CA1095226A - Oil recovery process utilizing aromatic solvent and steam - Google Patents
Oil recovery process utilizing aromatic solvent and steamInfo
- Publication number
- CA1095226A CA1095226A CA293,323A CA293323A CA1095226A CA 1095226 A CA1095226 A CA 1095226A CA 293323 A CA293323 A CA 293323A CA 1095226 A CA1095226 A CA 1095226A
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- Prior art keywords
- formation
- communication path
- steam
- oil
- well
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Abstract
ABSTRACT OF THE DISCLOSURE
Petroleum may be recovered from viscous petroleum containing formations including tar sand deposits by first creating a fluid communication path in the formation, fol-lowed by injecting via an injection well an aromatic sol-vant such as benzene, saturated with carbon dioxide at the injection pressure into the fluid communication path, fol-lowing the injection of the solvent with the injection of an oil-displacing fluid such as hot water, steam, or superheated steam and recovering oil from the formation via a production well.
Petroleum may be recovered from viscous petroleum containing formations including tar sand deposits by first creating a fluid communication path in the formation, fol-lowed by injecting via an injection well an aromatic sol-vant such as benzene, saturated with carbon dioxide at the injection pressure into the fluid communication path, fol-lowing the injection of the solvent with the injection of an oil-displacing fluid such as hot water, steam, or superheated steam and recovering oil from the formation via a production well.
Description
This invention pertains to an oil recovery method, and more specifically to a me~hod or recovering oil or pe~roleum from a subterranean viscous petroleum containing formation such as a tar sand deposit.
There are known to exist throughout the world many subterranean petroleum co~taining fromations from 1~ which the petroleum cannot be recovered by conventional means because of the relatively high viscosity thereo.
The best known of such viscous petroleum containing forma tions are the so-called tar sands or bituminous sand depasits. The largest and most famous such deposit is in 1~ the Athabasca area in the northeastern part of the pro~inGe of Alberta~ Canada which is known to contain over 700 ~illion barrels of petroleum~ Other extensive deposits are known to exist in western part of the United States, and Venezuela, and lesser deposits in Europe and Asia.
Tar sands are frequently defined as sand saturated with a highly viscous crude petroleum material not recover- ;
able in its natural state through a well by ordinary producti.on methods. The hydrocarbon contained ln tar sand `~
deposits are generally highly bituminous in character.
The tar sand deposits are generally arranged as follows.
Fine quartz sand is coated with a layer of water and the ,: ,."
bituminous material occupies most of the void space around the we~ted sand grains. The balance of the void volume may be filled with connate water, and occasionally a small volume of gas which is usually air or methane. The sand
There are known to exist throughout the world many subterranean petroleum co~taining fromations from 1~ which the petroleum cannot be recovered by conventional means because of the relatively high viscosity thereo.
The best known of such viscous petroleum containing forma tions are the so-called tar sands or bituminous sand depasits. The largest and most famous such deposit is in 1~ the Athabasca area in the northeastern part of the pro~inGe of Alberta~ Canada which is known to contain over 700 ~illion barrels of petroleum~ Other extensive deposits are known to exist in western part of the United States, and Venezuela, and lesser deposits in Europe and Asia.
Tar sands are frequently defined as sand saturated with a highly viscous crude petroleum material not recover- ;
able in its natural state through a well by ordinary producti.on methods. The hydrocarbon contained ln tar sand `~
deposits are generally highly bituminous in character.
The tar sand deposits are generally arranged as follows.
Fine quartz sand is coated with a layer of water and the ,: ,."
bituminous material occupies most of the void space around the we~ted sand grains. The balance of the void volume may be filled with connate water, and occasionally a small volume of gas which is usually air or methane. The sand
2~;
1 grains are packed to a void volume of about 35%, which corr@sponds to about 83~ by weight sand. The balance of the material is bitumen and.water. The sum of bitumen and water will almost always equal about 17% by weight, with the bitumen portion varying from around 2% to around 16%.
- It is an unusual characteristic o~ tar sand deposits that the sand grains are not in any s~nse con-solidated, that is to say the sand i~ essentially suspended in the solid or nearly sOlia hydrocarbon material. The API graYity of the bitumen usually ranges from about 6 to ~ ~:
about 8, and the specific gravity at 60F. is from about 1.006 to about 1.027~ Appro~imately 50~ o~ the bitumen is distillable without crackiny, and the sulfur content averag~s between 4 and 5~ by weight. The hitumen is also ~ery viscous, and so even if it is recoverable by an in situ sepaxation technique, some on-site refining of the produced petroleum must be undertaken in order ~o convert it to a pumpable ~luid.
