CA1075453A

CA1075453A - Oil recovery method and alkyl alkoxy propio sulfonate surfactants

Info

Publication number: CA1075453A
Application number: CA277,256A
Authority: CA
Inventors: Melvin E. Tuvell
Original assignee: Ethyl Corp
Current assignee: Ethyl Corp
Priority date: 1976-06-01
Filing date: 1977-04-28
Publication date: 1980-04-15
Also published as: FR2353527A1; GB1560346A; NL7705836A; MX146299A; JPS566477B2; AR214077A1; JPS52147583A; DE2724442A1

Abstract

Abstract New alkyl alkoxy propio sulfonate compounds are disclosed. These materials are useful as additive to aqueous solutions employed to obtain enhanced or further recoveries from petroleum bearing formations. When added to brine solutions such as are available in the field, the materials exhibit improved stability against hydrolysis at elevated temperatures and for prolonged periods.

Description

Case 4242/4242-A
Canada ~0'75~53 This invention relates to the use of surfactant salts to enhance the recovery of oil from oil bearing ~eologic formations. More particularly the invention includes new compounds which can be added to aqueous solutions for use in injecting into appropriate formations for the purpose of releasing entrapped petroleum materials. The new materials of the present invention, in aqueous systems having disolved salt and alk~aline earth metal ions, exhibits improved stability against hydrolysis at elevated temperatures and for prolonged periods.

Description of the Prior Art It is known to use surfactant components added to aqueous solutions to be used for injection into oil-bearing formations for the purpose of aiding recovery of petroleum portions. One, two or three surfactant materials can be used, singly or in combination. Such prior art is represented, for example, by U. S. Patents 3,308,068;3,508,612; 3,527,301;
3,714,062; 3,777,818; 3,782,472; and 3,;327,497; and the references cited therein.` It is evident from the foregoing typical art that an extremely wide variety of surfactant and auxiliary materials is known, it also being know that the effectiveness and longevity of various materials depend upon numerous factors such a temperature, and the fortuitous or planned presence or absence of salt and of metal ions contri-buted by the formation, or otherwise.

~7~3 The composition~ disclo3ed in U. S. Patent 3,827,497 have limitations ln regard to temperature sinc~ they ara ba ed on or include th~ ~alt~ of sulfated oxyal~ylated al~ohol. 5alt~
which contain the C-()-S llnkage ~re known to be hydrolytically wlstable ~t elevated temperature~. Sulfonat~s of 3,827,497 are ethyl sulfonat~3 which are difficult to produce.
Summary of -the Invention In accordance with the teachlngs of the pre~nt invent~on, improved surfactant ~alt compo~itions, aqueou~
compo~ition~ of such sal~s, and methods of using such in oil recov~ry are disclosed. Salts of ~ulfate~ oxyalkyla~ed alcohol are avoided. By the u~e o~ the propio~ulfonate ~alts of the present appllcation, compositlons are provided which are ea~ily produced and whlch inherently have improved hydrolytic stabillty at elevate~ temperatures, e~pecially in comparison to ~ulfated ethoxylated alcohols. As a re~ult the presen~ compo31tion~
are re~lstant to hydrolysi~ during the prolonged time the oil recovery surfactant compositions are r~quired to be in the ground ln contact with brine and alkaline earth metal ion~.
This property ~s of particular value in Qituatlons where the oil-bearing formations are located comparatlvely deep within the earth' 8 aru~t.
Although u~eful $n other ways, the compo3itions of ~he pre~ent invention are e~peclally useful in ternary combination 2S wlth polyalkyl~ne ylycol alkyl ethers and a ~urfactant ~alt oF
- an organic ~ulfonate such as those descrlbed in U. S. Patent : . 3,827,497. On the other hand, the surfactant compo~itions are ; characte~ized by being u~eful in aqueous solution~ in general and of having utillty per se, ~spe~lally for purposes of making aqueou~ ~olution~.

