CA1247850A - Steam foam process - Google Patents
Steam foam processInfo
- Publication number
- CA1247850A CA1247850A CA000474601A CA474601A CA1247850A CA 1247850 A CA1247850 A CA 1247850A CA 000474601 A CA000474601 A CA 000474601A CA 474601 A CA474601 A CA 474601A CA 1247850 A CA1247850 A CA 1247850A
- Authority
- CA
- Canada
- Prior art keywords
- steam
- reservoir
- foam
- oil
- linear
- 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.)
- Expired
Links
Classifications
-
- 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
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/16—Enhanced recovery methods for obtaining hydrocarbons
- E21B43/24—Enhanced recovery methods for obtaining hydrocarbons using heat, e.g. steam injection
-
- 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
- C09K8/58—Compositions for enhanced recovery methods for obtaining hydrocarbons, i.e. for improving the mobility of the oil, e.g. displacing fluids
- C09K8/584—Compositions for enhanced recovery methods for obtaining hydrocarbons, i.e. for improving the mobility of the oil, e.g. displacing fluids characterised by the use of specific surfactants
Abstract
A B S T R A C T
STEAM FOAM PROCESS
A steam foam process for diverting steam within a sub-terranean reservoir and improving oil displacement is carried out by injecting into the reservoir a steam-foam-forming mixture comprising steam and a linear C18-C30-alkylaryl sulphonate surfactant, and preferably a non-condensable gas.
STEAM FOAM PROCESS
A steam foam process for diverting steam within a sub-terranean reservoir and improving oil displacement is carried out by injecting into the reservoir a steam-foam-forming mixture comprising steam and a linear C18-C30-alkylaryl sulphonate surfactant, and preferably a non-condensable gas.
Description
L7~35~
STEAM FO~M PROCESS
The invention relates to a steam foam process for producing oil from, or displacing oil wlthin, a subterranean reservoir.
In certain respects, ~his invention is an improvement in the steam-channel-expanding steam foam drive process described in U.S.A. patent specifica~ion 4,086,964 (inventors: R.E. Dilgren, G.J. Hlrasaki, H.J. Hill, D.G. Whitten; filed 27th May, 1977;
published 2nd May, 1978).
The inventlon is particularly useful in an oll producing process of the type described in the above patent speciflcation.
In this process steam is injected lnto, and fluid is produced from, horizontally spaced locations within a portion of an oil reservolr in which the disposition of a steam flow path is de-termined by gravity and/or oil distribution. After a steam channel has been formed the composition of the fluid being lS injected ls changed fro~ steam to a steam-foam-forming mix~ure.
The composition of the mixture is correlated with the properties of the rocks and the fluids in the reservoir so that the pressure required to inject the mixture and to move it through the steam channel exceeds that required for s~eam alone but is less than the reservoir fracturing pressure. The composition and rate of in~ecting the mixture i8 ~ubsequently adjusted to the extent required to maintain a flow of steam foam within the channel at a relatively high pressure gradient at which the oil-displacing and channel-e~panding effects are significantly greater than those provided by the steam alone. Oil is recovered from the fluid produced from the reservoir.
The present invention also relates to an improvement in an oil recovery process in which steam is cyclically in~ected into and fluid i9 backflowed from a heavy oil reservoir which is s~
STEAM FO~M PROCESS
The invention relates to a steam foam process for producing oil from, or displacing oil wlthin, a subterranean reservoir.
In certain respects, ~his invention is an improvement in the steam-channel-expanding steam foam drive process described in U.S.A. patent specifica~ion 4,086,964 (inventors: R.E. Dilgren, G.J. Hlrasaki, H.J. Hill, D.G. Whitten; filed 27th May, 1977;
published 2nd May, 1978).
The inventlon is particularly useful in an oll producing process of the type described in the above patent speciflcation.
In this process steam is injected lnto, and fluid is produced from, horizontally spaced locations within a portion of an oil reservolr in which the disposition of a steam flow path is de-termined by gravity and/or oil distribution. After a steam channel has been formed the composition of the fluid being lS injected ls changed fro~ steam to a steam-foam-forming mix~ure.
The composition of the mixture is correlated with the properties of the rocks and the fluids in the reservoir so that the pressure required to inject the mixture and to move it through the steam channel exceeds that required for s~eam alone but is less than the reservoir fracturing pressure. The composition and rate of in~ecting the mixture i8 ~ubsequently adjusted to the extent required to maintain a flow of steam foam within the channel at a relatively high pressure gradient at which the oil-displacing and channel-e~panding effects are significantly greater than those provided by the steam alone. Oil is recovered from the fluid produced from the reservoir.
The present invention also relates to an improvement in an oil recovery process in which steam is cyclically in~ected into and fluid i9 backflowed from a heavy oil reservoir which is s~
- 2 -susceptible eo a gravity override that causes an oil layer to become adjacent to a gas or vapour-containing substantially oil-desaturated zone in which there is an undesirable intake and retention of the injected fluid within the desaturated zone. In such a process, the steam to be injected is premixed with surfactant components arranged to form a steam foam within the reservoir having physical and chemical properties such that it (a) is capable of being injected into the reservoir without plugging a~y portion of the reservoir at a pressure which exceeds thae required for injecting steam but is less than ehe reservoir fracturing pressure and (b) is chemically weakened by cantact with the reservoir oil so that it is more ~obile in sand containing that oil ~han in sand which is substantially free of that oil. The surfactant-containing steam is injected into the reservoir at a rate slow enough to be conducive to displacing a front of the stea~ foam along the oil-containing edge portions of the oil-desaturated zone than along the cantral portion of ~hat ~one. And, fluid is backflowed from the reservoir at a time at which part or all of the steam is condensed withln the steam foam in the reservoir.