Bi umen may be xecovered from tar sand deposits by mining or by in situ processes. Most of the recovery to date has beeA by means of mining, although this is limited to instances where the ratio of the overburden thickness to tar sand deposit thickness is economically sui~able, generally defined as one or less. In situ processes hav~ been proposed which may be categorized as thenmal, such as fire flooding or steam injec~ion, and ' A ,r,~ , steam plus emulsification drive processes. Generatio~ o~
thermal heat necessary to mobilize the bitumen by means of a subterranean atomlc explosion has been seriously con-sidered, although has not yet been attPmpted.
%~
l Despite the many proposed methods for recovering bitumen from tar sand deposits, there has still been no successul exploitation of such deposits by in situ pro- :
cessing on a coImnercial scale Up to the pxesent time.
Accordingly, in view of the lack of co~mercial success of any of the methods proposed to date, and especially in Yiew of the enormous reserves pxesent in this form which axe needed to help satisfy present ener~y needs, there is a substantial need for a satisfactory method for recovery of bitumen from tar sand deposits.
In its broadest aspect this inventi3n is a method for recovering petroleum from subterranean, viscous petroleum containing formations including tar sand deposits, said formations being penetrated by at least one injectio~
well and by at leas~ one production well, comprising:
(a~ establishing a 1uid communication path in the formation between the injaction well and the production.
well;
(b) injecting via an injection well a slug of an aromatic hydrocarbon solvent saturated at pressures ranging from about 100 to about 1,000 psi with a material ~elected f~om the group consisting of car~on dioxide, a gaseous hydrocarbon and mixtures thereof into the communi-cation path;
(c) injecting via the said injection well an ..x ~
oil-displacing fluid selected from the group consisting of hot water, stea~ and supexheated steam; and (d) recovering petroleum from the formation via the production well.
S~26 ~ ~ .
In the first step of this process a ccmmunication path is established in the formation. The ideal communica-tion path is an essentially horizontal, pancake shaped S zone of high permeability prefer~bly at or near the bottom of the tar sand or petroleum resexvoir.
It is sometimes discovered that there is a water saturated zone in the very bottom of f he petroleum resexvoir, and this may be utilized successfully to establish the fluid communication path in a~cordance with our process.
The water saturated zone may be opened up by injecting into the zone a heated ~luid such as ste~l, which will channel preferentially through ~his water saturated zone to the production well, Asphaltic or other solid or semi-solid hydrocarbon materials present in the water saturated :;
zone will be melted and rendered mobile, and the permeabi-lity will be opened up considera~ly thereby.
G~nerally, it will be necessaxy to open up the communication path through the ormation by some other means such as hydxaulic fracturing. Hydraulic fracturing is a well known technique for establishing a co~munication '~
path between an injection well and a production well.
Fracturing is usually accomplished by forcing a liquid ..
such as water, oil or any other suitable hydrocarbon fraction into the formation at prassures o from a~out 300 to about 1,500 psig which are sufficient to rupture the ,~, ,,~
forma~ion and to open up channels thPrein. By use of this method it is possible to position the fracture at any desired vertical location with respe~t to the bottom of the oil filled zone. It i not essential that the fracture ~5~
1 planes be h~rizontally oriented, although it is of course preferable that they be.
In any event, a communication path of some sort is created, generally confined to the lower portion of the petroleum reservoir~ After the fracture has been estab-lished, and without diminishing the fracture pressure, a propping agent may be injected into the fracture in order to prevent healin~ of t~e fracture which would aestroy its usefulness for fluid flow communication purposesO Gravel and sand or mixtures there~f are employed as propping agents, and i~ is desirable in the instance of tar sand deposits that a wide varia~ion of particle sizes be employed to avoid ~lowing of the tar sand materials bacX into the propped fracture zone.
lS I~ the next step of the process of this invention an aromatic solven~ saturated at pressures ranging from about 100 psi to about 1,000 psi with a material selected from the group consisting of carhon dioxide, gaseous hydrocarbons and mixtures thereof is injected into the communication path previously formed in the formation.
Generally, the injection pressure will vaxy from about 300 -~
to about l,SOO psiy or more.
A wide variety o aromatic hyd~ocarbon solvents in liquid form may be utilized in this step such as benzene, toluene, xylene/ etc. Preferably, the aromatic hydrocarbon solvent in liquid phase is saturated with carbon dioxide :,x ~
or a mixture at least in part compos~d of carhon dioxideO
~ny normal gaseous hydxocarbon such as methane, ethane, propane, butane, pentane, hexane and natural gas may likewise be employed in forming the saturated liquid -5~
2;2~
t aromatic hydrocarbon solvent solution. The temperature of the gas-saturated aromatic hydrocarbon solvent injected into ~he communication path ~an likewise be varied over a wide-range and generally will be from about -10C. to about 50C~ and preferably from about 20C. to about 40C.