-2-r~

:~75~i3 Compos~tions in accordance with the pxesent invantion are ~ropio8ulfonate 3alt5 of the formula RO(C~I2CE~2O)nCI~2C~I2CH2SO3M, where R i~ alkyl having from about 14 to about 24 carbon atom~, n 1~ from a~out 2 to about 10, and M i~ ~elected from the group con~i~kiny of alkali m~tal, amine and ~m~lonium. Preferably R ha~ from about 16 to about 20 carbon atom~. Preferably n i~
from 3 to about 5. Preferably M i~ ~odium. Preferably th~

16-l~H33-37(C~I2C~2) 3c~l2cH2cH2so3Na.
The foregoing salt compositions are in g~neral u6ed in aqueous media 30 ~hat other preferre~ compositions are aqueous ~olution~ of the foregoing proplo~ulfonate 9alt3.
Th~ present invention al~o is directecl to an improved process for recovering oil from a ~ubterranean oil-bearing format~on whereln the improvement oonsi~t~ in u~ing the foregoing propiosulfonate salt~.
In another aspect, the present invention relate~ to a : method of recoverlng oil from a ~ubterranean oil-beaxing formation whicll comprises A - injecting into the Pormation a ~aline solution containiny a mixture of the followlng components:
: 20 (a) from O.S to 15 percent by welght based on said ~olution of a surfactant salt of an organic ~ulfonate/ ~b) from 0.25 to 10 percent by weight ba~ed on ~aid solution of a polyalkyl~ne glycol alkyl ether, and (c) from 0.25 to 10 percent by weight based on ~aid solution of a ~alt of the formula RO~CE12CH2O)nC112CH2CH~$O3M

~5 wherein R i9 alkyl having rom about 14 to about 24 carbon atom3, n is from about 2 to about 10, and M i.s ~elected from the group con~i3ting of alkali metal, amine and ammonium an~
B - flooding the ~ormation with a saline solution to effect oil recovery ther~from. Preferabl~, Component a is an alkali metal ~al~ of a petroleum sulfonatQ, Component b i~ diethyl~ne , , , ~ , - - -, ; ,, 1 ~. .. . . . . .. . . . ...

~ .()'7S~3 glycol hexyl ether and Component G ~ ~ an alkali metal ~alt.
Preferably, th~ ~mounts of Component~ a, b and c axe, re~pectively, 2-10 pexc~nt, 1 8 percent and 1-8 percent by weigllt. Preferably, Component a is an alkali metal salt of a petroleum ~ulfonnt~, ~omponent b i~ a d~ethylene glycol hexyl ether and Component a ls an alkali metal salt, the amount~ of ComponQnts a, b and c, rcspectlv~ly, belng 2-10 percent, 1-8 percent and 1~8 percent b~ welght. Preferably, the ~allne solu~ion in Step ~ cont2ins a polymer to improve the mobility th~reof, ~uch polymer pre~rably ~lny a poly~accharide.
The composition~ of the pre~ent process can be u~ed in combin~tion with ~alt~ of 6ulfatQd oxyalkylated alcohol or ~ulfonate~ thereof, such a~ tho~e described in U. S. P~ent ~J827~497r a~ an extender. Thus, ln some ~nstances lt may be de~ired to inclu~e sulfa ed oxyalkylated alcohol salt in the pre~ent composition~ with the expectation that, as the ~urfactant salt containing system progresse~ ~hrough the form~t~on b~coming mor~ dilute due to the combination wi~h water or bxine pr~en~
in the formation it~elf, a progre~qlve timewise deterioratlon : 20 o~ ~he le.~ sta~le ~alt of ~ulfated oxyalkylated alcohol can produc~ a pr~ferred overall process, especially in the presence of certain alkali metal ion~ such a~ calcium or magne~ium ions.
~rle~ Description of the Vrawln~
.- The figure~ of the drawlng show ~tabill~y charact~r-i~tic~ for various compo~itlon~ embodylng ~he feature~ o~ th~
. present invention a3 w~ll as for compara~ive compo.~ition~ to ~how th~ superlority of the present compo~ition~ over prior ar~, Flg. 1 how~ the ~tability charactQri~tic6 o compo~i-tion~ u~lizing the salt C16_1~H33~37~E)3(C~2)3 3 ~0 Fig~ ~ ~how~ the ~tabllity propertle~ of the salt of Fig. 1 at the temperatur~ o~ ~50F.
!

