bocaus~ the gas enables restoration of desirable fluid communication b~tween the hydroc~rbon reservoir and thc well bor~ across th0 upp~r portion of thB interval ~ven a~er inj~ction of the p~rm~ability-r~ducing mat~rial into th~ upp~r portion. Thus, th~ procsss is advantagaously p~rtormsd without the usa of mechanical zons isola~ion and costly workovers which require a ng.
In a first ~mbodiment, the pras~nt invsn~ion is a treatmant process for solectivaly placing a pormeability-reducing material in the low~r portion of a - , .
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WO 92/0716~ PS:~r/lJS91/0~706 near well borc hydrocarbon production interval by means of an overdisplacing gas. In a second ~mbodirnent, the invention is a treatment process for selectiv~ly placing a permeability-reducing mat~rial in the lower portion of a near well bore injec~ion interval by means of an overdisplacing 5 ~as.
The process of both embodiments prefsrably ~pplies to an interval which is in fluid communication with both a hydrocarbon-bearing reservoir and an underlying aquifer, i.a., the interval exhibits good v~rtical p~rmeabili~y. The int~rval may ba in fluid communication with th0 aquifer 10 across a matrix or a substantially vert,ical fracture, ~ither of which is permeable to aquifer water or inj~cted drive fluids.
As used herein, the term ~vertical fracturo" ~ncompasses a single substantially vertical fracture connecting the int~rval and the aquifer, a plurality of substantially vertical fractures connecting the inteNal and the 15 aquifsr in parallel, or a n~twork of substantially vertical fracturcs connecting the interval and the aquifer in seri0s.
The term "near well bor~n, as dafined herein, constitut~s a volume of the formation in direct fluid Gommunication with the well bor~ and ext~nding a finite radial distancc from the well bore face. The n~ar well bore preferably 2 O ex~ends a radial distanca up to abou~ tO rneters from th~ well bore face andmore pr~farably up to about 30 meters frorn the well bor0 face. The near well bore is the desir~d trsatment zone of the present invention.
The permeability-redlJcing material is s~lectively placed in the lower portion of the near well bor~ intsrval by first conventionally injccting the 2 5 material in a liquid-like flowing stat~ acros the entire vertical near well bore interval. Ths overdisplaoing gas is subsequently injected into the intsrval at a controll~d rate and injection pressure known to one skilled in th~ art which optimizes preferential entry of the ov~rdisplacing gas into the upper portion of the in~erval and minimizes sntry of the overdisplacing gas into the lower 3 O portion of the intesval.
Th~ gas ov3rdispiao~s the flowin~ parmsability-rsducing material from the upper portion of the interval away from the near well bor~ in a substantialiy radial dir~ction. The radially displaced material is dissipa~ed out into tha forma~ion whsrc the matarial does not substantially diminish the 3 5 production or displacement capacity of th~ well. To soma ~xtent, the gas mayalso overdisplace a part of the perm~ability-r~ducing material ~rorn lh~ upper portion of th~ interval in a downward dir~ction in~o ~h~ lowar portion of the in~erval. The net ~3ff~ct of gas overdisplacement is to substan~ially restore . . .
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WO 92/0716g PCI/lJS~ 7~6 S
permeability in the uppar interval te desirable injected drive fluids or produced hydrocarbons.
The preference of the overdisplacing ~as to enter the upper portion of the interval is enhanced by the substantially lower density of the gas relative 5 to the density of the permeability-r~ducing material. The specific gravity of the gas is between about 0.001 and about 0.2 and preferably between about 0.00~ and about 0.1. The specific gravity of the perrneability-reducing material is between about 0.94 and about 2.0 and preferably between about 1.0 and about 1.~.
Th~ ov0rdisplacing gas i5 also pr~f~rably inert and immiscible with the permeability-reducing material. A preferred overdisplacing gas for use in conjunction with the pref~rred permeability-reducing rnaterial is nitrogen or natural gas, although virtually any other gas meeting tho density and miscibility requir~ments recited harein has utility in the present invention.
After the overdisplacing gas is injected, the well bore penetrating the interval is preferably shut in to enable th~ h0retofore flowing permeabi!ity-reducing material in the low~r portion of the interval to transform to a nonflowin~ state. As used herain, tho permeability-reducing material is deemed "flowin3" if it is displaccable frsm ths upper portion of the near well 2 0 bore intemal by an overdispl~cing gas. The material is dsemed "nonflowing"
if it has sufficient structure to resist pr~pagation from the lower portion of tha interval during well boro operations for injeclion or production purposes.
After thQ material sets up to a nonflowing state, th~ well bore is restored to normal operation as an injection or production well bore. In the 2 5 case of a production weli bor~, wat~r coning is preferably diminish~d and hydrocarbon production is maintained or increased over that prior to ~reatment while water production is decr0ased. In the case of an injection well bore, the amcunt of injected drivs fluid lost to the aquifer is preferably reduced wi~hout significanlly impairing ths injectivity of tha interval.