The quanti~y of the gas-saturated solven~ employed will generally be from about 0.01 to about 0~10 pore volumes or moreO Prior to the introduction of the gas-saturated, aromatic hydrocarbon solvent the formation m~y be heated i desired by forcing a heating fluid which can be for example, hot water or steam through the communication path in the formation.
After the aromatic hydrocarbon solvent saturated with carbon dioxide and/or other gaseous hydrocarbons has been forced i~to the formation ~ia an injection well, an oil-displacing fluid which is selected from the group consisting of hot water, steam, and superheated steam is injected into the formation via the co~munication path.
If hot water is employed, the temperature will range from ~bout 100 to about 300C. Saturated and superheated steam pressures will range from a~out lOQ to 1,000 psi or more.
If desired, the aqueous flooding fluid, that is the oil-displacing fluid, employed may comprise an alkaline oil-displacing ~luid or an alkaline oil-displacing fluid containing a minor amount of 2 solubilizing agent~ The :~
advantageous re~ults achieved with the aqueous alkaline ., .~ ,; ..
flooding medium used in the process of this invention are ~:
believed to be derived from the wetability improving characteristics of the alkaline agent and when the solubi-lizing agent is employed it is believed that the ~ ~ .,, , - : . .
1 advantageous rasul~s are derived from the solubilizing action on ~e crude oil such as in tar sands and other ormations and especially on the asphaltene fractions.
The . olubilizing agent is believed to be efective in releasing the crude from the pore surface or sand suxfaces as the case may be so that the surface can ~e exposed to th~ alkaline agen~.
Useful alkaline agents include compounds selected from the group consisting of an alkaline metal hydroxide, an alkaline earth metal hydroxide, and a basic salt of the alkaline metal or alkaline earth metals which is capable of hydrolyzing in an aqueous medium to give an alkaline solution, a concentration of the alkaline agent being ~bout Q~OOI to 0.5 molar to give the required alkaline 1~ solution. Also, alkali~e materials such as sodium hypo-chlorite are highly effective as al~aline agents. Exampl~s of these expecially useful alkaline agents include sodium hydroxide, potassium hydroxide, lithium hydroxide, clmmoni~un hydroxide, s~dium hypochlorite, sodium carbonate, and potassium car~o~ate.
A wide variety o~ the solubilizing agents ar~
useful in the process o this invention including water~
soluble, oxyalkylated nltrogen~containing aromatic compounds where prefe~ably the initiator, i.el, t~e aromatic c~mpound contains not more than 12 carbon atoms ~d the number of oxyalkyl units is about 5 to about 50. One Pspecially , ~. ~
useful group o~ the water-soluble, oxyalXylated, nitrogen-containi~g aromatic comp~und are those havlng the formula:
R(OR')n~, Wherein R is selected from the group consisting of: ~
o2N~3 [~ 52and wherein R' is alkylene of from 2 to ~ inclusive carbon atoms and n is an integer of from about 5 to about 50 and preferably from about 5 to about 20. These novel-solubie-water oxyalkylated products can be conveniently prepared by a number of processes well-known in the art and their preparation is more completely described in U. S. Patent
1 grains are packed to a void volume of about 35%, which corr@sponds to about 83~ by weight sand. The balance of the material is bitumen and.water. The sum of bitumen and water will almost always equal about 17% by weight, with the bitumen portion varying from around 2% to around 16%.
- It is an unusual characteristic o~ tar sand deposits that the sand grains are not in any s~nse con-solidated, that is to say the sand i~ essentially suspended in the solid or nearly sOlia hydrocarbon material. The API graYity of the bitumen usually ranges from about 6 to ~ ~:
about 8, and the specific gravity at 60F. is from about 1.006 to about 1.027~ Appro~imately 50~ o~ the bitumen is distillable without crackiny, and the sulfur content averag~s between 4 and 5~ by weight. The hitumen is also ~ery viscous, and so even if it is recoverable by an in situ sepaxation technique, some on-site refining of the produced petroleum must be undertaken in order ~o convert it to a pumpable ~luid.