~'75~S3 E'lg. 3 8hOWB ~che ~tability prop~3rtles of the salt 20+}~4l+o (E~) S (C~l2) 3S03Na at 75F.
FigO 4 show~ the stabllity properties of ~he composi-tion of Flg. 3 at 150~.
S Fi~. S shows unsati~factory st~bility properti~s o~
a comparative ~alt C20~H41~0 ~E0) 5 (CH2) 2S 3 Fig. 6 ~how~ the ~olubill~y properties of the salt of Fig. 5 a~ 150F~
Fi~. 7 ~hows the stabllity properti.es of th~ salt C20~l41+ (E0) 15 (C~I2) 3S03Na at 7SF, Fig. 8 shows the properties of the ~alt of Fig. 7 at 150 F .
Figs. 9-14 show the stabil.lty properties of the ~alt of ~ig. 1 at 75F and 150F with ~hree addi~ional petroleum ~ulfonate3.
Description of the Pr ferred Emb di!nents The pre~rred propio6ul~nate ~ur~ac~an~ ~alts of the present invention ar~ represented by the formula RO(C~12C~l2O)nC~2C~2CH2S03M where~n R is alkyl havlng Pxom about 20 lq to about 24 carbon atoms, n is from about 2 to about 10, and M i~ ~elected from ~he group consi3~ng of alkali metal, amin0 and ammonium. I~ ~ s notewor~ly that this composition contains only C-C llnkages, C-0-C linka~es and C-S-0 linkElge~
ln the undamental ~keleton ther~of. Notably ab~ent frorn - 25 th~e composition6 are the ]cnown unstable ester linkage C-0-C
and the C-O-S linkage of sul~ated oxyalkylated ~lcohol. I~
seen thare~ore that the cvmpositions of the pre~ent invention ~re ¢haracteri~ed by the ab~3enc~3 oE the usual llnkage~ known to be hydxolytically unstabl! at elevated ~emperature~ and by the 30 presence ln the molecule o~ the prcpiosulfonate group .

.. . . .. . . . . ..

~S~L53 -CH2~2CH2SO3M. An outstandin~ adv~ntage of ~uch structure6 1~ tha~ the term~ n~l group -C112Cli2CH~S03M can be provi~ed by the reaction of an oxyalkylat~d alcohol with propane sultone, a re~ctlon which proceeds readily under comparativ~ly ~imple condi~ion~ a~ de~crihed in further d~t~l hereinafter.
In general, the ~alt~ o~ the pr~ent lnvention ar~ us~d in ~ u~e~ olution~ so as to facilitate the introduction th~reof lnto oil bearing format.ions in the earth. Typical solutions contain from about 0.005 w~. percen~ to a~out a ~aturation amount of the preferred ~alt in wat~r howeve.r, these concen-tratlons may ~ary depending upon the method chosen for making the ~olution and lntroducin~ them into the formation.
Solutions may be intro~uced ~nto the ~ormation separately for each individual solute or in combinations ~uch a~ with ~urfactant 15 8alt8 of organic sulfonates and o pol~alkylen~ glycol alkyl ether~, Ruch ternary SyBtemS ln water fre~u¢ntly b~in~
especially pre~erred ~or in~ection. Such 6ystems can be used with more or less pu~e water or with water which contains al~ali ~etal halide such a~ sodium chloride in ~olution; vix, brine, a~ well as with water containing alkaline ~arth metal ion~, either with ~r without th2 alkali metal halide of the brine. A prefe~red proces~ then in accordance with the pr~sent inv~ntion involve~ th~ re~overy of oil from a subterranean oil-bearing formation by in~cting into the formation a ~aline ~olution ~on~alning the propio8ulf~nat2 0alt of the present invention, a ~urfactant salt o~ an organic sulfonate and ~
polyalkylene qlycol alkyl ether and tllen ~looding the formation with an aqueous medium t~ ~~ect oil reco~ry ther~rom. Pre-fcrr~d flood~ng aqueous medium i5 ~r~qu~ntly ~ brine or sallne ~olution to minimize C08t~ i~her~n~ in ob~aining non~salin~
a~ueou~ ~olutionæ in the field.