A preferred permeability-reducing material satisfyin~ the above-recited criteria is a crosslink0d polymer gel. The term "gel~ as use~ herein is directed to a continuous thrae-dimsnsional crosslinked polymeric network inte~rating a liquid into the interstices of ths network. The crosslinked polymer gel compriC;es a crosslinkablo polymer, a crosslinking agent, and a 3 5 liquid so!v~nt.
The crosslinkable polym~r is preferably a carboxylate-containing polymer and more preferably an acrylamide-containing polymer. ~:)f the acrylamide-containirlg polymars, the most preferr~d are polyacrylamida (PA), . .
: . - - . - - ..
-, .
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.. ; . . . . .
.. . . . .
- . . , : - . , ' ~ , ~ .
WO 92/0'~168 I'CI`/US~1/0~706 r~ 1~ 6 partially hydrolyz~d polyacrylamid0 (PHPA), copolymers of acrylamide and acrylate, and carboxylate-containing terpolym~rs of acrylate. PA, having utili~y herein has from about a. 1% to abou~ 3% of its amide groups hydrolyzed. PHPA, as defined herein, has greater than about 3% of its 5 amide groups hydrolyzed.
The crosslinking ag@nt in the g~l effects chemical crosslinking b~tween the carboxylate sites of the sam~ or different polymer molecules.
Crosslinking of the polymer crsates the network structure of the gel. The crosslinking agent is preferably a molecule or compl~x containing a reactive 10 transition metal cation. A most preferreci crosslinking agent comprises a trivalent chromium cation compl~xed or bonded to an anion, atomic oxygen or water. Ex~mplary crosslinking agQnts are chrornic triacetat~ (CrAc3) and chromic trichloride. Other transition metal cations which ar~ found in crosslinking agents having utility in th0 pr~sent invention, although less 15 preferred, are chromium Vl within a redox system, aluminum lll, iron ll, iron lll and zirconium IV.
The liquid solv~nt may b~ any iiquici in which the polymer and crosslinking agent can b0 dissolv~ci, mixed, susp0nded or otherwise dispersed to facilitate gel formation. Thc soivent is preferably an aqueous 2 O lic-iuid such as distilled water, frcsh water or a brin~.
A number of the most pref~rrQd gels which have utility within the -;~ present invention are taught in U.S. Patent 4,683,949 which is incorporated herein by rsfer0nce.
The gal is ~orm0d by admixing th~ polymer and crosslinking agent at 2 5 the surface. Sur~acc admixiny broadly encompass~s inter alia mixing of th~
gel cornponants in bulk at the surface prior to injection or simultaneously mixing the gel components at or near th~ wQllhead by in-line mixing means while injecting them. The volume of 9~1 rcquired is a function of the characteristics of the inteNal, th~ adjoinin~ formation and the fiuids 3 O contained therein and is readily determinabl~ by ona skilled in tha art.
Crosslinking, or g~lation as it is altsrnatively termed, is initiated as soon as the polymer and crosslinking ag~nt contact and proce~ds until either the crosslinking àg~nt or the crosslinking sites of the polymer ars consumed.
The gel is inject~d into ths interval in a flowing stat~ before crosslinking is 35 completed, i.e., while the ~el is immahJre. Th~ gel is crosslinked to completionl i.e., reaches maturity, in situ aftsr injection of tha ov0rdisplacing gas. Ccmpl~te crosslinking transforms thc ~el to a nonflowing state.
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wo ~2/07168 PCI/US9l/0'17a6 , 9 ~
The following example dsmonstrates the practica and utllity of the present invention, but is not to be oonstrlJed as lirniting th~ scope thereof.
EXAMPLE
An oil reservoir is located in a claan high-permeability sandston~
formation which is highly faultsd. The oil reservoir is at a depth of 1700 meters. The reservoir pressur~ is 21,000 kPa. The rescNoir temperature is 88C. In situ oil viscosity is 0.5 cp. Tha reservoir pay interval is about 26 meters thiok and directly overlays an active aquifer which extends up into the producing formation. Horizontal and vsrtical permeabilities of thc formation are nearly equal. Ths av~rag~ effective permeability at residual oil saturation under reservoir conditiens is 28~ md.
A well pen~trating tha formation is perforat~d ov~r the upper 21 meters of the reservoir pay interval. The well initially produces at 14,800 m3 of oil per day and at 0 m3 of water per day. However, aft0r several weeks of production, water produotion from the well begins and water cuts from th~
well incr~ase rapidly thereafter. The specific gravity of the produced water is 1.03. After two months of production tha well produc~s at only 330 m3 of oil per day and 10,800 m3 of watar per day as the result of watar coning through the matrix raservoir rock.
In respons~ to wat~r coning, 1260 m3 of an immature flewing crosslinked polyacrylamide gel ara injeot0d into the per~ora~ed interval of the well. The gel comprisas polyacrylamid0 at a concentration of 4.5 weight percent in fresh water whieh has a molecular weight of 500,0ûO and which is hydrolyzed at 0.5 mole percent. The polyacrylamide is crosslinked with chromic acetate ~t a PA:C:rAc3 weight ratio of 9:1. The gal treatmen~ is designed for totai rnatrix shut off up to a radial distanee of 4.3 meters from the wsll borc face.
llhe imm~ture gQI in the upper half of the producing interval is overdisplac0d by injecting a natural gas volume ~f 56,6ûO standard cubic metars into the int~ l over a 31 hour period at a downhola injection differential prsssure of 140 kPa subject to fluctuations. Upon completion of the ~as injection~ the well i5 shut in for 48 hours to enable maturity of the gel.