Bi umen may be xecovered from tar sand deposits by mining or by in situ processes. Most of the recovery to date has beeA by means of mining, although this is limited to instances where the ratio of the overburden thickness to tar sand deposit thickness is economically sui~able, generally defined as one or less. In situ processes hav~ been proposed which may be categorized as thenmal, such as fire flooding or steam injec~ion, and ' A ,r,~ , steam plus emulsification drive processes. Generatio~ o~
thermal heat necessary to mobilize the bitumen by means of a subterranean atomlc explosion has been seriously con-sidered, although has not yet been attPmpted.
%~
l Despite the many proposed methods for recovering bitumen from tar sand deposits, there has still been no successul exploitation of such deposits by in situ pro- :
cessing on a coImnercial scale Up to the pxesent time.
Accordingly, in view of the lack of co~mercial success of any of the methods proposed to date, and especially in Yiew of the enormous reserves pxesent in this form which axe needed to help satisfy present ener~y needs, there is a substantial need for a satisfactory method for recovery of bitumen from tar sand deposits.
In its broadest aspect this inventi3n is a method for recovering petroleum from subterranean, viscous petroleum containing formations including tar sand deposits, said formations being penetrated by at least one injectio~
well and by at leas~ one production well, comprising:
(a~ establishing a 1uid communication path in the formation between the injaction well and the production.
well;
(b) injecting via an injection well a slug of an aromatic hydrocarbon solvent saturated at pressures ranging from about 100 to about 1,000 psi with a material ~elected f~om the group consisting of car~on dioxide, a gaseous hydrocarbon and mixtures thereof into the communi-cation path;
(c) injecting via the said injection well an ..x ~
oil-displacing fluid selected from the group consisting of hot water, stea~ and supexheated steam; and (d) recovering petroleum from the formation via the production well.
S~26 ~ ~ .
In the first step of this process a ccmmunication path is established in the formation. The ideal communica-tion path is an essentially horizontal, pancake shaped S zone of high permeability prefer~bly at or near the bottom of the tar sand or petroleum resexvoir.
It is sometimes discovered that there is a water saturated zone in the very bottom of f he petroleum resexvoir, and this may be utilized successfully to establish the fluid communication path in a~cordance with our process.
The water saturated zone may be opened up by injecting into the zone a heated ~luid such as ste~l, which will channel preferentially through ~his water saturated zone to the production well, Asphaltic or other solid or semi-solid hydrocarbon materials present in the water saturated :;
zone will be melted and rendered mobile, and the permeabi-lity will be opened up considera~ly thereby.
G~nerally, it will be necessaxy to open up the communication path through the ormation by some other means such as hydxaulic fracturing. Hydraulic fracturing is a well known technique for establishing a co~munication '~
path between an injection well and a production well.
Fracturing is usually accomplished by forcing a liquid ..
such as water, oil or any other suitable hydrocarbon fraction into the formation at prassures o from a~out 300 to about 1,500 psig which are sufficient to rupture the ,~, ,,~
forma~ion and to open up channels thPrein. By use of this method it is possible to position the fracture at any desired vertical location with respe~t to the bottom of the oil filled zone. It i not essential that the fracture ~5~
1 planes be h~rizontally oriented, although it is of course preferable that they be.
In any event, a communication path of some sort is created, generally confined to the lower portion of the petroleum reservoir~ After the fracture has been estab-lished, and without diminishing the fracture pressure, a propping agent may be injected into the fracture in order to prevent healin~ of t~e fracture which would aestroy its usefulness for fluid flow communication purposesO Gravel and sand or mixtures there~f are employed as propping agents, and i~ is desirable in the instance of tar sand deposits that a wide varia~ion of particle sizes be employed to avoid ~lowing of the tar sand materials bacX into the propped fracture zone.
lS I~ the next step of the process of this invention an aromatic solven~ saturated at pressures ranging from about 100 psi to about 1,000 psi with a material selected from the group consisting of carhon dioxide, gaseous hydrocarbons and mixtures thereof is injected into the communication path previously formed in the formation.
Generally, the injection pressure will vaxy from about 300 -~
to about l,SOO psiy or more.
A wide variety o aromatic hyd~ocarbon solvents in liquid form may be utilized in this step such as benzene, toluene, xylene/ etc. Preferably, the aromatic hydrocarbon solvent in liquid phase is saturated with carbon dioxide :,x ~
or a mixture at least in part compos~d of carhon dioxideO
~ny normal gaseous hydxocarbon such as methane, ethane, propane, butane, pentane, hexane and natural gas may likewise be employed in forming the saturated liquid -5~
2;2~
t aromatic hydrocarbon solvent solution. The temperature of the gas-saturated aromatic hydrocarbon solvent injected into ~he communication path ~an likewise be varied over a wide-range and generally will be from about -10C. to about 50C~ and preferably from about 20C. to about 40C.