~C~7~53 ~ 'I'~le or~ani.c s-llfona~e coml)on~llt~ u~eful .in connectlor wlth the pr~sent lnvention are typlcally a~ de~crlbed in U. S. P~ten~ 3,~27,~97~ however, pre~crably tho~ havlng the un~t~bla struc~ure~ ~Ire avoided where utmo~t ~tabflity o~ the over2].1 6y~tem i~ de~ir~d. Prcferably, sulfonnt~ ar~ used which ~re r~adily ~vailabl~ comnlorclally such a~ "~ryton Ch~mical F467", "Witco Chemical T~S-lO~o Suitabl~ sulfonate~
are usually an~ preferably metal ~alts o~ al}iaryl sulfollate~, pr~erab].y alkali metal ~alts and alkyl benzenc 3ul0nate3 10 containin~ 12 to 30 carbon ~tom~. 5uitnble ~ulfonates also can be aliphatic sulfonates, alkylated naphthalene sulfonates and the like, the essential requirement belng that th~y ha~
surfactant propertie~ The cationic portion of such sulfonates cnn be ammonium or amine a~ w~ s al~ali metal but is usually and preferably sodium. The molecular weight of the organic sulfonate ~urfactant is uRually ln the range of 300-600, preferably 350-525. These material~ can be prepared by w~ll known procedures such as those described ln U. S. Patent

3,308,068. They can be prepared synthetically or can be prepared from.petrole~n and commonly known as petrole~n sul~o-nates.
The polyalkylene glycol monoalkyl etilers are ~i~ely available commerclally. The alkylene group is usually ethylene but can be propylene or others up to about five carbon atom~.
~5 It can repea~ it~elf up to about 10 times (i.eO the "poly" can be up to about 10~ but usually repeats ltself ~-6 time~, more usually twice, e.g. diethylene~ It should also be under3tood thst for any ~pecified polyalkylene, the number of alkyl~ne unit~ i8 either ~xactly as ~pecified or varle~ but the average i~ a~ ~p~cifle~ Thls ~ame princlple applie~ al~o to the ' ~5A~53 alkyl ~roup. Pr~erably the glycol portion i~ diethylenQ glycol.
The al~yl ~roup will normally contain ~-12 carbon atom~, prefer-ably 4-10. In general the more ~lk~l~ne units or the lon~er the alk~lene unit, the lon~er the alkyl ~roup should be. The preferr~d comporlent is ~ie~hylene glycol hexyl ether. Th~se material~ are nvallable commercially or can be made by known proc~dure~.
It is evid0nt from the foregoing that the preE~rr~d compositions in accordance with the pres~nt inventioA are those cha~acterized by a propiosulfonate structur~ and a preferred alkoxylated alcohol structure. Such materials typically ara readily prepared by the reaction o~ alkoxylatcd alcohol~ with propane 3ul~0ne. This introduc~s the prop~oqulfonate struckure readily and a~ good yields. Such proces~ preferably utilizes lS ethoxylated alcohols of the formula RO(CE32CII20)n~l where n 1~

~rom about 2 to ~bout 10 produced by reactin~ alcohol RO}I with ethylene oxid~. The alcohol ~o reacted may be an aliphatic alcohol having from about 8 to about 30 carbon atoms per molecule with a range of ~rom about 14 to about 24 carbon atoms being especially E~eferred. Pre~erably, the alcohol used is predominantly a primary alkanol, preerably a synth~tic primary alcohol mlxture containing up to about 50 ~ercent of branched primary alcohols. Oth~r ~lcoholic ma~erials can be used ~uch a~ alkyl phenols cont~inlng ~rom about 5 to about 20 carbon atoms - 25 p~r alkyl group and the likei Al~hough ethylene oxide i~
preferabl~ reacted with the alcohol in the ratio of from about 2 to a~out 10 molecules of ethylene oxide per molecule o alcohol, oth~r lower alkylent oxides containing from 2 to abou~

6 carbon atoms axe ~uitable; for example, propylene oxide or butylene oxide. Typic~l alkoxylated alcohols u~eful in the !