As used herein the following terms have the following meanings: "steam oam" refers to a foam i.e. gas-liquid dis-persion which (a) is capable of both reducing the effective mobility, or ease with which such a foam or dispersion will flow wiehin a permeable porou~ medium and ~b) has steam in the gas phase thereof. "~obility'l or "permeability" refers to an effective mobility or eas~ of flow of a foam within a per~eable porous medium. ~ "permeability reduction" or "mobility reduction" refers to reducing t~.e ease of such a foam flow due to an increase in the effective viscosity of the fluid and/or a decrease-in the effective permeability of the porous medium. A reduction ln such a mobility or permeability can be detected and/or determined by measuring dlfferences ln internal pressures within a colu~n of permeable porous material during a R~eady state flow of fluid through a column of such material. "Steam quality" as used ~ ~4~5C3
As used herein the following terms have the following meanings: "steam oam" refers to a foam i.e. gas-liquid dis-persion which (a) is capable of both reducing the effective mobility, or ease with which such a foam or dispersion will flow wiehin a permeable porou~ medium and ~b) has steam in the gas phase thereof. "~obility'l or "permeability" refers to an effective mobility or eas~ of flow of a foam within a per~eable porous medium. ~ "permeability reduction" or "mobility reduction" refers to reducing t~.e ease of such a foam flow due to an increase in the effective viscosity of the fluid and/or a decrease-in the effective permeability of the porous medium. A reduction ln such a mobility or permeability can be detected and/or determined by measuring dlfferences ln internal pressures within a colu~n of permeable porous material during a R~eady state flow of fluid through a column of such material. "Steam quality" as used ~ ~4~5C3
-3- Z32g3-~97 regar~ing any steam-containiny fluid re~ers to the weight percent of the water in that fluid which is in the vapour phase of the fluid at the boiling temperature of that water at the pressure of the fluid. For example: in a monocomponent steam-containing fluid which consists entirely of water and has a steam quality of 50%, one-half of the weight of the water iæ in the vapour phase; and, in a multicomponent steam-containing fluid which contains nitrogen in the vapour phase and dissolved or dispersed surfactant and electrolyte in the liquid phase and has a steam quality of 50~, one-half the weight of the weight of the water in the multi-component steam-containing fluid is in the vapour phaæe. Thus, the steam quality of a steam-containing fluid can be calculated as, for example, 100 times the mass (or mass flow rate~ of the water vapour in that fluid divided by the sum of the mass (or mass flow rate) of both the water vapour and the liquid water in that fluid. "Steam-foam-formin~ mixture" tor composition~ refers to a mixture of steam and a~uaous liquid solution (or dispersion) of surfactant, with some or all, of the steam being present in the gas phase of a steam foam. The gas phase may include non-condensable gas~es) such as nitroqen.
The invention provides a process for displacing oilwithin an oil-containing subterranean reservoir by flowing a steam-containing fluid in con~unction with a surfactant component through a relatively steam permeable zone within said reservoir characterized in that a sur$actant component is employed which comprises in substantial par~ at least one sulphonate of the formula RS03X in which R is alkylaryl including benzene~ toluene or ,'~'`;l. :1 71~50 -3a- 63293-2497 xylene having atached thereto a linear alkyl group containlng 18-30 carbon a~oms in the alkyl chain and X ls sodium, potassium, lithium or ammonium.
The alkylaryl sulphonate-containing steam-foam-formlng mixture suitably includes an aqueous solution of electrolyte and advantageously further also includes a substantially noncondensable gast with each of the surfatant, electrolyte and yas components being present in proportions effective for s~eam-foam-7~5~
formation in the presence of the reservoir oil. The inventionalso relates to the alkylaryl sulphonate-containing steam-foam-forming mixtures which are described herein.
The invention is useful where it is desirable to remove oil from, or displace oil within, a subterranean :reservoir. ~or exa~ple, the invention can be used to move oil or an emulsion of oil and water away from a well borehole in a ~ell cleanlng type of operation, and/or to displace oil into a producing location in an oll-reco~ery operation.
In particular, the present inventlon relaees to a process for recovering oil from a subterranean reservoir, comprising:
in~ecting steam and producing fluid at horizontally spaced location~ within a portion of an oil reservoir in which the disposition of a steam flow path is determined by the effect of gra~ity and/or oil distribution, rather than being substantially confined within at least the one most permeable layer of reservoir rocks;
advantageously maintaining rates of steam in~ecting and fluid productlon such that a steam channel has been extended from the injection location;
changing the composition of the fluid being in~ected from steam tD a steam-foam-forming mixture including steam and an aqueous, electrolyte-containing solution or dispersion of an alkylaryl sulphonate-containing sur~actant, whilst continuing to produce fluid from the reservoir;
correlating the composition of the steam-foam-forming mixture wlth the properties of the rocks and fluids in the reservoir s~ that the p~essure required to inject the mixture and the foam it forms or comprises into and through the steam channel exceeds that required for steam alone but is less than the reservoir fracturing pressure; and ad~usting the co~position cf the fluid being injected into the steam channel to the extent required to maintain a flow of bo~h steam and foam within the channel in response to a relative-ly hlgh pressuré gratlent at which the oil-dlsplacing and channel-5~
expanding effects are signif~cantly greater than those providedby steam alone, without plugging the channel.
The inventlon also relates to an oil recovery process in which steam is cyclically in~ected into and fluid is backflowed from a subterranean heavy oil reservoir which is susceptible to gravity override and tends to intake and retain undesirably large proport$ons of the in~ec~ed fluid. This process comprise9: tl) ln~ecting steam mixed ~ith a linear C10-C30-alkylaryl sulphonate-contalning steam-foam-forming compound which is arranged for forming a steam foam whieh (a) can be displace~ through the pores of the reservoir, witho~t plugging any portion of the reservoir, in response to a pressure ~hlch exceeds that required for dis-placing steam through the reservoir but is less than the fractur-ing pressure of the reservoir, and (b) can be weakened by contact with the reservoir oil to an extent such that the weakened foam is significantly more mobile ~n reservoir oil-containing pores of a porous medium than in oil-free pores of that med~um; (2) in~ecting the steam-foam-for~ing mixture at a rate equivalene to one whlch is slow enough to cause th~ foam formed by that mixture to advance more rapidly through the pores of a reservoir o~l-containing permeable medium than through the pores of a substant-ially oil-free permeable medium; ant (3) backflowing fluid from the reservoir after a steam soak time sufficient to condense part or all of the steam in the injected steam-foam-forming mixture. The steam foam-forming mixture preferably comprises steam, a noncondensable gas, a linear C18-C30-alkylaryl sulphonate surfactant and an electrolyte.
The invention provides unobvious and beneficial advantages in oil displacement procedures by the use of the alkylaryl sulphonate surfactant in the steam-foam-forming compositions.
For example, where a steam-foam forming mixture contains such a surfactant and an electrolyte in proportions near optimum for foa~ formation, the present surfactant components provide ex-ceptionally strong steam foams havlng mobilities many times less than those of steam foams using other surfactants. In addition, 5~
significant reductions are reached in the mobilities of the steam foams at concentrations which are much less than those required for equal mobility reduc~ions by the surfactants which were previously considered to be the best available for such a purpose.
The use of the present alXylaryl sulphonate surfactant components involves no problems with respect to thermal and hydrolytic stability. No chemical or physical deterioration has been detect-able in the present alkylaryl sulphonate surfactants that were recovered along with the fluids produced during product~ons of oil from subterranean reservoirs. In each of ~:hose t-~pes of sulphonate surfactants the sulphur ato~s of the sulphonate groups are bonded directly to carbon atoms. The surfactants which were recovered and tested during the production of oil had travelled through the reservoirs at steam temperatures for ~ignificant eimes and distances.