The quanti~y of the gas-saturated solven~ employed will generally be from about 0.01 to about 0~10 pore volumes or moreO Prior to the introduction of the gas-saturated, aromatic hydrocarbon solvent the formation m~y be heated i desired by forcing a heating fluid which can be for example, hot water or steam through the communication path in the formation.
After the aromatic hydrocarbon solvent saturated with carbon dioxide and/or other gaseous hydrocarbons has been forced i~to the formation ~ia an injection well, an oil-displacing fluid which is selected from the group consisting of hot water, steam, and superheated steam is injected into the formation via the co~munication path.
If hot water is employed, the temperature will range from ~bout 100 to about 300C. Saturated and superheated steam pressures will range from a~out lOQ to 1,000 psi or more.
If desired, the aqueous flooding fluid, that is the oil-displacing fluid, employed may comprise an alkaline oil-displacing ~luid or an alkaline oil-displacing fluid containing a minor amount of 2 solubilizing agent~ The :~
advantageous re~ults achieved with the aqueous alkaline ., .~ ,; ..
flooding medium used in the process of this invention are ~:
believed to be derived from the wetability improving characteristics of the alkaline agent and when the solubi-lizing agent is employed it is believed that the ~ ~ .,, , - : . .
1 advantageous rasul~s are derived from the solubilizing action on ~e crude oil such as in tar sands and other ormations and especially on the asphaltene fractions.
The . olubilizing agent is believed to be efective in releasing the crude from the pore surface or sand suxfaces as the case may be so that the surface can ~e exposed to th~ alkaline agen~.
Useful alkaline agents include compounds selected from the group consisting of an alkaline metal hydroxide, an alkaline earth metal hydroxide, and a basic salt of the alkaline metal or alkaline earth metals which is capable of hydrolyzing in an aqueous medium to give an alkaline solution, a concentration of the alkaline agent being ~bout Q~OOI to 0.5 molar to give the required alkaline 1~ solution. Also, alkali~e materials such as sodium hypo-chlorite are highly effective as al~aline agents. Exampl~s of these expecially useful alkaline agents include sodium hydroxide, potassium hydroxide, lithium hydroxide, clmmoni~un hydroxide, s~dium hypochlorite, sodium carbonate, and potassium car~o~ate.
A wide variety o~ the solubilizing agents ar~
useful in the process o this invention including water~
soluble, oxyalkylated nltrogen~containing aromatic compounds where prefe~ably the initiator, i.el, t~e aromatic c~mpound contains not more than 12 carbon atoms ~d the number of oxyalkyl units is about 5 to about 50. One Pspecially , ~. ~
useful group o~ the water-soluble, oxyalXylated, nitrogen-containi~g aromatic comp~und are those havlng the formula:
R(OR')n~, Wherein R is selected from the group consisting of: ~
o2N~3 [~ 52and wherein R' is alkylene of from 2 to ~ inclusive carbon atoms and n is an integer of from about 5 to about 50 and preferably from about 5 to about 20. These novel-solubie-water oxyalkylated products can be conveniently prepared by a number of processes well-known in the art and their preparation is more completely described in U. S. Patent
3,731,741.
Another group of solubilizing agents which are highly useful in the process of this invention include compounds of the formula:
~ N~ ~ N - lCH2CH~O)rR'' wherein r i6 an integer from about 5 to about 50 or more and preferably from about 5 to about 15, R" is selected from the group consisting of hydrogen and -SO3M wherein M
is selected from the group consisting of sodium, potassium and the ammonium ion and wherein R"' is selected from the group consisting of hydrogen and -(CE~2CH2O)rR" where r and R" have the same meaning as previously described. Solubi-lizing agents of this type where R" is hydrogen can beformed by reaching ethylene oxide with an aminoquinoline 5-aminoquinoline, 6-aminoquinoline, 7=aminoquinoline, etc.
in the presence of a catalyst such as solid sodium hydroxide.
The quinoline starting material may also be substituted by 30 other innoculous groups such as alkoxy of from 1 to 4 :
.~ .
~5~
1 carbon atoms, alkyl, etc. The corresponding sulfated compounds can be prepared by reacting the hydroxyl termin ated derivatives described above wi~h sulfuric acid followed by neutxalization if desired.
E X A M P L E
This invention i~s best understood by a reference to the following example, which is offered only as an illu~trative embodiment of our invention, and is not intended to be limitative or restricted thereof.