Thereaft~r, oil produc;~ion from th~ w~ll is r~sumed.
Post treatment production frorn th~ well initially stabilizes at 1 82Q m3 of oil p~r day and ~210 m3 of water p~r day. Aftar two months of post-treatment production, the well produces at 1640 m3 of oil per day and 3740 m3 of water per day. A post-treatment production log indioates that fluid ,, .. . . . . , - .. ,.,,, . .- ., : . .............. .. .
:,,.-. : ,: ~ . . .,. , ........ . ., ~ . :,- .. - . ..
.. ... . . ., . . . . ............ ,.. - . . . . .
.. .. . ... , ... ,. . , . ~,, ... ,- -. .. . . .
WO 92tO7168 ~ 3S ~ ) PC;r/US91/0~170t procluction is almost exclusively from the upper half of the perforated interval, whereas a pre-treatment prodwt,tion log indicates that a majority of the fluids are produced from the lower half of the producing interval.
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~ . , .. . .: ~ ., ~ . . . . . . .
A treatment process is need~d for s~l~ctiv01y placing a permeability-reducing matarial in ths lower portion of a near well bore production or injection interval in fluid communication with an undorlying aquifer via permeable matrix or v0rtical fractures. A treatment process is further needed which does not significantly dir~inish fluid communioation b~tween the upper portion of the near well bore interval and an outlying hydrocarbon-bearing formation when the permeability~r~ducing matorial is placed in the lower 3 5 pbrtion of the interval.
. : ~
wo 92/07168 ~ ) J 3 ~ Pcr~us9~
The presont invention is a process for inhibiting fluid flow between a near well boro int~irvai and an aquifer und~rlying the int0rval. The interval ispenetrat~d by a weJI bore which is either an inj~ction well bore or a production well bore in fluid communication with a hydrocarbon-bearing r~s~rvoir.
In tha case of a production w~ll bore, th~ pres~nt process inhibits water coning and its attendant consequences includiny the reduction of the relative pern eability of oil in the near well bore production interval and the 1 0 production of aquifer water into the well bore. In thc case of an injection well bore, ths pres~nt process inhibits the flow of drive fluid from the near w~ll bore injection int~rval into the underlying aquifer.
The proc~ss comprises injsction of a flowing porm~ability-reducins material across the entiro vertical interval of the near well bore. Injection oftha permeability-reducin~ matarial is followed by the controlled injection of a Iess danse gas into the upper portion of t~e intorval. The gas overdisplaces the permeability-reducing material from the upper portion of th~ interval out into the formation where it dissipates without substantially altering the injection or production capacity of the wcll. The p~rmeability-reducing material inj0ctsd into the lower portion 9f the in~erval, which encompasses permeable matrix or fractures in fluid communication with tho underlying - aquifer, remains th~rein and transforms ~rorn a flowing state to a nonflowing state to ~ffect penn~ability r~duction.
Th~ pres~nt proc~s enabl~s ~elective placement of tha permeability-reducing mat~rial in th0 low~r pwtion of th~ production in~sNal a suffici~nt distance from the well bore to ~ff~cUvely inhibit undesirable water coning or drive fluid dissipation, without excessively damaging ~he upper portion of the intemal. The overdisplacing gas obviates the n~ed for selective injec~ion of the permeabili~y-reducing material into the interval bocaus~ the gas enables restoration of desirable fluid communication b~tween the hydroc~rbon reservoir and thc well bor~ across th0 upp~r portion of thB interval ~ven a~er inj~ction of the p~rm~ability-r~ducing mat~rial into th~ upp~r portion. Thus, th~ procsss is advantagaously p~rtormsd without the usa of mechanical zons isola~ion and costly workovers which require a ng.
In a first ~mbodiment, the pras~nt invsn~ion is a treatmant process for solectivaly placing a pormeability-reducing material in the low~r portion of a - , .
': :
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WO 92/0716~ PS:~r/lJS91/0~706 near well borc hydrocarbon production interval by means of an overdisplacing gas. In a second ~mbodirnent, the invention is a treatment process for selectiv~ly placing a permeability-reducing mat~rial in the lower portion of a near well bore injec~ion interval by means of an overdisplacing 5 ~as.
The process of both embodiments prefsrably ~pplies to an interval which is in fluid communication with both a hydrocarbon-bearing reservoir and an underlying aquifer, i.a., the interval exhibits good v~rtical p~rmeabili~y. The int~rval may ba in fluid communication with th0 aquifer 10 across a matrix or a substantially vert,ical fracture, ~ither of which is permeable to aquifer water or inj~cted drive fluids.
As used herein, the term ~vertical fracturo" ~ncompasses a single substantially vertical fracture connecting the int~rval and the aquifer, a plurality of substantially vertical fractures connecting the inteNal and the 15 aquifsr in parallel, or a n~twork of substantially vertical fracturcs connecting the interval and the aquifer in seri0s.
