CA1249429A - Waterflood oil recovery process using internal olefin sulfonate surfactant - Google Patents
Waterflood oil recovery process using internal olefin sulfonate surfactantInfo
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- CA1249429A CA1249429A CA000496910A CA496910A CA1249429A CA 1249429 A CA1249429 A CA 1249429A CA 000496910 A CA000496910 A CA 000496910A CA 496910 A CA496910 A CA 496910A CA 1249429 A CA1249429 A CA 1249429A
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- surfactant
- oil
- internal olefin
- fluid
- surfactants
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Abstract
WATERFLOOD OIL RECOVERY PROCESS
USING INTERNAL OLEFIN SULFONATE SURFACTANT
Abstract of the Disclosure The present invention relates to a process wherein an aqueous surfactant system containing a primary surfactant which is an internal olefin sulfonate surfactant having a water solubility which concentrates the surfactant at the oil/water interface and is an effective oil dis-placing fluid.
USING INTERNAL OLEFIN SULFONATE SURFACTANT
Abstract of the Disclosure The present invention relates to a process wherein an aqueous surfactant system containing a primary surfactant which is an internal olefin sulfonate surfactant having a water solubility which concentrates the surfactant at the oil/water interface and is an effective oil dis-placing fluid.
Description
WATERFLOOD OIJ~ RECOVERY PROCESS
USING INTERNAL OLEFIN SULFON~TE SURFACTANT
Background of the Invention rhis inventioll relates to a surfactant-aided waterflood or chem1c.l1 Çlood process ln whlcll oil is displaced toward a production location by in~ecting a surfactant-containlng aqueous fluid into a subterranean reservoir. More particularly, the invention relates to improving such a process by in;ecting a relatively large and relatively dilute slug of aqueous fluid and using a surfactant which is predominantly an internal olefin sulfonate surfactant.
~ Internal olefin sulfonates (IOS's) are sulfonates derived from linear, branched chain, or alicyclic olefins in which there is a double bond between a pair of carbon atoms not inclusive of a terminal carbon atom. U. S. Patent No. 4,393,937 by R. C. Dilgren and K. B.
Owens indicate that IOS's can be used in steam-foam-forming mixtures which contain olefin sulfonate surfactants, although such surfactants are preferably at least in maJor part alpha-olefin sulfonate surfactants.
In general, previously propose~ chemical flooding procedures have utilized inJections of relatively complex and costly surfactant-containing aqueous liquids in the form of small but highly concentrated slugs of surfactant systems which commonly contain substantial quantities of cosurfactants~ alcohols and sometimes oil. Some of the systems were oil-based surfactant-containing fluids. In most instances~ the processes required aqueous prefloods. Not only were such systems of questionable economics but in view of the multiplicity of their ingredients there was an uncertainty as to whether such 81ugs could be propagated intact through BKAE8426~04 4~29 the reservoir. ~owever, such prior processes did achieve a virtually total displacement of oil from cores in laboratory tests.
A particularly distinguishing feature of the present process is its simplicity. In a preferred embodiment the invention entails only an injection of a relatively large and relatively dilute slug of a single surfactant. No other ingredient need be included, with the exception of a mobility control agent, where such a control is desired. In addition, the present process tends to require less chemicals in the surEactant-containing fluid than was employed in most but not all of the earlier processes.
Summary of the Invention The present invention relates to a fluid drive oil process in which oil is displaced within a subterranean reservoir by injecting a surfactant~containing aqueous fluid into the reservoir. The surfactant-containing fluid is in~ected in the form of a relatively dilute and rela-tively large volume solution. The solution preferably contains about 0.5 to 2 percent surfactant and equals about 0.25 to 0.5 pore volume of the reservolr within the fluid drive pattern. The surfactant contained in the solution consists essen~ially of one or a mixture of surfactants that are ~0 predominantly internal olefin sulfonate surfactants, preferably those con-taining about 15-30 carbon atoms and having molecular structures causing them to concentrate at oil/water :Lnterfaces and reduce the interfacial tension between the solution and the oil.