- A tar sand deposit is located at a depth of 450 feet and it is determined that the thickness of the forma-tion is 65 feet. It is also determined that the petroleum is in the form of a highly bituminous hydxocarbon, and its viscosity at the formation temperature is much too high to permit recovery thereof by conventional means. An iniection well is drilled to the bottom of the formationl and perfor-ations are formed between the i~terval of 490~5l5 feet, i.eO, ~he bottom of the petroleum saturated zone. A
production well is drllled approximately 330 eet distance ~rom the injection well, and perforations are similarl~
made slightly above the bottom of the petroleum satuxated zone. The production well is also equipped with a steam trap so that only liquids can be produced from the forma-tlon, and vapors are excluded therefrom.
A fluid communication path low in the formation is formulated by fracturing the formation using con~entional ,~ .-~ -hydraulic fracturing techniques, and injecting a gravel sand mixture into the frac~ure to hold it open and prevent healing of the fracture.
~ 9 ~ ~ ~ ,. : : .. . .
i2~
1 Following the fracturing operation, the formation optionally may be heated by injecting hot ~ater at a temperature of 205F. into the formation and continuing ~:
the injection until the temp~rature of ~he water produced at the production well rises to about 195F., indicating that the comm~nication path is open and is heated uniformly between the two wells.
In the next step 2,500 barrels of benzene saturated with carbon dioxide at a.temperature 60F. and l 500 psig is injected into the formation at this same pressure and at a rate of lO barrels per minute. A~ter the benzene saturated with carbon dioxide is injected via the production well into the formation, the injection of 80~ quali~y steam at a temperature of 417F. and a pressur~
of 285 psig is commenced at the rate o~ 15,000 pounds per hour. The production of viscous oil via the production well gradually increases as injection of the oil-displacing fluid is continued and at the end of thirty`~30) days productiQn of the viscous hydrocarbons is significantly increased over production of sLmilar wells in the same formation utilizing only steam injection.
E X A M P L E II
In this example viscous oil is recvvered from a -tar sand at a depth of 73~ fee~ and having a ~hickne~s of ~5 about 28 feet. An injection well is drilled to the ~ottom Qf the hydrocarbon bearing structure a~d the casing per- -; ~. -.~ : .
forated in the interval 735 to 745 feet. In a like manner a production well drilled at a distance of about 400 feet from the injection well is perforated at a de~th of 730-740 feet, i~e~, the center of ~he tar sand formation at . that location.
`
' 1 In the next step a fluid communication path is formed by fr~cturing the formation in both wells using conventional hydraulic fracturing teehnique. A g~a~el-sand mixture is injected into the formation to hold it op~n and to prevent healing of the frac~ure~ A ~otal of 3,400 barrels of toluene saturated with car~on dioxide at a temperature of 60~E. and a pressure of 500 psig is injected into the formation at th same pressure and at a rate of 10 barrels pex minute. Following the injection of the carbon dioxide saturated toluene, the injection of superhea~ed steam (temp~rature 600F, pressure 300 psig) containing about 0.01 percent by weight of a solubilizlng agent of the formula:
(CH2CH20~ sH-~ - N - (CH2cE2O)~
where s plus t is about 14, is commenced at the xate of 13,000 pounds per hourO Production of viscous oil from . :~
the production well is continued and at the end of twelve ~12) days the rate of production is substantially greater than with steam injection alone.
E X A M P L E III
A test identical to that described in Example I
is conducted with the exception that the steam injected contains about 0.006 weight percent of a solubilizing ~ ,. ~:, ., agent of the formula-CH2CH20) XS03Na ~ N N ~ (CH2CH2O)ySO3Na ~. . , " . , , ~ -~ \ ~
where x plus y is about 12. At the end o 40 days of steam injection the production of ~iscous hydrocarbons is significan~ly increased over prc:duction of similar wells in the same formation employing only steam in; ection .
.
.
2~
:
--1~
,. . ~ . :
. . .
Another group of solubilizing agents which are highly useful in the process of this invention include compounds of the formula:
~ N~ ~ N - lCH2CH~O)rR'' wherein r i6 an integer from about 5 to about 50 or more and preferably from about 5 to about 15, R" is selected from the group consisting of hydrogen and -SO3M wherein M
is selected from the group consisting of sodium, potassium and the ammonium ion and wherein R"' is selected from the group consisting of hydrogen and -(CE~2CH2O)rR" where r and R" have the same meaning as previously described. Solubi-lizing agents of this type where R" is hydrogen can beformed by reaching ethylene oxide with an aminoquinoline 5-aminoquinoline, 6-aminoquinoline, 7=aminoquinoline, etc.
in the presence of a catalyst such as solid sodium hydroxide.