The term "near well bor~n, as dafined herein, constitut~s a volume of the formation in direct fluid Gommunication with the well bor~ and ext~nding a finite radial distancc from the well bore face. The n~ar well bore preferably 2 O ex~ends a radial distanca up to abou~ tO rneters from th~ well bore face andmore pr~farably up to about 30 meters frorn the well bor0 face. The near well bore is the desir~d trsatment zone of the present invention.
The permeability-redlJcing material is s~lectively placed in the lower portion of the near well bor~ intsrval by first conventionally injccting the 2 5 material in a liquid-like flowing stat~ acros the entire vertical near well bore interval. Ths overdisplaoing gas is subsequently injected into the intsrval at a controll~d rate and injection pressure known to one skilled in th~ art which optimizes preferential entry of the ov~rdisplacing gas into the upper portion of the in~erval and minimizes sntry of the overdisplacing gas into the lower 3 O portion of the intesval.
Th~ gas ov3rdispiao~s the flowin~ parmsability-rsducing material from the upper portion of the interval away from the near well bor~ in a substantialiy radial dir~ction. The radially displaced material is dissipa~ed out into tha forma~ion whsrc the matarial does not substantially diminish the 3 5 production or displacement capacity of th~ well. To soma ~xtent, the gas mayalso overdisplace a part of the perm~ability-r~ducing material ~rorn lh~ upper portion of th~ interval in a downward dir~ction in~o ~h~ lowar portion of the in~erval. The net ~3ff~ct of gas overdisplacement is to substan~ially restore . . .
: ' -.
WO 92/0716g PCI/lJS~ 7~6 S
permeability in the uppar interval te desirable injected drive fluids or produced hydrocarbons.
The preference of the overdisplacing ~as to enter the upper portion of the interval is enhanced by the substantially lower density of the gas relative 5 to the density of the permeability-r~ducing material. The specific gravity of the gas is between about 0.001 and about 0.2 and preferably between about 0.00~ and about 0.1. The specific gravity of the perrneability-reducing material is between about 0.94 and about 2.0 and preferably between about 1.0 and about 1.~.
Th~ ov0rdisplacing gas i5 also pr~f~rably inert and immiscible with the permeability-reducing material. A preferred overdisplacing gas for use in conjunction with the pref~rred permeability-reducing rnaterial is nitrogen or natural gas, although virtually any other gas meeting tho density and miscibility requir~ments recited harein has utility in the present invention.
After the overdisplacing gas is injected, the well bore penetrating the interval is preferably shut in to enable th~ h0retofore flowing permeabi!ity-reducing material in the low~r portion of the interval to transform to a nonflowin~ state. As used herain, tho permeability-reducing material is deemed "flowin3" if it is displaccable frsm ths upper portion of the near well 2 0 bore intemal by an overdispl~cing gas. The material is dsemed "nonflowing"
if it has sufficient structure to resist pr~pagation from the lower portion of tha interval during well boro operations for injeclion or production purposes.
After thQ material sets up to a nonflowing state, th~ well bore is restored to normal operation as an injection or production well bore. In the 2 5 case of a production weli bor~, wat~r coning is preferably diminish~d and hydrocarbon production is maintained or increased over that prior to ~reatment while water production is decr0ased. In the case of an injection well bore, the amcunt of injected drivs fluid lost to the aquifer is preferably reduced wi~hout significanlly impairing ths injectivity of tha interval.
A preferred permeability-reducing material satisfyin~ the above-recited criteria is a crosslink0d polymer gel. The term "gel~ as use~ herein is directed to a continuous thrae-dimsnsional crosslinked polymeric network inte~rating a liquid into the interstices of ths network. The crosslinked polymer gel compriC;es a crosslinkablo polymer, a crosslinking agent, and a 3 5 liquid so!v~nt.
The crosslinkable polym~r is preferably a carboxylate-containing polymer and more preferably an acrylamide-containing polymer. ~:)f the acrylamide-containirlg polymars, the most preferr~d are polyacrylamida (PA), . .
: . - - . - - ..
-, .
.
.. ; . . . . .
.. . . . .
- . . , : - . , ' ~ , ~ .
WO 92/0'~168 I'CI`/US~1/0~706 r~ 1~ 6 partially hydrolyz~d polyacrylamid0 (PHPA), copolymers of acrylamide and acrylate, and carboxylate-containing terpolym~rs of acrylate. PA, having utili~y herein has from about a. 1% to abou~ 3% of its amide groups hydrolyzed. PHPA, as defined herein, has greater than about 3% of its 5 amide groups hydrolyzed.
The crosslinking ag@nt in the g~l effects chemical crosslinking b~tween the carboxylate sites of the sam~ or different polymer molecules.
Crosslinking of the polymer crsates the network structure of the gel. The crosslinking agent is preferably a molecule or compl~x containing a reactive 10 transition metal cation. A most preferreci crosslinking agent comprises a trivalent chromium cation compl~xed or bonded to an anion, atomic oxygen or water. Ex~mplary crosslinking agQnts are chrornic triacetat~ (CrAc3) and chromic trichloride. Other transition metal cations which ar~ found in crosslinking agents having utility in th0 pr~sent invention, although less 15 preferred, are chromium Vl within a redox system, aluminum lll, iron ll, iron lll and zirconium IV.