5~53 present invention rnay incl~lcle substituents such as hydroxy:L or amine groups anct the lil<e on either the alcohol moiety or the oxyalkyl portion.
I`he compositions of the present inven-tion provide stable emulsions in various ways. As an example, an aqueous system cOntaining lO wt. percen-t Cl6_l8~133_37(E)3( 2)3 3 wi-th 1-l/2 wt. percent NaCl added, 2 cc of C6H130(E0)2~l added and 20 percen-t by volume of crude oil added was stable.
Propiosulfonates prepared as described in the following examples and comparative samples were tested using the following procedure.
To a 4-ounce bottle was added 2.5 grams of petroleum sulfonate (Petronate~ L of Witco Chemical Company) which is a petroleum sulfona-te of 415 to 430 equivalent weight range.
Then 1 gram of hexanol ethoxylate averaging two ethoxy groups per molecule was added.
Next, 1.5 grams (ac-tive basis) of candidate propio-sulfonate composition or comparative material was added prefer-ably as an aqueous solution of 10-40 percent concentration, or as lO0 percent active material.
Next the appropriate amount of sodium chloride was added preferably as a lO percent aqueous solution to give the desired final concentration of salt (brine).
Similarly, the appropriate amoun-t of calcium ion was added preferably as a 1 per cent solution of calcium ion prepared as calcium chloride.
The sample was then adjus-ted to lO0 grams to provide the desired concentration of the ingredients. The sample was then heated and stirred vigorously in a scaled sys-tem to prevent evaporation of any of the components and when dispersion ::

~'7591~j3 or dissolution wa~ complete the ~amples were placed in an environment o~ the de~ired temperaturs and observed after 24 hours or mo~e. Ob~xvations were ma~e a~ to the.~stability or in~tability of the ~y~tem. In~tability in general i8 a defillite and ea~lly vislble pha~e ~eparation 80 that a curd of watex-in~oluble material s~parate~ eithQr at the bottom or the top depending on the brlne concentration6. Generally, all ~olutions are opaqu~. ~ati~factory condltions are stable di~p~rsions. Rarely, clear ~y~tems are obtained and indicated by "C". Those which showed good result~ were te~ted further ~
by dllution w~th the appropriate ~odium chloride and calcium ion solutions at proportions of 1~ 2, 1:5 and 1:10, and reexamined at the indicated temperatures for stability or in~tability. Samples w~re tested with 1, 2, 3, 4 and 5 percent by weight of sodium ahloride and with 200, 500, 1000 and 2000 part~ per million of calcium ion. Data are shown o~ the Figure~ for the various con~ent~ o~ ~odium chloride, calcium ion and fox ~he various dilutlons of 0, 1:1 with bxin~ and calcium ion ~olution, 1:2 with brine and calcium lon ~olutlon, etc.
The following example~ indlcat~ preferred embod.iments and a~pects of the present invention.
EX~MPLE I

16-l8H33-37o(c~cH2o)3(cH2~3so3Na To a 12-liter round bot~om fla~k equipped w~th an agltator and an off-ga~ trap was charged 1312 gram~ o C16-18~33_37(~2C~12)3~1 a~exaging three ethoxy units per molecule. The average molecular weight of ~he alcohol prior to ethoxylatlon wa~ 260Ø To the fla~k wa~ also added 421 grams o~ sodium bicarbonate and 2 liter~ of xylene, the latter being : added ~o a~eotrope water.