The present C18-C30-alkylaryl sulphonate-containing steam foams have been found to represent a substantial i~provement in mobility reduction over foams based on the C12-C15-alkylaryl sulphonates e.g., dodecylbenzene sulphonates. The foams to be used according to the present invention represent also sub-stantial improvement over the C16-C1O alpha-olefinsulphonate-containing foams.
The present invention further relates to compositions ; containing at lea~t one C18-C30-alkylaryl sulphonate, and steam, optionally electrolyte, and optionally noncondensable gas, that are suitable for use in oil-displacing and/or producing processes.
Of particular interest in this respect are steam-foam-forming compoRitions consi~ting essentially of (a) water, which is pre~nt in the composition, at a temperature substantially equalling its boillng temperature, at the pressure of the com-position, in both a llquid phase and a vapour phase; (b) a sur-factant component present in the liquid phase of the co~position in an amount between 0.01 and 10 percent by weight, calculated on the weight of the liquid phase, said surfactant component comprising in substantial part at lea~t one C18-C30-alkylaryl ~ 7 -sulphonat2; (c) an electrolyte present in the liquid phase of the composition in an amount between 0,001 percent by weight (calcu~
lated on the weight of the liquid phase) and an amount tending to partition the surfactant into a separate liquid phase; and (d) a noncondensable gas present in the vapour phase in an amount between about 0.0001 and 0O3 percent by mol, calculated on total mol~ in the vapour phase.
Illustrative of the alkylaryl sulphonate ~urfacta~ts suitably employed in steam-foam drive processes of e~ha~ced performance, according to the invention, are the alkylaryl sulphona~es obtained by reaceing a linear C18~C30-alkylbenzene linear C18-C3~-alkyl-toluene and/or C18-C30-alkylxylene with sulphurtrioxide followed by neutralizatlon of the sulphonic acid. Particularly suitable for purposes of the invention is a sulphonate derived from substa~tially linear C18-C30-alkyltoluene.
Different reservoir materials have different debilitating effects on the serength of a steam foam. Tests should there-fore be carriet oue to determine the sulphonates or sulphonate-containing steam-foam-forming composi~ions that perfor~ optimally in a given reservoir. This is preferably done by testing the influence of specific sulphonates on the mobility of a steam-containing fluid having the steam quality selected for use in the reservoir in the presence of the reservoir ma~erial.
Such tests are preferably conducted by flowing steam-contain-ing fluids through a sand pack. The permeability of the sand packand foam-debilitating properties of the oil in the ~and pack should be at least substantially equivalent to those of the reservoir eo be ~reated. Comparisons are made of ~he mobility of the steam-containing fluid with and without the surfactant component. The mobility is indica~ed by the substantially steady-state pressure drop between a palr of points located between the inlet and ou~let portions of the sand pack in positlons which are substantlally free of end effects on the pressures.
Some laboraeory tests to determine steam mobility will now be described with reference to Figures 1 and 2.
~4~ 5iO
Figure l shows schematically a sand pack test apparatus which can be made of currently available apparatus components.
Th~ apparatus consists of a cylindrical tube l that is 400 mm long and has a cross-sectional area of 8 cm2. Such a tube is preferably arranged for a horizontal flow of fluid from an inlet 2 to an outlet 3. The tube is preferably provided ~ith 5 pressure ~aps 49 5, 6, 7 and 8. The locatlon of the first pressure tap 4 is at a distance of 150 mm from the inlet 2. The locations of the other taps are chosen 50 as to divide the part of the tube 1 sltuated behind tap 4 into equal parts of 50 mm. The tube 1 contains a permeable and porou~ column of suitable material, such as a sand pack, which is capable of providing an adequately realistic laboratory model of a subterranean reservoir.
At the inlet end 2, the sand pack or equivalent column of permeable m~ter~al is arranged to recelve separate streams of steam, noncondensable gas such as nitrogen, and one or more aqueous llquid solutions or dispersions containing a surfactant to be tested and/or a dissolved or dispersed electrolyte. So~e or all of those components are in~ected at constant mass flow rates proportioned so that steam of a selected quality, or a selected seeam-cOntaining fluid or composition, or a steam-foam-forming mlxture of a selected steam quality can be injected and will be substantially homogeneous substantially as soon as it enters the face of the sand pack.
In the tes~s9 steam-foam-forming mixtures are compared with and without surfactant components added thereto, by measurlng pressure gradients formed within a sand pack during flows through the pack at the same substantially constant mass flow rate.
Numerous te~ts have been made of different steam-foam-for~ing mixture~ using sand pa ks composed of a reservoir sand and havlng a high permeability, such as lO darcys. The pressures were measured wieh pressure detectors (not shown) (such as piezo-electric devices) installed at the ~nlet 2 and at the taps 4, 5, 6, 7 and 8 of the tube 1. rhe results of such te~ts have proven to be generally comparable with the results obtained in the fleld.
71~Q
g In the laboratory tests, the steam-foam-forming components were in~ected at constant mass rates until substantially steady-state pressures were obtained at the inlet and at ehe taps. The ratio between the steady-state pressures at the taps during flow of steam mixed with the foam-forming surfactant component and the steady-state pressure at the taps during flow of the steam by itself are indicative for the mobility reduction. The higher this ratio, the stronger the steam foam and the higher the mobility reduction caused by the steam-foam-forming mix~ure.
Figure 2 illustrates the results of co~parative tests with steam and various steam-foam-forming mixtures in sand pack~
containing Oude Pekela Reservoir sand having a permeability of 8 darcys. The backpressure was 21 bar, corresponding with a tem-perature of 215 C. The steam in~ection rate was 600 cm3/min. The lS figure shows the variation of the pressurP in bar (Y-axis) with distance in centimetres (X-a~is) from the pack inlet 2. The pressures were measured at the inlet 2, at the taps 4, 5, 6, 7 and 8, and at the outlet 3 of the pipe 1 of Figure 1. Curve A
relates to the displacement wherein a mixture of 90% quality steam was used as a displacing composition.
Curve B relates to using a steam-contalning fluid having a steam quality of 90~ and a water phase which contains 0.25% by weight of a surfactant. In the Curv~ B test, the surfactant was a branched side-chain C15-C18-alkyltoluene sodium sulphonate available from Sun Refining Company under the trademark SUNTECH
IV-1015.
Curve C relates to using ~he mixture used for Curve B e~cept that the surfactant was a linear side-chain C20-C24-alkyltoluene sodium sulphonate.
The greatly Improved steam per~eability reduction performance of the presently described C20-C24-al~ylaryl sulphonate-containing surfactant component is clear from the Curve C as compared to the Curves A and B in Figure 2.