The liquid solv~nt may b~ any iiquici in which the polymer and crosslinking agent can b0 dissolv~ci, mixed, susp0nded or otherwise dispersed to facilitate gel formation. Thc soivent is preferably an aqueous 2 O lic-iuid such as distilled water, frcsh water or a brin~.
A number of the most pref~rrQd gels which have utility within the -;~ present invention are taught in U.S. Patent 4,683,949 which is incorporated herein by rsfer0nce.
The gal is ~orm0d by admixing th~ polymer and crosslinking agent at 2 5 the surface. Sur~acc admixiny broadly encompass~s inter alia mixing of th~
gel cornponants in bulk at the surface prior to injection or simultaneously mixing the gel components at or near th~ wQllhead by in-line mixing means while injecting them. The volume of 9~1 rcquired is a function of the characteristics of the inteNal, th~ adjoinin~ formation and the fiuids 3 O contained therein and is readily determinabl~ by ona skilled in tha art.
Crosslinking, or g~lation as it is altsrnatively termed, is initiated as soon as the polymer and crosslinking ag~nt contact and proce~ds until either the crosslinking àg~nt or the crosslinking sites of the polymer ars consumed.
The gel is inject~d into ths interval in a flowing stat~ before crosslinking is 35 completed, i.e., while the ~el is immahJre. Th~ gel is crosslinked to completionl i.e., reaches maturity, in situ aftsr injection of tha ov0rdisplacing gas. Ccmpl~te crosslinking transforms thc ~el to a nonflowing state.
~' ' . ' ' .'` ':
.
wo ~2/07168 PCI/US9l/0'17a6 , 9 ~
The following example dsmonstrates the practica and utllity of the present invention, but is not to be oonstrlJed as lirniting th~ scope thereof.
EXAMPLE
An oil reservoir is located in a claan high-permeability sandston~
formation which is highly faultsd. The oil reservoir is at a depth of 1700 meters. The reservoir pressur~ is 21,000 kPa. The rescNoir temperature is 88C. In situ oil viscosity is 0.5 cp. Tha reservoir pay interval is about 26 meters thiok and directly overlays an active aquifer which extends up into the producing formation. Horizontal and vsrtical permeabilities of thc formation are nearly equal. Ths av~rag~ effective permeability at residual oil saturation under reservoir conditiens is 28~ md.
A well pen~trating tha formation is perforat~d ov~r the upper 21 meters of the reservoir pay interval. The well initially produces at 14,800 m3 of oil per day and at 0 m3 of water per day. However, aft0r several weeks of production, water produotion from the well begins and water cuts from th~
well incr~ase rapidly thereafter. The specific gravity of the produced water is 1.03. After two months of production tha well produc~s at only 330 m3 of oil per day and 10,800 m3 of watar per day as the result of watar coning through the matrix raservoir rock.
In respons~ to wat~r coning, 1260 m3 of an immature flewing crosslinked polyacrylamide gel ara injeot0d into the per~ora~ed interval of the well. The gel comprisas polyacrylamid0 at a concentration of 4.5 weight percent in fresh water whieh has a molecular weight of 500,0ûO and which is hydrolyzed at 0.5 mole percent. The polyacrylamide is crosslinked with chromic acetate ~t a PA:C:rAc3 weight ratio of 9:1. The gal treatmen~ is designed for totai rnatrix shut off up to a radial distanee of 4.3 meters from the wsll borc face.
llhe imm~ture gQI in the upper half of the producing interval is overdisplac0d by injecting a natural gas volume ~f 56,6ûO standard cubic metars into the int~ l over a 31 hour period at a downhola injection differential prsssure of 140 kPa subject to fluctuations. Upon completion of the ~as injection~ the well i5 shut in for 48 hours to enable maturity of the gel.
Thereaft~r, oil produc;~ion from th~ w~ll is r~sumed.
Post treatment production frorn th~ well initially stabilizes at 1 82Q m3 of oil p~r day and ~210 m3 of water p~r day. Aftar two months of post-treatment production, the well produces at 1640 m3 of oil per day and 3740 m3 of water per day. A post-treatment production log indioates that fluid ,, .. . . . . , - .. ,.,,, . .- ., : . .............. .. .
:,,.-. : ,: ~ . . .,. , ........ . ., ~ . :,- .. - . ..
.. ... . . ., . . . . ............ ,.. - . . . . .
.. .. . ... , ... ,. . , . ~,, ... ,- -. .. . . .
WO 92tO7168 ~ 3S ~ ) PC;r/US91/0~170t procluction is almost exclusively from the upper half of the perforated interval, whereas a pre-treatment prodwt,tion log indicates that a majority of the fluids are produced from the lower half of the producing interval.
.
~ . , .. . .: ~ ., ~ . . . . . . .