- 10~

r ~07S~L53 The fla~k was heated ~o 120D~ and ~e~d of propane ~ultone ~tarted. 435 cc o propane sultone. wa~ Added o~r a 3 hour period, the reaction tempera~ur~ beiny held at about 1~0-14SC.
Agitatlon wa~ cont~nued at a temperatur~ of 144-145C for an a~di~lonal ~ 2 hours. Th~ heat wa~ then turned off, ~he flask content~ diluted with 5.~ ers of w~te.r, and the content~ of the fla~k ~tirred for 1-1/2 days.
The cont~nt~ of the flask wer~ then stripped by pa~slng in nitrog~n at from 0.72 to 0~19 liters p~r minut~ for about 1 hour.
A va~uum was then appl~d, a vacuum of 15 to 18 milllm~ters o mercury being maintained for about 2 llours.
'rhe heat was turn~d of ~t ~bout th~ midpoint of th~ two hours vacuum treating perio~.
The product waR then d~luted ~o 26 wt. percent product ln wAter.
The resulting C16_1a propio~ulfona~e was tl~n tested a~ d~3cri~ed. Data are pres~nted in Figs. 1 and 2 ~or 75~
and 150~F, r~spec~lvely.
EXAMPLE II
C2o~H4l~o(c~2c~l2o~5~cE~2~3so3Na g C2~l4~ H2C~2O)5~, containing 2S perc~n~
hydrocarbon, -OH ~alue (wt. percent~ 2.17, average m~lecul~r w~ight 783 (126 millimol~) was charg~d ~o a l-liter fla~k equippe~ with a magneti~ stlrr~r.
27 grams ~221 mill~mol~) of propane sultone was -; add~d.
18.7 grams ~2~1 milli~ols) of sodium bicarbonat~ was add~.

.: .
r .

~)'7545;~
The mixture was ~tlrred overnight at 130C.
The crud~ product wa~ di~solved ln a mlx-ture o~ 500 ml ~2 and 500 ml m~thyl ethyl ketonQ and extracted three times with 150 ml portions of a 2:1 volume mixture of m~thyl ethyl ketone and h~xan~ (lO0 ml m~thyl ethyl keton~ + 50 ml hex~ne).
Th~ mixture wa~ heated to ~eparate the phase~.
The aqueou~ phase was evaporatod overnight on a hot plate to dryneR~ giving 64 grams of crude product.
The crude product wa~ desalted with 1600 ml of 50 percent aqueous isopropanol and 224 grams Na2CO3. The solvent was evaporated and product ~ried in oven ov~rn~ght. The product was anal~z~d by in~rared and wat chemical analy~is and found to be con~ist~nt for the produc~.
The resulting C20 propiosul~onate wa~ then tested a~ de~cribed. ~ata are pre~ented ln Figs. 3 and 4 for 7S~F
and 150F, respectively.

EXAMPLE III
C20~1141+ (Cl'l~CH2) 5cH2cl~2so3Na 70 7 gram~ (90.3 millimol~) of the C20~H22+Ol 2 ~ 5 e~lo~ylated alcohol of Example II was placed in a flask and heat~d with lB.0 grams (77.4 millimol~ oE sodium methoxide a~ a 24 percent Rolution in methanol wl~h ~tirring ~or 1.5 : hou~s at 130C and 200 mm~pres~ure. Thi~ produ¢es th~ ethoxy al~ohol alkoxlde.
17,7 grams (77~4 mllllmols) of bromoe~hane sulfonate ~BrC~2CH~SO3Na~ in water wa~ azeotroped with toluene to remove ; ~he water.
The ethoxy alcohol alkoxide wa~ then added to the bromoethane Hulonate. About 40 ml undecane w~ added to facilitate ~tir.ring and the mixture waR. heated to 200C and ~tirred fox 3 hours.

~ ~ r - ~

~75~5;3 ~he reaction mixture wa6 cooled to roorn temperature and disqolved in 700 ml of 50 percent aqueous methyl ethyl lsetone and ~xtracted twice with 200 ml portions of ~:1 rnethyl ethyl ketone ~ hexane .
The aqueou~ solutlon wa~ evaporate~l to about 150 ml ~nd then d~altecl with 900 ml of 50 parc~nt aqueous i.~opropanol and 126 gram~ of Na2C03. The ~ystem was then evaporated overnight to dryn~s in a 120 ov~n.
The resultlng C20~ ~2thyl sulfonate wa~ then te~ted 10 a~; described. Data are presentec3 in Figs. 5 and 6 for 75F and 150F, xe~pectiYely and ara ~een to be inferior to the propio~ulfonate~ of Figs. l-g~
EX~PLE IV