_rief Description of the Drawings Figure 1 shows a graph of comparative oil recoveries versus salinities of aqueous liquids containing, respectively, an internal olefin sulfonate surfactant and a petroleum sulfonate surfactant.
_ 3 _ 3293-2609 Figure 2 shows a graph of, respectively, oil saturation and oiL
cut with amount of produced liquid in a core Elood using an internal ole-fin sulfonate surfactant.
Figure 3 shows a graph of oil recovery with amount of fluid in-jected using internal olefin sulfonate surfactants in cores oriented,respectively, vertically and horizontally.
Descrlption of the InventLon The present invention is, at least in part~ premised on a dis-covery that when surfactants are contained in aqueous liquids which are relatively dilute and used in relatively large volume, internal olefin sulfonate surfactants of the specified molecular structures are capable of displacing significantly greater amounts of oil within permeable earth formations than can be displaced by other types of sulfonate surfactants.
Figure 1 shows the results of comparative tests of injecting, 15- respectlvely, an internal olefin sulfonate surfactant, C20 24 IOS, and a petroleum sulfonate "Witco TRS-10" as surfactants in aqueous liquid solu-tions of surfactants ~Jhich were injected in~o Berea sandstone cores which had been previously saturated with Whitecastle crude oil and then water-flooded to a residual oil saturation with Sl)SW (Synthetic D Sand Water contalning 10.~ percent NaCl, 1.()8~ MgCl2~6 1120, 0.59% CaCl2~2 ~l2) Tlle preparatioll of the C20 24 IOS sulfonate surfactant was conducted as folk~ws: ~ sulfonation of ~ C20 24 predominantlY linear - internal olefin was carried out in a three-stage falling film reactor at sulfur trioxide to olefin molaL- ratios between 1.05 and 1.15. Each of the reactor stages was heated to 50C. The gaseous S03 was delivered to the reactor as a 1.3% by weight concentation in nitrogen. The acid reaction mixture (ARM) was collected over one-an-hour time period. The ~R~I was aged for 3 hours at 35C, then the ~RM was neutralized with NaO~I
at a 1:1 ratio of NaOII to S03 consumed. Each of the mixtures was diluted * Trade Mark ' ~ k~
` I~KAE8426804 ~ 3293-2609 with water to give about ~ 25% by weight concentration of IOS. Finally, hyclrolysis was completed in a one-gallon autoclave at 140nC for 3 ilours Witil 100~ rpm stirr-ing.
1`he oil recovery experiments were conductecl in 10-inch long,
USING INTERNAL OLEFIN SULFON~TE SURFACTANT
Background of the Invention rhis inventioll relates to a surfactant-aided waterflood or chem1c.l1 Çlood process ln whlcll oil is displaced toward a production location by in~ecting a surfactant-containlng aqueous fluid into a subterranean reservoir. More particularly, the invention relates to improving such a process by in;ecting a relatively large and relatively dilute slug of aqueous fluid and using a surfactant which is predominantly an internal olefin sulfonate surfactant.
~ Internal olefin sulfonates (IOS's) are sulfonates derived from linear, branched chain, or alicyclic olefins in which there is a double bond between a pair of carbon atoms not inclusive of a terminal carbon atom. U. S. Patent No. 4,393,937 by R. C. Dilgren and K. B.
Owens indicate that IOS's can be used in steam-foam-forming mixtures which contain olefin sulfonate surfactants, although such surfactants are preferably at least in maJor part alpha-olefin sulfonate surfactants.
In general, previously propose~ chemical flooding procedures have utilized inJections of relatively complex and costly surfactant-containing aqueous liquids in the form of small but highly concentrated slugs of surfactant systems which commonly contain substantial quantities of cosurfactants~ alcohols and sometimes oil. Some of the systems were oil-based surfactant-containing fluids. In most instances~ the processes required aqueous prefloods. Not only were such systems of questionable economics but in view of the multiplicity of their ingredients there was an uncertainty as to whether such 81ugs could be propagated intact through BKAE8426~04 4~29 the reservoir. ~owever, such prior processes did achieve a virtually total displacement of oil from cores in laboratory tests.