The quinoline starting material may also be substituted by 30 other innoculous groups such as alkoxy of from 1 to 4 :
.~ .
~5~
1 carbon atoms, alkyl, etc. The corresponding sulfated compounds can be prepared by reacting the hydroxyl termin ated derivatives described above wi~h sulfuric acid followed by neutxalization if desired.
E X A M P L E
This invention i~s best understood by a reference to the following example, which is offered only as an illu~trative embodiment of our invention, and is not intended to be limitative or restricted thereof.
- A tar sand deposit is located at a depth of 450 feet and it is determined that the thickness of the forma-tion is 65 feet. It is also determined that the petroleum is in the form of a highly bituminous hydxocarbon, and its viscosity at the formation temperature is much too high to permit recovery thereof by conventional means. An iniection well is drilled to the bottom of the formationl and perfor-ations are formed between the i~terval of 490~5l5 feet, i.eO, ~he bottom of the petroleum saturated zone. A
production well is drllled approximately 330 eet distance ~rom the injection well, and perforations are similarl~
made slightly above the bottom of the petroleum satuxated zone. The production well is also equipped with a steam trap so that only liquids can be produced from the forma-tlon, and vapors are excluded therefrom.
A fluid communication path low in the formation is formulated by fracturing the formation using con~entional ,~ .-~ -hydraulic fracturing techniques, and injecting a gravel sand mixture into the frac~ure to hold it open and prevent healing of the fracture.
~ 9 ~ ~ ~ ,. : : .. . .
i2~
1 Following the fracturing operation, the formation optionally may be heated by injecting hot ~ater at a temperature of 205F. into the formation and continuing ~:
the injection until the temp~rature of ~he water produced at the production well rises to about 195F., indicating that the comm~nication path is open and is heated uniformly between the two wells.
In the next step 2,500 barrels of benzene saturated with carbon dioxide at a.temperature 60F. and l 500 psig is injected into the formation at this same pressure and at a rate of lO barrels per minute. A~ter the benzene saturated with carbon dioxide is injected via the production well into the formation, the injection of 80~ quali~y steam at a temperature of 417F. and a pressur~
of 285 psig is commenced at the rate o~ 15,000 pounds per hour. The production of viscous oil via the production well gradually increases as injection of the oil-displacing fluid is continued and at the end of thirty`~30) days productiQn of the viscous hydrocarbons is significantly increased over production of sLmilar wells in the same formation utilizing only steam injection.
E X A M P L E II
In this example viscous oil is recvvered from a -tar sand at a depth of 73~ fee~ and having a ~hickne~s of ~5 about 28 feet. An injection well is drilled to the ~ottom Qf the hydrocarbon bearing structure a~d the casing per- -; ~. -.~ : .
forated in the interval 735 to 745 feet. In a like manner a production well drilled at a distance of about 400 feet from the injection well is perforated at a de~th of 730-740 feet, i~e~, the center of ~he tar sand formation at . that location.
`
' 1 In the next step a fluid communication path is formed by fr~cturing the formation in both wells using conventional hydraulic fracturing teehnique. A g~a~el-sand mixture is injected into the formation to hold it op~n and to prevent healing of the frac~ure~ A ~otal of 3,400 barrels of toluene saturated with car~on dioxide at a temperature of 60~E. and a pressure of 500 psig is injected into the formation at th same pressure and at a rate of 10 barrels pex minute. Following the injection of the carbon dioxide saturated toluene, the injection of superhea~ed steam (temp~rature 600F, pressure 300 psig) containing about 0.01 percent by weight of a solubilizlng agent of the formula:
(CH2CH20~ sH-~ - N - (CH2cE2O)~
where s plus t is about 14, is commenced at the xate of 13,000 pounds per hourO Production of viscous oil from . :~
the production well is continued and at the end of twelve ~12) days the rate of production is substantially greater than with steam injection alone.
E X A M P L E III
A test identical to that described in Example I
is conducted with the exception that the steam injected contains about 0.006 weight percent of a solubilizing ~ ,. ~:, ., agent of the formula-CH2CH20) XS03Na ~ N N ~ (CH2CH2O)ySO3Na ~. . , " . , , ~ -~ \ ~
where x plus y is about 12. At the end o 40 days of steam injection the production of ~iscous hydrocarbons is significan~ly increased over prc:duction of similar wells in the same formation employing only steam in; ection .
.
.
2~
:
--1~
,. . ~ . :
. . .