C20~H41+~c~2c~l20)15(c~I2)3so3~a ; 15 g C20+H41+(CH2~H2)15~l/ co~tainlng 15 per-cent by hydrocarbon, -OH value (wt. percent) 1.39, average molecular weight 1223 (81 millimols) wa~ charged to a l~liter fla~k equipped with a magnetic ~tirrer. To the fla~k was added 14. 8 gram~ ~122 millimols) of propan~ sulton~ and 10 . 3 ~rams ~122 millimols) of sodium bicarbonate.
The mixture was ~tirred for 8 houxs at 135C and allowed to stand overnight. Product work-up was a~ descri~ed in ~ Example II.
- Th~ resulting product wa~ te~ted as described. O~ta 25 are presented in Figs. 7 and 8 for 75F and 150F, re~pectilrely.
Re~ult~ with a propiosulfonate hav~ ng 15 ~thylene oxi~le units per molecule are shown to be inferior to those with the propio-sulfonate~ of Fig~ 4.
~rom the oregolng, it 18 evidenl: that the featur~
30 of the present invention may b~ employed in various ways.

. ~75g~i3 ~ltl~ough khe ~'20~ an~l Clfi_l~ 0~1t coln~o~ition~ ~r~ pr~crre-l mlx1:ure~3~ lndlvlllu~l l3alt; ~uch ~ tho~ w~lereln th~ nlhyl grouI~ ha~ 16, l~, ~0, 22, ~to. carbon atom~ m~y bQ n~ed.
I~XA~IPJ.l`~,~ V~VII

C16-lU~133~37 (C~2C~1~0) 3 (C~l~) 3~;031~a IqlG AbOV~ prOpl08UlfOll~tQ nEI UElUtl ln ExuLm~ I w~
te~ted wlth ~i~feront p~trol~ ulfonate6 ~lth (1~ ~er~nt proportlonL~ .
For each of 1:h~ followin~ eX2111ple~, ln~te~d o~
- 10 2.5 ~rams o~ tho petrole~lm ~ulfonnto, 3.0 grarn wa~ used~ A8 be~ore, one gram o~ thQ hexanol ethoxylut~ ~vera~lrlg two ethoxy qxoup~ p~r molecul~} was u~ed. In~t~ad o~ l. 5 gram~
(~ctiv~: bAsi~ o~ candidatQ proplo~ulfonat~, l . 0 gram~ wa~
u~ed. Otherwis~ tha procedur~ d~scrlbed previously w~
followe~ at 1, 3 and 5 percent by wei~ht vf ~odlum chlorld~ and w~h 200, 500, 10~0 and 2000 par~s per mi11ion of calcium ion, th~ te~t1n~ ~or th~ non~iluted ~mple of Example ~I (Fi~
~nd 1~ ing extende~ to includ~ 6, 8, 10 and 12 pe~c~nt by w~ight of sodi-~ chlori~ ancl 5000 and 10,000 ~art~ ~er m~11ion ~f cRlcium ion- to Yhow how far ~tabi1ity extended beyond t~
:~ rsnge~ o~ usual inter~
EX~LE V
Th~ p~tro1~um s~lfon~te used was Petroste~4~0 of ~t~pan Chemic~1 Company ~hich 15 ~ 60 p~rcent activs material having ~1 percent ~ree o~l, 17.5 percent water, 1.5 percen~
inor~anlc sa1t~ and ~n appro~ima~o equival~nt welght ~f 4200 D~ta ara ~hown for 75~ and 150F by Figs. 9 and 10, re~pPctively O

.
, , _, ., . . .. . . . _ _ . ... .. . , _ .. . ..
~.~.. , . ' .
- :

i915~
L~: VI
Tl~ pctrol~lm sul~onatc~ u~d waE3 }~otrOEIt~p 450 o Stap~n C:hcmical Compnrly ~hlch ~ cl a 60 percc~nt ~ctivC ~at:~x~ al h~ving 13.5 porc~nt freo oil, 2~.5 percf~nt w~tcr, 2.0 ~cxcent 5 inor~atlic oaJ.ts nntl an approxlmat~ equlvnlent w~lc3ht of ~50.
Data ar~3 showIl or 75~F ~lnd 150F by FicJ~. 11 nnd 12, ra~pectively .
t~lrL~ VI I
Th~3 petroleum ~ulfon~tc used ~A3 Petrost:er) ~S of 10 StQparl Chemical Co~npany ~"hich 1~ ~ 60 percent: actlve mat~rial havin~ 13.1 perc~n~ r~e oil, 23 . 5 percent wa~ex, 3. 6 percent inorganic 8alt5 and an approxlmat~ equlvalent weic3ht o 465. Data arc shown for 75~F and 150F ~y Fig~. 13 ancl 14, re~pec~tively.