S~
Figure 3 illustrates the results of comparative tests with steam and various steam-foam-forming mixtures in sand packs containing Venezuelan Reservoir sand having a permeability of 10 darcys. The backpress~re was 21 bar, corresponding with a temperature of 215 C. The injection rate was 900 cm3/min. The figure shows the variation of the pressure in bar (Y-axis) wlth dis~ance in centimetres (X-axis) from the pack inlet 2. The pressures were measured at the inlet 2, at the taps ~, 5, 6, 7 and 8, and at the outlet 3 of the pipe 1 of Figure 1. Curve A
relates to the displacement wherein a mixture of 90% quality steam was used as a displacing composition.
Curve B relates to using a steam-containing fluid having a steam quality of 90% and a water phase which contains 1% by weight sodium chloride and 0.25~ by weight of a surfactant. In the Curve B test, the surfactant was a branched side-chain C15-C18-alkyltoluene sodium sulphonate available from Sun Refining Company under the trademark SUNTECH IV-1015.
Curve C rclates to using the mixture used for Curve B except that the surfactant was a linear side-chain octadecylbenzene sodium sulphonate.
In the tests represented by Curve D the formulation was the same as those used in the tests represented by Curves B and C
except that the sulphonate component was linear side-chain octadecyltoluene sulphonate.
The greatly improved steam permeability reduction performance of the presently described C18-alkylaryl sulphonate-containing surfactant component is clear from the Curves C and D as compared to the Curves A and B in Figure 3.
Com ositions and rocedures suitable for use in the resent P P P
invention For purposes of the present invention, the surfactant component of the ste~-foam-forming mixture is necessarily comprised in substantial part of linear C18-C30-alkylaryl sulphonate. Materials of this class but with a much shorter alkyl chain have heretofore found commercial utility, for example, in ~ ~z9;~5~
detergent formulations for industrial, household and personal care application.
A class of alkylaryl sulphonates very suitable for use in the present invention is that derived from a particular class of olefins, which may be defined for present purposes in terms of the configuration and number of carbon atoms in their molecular structure. These olefins have a carbon number of 18.
In terms of molecular structure, these olefins are aliphatic and linear. Either alpha- or internal olefins are considered suitable for the alky~ation route chosen to produce the products to be used according to the invention. For purposes of derivation of the alkylaryl sulphonates for use ln the process according to the invention, olefins are advantageously applied in which at least 90% of the molecules are alpha-olefins.
Particularly attractive are sulphonates derived from the ~eodene alpha-olefins (trademark) sold by Shell Chemical Company, in part for their llnear structure and high alpha-olefin con~ent, i.e., greater than 95% in each case. The Neodene alpha-olefins are prepared by ethylene oligomerization. Products having a high content of internal C18-C30 olefins are also commercially manufactured, for instance, by the chlorination-dehydro-chlorination of paraffins or by paraffin dehydrogenation, and can also be prepared by isomerization of alpha-olefins. Internal-olefin-rich products are manufactured and sold, for example, by Shell Chemical ~ompany.
For preparation of alkylaryl sulphonates, the olefins as described above are subjected to reaction with benzene, toluene or xylene. ~eaction conditions and catalyst type are chosen in such a way that preferably para alkyltoluene is for~ed. The alkylbenzene, alkylxylene or alkyltoluene isomers are reacted with sulphur trioxide. The term "sulphur trioxide" as used in the present specification and claims is intended to include any compounds or complexes which contain or yield S03 for a sul-phonation reaction as well as S03 per se. This reaction may be conducted according to methods well kno~n in the chemical arts, 785~
typically by contact of a flow of dilute S03 vapour with a thin film of liquid alkylate at a temperature in the range of about 5 to 50C~ The r~activn between the S03 and the alkylate yields a sulphonic acid which is neutralized by reaction with a base, preferably an alkali metal hydroxide, oxide, or carbonate.
The specific composition of alkylaryl sulphonates prepared as described above (and also, for instance, the methods used for sulphonation, hydrolysis, and neutralization of the specified olefins) have not been found to be a critical factor to the performance of the surfactant in the steam foam process according to this invention. In this regard, it is observed that factors which have conventionally governed the choice of sulphonation conditions, e.g., product colour, clarity, odour, etc., do not carry the same weight in the preparation of alkylaryl sulphonates for purposes of use in the process according to the invention that they have been accorded in detergent manufacture.
Consequently, reactlon condltions outside of those heretofore considered desirable for alkylate sulphonation are still suitably applied in the preparation of surfactant components suitable for use in the steam-foam-forming mixture.
For purposes related to maintaining product stability, conventional manufacture typically yields a dilute solution or dispersion of the alkylaryl sulphonates, f or instance, products with a 15-30 %wt active matter content in water. Such products may be directly applied to the preparation of steam-foam-forming mixtures for purposes of this invention.
Suitable alkylaryl sulphonates, generally prepared by methods such as described above, are themselves commerclally available products.
The strength of the foam formed by the steam-foam-forming composition including alkylaryl sulphonate tends to increase with increases in the proportion of the surfactant andlor electrclyte components of the composition. Also, there tends to be an optimum ratio of surfactant and electrolyte components at which the surface activity of the composition is maximized.
S~
The steam-foam-forming composition according to the present invention can form a steam-foam capable of reducing the effective mobility of the steam to less than about l/lOth and even to 1/50th-1/llOth of the mobility it would have within a permeable porous medium in the absence of the surfactant.
The steam used in the present process and/or compositions can be generated and supplied in the form of substantially any dry, wet, superheated, or low grade steam in which the steam condensate and/or liquid components are compatible with, and do not inhibit, the foam-forming properties of the foam-forming components of a steam-foam-forming mixture according to the present invention. The steam quality of the steam as generated and/or amount of aqueous liquid with which it is mixed be such that the steam quality of the resulting mixture is preferably from 10 to 90%. The desired steam-foam is advantageously prepared by mixing the steam with aqueous solutionts) of the sur~actant component and optionally, an electrolyte. The water content of these aqueous solutions must, of course, be taken ineo account in determining the steam quality of the mixture being formed.
Su~tably, the noncondensable gas advantageously used in a steam-foam-forming mixture according to the present invention can comprise substantially any gas which (a) undergoes little or no condensation at the temperatures ~100-350 C) and pressures (1-100 bar) at which the steam-foam-forming mixture is preferably in~ected into and displaced through the reservoir to be treated and (b) i9 substantially inert to and compatible with the foam-forming surfactant and other components of that mixture. Such a gas is preferably ni~rogen but can comprise other substantially inert gases, such as air, ethane, methane, flue gas, fuel gas, or the like. Suitable concentrations of noncondensable gas in the steam-foam mixture fall in the range of from 0.0001 to 0.3 mole percent such as 0.001 and 0.2 mole percent, or between 0.003 and 0.1 mole percent of the gas phase of the mixture.