Claims (18)
[received by the International Bureau on 24 March 1992 (24.03.92);
original claim 19 cancelled;
original claim 1 amended; other claims unchanged (2 pages)]
1. A process for selectively placing a permeability-reducing material in a near well bore interval which has an underlying aquifer in fluid communication with said interval comprising:
injecting a flowing permeability-reducing material into an upper portion and a lower portion of said near well bore interval;
injecting a gas having a density substantially less than the density of said flowing permeability-reducing material into said upper portion of said interval to displace said flowing permeability-reducing material from said upper portion of said interval; and transforming said flowing permeability-reducing material in said lower portion of said interval to a nonflowing permeability-reducing material which substantially reduces fluid communication between said upper portion of said interval and said underlying aquifer.
injecting a flowing permeability-reducing material into an upper portion and a lower portion of said near well bore interval;
injecting a gas having a density substantially less than the density of said flowing permeability-reducing material into said upper portion of said interval to displace said flowing permeability-reducing material from said upper portion of said interval; and transforming said flowing permeability-reducing material in said lower portion of said interval to a nonflowing permeability-reducing material which substantially reduces fluid communication between said upper portion of said interval and said underlying aquifer.
2. The process of Claim 1 wherein said flowing permeability-reducing material is an immature crosslinked polymer gel.
3. The process of Claim 2 wherein said gel comprises an acrylamide-containing polymer and a metal cation-containing crosslinking agent.
4. The process of Claim 3 wherein said acrylamide-containing polymer is selected from the group consisting of polyacrylamide, partially hydrolyzed polyacrylamide, copolymers and acrylamide and acrylate, and carboxylate-containing terpolymers of acrylate.
5. The process of Claim 3 wherein said metal cation is selected from the group consisting of chromium, aluminum, iron and zirconium.
6. The process of Claim 3 wherein said metal cation is trivalent chromium.
7. The process of Claim 1 wherein said interval is a hydrocarbon-production interval in fluid communication with a hydrocarbon reservoir.
8. The process of Claim 1 wherein said interval is an injection interval in fluid communication with a hydrocarbon reservoir.
9. The process of Claim 1 wherein fluid communication between said interval and said aquifer is across permeable matrix.
10. The process of Claim 1 wherein fluid communication between said interval and said aquifer is across a substantially vertical fracture.
11. The process of Claim 1 wherein said gas is substantially immiscible with said permeability-reducing material.
12. The process of Claim 1 wherein said gas is selected from the group consisting of nitrogen and natural gas.
13. A process for selectively placing a permeability-reducing gel in a near well bore hydrocarbon production interval to substantially reduce water coning resulting from fluid communication between said interval and an underlying aquifer comprising:
injecting an immature flowing crosslinked polymer gel into an upper portion and a lower portion of said near well bore hydrocarbon production interval, wherein said immature flowing gel comprises an acrylamide-containing polymer and a metal cation-containing crosslinking agent;
injecting an overdisplacing gas having a density substantially less than said immature flowing gel and substantially immiscible with said immature flowing gel into said upper portion of said near well bore hydrocarbon production interval to displace said immature flowing gal from said upper portion of said interval;
shutting in said well bore for a time sufficient to enable said immature gel in said lower portion of said interval to mature into a nonflowing gel; and producing hydrocarbons across said upper portion of said interval while substantially reducing water coning therein.
injecting an immature flowing crosslinked polymer gel into an upper portion and a lower portion of said near well bore hydrocarbon production interval, wherein said immature flowing gel comprises an acrylamide-containing polymer and a metal cation-containing crosslinking agent;
injecting an overdisplacing gas having a density substantially less than said immature flowing gel and substantially immiscible with said immature flowing gel into said upper portion of said near well bore hydrocarbon production interval to displace said immature flowing gal from said upper portion of said interval;
shutting in said well bore for a time sufficient to enable said immature gel in said lower portion of said interval to mature into a nonflowing gel; and producing hydrocarbons across said upper portion of said interval while substantially reducing water coning therein.
14. The process of Claim 13 wherein said immature gel penetrates formation matrix in said lower portion of said interval to reduce the permeability of said matrix to water in said aquifer.
15. The process of Claim 13 wherein said immature gel penetrates a vertical fracture in said lower portion of said interval to reduce the permeability of said vertical fracture to water in said aquifer.
16. A process for selectively placing a permeability-reducing gel in a near well bore injection interval in fluid communication with an underlying aquifer and a hydrocarbon-bearing reservoir to substantially divert an injected drive fluid from said aquifer to said hydrocarbon-bearing reservoir comprising:
injecting an immature flowing crosslinked polymer gel into an upper portion and a lower portion of said near well bore injection interval, wherein said immature flowing gel comprises an acrylamide-containing polymer and a metal cation-containing crosslinking agent;
injecting an overdisplacing gas having a density substantially less than said immature flowing gel and substantially immiscible with said - 10a -immature flowing gel into said upper portion of said near well bore injection interval to displace said immature flowing gel from said upper portion of said interval;
shutting in said well bore for a time sufficient to enable said immature gel in said lower portion of said interval to mature into a nonflowing gel; and injecting a drive fluid across said upper portion of said interval into said hydrocarbon-bearing reservoir.
injecting an immature flowing crosslinked polymer gel into an upper portion and a lower portion of said near well bore injection interval, wherein said immature flowing gel comprises an acrylamide-containing polymer and a metal cation-containing crosslinking agent;
injecting an overdisplacing gas having a density substantially less than said immature flowing gel and substantially immiscible with said - 10a -immature flowing gel into said upper portion of said near well bore injection interval to displace said immature flowing gel from said upper portion of said interval;
shutting in said well bore for a time sufficient to enable said immature gel in said lower portion of said interval to mature into a nonflowing gel; and injecting a drive fluid across said upper portion of said interval into said hydrocarbon-bearing reservoir.