Claims (7)
1. A method for recovering petroleum from a subterranean formation containing viscous petroleum pene-trated by at least one injection well and by at least one production well characterized in that, (a) a fluid communication path between the in-jection well and the production well is established in the formation;
(b) a slug of an aromatic hydrocarbon solvent saturated at pressures ranging from about 100 to about 1,000 psi with carbon dioxide, a gaseous hydrocarbon or a mixtures thereof is injected into the communication path through the injection well;
(c) hot water, steam or superheated steam is injected through the injection well into the communication path as an oil-displacing fluid; and (d) petroleum is recovered from the formation through the production well, and wherein a solubilizing agent having the formula:
wherein r is an integer of from about 5 to about 50; wherein R" is selected from the group consisting of hydrogen and -SO3M, wherein M is selected from the group consisting of hydrogen, sodium, potassium and the ammonium ion and R" is selected from the group consisting of hydrogen and (CH2CH2O)R" wherein r and R" have the same meaning as pre-viously described, is included with the oil-displacing fluid.
(b) a slug of an aromatic hydrocarbon solvent saturated at pressures ranging from about 100 to about 1,000 psi with carbon dioxide, a gaseous hydrocarbon or a mixtures thereof is injected into the communication path through the injection well;
(c) hot water, steam or superheated steam is injected through the injection well into the communication path as an oil-displacing fluid; and (d) petroleum is recovered from the formation through the production well, and wherein a solubilizing agent having the formula:
wherein r is an integer of from about 5 to about 50; wherein R" is selected from the group consisting of hydrogen and -SO3M, wherein M is selected from the group consisting of hydrogen, sodium, potassium and the ammonium ion and R" is selected from the group consisting of hydrogen and (CH2CH2O)R" wherein r and R" have the same meaning as pre-viously described, is included with the oil-displacing fluid.
2. A method according to Claim 1 characterized in that the communication path is created by hydraulic fracturing.
3. A method according to Claim 1 characterized in that the formation contains a substantially water sat-urated, porous zone in the lower part thereof, and the communication path low in the formation is created by in-jecting steam or hot water.
4. A method according to Claims 1 to 3 char-acterized in that the oil-displacing fluid contains sodium hydroxide or sodium hypochlorite.
5. A method according to Claims 1 to 3 char-acterized in that the oil-displacing fluid contains a sur-ractant.
6. A method according to Claims 1 to 3 char-acterized in that the aromatic hydrocarbon solvent is ben-zene, toluene, xylene or a mixture thereof.
7. A method according to Claim 1 to 3, characterized in that the aromatic hydrocarbon solvent is benzene, toluene, xylene or a mixture thereof, and the aromatic hydrocarbon is saturated with methane, ethane, propane, butane, hexane or natural gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA293,323A CA1095226A (en) | 1977-12-19 | 1977-12-19 | Oil recovery process utilizing aromatic solvent and steam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA293,323A CA1095226A (en) | 1977-12-19 | 1977-12-19 | Oil recovery process utilizing aromatic solvent and steam |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1095226A true CA1095226A (en) | 1981-02-10 |
Family
ID=4110311
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA293,323A Expired CA1095226A (en) | 1977-12-19 | 1977-12-19 | Oil recovery process utilizing aromatic solvent and steam |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1095226A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10012064B2 (en) | 2015-04-09 | 2018-07-03 | Highlands Natural Resources, Plc | Gas diverter for well and reservoir stimulation |
| US10344204B2 (en) | 2015-04-09 | 2019-07-09 | Diversion Technologies, LLC | Gas diverter for well and reservoir stimulation |
| US10982520B2 (en) | 2016-04-27 | 2021-04-20 | Highland Natural Resources, PLC | Gas diverter for well and reservoir stimulation |
-
1977
- 1977-12-19 CA CA293,323A patent/CA1095226A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10012064B2 (en) | 2015-04-09 | 2018-07-03 | Highlands Natural Resources, Plc | Gas diverter for well and reservoir stimulation |
| US10344204B2 (en) | 2015-04-09 | 2019-07-09 | Diversion Technologies, LLC | Gas diverter for well and reservoir stimulation |
| US10385257B2 (en) | 2015-04-09 | 2019-08-20 | Highands Natural Resources, PLC | Gas diverter for well and reservoir stimulation |
| US10385258B2 (en) | 2015-04-09 | 2019-08-20 | Highlands Natural Resources, Plc | Gas diverter for well and reservoir stimulation |
| US10982520B2 (en) | 2016-04-27 | 2021-04-20 | Highland Natural Resources, PLC | Gas diverter for well and reservoir stimulation |
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