Suitably, the electrolyte used should have a composition similar to and should be used in a proportion similar to those 29~7135~
described as suitable alkali metal salt electrolytes in the above-mentioned USA patent speciflcatlon 4,086,964. An aqueous solution may be applied that contains an amount of electrolyte substantially equivalent in salting-out effect eo a sodium chloride concentration of from 0.001 to 10% (but less than enough to cause significant salting out) of the liquid-phase of the steam. Some or all of the electrolyte can comprise an inorganic salt, such as an alkali metal salt, an alkali metal halide, and sodium chloride. Other inorganic salts, for example, halides, sulphonates, carbonates, nitrates and phosphates, in the form of salts of alkaline earth metals, can be used.
Generally stated, an electrolyte concentration may b~
applied which has approximately the same effect on mobility reduction of the foam as does a sodium chloride concentration of between 0.001 and 5 percent by weight (but less than a salting out-inducing proportion) of the llquid phase of the steam-foam-forming mixture. The electrolyte concentration may be between 0.001 and 10 percent calculated on the same basis.
In compounding a steam-foam-forming mixture or composition in accordance with the present invention, the steam can be generated by means of substantially any of the commercially available devices and techniques for steam generation. A stream of the steam being injected into a reservoir is preferably generated and mixed~ in substantially any surface or downhole location, with selected proportions of substantially noncondens-able gas, aqueous electrolyte solution, and foam-forming sur-factant. For exampleJ in such a mixture, the quality of the steam which is generated and the cor.centration of the electrolyte and surfactant-containing aqueous liquid with which it is mixed are preferably arranged so that (1) the proportion of àqueous liquid mixad with the dry steam which is injected into the reservoir is sufficient to provide a steam-containing fluid having a steam quality of from 10-90% (prsferably from 30-~0%); ~2) the weight proportion of surfactant dissolved or dispersed in the aqueous liquid is from 0.01 to 10.0 (preferably from 1.0 to 4.0); and (3) 3L.rl~ 9L'7 ~
the amount of noncondensable gas is from 0.0003 to 0.3 ~ole fraction of ~he gas phase of the mixture.
The invention provides a process for displacing oilwithin an oil-containing subterranean reservoir by flowing a steam-containing fluid in con~unction with a surfactant component through a relatively steam permeable zone within said reservoir characterized in that a sur$actant component is employed which comprises in substantial par~ at least one sulphonate of the formula RS03X in which R is alkylaryl including benzene~ toluene or ,'~'`;l. :1 71~50 -3a- 63293-2497 xylene having atached thereto a linear alkyl group containlng 18-30 carbon a~oms in the alkyl chain and X ls sodium, potassium, lithium or ammonium.
The alkylaryl sulphonate-containing steam-foam-formlng mixture suitably includes an aqueous solution of electrolyte and advantageously further also includes a substantially noncondensable gast with each of the surfatant, electrolyte and yas components being present in proportions effective for s~eam-foam-7~5~
formation in the presence of the reservoir oil. The inventionalso relates to the alkylaryl sulphonate-containing steam-foam-forming mixtures which are described herein.
The invention is useful where it is desirable to remove oil from, or displace oil within, a subterranean :reservoir. ~or exa~ple, the invention can be used to move oil or an emulsion of oil and water away from a well borehole in a ~ell cleanlng type of operation, and/or to displace oil into a producing location in an oll-reco~ery operation.
In particular, the present inventlon relaees to a process for recovering oil from a subterranean reservoir, comprising:
in~ecting steam and producing fluid at horizontally spaced location~ within a portion of an oil reservoir in which the disposition of a steam flow path is determined by the effect of gra~ity and/or oil distribution, rather than being substantially confined within at least the one most permeable layer of reservoir rocks;
advantageously maintaining rates of steam in~ecting and fluid productlon such that a steam channel has been extended from the injection location;
changing the composition of the fluid being in~ected from steam tD a steam-foam-forming mixture including steam and an aqueous, electrolyte-containing solution or dispersion of an alkylaryl sulphonate-containing sur~actant, whilst continuing to produce fluid from the reservoir;
correlating the composition of the steam-foam-forming mixture wlth the properties of the rocks and fluids in the reservoir s~ that the p~essure required to inject the mixture and the foam it forms or comprises into and through the steam channel exceeds that required for steam alone but is less than the reservoir fracturing pressure; and ad~usting the co~position cf the fluid being injected into the steam channel to the extent required to maintain a flow of bo~h steam and foam within the channel in response to a relative-ly hlgh pressuré gratlent at which the oil-dlsplacing and channel-5~
expanding effects are signif~cantly greater than those providedby steam alone, without plugging the channel.
The inventlon also relates to an oil recovery process in which steam is cyclically in~ected into and fluid is backflowed from a subterranean heavy oil reservoir which is susceptible to gravity override and tends to intake and retain undesirably large proport$ons of the in~ec~ed fluid. This process comprise9: tl) ln~ecting steam mixed ~ith a linear C10-C30-alkylaryl sulphonate-contalning steam-foam-forming compound which is arranged for forming a steam foam whieh (a) can be displace~ through the pores of the reservoir, witho~t plugging any portion of the reservoir, in response to a pressure ~hlch exceeds that required for dis-placing steam through the reservoir but is less than the fractur-ing pressure of the reservoir, and (b) can be weakened by contact with the reservoir oil to an extent such that the weakened foam is significantly more mobile ~n reservoir oil-containing pores of a porous medium than in oil-free pores of that med~um; (2) in~ecting the steam-foam-for~ing mixture at a rate equivalene to one whlch is slow enough to cause th~ foam formed by that mixture to advance more rapidly through the pores of a reservoir o~l-containing permeable medium than through the pores of a substant-ially oil-free permeable medium; ant (3) backflowing fluid from the reservoir after a steam soak time sufficient to condense part or all of the steam in the injected steam-foam-forming mixture. The steam foam-forming mixture preferably comprises steam, a noncondensable gas, a linear C18-C30-alkylaryl sulphonate surfactant and an electrolyte.
The invention provides unobvious and beneficial advantages in oil displacement procedures by the use of the alkylaryl sulphonate surfactant in the steam-foam-forming compositions.
For example, where a steam-foam forming mixture contains such a surfactant and an electrolyte in proportions near optimum for foa~ formation, the present surfactant components provide ex-ceptionally strong steam foams havlng mobilities many times less than those of steam foams using other surfactants. In addition, 5~
significant reductions are reached in the mobilities of the steam foams at concentrations which are much less than those required for equal mobility reduc~ions by the surfactants which were previously considered to be the best available for such a purpose.