17. The process of Claim 16 wherein said immature gel penetrates formation matrix in said lower portion of said interval to reduce the permeability of said matrix to said drive fluid.
18. The process of Claim 16 wherein said immature gel penetrates a vertical fracture in said lower portion of said interval to reduce the permeability of said vertical fracture to said drive fluid.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/596,796 US5067564A (en) | 1990-10-12 | 1990-10-12 | Selective placement of a permeability-reducing material to inhibit fluid communication between a near well bore interval and an underlying aquifer |
| US596,796 | 1990-10-12 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2086594A1 true CA2086594A1 (en) | 1992-04-13 |
Family
ID=24388746
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002086594A Abandoned CA2086594A1 (en) | 1990-10-12 | 1991-07-02 | Selective placement of a permeability-reducing material to inhibit fluid communication between a near well bore interval and an underlying aquifer |
Country Status (10)
| Country | Link |
|---|---|
| US (1) | US5067564A (en) |
| CN (1) | CN1023139C (en) |
| AU (1) | AU649760B2 (en) |
| BR (1) | BR9106936A (en) |
| CA (1) | CA2086594A1 (en) |
| GB (1) | GB2263293B (en) |
| NL (1) | NL191714C (en) |
| RU (1) | RU2062863C1 (en) |
| TN (1) | TNSN91087A1 (en) |
| WO (1) | WO1992007168A1 (en) |
Families Citing this family (21)
| Publication number | Priority date | Publication date | Assignee | Title |
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| US5203834A (en) * | 1990-12-21 | 1993-04-20 | Union Oil Company Of California | Foamed gels having selective permeability |
| US5150754A (en) * | 1991-05-28 | 1992-09-29 | Mobil Oil Corporation | Aqueous and petroleum gel method for preventing water-influx |
| US5259453A (en) * | 1992-06-25 | 1993-11-09 | Phillips Petroleum Company | Blocking water coning in oil and gas producing reservoirs |
| US5358043A (en) * | 1993-03-22 | 1994-10-25 | Phillips Petroleum Company | Gelling compositions useful for oil field applications |
| US5476145A (en) * | 1994-05-10 | 1995-12-19 | Marathon Oil Company | Selective placement of a permeability-reducing material in a subterranean interval to inhibit vertical flow through the interval |
| GB2335680B (en) * | 1998-03-27 | 2000-05-17 | Sofitech Nv | Method for water control |
| CN1075790C (en) * | 1998-07-24 | 2001-12-05 | 山西省稷山县福利化工厂 | Alkaline process for producing active zinc oxide |
| US7021376B2 (en) * | 1998-12-21 | 2006-04-04 | Geoffrey Stanley Bayliss | Method for placement of blocking gels or polymers at multiple specific depths of penetration into oil and gas, and water producing formations |
| US6431280B2 (en) * | 1998-12-21 | 2002-08-13 | Geoffrey Stanley Bayliss | Method for placement of blocking gels or polymers at specific depths of penetration into oil and gas, and water producing formations |
| US6777377B2 (en) * | 2001-12-03 | 2004-08-17 | Wyo-Ben, Inc. | Composition for use in sealing a porous subterranean formation, and methods of making and using |
| US7281579B2 (en) * | 2001-12-07 | 2007-10-16 | Aqueolic Canada Ltd. | Method for terminating or reducing water flow in a subterranean formation |
| JP2005526887A (en) * | 2002-05-24 | 2005-09-08 | スリーエム イノベイティブ プロパティズ カンパニー | Use of surface modified nanoparticles for oil recovery |
| CA2613861C (en) * | 2005-06-30 | 2011-02-22 | M-I Llc | Brine based fluid loss pills comprising crosslinked polymer gels and solid salt particles |
| US7934557B2 (en) * | 2007-02-15 | 2011-05-03 | Halliburton Energy Services, Inc. | Methods of completing wells for controlling water and particulate production |
| US7832478B2 (en) | 2007-11-07 | 2010-11-16 | Schlumberger Technology Corporation | Methods for manipulation of air flow into aquifers |
| US7987910B2 (en) * | 2007-11-07 | 2011-08-02 | Schlumberger Technology Corporation | Methods for manipulation of the flow of fluids in subterranean formations |
| US8657005B2 (en) | 2010-04-30 | 2014-02-25 | Exxonmobil Upstream Research Company | Systems and methods for hydraulic barrier formation to improve sweep efficiency in subterranean oil reservoirs |