A particularly distinguishing feature of the present process is its simplicity. In a preferred embodiment the invention entails only an injection of a relatively large and relatively dilute slug of a single surfactant. No other ingredient need be included, with the exception of a mobility control agent, where such a control is desired. In addition, the present process tends to require less chemicals in the surEactant-containing fluid than was employed in most but not all of the earlier processes.
Summary of the Invention The present invention relates to a fluid drive oil process in which oil is displaced within a subterranean reservoir by injecting a surfactant~containing aqueous fluid into the reservoir. The surfactant-containing fluid is in~ected in the form of a relatively dilute and rela-tively large volume solution. The solution preferably contains about 0.5 to 2 percent surfactant and equals about 0.25 to 0.5 pore volume of the reservolr within the fluid drive pattern. The surfactant contained in the solution consists essen~ially of one or a mixture of surfactants that are ~0 predominantly internal olefin sulfonate surfactants, preferably those con-taining about 15-30 carbon atoms and having molecular structures causing them to concentrate at oil/water :Lnterfaces and reduce the interfacial tension between the solution and the oil.
_rief Description of the Drawings Figure 1 shows a graph of comparative oil recoveries versus salinities of aqueous liquids containing, respectively, an internal olefin sulfonate surfactant and a petroleum sulfonate surfactant.
_ 3 _ 3293-2609 Figure 2 shows a graph of, respectively, oil saturation and oiL
cut with amount of produced liquid in a core Elood using an internal ole-fin sulfonate surfactant.
Figure 3 shows a graph of oil recovery with amount of fluid in-jected using internal olefin sulfonate surfactants in cores oriented,respectively, vertically and horizontally.
Descrlption of the InventLon The present invention is, at least in part~ premised on a dis-covery that when surfactants are contained in aqueous liquids which are relatively dilute and used in relatively large volume, internal olefin sulfonate surfactants of the specified molecular structures are capable of displacing significantly greater amounts of oil within permeable earth formations than can be displaced by other types of sulfonate surfactants.
Figure 1 shows the results of comparative tests of injecting, 15- respectlvely, an internal olefin sulfonate surfactant, C20 24 IOS, and a petroleum sulfonate "Witco TRS-10" as surfactants in aqueous liquid solu-tions of surfactants ~Jhich were injected in~o Berea sandstone cores which had been previously saturated with Whitecastle crude oil and then water-flooded to a residual oil saturation with Sl)SW (Synthetic D Sand Water contalning 10.~ percent NaCl, 1.()8~ MgCl2~6 1120, 0.59% CaCl2~2 ~l2) Tlle preparatioll of the C20 24 IOS sulfonate surfactant was conducted as folk~ws: ~ sulfonation of ~ C20 24 predominantlY linear - internal olefin was carried out in a three-stage falling film reactor at sulfur trioxide to olefin molaL- ratios between 1.05 and 1.15. Each of the reactor stages was heated to 50C. The gaseous S03 was delivered to the reactor as a 1.3% by weight concentation in nitrogen. The acid reaction mixture (ARM) was collected over one-an-hour time period. The ~R~I was aged for 3 hours at 35C, then the ~RM was neutralized with NaO~I
at a 1:1 ratio of NaOII to S03 consumed. Each of the mixtures was diluted * Trade Mark ' ~ k~
` I~KAE8426804 ~ 3293-2609 with water to give about ~ 25% by weight concentration of IOS. Finally, hyclrolysis was completed in a one-gallon autoclave at 140nC for 3 ilours Witil 100~ rpm stirr-ing.
1`he oil recovery experiments were conductecl in 10-inch long,
2-inch diameter Berea cores at a temperature oE 159F. In each test the floocling sequence (following establishment of residual oil saturation) was 0.5 pore volume of a solution containing 1% of the inclicated surfac-tanc, the inclicatecl amount or so~lium chlori(le and enough P-lsher-700 water-thickellillg polyacrylamide polymer ava:ilable from Dow Chemlcal Com-pany) to provide a viscosity of about 8 cp. Each solution was followedhy 1.0 pore volume of drive water containing 1.6% sodium chloride and the same type of polymer in an amount providing a viscosity of about 12 cps.