The use of the present alXylaryl sulphonate surfactant components involves no problems with respect to thermal and hydrolytic stability. No chemical or physical deterioration has been detect-able in the present alkylaryl sulphonate surfactants that were recovered along with the fluids produced during product~ons of oil from subterranean reservoirs. In each of ~:hose t-~pes of sulphonate surfactants the sulphur ato~s of the sulphonate groups are bonded directly to carbon atoms. The surfactants which were recovered and tested during the production of oil had travelled through the reservoirs at steam temperatures for ~ignificant eimes and distances.
The present C18-C30-alkylaryl sulphonate-containing steam foams have been found to represent a substantial i~provement in mobility reduction over foams based on the C12-C15-alkylaryl sulphonates e.g., dodecylbenzene sulphonates. The foams to be used according to the present invention represent also sub-stantial improvement over the C16-C1O alpha-olefinsulphonate-containing foams.
The present invention further relates to compositions ; containing at lea~t one C18-C30-alkylaryl sulphonate, and steam, optionally electrolyte, and optionally noncondensable gas, that are suitable for use in oil-displacing and/or producing processes.
Of particular interest in this respect are steam-foam-forming compoRitions consi~ting essentially of (a) water, which is pre~nt in the composition, at a temperature substantially equalling its boillng temperature, at the pressure of the com-position, in both a llquid phase and a vapour phase; (b) a sur-factant component present in the liquid phase of the co~position in an amount between 0.01 and 10 percent by weight, calculated on the weight of the liquid phase, said surfactant component comprising in substantial part at lea~t one C18-C30-alkylaryl ~ 7 -sulphonat2; (c) an electrolyte present in the liquid phase of the composition in an amount between 0,001 percent by weight (calcu~
lated on the weight of the liquid phase) and an amount tending to partition the surfactant into a separate liquid phase; and (d) a noncondensable gas present in the vapour phase in an amount between about 0.0001 and 0O3 percent by mol, calculated on total mol~ in the vapour phase.
Illustrative of the alkylaryl sulphonate ~urfacta~ts suitably employed in steam-foam drive processes of e~ha~ced performance, according to the invention, are the alkylaryl sulphona~es obtained by reaceing a linear C18~C30-alkylbenzene linear C18-C3~-alkyl-toluene and/or C18-C30-alkylxylene with sulphurtrioxide followed by neutralizatlon of the sulphonic acid. Particularly suitable for purposes of the invention is a sulphonate derived from substa~tially linear C18-C30-alkyltoluene.
Different reservoir materials have different debilitating effects on the serength of a steam foam. Tests should there-fore be carriet oue to determine the sulphonates or sulphonate-containing steam-foam-forming composi~ions that perfor~ optimally in a given reservoir. This is preferably done by testing the influence of specific sulphonates on the mobility of a steam-containing fluid having the steam quality selected for use in the reservoir in the presence of the reservoir ma~erial.
Such tests are preferably conducted by flowing steam-contain-ing fluids through a sand pack. The permeability of the sand packand foam-debilitating properties of the oil in the ~and pack should be at least substantially equivalent to those of the reservoir eo be ~reated. Comparisons are made of ~he mobility of the steam-containing fluid with and without the surfactant component. The mobility is indica~ed by the substantially steady-state pressure drop between a palr of points located between the inlet and ou~let portions of the sand pack in positlons which are substantlally free of end effects on the pressures.
Some laboraeory tests to determine steam mobility will now be described with reference to Figures 1 and 2.
~4~ 5iO
Figure l shows schematically a sand pack test apparatus which can be made of currently available apparatus components.
Th~ apparatus consists of a cylindrical tube l that is 400 mm long and has a cross-sectional area of 8 cm2. Such a tube is preferably arranged for a horizontal flow of fluid from an inlet 2 to an outlet 3. The tube is preferably provided ~ith 5 pressure ~aps 49 5, 6, 7 and 8. The locatlon of the first pressure tap 4 is at a distance of 150 mm from the inlet 2. The locations of the other taps are chosen 50 as to divide the part of the tube 1 sltuated behind tap 4 into equal parts of 50 mm. The tube 1 contains a permeable and porou~ column of suitable material, such as a sand pack, which is capable of providing an adequately realistic laboratory model of a subterranean reservoir.
At the inlet end 2, the sand pack or equivalent column of permeable m~ter~al is arranged to recelve separate streams of steam, noncondensable gas such as nitrogen, and one or more aqueous llquid solutions or dispersions containing a surfactant to be tested and/or a dissolved or dispersed electrolyte. So~e or all of those components are in~ected at constant mass flow rates proportioned so that steam of a selected quality, or a selected seeam-cOntaining fluid or composition, or a steam-foam-forming mlxture of a selected steam quality can be injected and will be substantially homogeneous substantially as soon as it enters the face of the sand pack.
In the tes~s9 steam-foam-forming mixtures are compared with and without surfactant components added thereto, by measurlng pressure gradients formed within a sand pack during flows through the pack at the same substantially constant mass flow rate.
Numerous te~ts have been made of different steam-foam-for~ing mixture~ using sand pa ks composed of a reservoir sand and havlng a high permeability, such as lO darcys. The pressures were measured wieh pressure detectors (not shown) (such as piezo-electric devices) installed at the ~nlet 2 and at the taps 4, 5, 6, 7 and 8 of the tube 1. rhe results of such te~ts have proven to be generally comparable with the results obtained in the fleld.
71~Q
g In the laboratory tests, the steam-foam-forming components were in~ected at constant mass rates until substantially steady-state pressures were obtained at the inlet and at ehe taps. The ratio between the steady-state pressures at the taps during flow of steam mixed with the foam-forming surfactant component and the steady-state pressure at the taps during flow of the steam by itself are indicative for the mobility reduction. The higher this ratio, the stronger the steam foam and the higher the mobility reduction caused by the steam-foam-forming mix~ure.
Figure 2 illustrates the results of co~parative tests with steam and various steam-foam-forming mixtures in sand pack~
containing Oude Pekela Reservoir sand having a permeability of 8 darcys. The backpressure was 21 bar, corresponding with a tem-perature of 215 C. The steam in~ection rate was 600 cm3/min. The lS figure shows the variation of the pressurP in bar (Y-axis) with distance in centimetres (X-a~is) from the pack inlet 2. The pressures were measured at the inlet 2, at the taps 4, 5, 6, 7 and 8, and at the outlet 3 of the pipe 1 of Figure 1. Curve A
relates to the displacement wherein a mixture of 90% quality steam was used as a displacing composition.
Curve B relates to using a steam-contalning fluid having a steam quality of 90~ and a water phase which contains 0.25% by weight of a surfactant. In the Curv~ B test, the surfactant was a branched side-chain C15-C18-alkyltoluene sodium sulphonate available from Sun Refining Company under the trademark SUNTECH
IV-1015.