~-lS-. ~' :
.... .

~ - ~ . . .
. . . . , , . . ~ , . , ~, . ..

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a process for recovering oil from a subterranean oil-bearing formation the improvement of using a surfactant salt of the following composition RO(CH2CH2O)nCH2CH2CH2SO3M
wherein R is alkyl having from about 14 to about 24 atoms, n is from about 2 to about 10, and M is selected from the group consisting of alkali metal, amine and ammonium.

2. As a composition of matter an aqueous solution containing RO(CH2CH2O)nCH2CH2CH2SO3M
wherein R is alkyl having from about 14 to about 24 carbon atoms, n is from about 2 to about 10, and M is selected from the group consisting of alkali metal, amine and ammonium.

3. The composition RO(CH2CH2O)nCH2CH2CH2SO3M
wherein R is alkyl having from about 14 to about 24 carbon atoms, n is from about 2 to about 10, and M is selected from the group consisting of alkali metal, amine and ammonium.

4. Method of recovering oil from a subterranean oil-bearing formation which comprises:
A. injecting into the formation a saline solution containing a mixture of the following components:
a. 0.5-15 percent by weight based on said solution of a surfactant salt of an organic sulfonate, b. 0.25-10 percent by weight based on said solution of a polyalkylene glycol alkyl ether, and c. 0.25-10 percent by weight based on said solution of a salt of the formula RO(CH2CH2O)nCH2CH2CH2SO3M
wherein R is alkyl having from about 14 to about 24 carbon atoms, n is from about 2 to about 10, and M is selected from the group consisting of alkali metal, amine and ammonium, and B. flooding the formation with a saline solution to effect oil recovery therefrom.

5. Method according to Claim 4 wherein Component (a) is an alkali metal salt of a petroleum sulfonate and Component (b) is diethylene glycol hexyl ether and Component (c) is an alkali metal salt.

6. Method according to Claim 5 wherein the amounts of Components (a), (b) and (c) respectively are 2-10 percent, 1-8 percent and 1-8 percent.

7. Method according to Claim 4 wherein the amounts of Components (a), (b) and (c) respectively are 2-10 percent, 1-8 percent and 1-8 percent.

8. Method according to Claim 4 wherein the saline solution in Step (B) contains a polymer to improve the mobility thereof.

9. Method according to Claim 8 wherein said polymer is a polysaccharide.

10. A process in accordance with Claim 1 wherein R
has from about 16 to about 20 carbon atoms.

11. A process in accordance with Claim 1 wherein n is from 3 to about 5.

12. A process in accordance with Claim 1 wherein the salt is:
C16-18H33-37O(CH2CH2O)3CH2CH2CH2SO3Na.

13. A process in accordance with Claim 1 wherein M
is sodium.

14. A composition in accordance with Claim 2 wherein R has from about 16 to about 20 carbon atoms.

15. A composition in accordance with Claim 2 wherein n is from 3 to about 5.

16. A composition in accordance with Claim 2 wherein M is sodium.

17. A composition in accordance with Claim 2 wherein the salt is:
C16-18H33-37O(CH2CH2O)3CH2CH2CH2SO3Na.

18. A composition in accordance with Claim 3 wherein R has from about 16 to about 20 carbon atoms.

19. A composition in accordance with Claim 3 wherein n is from 3 to about 5.

20. A composition in accordance with Claim 3 wherein M is sodium.

21. A composition in accordance with Claim 3 wherein the salt is:
C16-18H33-37O(CH2CH2O)3CH2CH2CH2SO3Na.