As indicatecl in Figure 1, the oil recovery peaked at sodium chloride concentrations of respectively, 0.5 and 0.8 in the chemical slugs and drive waters. The internal olefin sulfonate was significantly more effective than the petroleum sulfonate. It not only recovered more oil but operated over a broader concentration range of sodium chloride.
~ lthougll the optimum NaCl concentration for displacing oil with a solution containing 1% oE the above internal olefin sulfonate surfactant is about 2.6%, in the experiments performed to evaluate the e~fect of the presence of multivalent lons in cores which had heen flooded to residual oil saturation with SDS water prior to the injection of the surfactallt, it became apparent that the ~ixing of the SDS water with an IOS surfactant slug whicil containecl 2.6% NaCl pushed the system into an over optimum region. When successive experiments were performed with decreasing amounts of salt in the surEactant slugs, it became apparent that, with respect to earth formations containing a relativel~
saline l)rine and a significant proportion of multivalent ions, such as tlle SDS water, the extent of oil clisplacement by C20_24 IOS surfactant contai~ lg chemical slug peaks at a salt concentration oE about 0.8%.
* Trade Mark BK~E8426804 ~ ~ .
As indicatecl in Figure 1, the oil recovery peaked at sodium chloride concentrations of respectively, 0.5 and 0.8 in the chemical slugs and drive waters. The internal olefin sulfonate was significantly more effective than the petroleum sulfonate. It not only recovered more oil but operated over a broader concentration range of sodium chloride.
~ lthougll the optimum NaCl concentration for displacing oil with a solution containing 1% oE the above internal olefin sulfonate surfactant is about 2.6%, in the experiments performed to evaluate the e~fect of the presence of multivalent lons in cores which had heen flooded to residual oil saturation with SDS water prior to the injection of the surfactallt, it became apparent that the ~ixing of the SDS water with an IOS surfactant slug whicil containecl 2.6% NaCl pushed the system into an over optimum region. When successive experiments were performed with decreasing amounts of salt in the surEactant slugs, it became apparent that, with respect to earth formations containing a relativel~
saline l)rine and a significant proportion of multivalent ions, such as tlle SDS water, the extent of oil clisplacement by C20_24 IOS surfactant contai~ lg chemical slug peaks at a salt concentration oE about 0.8%.
* Trade Mark BK~E8426804 ~ ~ .
3~,`i `~
, 't.- ,_t Figure 2 shows a typical oil desaturation curve and oil cut curve for a core flood using a 0.5 pore volume aqueous sur-factant system containing 1~ IOS surfactant and 0.8% sodium chloride in a core containing SDS water and residual oil. The liquids recovered in the steep linear portion of the oil satura-tion curv~ (between 0.3 to 0.9 pore volume) were produced in the form of clean oil and water. At about 0.9 pore volume produced liquid, the first trace of surfactant appeared in the effluent.
That was marked by flattening meniscus and the first appearance of turbidity in the aqueous phase. Thereafter, a mixture of oil and finely dispersed oil-in-water emulsion was producecl and after about 1.`2 pore volume, most of the production occurred as an emulsion requiring an emulsion breaking treatment. The arrows and labels on the oil saturation curve mark the end of the chemi-cal slug, the duration of the production of clean oil and water, and the region of increasing emulsification.
Figure 3 shows the results of oil recovery experiments with Berea cores containing White Castle S* sand oil preflooded to a residual saturation with 2.6~ aqueous NaCl. The surfactant slugs used contained a C20 24 IOS surfactant with mobility con-trol and were conducted at a temperature of 159F with the cores mounted, respectively, in vertical and horizontal positions. The viscosit~ of the reservoir oil was 4.2 cp. The composition of the chemical slugs were 1% surfactant, 2.60~ NaCl, 2100 ppm Pusher-700 and 500 ppm foramldehyde. The viscosities were 8.7 centipoise for the vertically displaced flood and 9.9 centipose for its horizontally displaced flood.