Curve C relates to using ~he mixture used for Curve B e~cept that the surfactant was a linear side-chain C20-C24-alkyltoluene sodium sulphonate.
The greatly Improved steam per~eability reduction performance of the presently described C20-C24-al~ylaryl sulphonate-containing surfactant component is clear from the Curve C as compared to the Curves A and B in Figure 2.
S~
Figure 3 illustrates the results of comparative tests with steam and various steam-foam-forming mixtures in sand packs containing Venezuelan Reservoir sand having a permeability of 10 darcys. The backpress~re was 21 bar, corresponding with a temperature of 215 C. The injection rate was 900 cm3/min. The figure shows the variation of the pressure in bar (Y-axis) wlth dis~ance in centimetres (X-axis) from the pack inlet 2. The pressures were measured at the inlet 2, at the taps ~, 5, 6, 7 and 8, and at the outlet 3 of the pipe 1 of Figure 1. Curve A
relates to the displacement wherein a mixture of 90% quality steam was used as a displacing composition.
Curve B relates to using a steam-containing fluid having a steam quality of 90% and a water phase which contains 1% by weight sodium chloride and 0.25~ by weight of a surfactant. In the Curve B test, the surfactant was a branched side-chain C15-C18-alkyltoluene sodium sulphonate available from Sun Refining Company under the trademark SUNTECH IV-1015.
Curve C rclates to using the mixture used for Curve B except that the surfactant was a linear side-chain octadecylbenzene sodium sulphonate.
In the tests represented by Curve D the formulation was the same as those used in the tests represented by Curves B and C
except that the sulphonate component was linear side-chain octadecyltoluene sulphonate.
The greatly improved steam permeability reduction performance of the presently described C18-alkylaryl sulphonate-containing surfactant component is clear from the Curves C and D as compared to the Curves A and B in Figure 3.
Com ositions and rocedures suitable for use in the resent P P P
invention For purposes of the present invention, the surfactant component of the ste~-foam-forming mixture is necessarily comprised in substantial part of linear C18-C30-alkylaryl sulphonate. Materials of this class but with a much shorter alkyl chain have heretofore found commercial utility, for example, in ~ ~z9;~5~
detergent formulations for industrial, household and personal care application.
A class of alkylaryl sulphonates very suitable for use in the present invention is that derived from a particular class of olefins, which may be defined for present purposes in terms of the configuration and number of carbon atoms in their molecular structure. These olefins have a carbon number of 18.
In terms of molecular structure, these olefins are aliphatic and linear. Either alpha- or internal olefins are considered suitable for the alky~ation route chosen to produce the products to be used according to the invention. For purposes of derivation of the alkylaryl sulphonates for use ln the process according to the invention, olefins are advantageously applied in which at least 90% of the molecules are alpha-olefins.
Particularly attractive are sulphonates derived from the ~eodene alpha-olefins (trademark) sold by Shell Chemical Company, in part for their llnear structure and high alpha-olefin con~ent, i.e., greater than 95% in each case. The Neodene alpha-olefins are prepared by ethylene oligomerization. Products having a high content of internal C18-C30 olefins are also commercially manufactured, for instance, by the chlorination-dehydro-chlorination of paraffins or by paraffin dehydrogenation, and can also be prepared by isomerization of alpha-olefins. Internal-olefin-rich products are manufactured and sold, for example, by Shell Chemical ~ompany.
For preparation of alkylaryl sulphonates, the olefins as described above are subjected to reaction with benzene, toluene or xylene. ~eaction conditions and catalyst type are chosen in such a way that preferably para alkyltoluene is for~ed. The alkylbenzene, alkylxylene or alkyltoluene isomers are reacted with sulphur trioxide. The term "sulphur trioxide" as used in the present specification and claims is intended to include any compounds or complexes which contain or yield S03 for a sul-phonation reaction as well as S03 per se. This reaction may be conducted according to methods well kno~n in the chemical arts, 785~
typically by contact of a flow of dilute S03 vapour with a thin film of liquid alkylate at a temperature in the range of about 5 to 50C~ The r~activn between the S03 and the alkylate yields a sulphonic acid which is neutralized by reaction with a base, preferably an alkali metal hydroxide, oxide, or carbonate.
The specific composition of alkylaryl sulphonates prepared as described above (and also, for instance, the methods used for sulphonation, hydrolysis, and neutralization of the specified olefins) have not been found to be a critical factor to the performance of the surfactant in the steam foam process according to this invention. In this regard, it is observed that factors which have conventionally governed the choice of sulphonation conditions, e.g., product colour, clarity, odour, etc., do not carry the same weight in the preparation of alkylaryl sulphonates for purposes of use in the process according to the invention that they have been accorded in detergent manufacture.
Consequently, reactlon condltions outside of those heretofore considered desirable for alkylate sulphonation are still suitably applied in the preparation of surfactant components suitable for use in the steam-foam-forming mixture.
For purposes related to maintaining product stability, conventional manufacture typically yields a dilute solution or dispersion of the alkylaryl sulphonates, f or instance, products with a 15-30 %wt active matter content in water. Such products may be directly applied to the preparation of steam-foam-forming mixtures for purposes of this invention.
Suitable alkylaryl sulphonates, generally prepared by methods such as described above, are themselves commerclally available products.
The strength of the foam formed by the steam-foam-forming composition including alkylaryl sulphonate tends to increase with increases in the proportion of the surfactant andlor electrclyte components of the composition. Also, there tends to be an optimum ratio of surfactant and electrolyte components at which the surface activity of the composition is maximized.
S~
The steam-foam-forming composition according to the present invention can form a steam-foam capable of reducing the effective mobility of the steam to less than about l/lOth and even to 1/50th-1/llOth of the mobility it would have within a permeable porous medium in the absence of the surfactant.
The steam used in the present process and/or compositions can be generated and supplied in the form of substantially any dry, wet, superheated, or low grade steam in which the steam condensate and/or liquid components are compatible with, and do not inhibit, the foam-forming properties of the foam-forming components of a steam-foam-forming mixture according to the present invention. The steam quality of the steam as generated and/or amount of aqueous liquid with which it is mixed be such that the steam quality of the resulting mixture is preferably from 10 to 90%. The desired steam-foam is advantageously prepared by mixing the steam with aqueous solutionts) of the sur~actant component and optionally, an electrolyte. The water content of these aqueous solutions must, of course, be taken ineo account in determining the steam quality of the mixture being formed.