| IT1406670B1 (en) * | 2010-12-27 | 2014-03-07 | Eni Spa | METHOD TO CONTAIN THE FORMATION OF WATER OR GAS CONES IN AN EXTRACTION WELL OF A HYDROCARBURIC FLUID |
| IT1406671B1 (en) * | 2010-12-27 | 2014-03-07 | Eni Spa | METHOD FOR RECOVERY OF OIL FROM A FIELD USING MICRO (NANO) FLUIDS STRUCTURED TO RELEASE CONTROLLED BARRIER SUBSTANCES |
| CN103498643B (en) * | 2013-10-23 | 2016-05-25 | 天津亿利科能源科技发展股份有限公司 | A kind of composite slug deep shutoff method for high water-cut reservoir |
| EA039360B1 (en) * | 2020-01-09 | 2022-01-18 | Научно-Исследовательский И Проектный Институт Нефти И Газа (Нипинг) | Method for development of heterogeneous oil reservoir |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2402588A (en) * | 1940-09-14 | 1946-06-25 | Essex Royalty Corp | Method of oil recovery |
| US3004598A (en) * | 1958-05-14 | 1961-10-17 | Gulf Research Development Co | Method of reducing the permeability of underground formations |
| US3148730A (en) * | 1960-06-27 | 1964-09-15 | Sinclair Research Inc | Secondary recovery process |
| US3299953A (en) * | 1964-07-24 | 1967-01-24 | Union Oil Co | Method of using a foaming agent in a cementing process |
| US3369605A (en) * | 1966-08-19 | 1968-02-20 | Interior Usa | Method of treating oil wells to prevent water coning |
| US4418755A (en) * | 1979-02-14 | 1983-12-06 | Conoco Inc. | Methods of inhibiting the flow of water in subterranean formations |
| US4428429A (en) * | 1981-05-26 | 1984-01-31 | Standard Oil Company | Method for sweep improvement utilizing gel-forming lignins |
| US4413680A (en) * | 1981-12-21 | 1983-11-08 | Union Oil Company Of California | Permeability reduction in subterranean reservoirs |
| US4657944A (en) * | 1984-02-09 | 1987-04-14 | Phillips Petroleum Company | CO2 -induced in-situ gelation of polymeric viscosifiers for permeability contrast correction |
| US4569393A (en) * | 1984-02-09 | 1986-02-11 | Phillips Petroleum Company | CO2 -Induced in-situ gelation of polymeric viscosifiers for permeability contrast correction |
| US4776398A (en) * | 1985-01-31 | 1988-10-11 | Mobil Oil Corporation | Oil reservoir permeability control |
| US4694906A (en) * | 1985-08-30 | 1987-09-22 | Union Oil Company Of California | Method for emplacement of a gelatinous foam in gas flooding enhanced recovery |
| US4683949A (en) * | 1985-12-10 | 1987-08-04 | Marathon Oil Company | Conformance improvement in a subterranean hydrocarbon-bearing formation using a polymer gel |
| US4665982A (en) * | 1986-06-26 | 1987-05-19 | Brown Billy R | Formation fracturing technique using liquid proppant carrier followed by foam |
| US4722397A (en) * | 1986-12-22 | 1988-02-02 | Marathon Oil Company | Well completion process using a polymer gel |
| US4928763A (en) * | 1989-03-31 | 1990-05-29 | Marathon Oil Company | Method of treating a permeable formation |
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1990
- 1990-10-12 US US07/596,796 patent/US5067564A/en not_active Expired - Fee Related
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1991
- 1991-07-02 RU RU9193032323A patent/RU2062863C1/en active
- 1991-07-02 NL NL9120020A patent/NL191714C/en not_active IP Right Cessation
- 1991-07-02 CA CA002086594A patent/CA2086594A1/en not_active Abandoned
- 1991-07-02 AU AU90318/91A patent/AU649760B2/en not_active Expired - Fee Related
- 1991-07-02 WO PCT/US1991/004706 patent/WO1992007168A1/en active Application Filing
- 1991-07-02 BR BR919106936A patent/BR9106936A/en unknown
- 1991-09-16 CN CN91109002.9A patent/CN1023139C/en not_active Expired - Fee Related
- 1991-10-11 TN TNTNSN91087A patent/TNSN91087A1/en unknown
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1993
- 1993-01-18 GB GB9300892A patent/GB2263293B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1060512A (en) | 1992-04-22 |
| NL9120020A (en) | 1993-07-01 |
| WO1992007168A1 (en) | 1992-04-30 |
| GB2263293A (en) | 1993-07-21 |
| AU649760B2 (en) | 1994-06-02 |
| NL191714C (en) | 1996-04-02 |
| BR9106936A (en) | 1994-01-25 |
| AU9031891A (en) | 1992-05-20 |
| CN1023139C (en) | 1993-12-15 |
| TNSN91087A1 (en) | 1992-10-25 |
| RU2062863C1 (en) | 1996-06-27 |
| US5067564A (en) | 1991-11-26 |
| GB9300892D0 (en) | 1993-03-17 |
| GB2263293B (en) | 1994-08-17 |
| NL191714B (en) | 1995-12-01 |
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