The vertical drive recovered 84~ of residual oil at 1 Vp and 95~ at 1.5 VpO Most of the oil was recovered at a 50%
3~ oil cut. Results of the horizontal experiment were less striking but still quite favorable, producing 80% of the residual oil at 1 pore volume and 87~ at 1.5 pore volume.
* Trademark Internal olefin sulfonates often contain about 30% active matter and an excess of sodium hydroxide. For example, a 1% solution by weight (based on active material) of the C20 24 IOS surfactant exhibits a p~l of 10.5. Many crude oils have appreciable acid numbers. In order to deter-mine the primary surfactant characteristics of such an IOS surfactant inthe absence of any cosurfnctants comprising alkali metal soaps o the petrole~m acLds in tlle oll, compar~tive tests were made with IOS samples as recelved and as nautralt7.e~ with ~ICl. ~omparatlve oil dlsplacement experiments were conducted ln 10-lnch long, 2-inch diameter ~erea cores using in one case, a solution of IOS at pH of 10.8 and, in a second case, a solution of the same surfactant neutralized to a pH of 8.7. The cores wPre preflooded with 2.9% sodium chloride and the same concentration was used in the aqueous liquid containing the surfactants. The ~ores were oriented vertically and the surfactant pumped upward at 1 foot per day with no mobility control. About 45% waterflood residual oil was recovered with 1 Vp of each of the surfactant solutions and 93% with 2 Vp~ No substantial difference in oil recovery between the neutralized and un-modified surfactants were noted. The oil used has an acid number of about one.
In general, IOS surfactants suitable for use in this invention are those having a higll content of :Lnternal olefins in the 12-30 carbon atom range. Such olefins are commercially manufactured by processes such as the chlorination dehydrochlorination of paraffins or paraffin dehydro-genatioll. They can also be prepared by isomerization of alpha-olefins or by the isomerization~disproportionation as employed in the Shell Higher Olefin Process. Internal-olefin-rich products'are manufactured and sold, for example, by Shell Chemical Company and by Chimica Augusta Company.
Preferably, the carbon content of the internal olefin sulfonate surfac-tants is about 15 to 30 carbon atoms per molecule in a molecular struc-ture causing the surfactants to concentrate at oil/water interfaces.
w ~ 2~
Known types of microscopic tests, emulsification tests, inter-facial tension measurements, or the like can be utili~ed for determining interfacial activity of internal olefin surfactants. ~uch microscopic tests are performed ~y microscopic observations of emulsification and oil~stringer formation in small droplets of oil which are deposited in flowing streams of aqueous liquids containing the surfactants being tested.
By conducting core flood tests with different concentrations of sodium chloride in aqueous liquLds containing a particular surfactant, determl-nations can be made of the salinity range at which the surfactant is most active.
The C20 24 internal olefin sulfonate surfactants prepared by sulfonating isomerizatlon-dlsproportlonatlon streams or -lnternal olefin sulfonate surfactants of similar compositions available from other so~rces are particularly suitable. Where desirable, at least a portion of the surfactant in the surfactant-containing aqueous liquid used in the present invention can comprise one or more other types of synthetic, olefin or petroleum sulfonate surfactants, as long as the total concentration of surfactant in the aqueous liquid is predominantly an internal olefin sulfonate surfactant containing about 12 to 30 carbon atoms having the specified tendency to concentrate at oil/water interfaces.
Where mobility control is desired, substantially any of the conventional water-thickening polymers can be used. Pusher~700, available from Dow Chemical Company, is particularly suitable, with or without an aldehyde such as for~aldehyde.