Su~tably, the noncondensable gas advantageously used in a steam-foam-forming mixture according to the present invention can comprise substantially any gas which (a) undergoes little or no condensation at the temperatures ~100-350 C) and pressures (1-100 bar) at which the steam-foam-forming mixture is preferably in~ected into and displaced through the reservoir to be treated and (b) i9 substantially inert to and compatible with the foam-forming surfactant and other components of that mixture. Such a gas is preferably ni~rogen but can comprise other substantially inert gases, such as air, ethane, methane, flue gas, fuel gas, or the like. Suitable concentrations of noncondensable gas in the steam-foam mixture fall in the range of from 0.0001 to 0.3 mole percent such as 0.001 and 0.2 mole percent, or between 0.003 and 0.1 mole percent of the gas phase of the mixture.
Suitably, the electrolyte used should have a composition similar to and should be used in a proportion similar to those 29~7135~
described as suitable alkali metal salt electrolytes in the above-mentioned USA patent speciflcatlon 4,086,964. An aqueous solution may be applied that contains an amount of electrolyte substantially equivalent in salting-out effect eo a sodium chloride concentration of from 0.001 to 10% (but less than enough to cause significant salting out) of the liquid-phase of the steam. Some or all of the electrolyte can comprise an inorganic salt, such as an alkali metal salt, an alkali metal halide, and sodium chloride. Other inorganic salts, for example, halides, sulphonates, carbonates, nitrates and phosphates, in the form of salts of alkaline earth metals, can be used.
Generally stated, an electrolyte concentration may b~
applied which has approximately the same effect on mobility reduction of the foam as does a sodium chloride concentration of between 0.001 and 5 percent by weight (but less than a salting out-inducing proportion) of the llquid phase of the steam-foam-forming mixture. The electrolyte concentration may be between 0.001 and 10 percent calculated on the same basis.
In compounding a steam-foam-forming mixture or composition in accordance with the present invention, the steam can be generated by means of substantially any of the commercially available devices and techniques for steam generation. A stream of the steam being injected into a reservoir is preferably generated and mixed~ in substantially any surface or downhole location, with selected proportions of substantially noncondens-able gas, aqueous electrolyte solution, and foam-forming sur-factant. For exampleJ in such a mixture, the quality of the steam which is generated and the cor.centration of the electrolyte and surfactant-containing aqueous liquid with which it is mixed are preferably arranged so that (1) the proportion of àqueous liquid mixad with the dry steam which is injected into the reservoir is sufficient to provide a steam-containing fluid having a steam quality of from 10-90% (prsferably from 30-~0%); ~2) the weight proportion of surfactant dissolved or dispersed in the aqueous liquid is from 0.01 to 10.0 (preferably from 1.0 to 4.0); and (3) 3L.rl~ 9L'7 ~
the amount of noncondensable gas is from 0.0003 to 0.3 ~ole fraction of ~he gas phase of the mixture.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for displacing oil within an oil-containing subterranean reservoir by flowing a steam-containing fluid in con-junction with a surfactant component through a relatively steam-permeable zone within said reservoir, characterized in that a surfactant component is employed which comprises in substantial part at least one sulphonate of the formula RSO3X in which R is alkylaryl including benzene, toluene or xylene having attached thereto a linear alkyl group containing 18-30 carbon atoms in the alkyl chain and X is sodium, lithium, potassium or ammonium.
2. A process according to claim 1, characterized in that an electrolyte is employed in the flow within the reservoir in con-junction with the steam-containing fluid.
3. A process according to claim 1 or 2, characterized in that a substantially noncondensable gas is employed in the flow within the reservoir in conjunction with the steam-containing fluid.
4. A process according to claim 1, characterized in that the surfactant component comprises in substantial part sulphonate obtained by reacting a linear C18-C30-alkylbenzene linear C18-C30-alkyltoluene and/or linear C18-C30-alkylxylene with sulphur trioxide followed by neutralization of the sulphonic acid.
5. A process according to claim 4, characterized in that the sulphonate is derived from linear C20-28-alkyltoluene, alkyl-benzene or alkylxylene.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8407747 | 1984-03-26 | ||
| GB08407747A GB2156400B (en) | 1984-03-26 | 1984-03-26 | Steam foam process |
| GB8424319 | 1984-09-26 | ||
| GB08424319A GB2164978B (en) | 1984-09-26 | 1984-09-26 | Steam foam process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1247850A true CA1247850A (en) | 1989-01-03 |
Family
ID=26287511
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000474601A Expired CA1247850A (en) | 1984-03-26 | 1985-02-19 | Steam foam process |
Country Status (5)
| Country | Link |
|---|---|
| BR (1) | BR8501321A (en) |
| CA (1) | CA1247850A (en) |
| DE (1) | DE3510765C2 (en) |
| NL (1) | NL192394C (en) |
| NO (1) | NO851186L (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5193618A (en) * | 1991-09-12 | 1993-03-16 | Chevron Research And Technology Company | Multivalent ion tolerant steam-foaming surfactant composition for use in enhanced oil recovery operations |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2196665B (en) * | 1986-10-10 | 1990-06-20 | Shell Int Research | Steam foam process |
| US5005644A (en) * | 1987-05-28 | 1991-04-09 | Chevron Research Company | Steam enhanced oil recovery method using branched alkyl aromatic sulfonates |
| CN108329900B (en) * | 2018-03-19 | 2020-11-24 | 中国石油大学(华东) | Micro-foam for oil displacement and preparation method thereof |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4086964A (en) * | 1977-05-27 | 1978-05-02 | Shell Oil Company | Steam-channel-expanding steam foam drive |
| US4458759A (en) * | 1982-04-29 | 1984-07-10 | Alberta Oil Sands Technology And Research Authority | Use of surfactants to improve oil recovery during steamflooding |
| DE3368606D1 (en) * | 1982-12-13 | 1987-02-05 | Shell Int Research | Alkylxylene sulphonate compounds, their preparation and use |
| CA1248343A (en) * | 1984-04-03 | 1989-01-10 | Howard P. Angstadt | Stable forms of polyalkylaromatic sulfonates |
-
1985
- 1985-02-19 CA CA000474601A patent/CA1247850A/en not_active Expired
- 1985-03-25 NO NO851186A patent/NO851186L/en unknown
- 1985-03-25 DE DE19853510765 patent/DE3510765C2/en not_active Expired - Fee Related
- 1985-03-25 BR BR8501321A patent/BR8501321A/en not_active IP Right Cessation
- 1985-03-26 NL NL8500877A patent/NL192394C/en not_active IP Right Cessation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5193618A (en) * | 1991-09-12 | 1993-03-16 | Chevron Research And Technology Company | Multivalent ion tolerant steam-foaming surfactant composition for use in enhanced oil recovery operations |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3510765A1 (en) | 1985-09-26 |
| NL8500877A (en) | 1985-10-16 |
| DE3510765C2 (en) | 1994-05-26 |
| NO851186L (en) | 1985-09-27 |
| BR8501321A (en) | 1985-11-19 |
| NL192394C (en) | 1997-07-04 |
| NL192394B (en) | 1997-03-03 |
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