, 't.- ,_t Figure 2 shows a typical oil desaturation curve and oil cut curve for a core flood using a 0.5 pore volume aqueous sur-factant system containing 1~ IOS surfactant and 0.8% sodium chloride in a core containing SDS water and residual oil. The liquids recovered in the steep linear portion of the oil satura-tion curv~ (between 0.3 to 0.9 pore volume) were produced in the form of clean oil and water. At about 0.9 pore volume produced liquid, the first trace of surfactant appeared in the effluent.
That was marked by flattening meniscus and the first appearance of turbidity in the aqueous phase. Thereafter, a mixture of oil and finely dispersed oil-in-water emulsion was producecl and after about 1.`2 pore volume, most of the production occurred as an emulsion requiring an emulsion breaking treatment. The arrows and labels on the oil saturation curve mark the end of the chemi-cal slug, the duration of the production of clean oil and water, and the region of increasing emulsification.
Figure 3 shows the results of oil recovery experiments with Berea cores containing White Castle S* sand oil preflooded to a residual saturation with 2.6~ aqueous NaCl. The surfactant slugs used contained a C20 24 IOS surfactant with mobility con-trol and were conducted at a temperature of 159F with the cores mounted, respectively, in vertical and horizontal positions. The viscosit~ of the reservoir oil was 4.2 cp. The composition of the chemical slugs were 1% surfactant, 2.60~ NaCl, 2100 ppm Pusher-700 and 500 ppm foramldehyde. The viscosities were 8.7 centipoise for the vertically displaced flood and 9.9 centipose for its horizontally displaced flood.
The vertical drive recovered 84~ of residual oil at 1 Vp and 95~ at 1.5 VpO Most of the oil was recovered at a 50%
3~ oil cut. Results of the horizontal experiment were less striking but still quite favorable, producing 80% of the residual oil at 1 pore volume and 87~ at 1.5 pore volume.
* Trademark Internal olefin sulfonates often contain about 30% active matter and an excess of sodium hydroxide. For example, a 1% solution by weight (based on active material) of the C20 24 IOS surfactant exhibits a p~l of 10.5. Many crude oils have appreciable acid numbers. In order to deter-mine the primary surfactant characteristics of such an IOS surfactant inthe absence of any cosurfnctants comprising alkali metal soaps o the petrole~m acLds in tlle oll, compar~tive tests were made with IOS samples as recelved and as nautralt7.e~ with ~ICl. ~omparatlve oil dlsplacement experiments were conducted ln 10-lnch long, 2-inch diameter ~erea cores using in one case, a solution of IOS at pH of 10.8 and, in a second case, a solution of the same surfactant neutralized to a pH of 8.7. The cores wPre preflooded with 2.9% sodium chloride and the same concentration was used in the aqueous liquid containing the surfactants. The ~ores were oriented vertically and the surfactant pumped upward at 1 foot per day with no mobility control. About 45% waterflood residual oil was recovered with 1 Vp of each of the surfactant solutions and 93% with 2 Vp~ No substantial difference in oil recovery between the neutralized and un-modified surfactants were noted. The oil used has an acid number of about one.
In general, IOS surfactants suitable for use in this invention are those having a higll content of :Lnternal olefins in the 12-30 carbon atom range. Such olefins are commercially manufactured by processes such as the chlorination dehydrochlorination of paraffins or paraffin dehydro-genatioll. They can also be prepared by isomerization of alpha-olefins or by the isomerization~disproportionation as employed in the Shell Higher Olefin Process. Internal-olefin-rich products'are manufactured and sold, for example, by Shell Chemical Company and by Chimica Augusta Company.
Preferably, the carbon content of the internal olefin sulfonate surfac-tants is about 15 to 30 carbon atoms per molecule in a molecular struc-ture causing the surfactants to concentrate at oil/water interfaces.
w ~ 2~
Known types of microscopic tests, emulsification tests, inter-facial tension measurements, or the like can be utili~ed for determining interfacial activity of internal olefin surfactants. ~uch microscopic tests are performed ~y microscopic observations of emulsification and oil~stringer formation in small droplets of oil which are deposited in flowing streams of aqueous liquids containing the surfactants being tested.
By conducting core flood tests with different concentrations of sodium chloride in aqueous liquLds containing a particular surfactant, determl-nations can be made of the salinity range at which the surfactant is most active.
The C20 24 internal olefin sulfonate surfactants prepared by sulfonating isomerizatlon-dlsproportlonatlon streams or -lnternal olefin sulfonate surfactants of similar compositions available from other so~rces are particularly suitable. Where desirable, at least a portion of the surfactant in the surfactant-containing aqueous liquid used in the present invention can comprise one or more other types of synthetic, olefin or petroleum sulfonate surfactants, as long as the total concentration of surfactant in the aqueous liquid is predominantly an internal olefin sulfonate surfactant containing about 12 to 30 carbon atoms having the specified tendency to concentrate at oil/water interfaces.
Where mobility control is desired, substantially any of the conventional water-thickening polymers can be used. Pusher~700, available from Dow Chemical Company, is particularly suitable, with or without an aldehyde such as for~aldehyde.
Claims (5)
1. In a fluid drive oil recovery process in which oil is displaced within a subterranean reservoir by injecting a surfactant-containing aqueous fluid, the improvement of which comprises:
using as said aqueous surfactant-containing fluid, a rela-tively dilute and large volume of fluid containing about 0.5 to 2% of surfactant and amounting to about 25 to 50% of the reservoir pore volume within the fluid drive pattern; and using as said surfactant one or more surfactants which are predominantly internal olefin sulfonate surfactants containing about 12 to 30 carbon atoms in molecular structures causing the surfactants to concentrate at oil/water interfaces in a manner enhancing the interfacial tension-lowering and oil-displacing capability of the fluid.
using as said aqueous surfactant-containing fluid, a rela-tively dilute and large volume of fluid containing about 0.5 to 2% of surfactant and amounting to about 25 to 50% of the reservoir pore volume within the fluid drive pattern; and using as said surfactant one or more surfactants which are predominantly internal olefin sulfonate surfactants containing about 12 to 30 carbon atoms in molecular structures causing the surfactants to concentrate at oil/water interfaces in a manner enhancing the interfacial tension-lowering and oil-displacing capability of the fluid.
2. The process of Claim 1 in which tests for determining interfacial activity are used to determine the optimum salinity range in which said surfactant-containing fluid is most active for displacing oil in the reservoir to be treated.
3. The process of Claim 2 in which said surfactant consists essentially of an internal olefin sulfonate surfactant produced by the sulfonation of the appropriate internal olefin with gaseous SO3 or other suitable sulfonating agents.
4. The process of Claim 1 in which the reservoir oil is, or is substantially equivalent to, a White Castle crude oil.
5. The process of Claim 4 in which the internal olefin sulfo-nate surfactant contains about 20 to 24 carbon atoms.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US68762084A | 1984-12-31 | 1984-12-31 | |
| US687,620 | 1984-12-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1249429A true CA1249429A (en) | 1989-01-31 |
Family
ID=24761131
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000496910A Expired CA1249429A (en) | 1984-12-31 | 1985-12-05 | Waterflood oil recovery process using internal olefin sulfonate surfactant |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1249429A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8513168B2 (en) | 2008-02-07 | 2013-08-20 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
| US8664166B2 (en) | 2008-02-07 | 2014-03-04 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
| US8664167B2 (en) | 2008-02-07 | 2014-03-04 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
| US8759261B2 (en) | 2008-02-07 | 2014-06-24 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
| US9102862B2 (en) | 2008-02-07 | 2015-08-11 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
-
1985
- 1985-12-05 CA CA000496910A patent/CA1249429A/en not_active Expired
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8513168B2 (en) | 2008-02-07 | 2013-08-20 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
| US8664166B2 (en) | 2008-02-07 | 2014-03-04 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
| US8664167B2 (en) | 2008-02-07 | 2014-03-04 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
| US8759261B2 (en) | 2008-02-07 | 2014-06-24 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
| US9102862B2 (en) | 2008-02-07 | 2015-08-11 | Shell Oil Company | Method and composition for enhanced hydrocarbons recovery |
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