FR2549524A1 - PROCESS FOR THE RECOVERY OF PETROLEUM EMPLOYING ANIONIC SURFACTANTS OF THE FAMILY OF ESTERS OF A-SULFOCARBOXYLIC ACIDS - Google Patents

Abstract

THE USE, IN THE ASSISTED RECOVERY OF OIL, OF ANIONIC SURFACTANTS CONSISTING OF ESTERS OF A-SULFOCARBOXYLIC ACIDS. MONO AND DI-ESTERS ARE SPECIFICALLY USED THAT RESPECTIVELY MEET THE GENERAL FORMULAS: (CF DRAWING IN BOPI) OR R IS A MONOVALENT HYDROCARBON RADICAL, R A MONOVALENT HYDROCARBON RADICAL OR A RADICAL (POLY-) OXYALKYL, R A DIVARENT A RADICAL (POLY) OXYALKYLENE AND M REPRESENTS A CATION OF ALKALINE METAL, AMMONIUM OR ALKALINOTERREUX METAL (12 M). THESE ESTERS OF A-SULFOCARBOXYLIC ACIDS CAN BE USED IN THE FORM OF AQUEOUS SOLUTIONS OR MICROEMULSIONS. THEY ARE EFFECTIVE EVEN IN THE PRESENCE OF DEPOSITED WATERS OF HIGH SALINITY, PRESENTING IN PARTICULAR HIGH CONCENTRATIONS OF DIVALENT CATIONS (CALCIUM AND OR MAGNESIUM).

Description

The present invention relates to a process for recovering oil

  from underground reservoirs and more particularly to a process for recovering oil by means of surfactant.

  Still more particularly, this invention relates to a petroleum recovery process which utilizes one or more anionic surfactants of the α-sulfocarboxylic acid ester family.

  This family of surfactants has the particular interest of being composed of a range of products having a high efficiency in a wide zone of saline concentrations. Some members of this family are, in fact, stable in formations whose water is present. high salinity, especially high concentrations

  divalent ions, such as calcium or magnesium.

  In the recovery of oil from underground deposits, it

  It is usually only possible to recover a small portion of the oil in place by means of the so-called primary recovery methods, which methods only use the natural forces present in the deposit (decompression of the fluids, expansion of the dissolved gases, expansion of the gas dome, thrust of the aquifer, etc.).

  The rate of such recovery is, on average, 15% of the oil in place. Also, a wide variety of additional techniques have been employed in order to increase oil recovery. One of the recovery methods additional most prevalent is the

  water sweeping, which involves the injection of water into the tank.

  To improve the efficiency of this latter process, and in particular to improve the efficiency of the microscopic displacement, can be added to water a surfactant which will cause a lowering of the interfacial tension water / oil and act on the forces capillaries responsible for trapping oil in the Lores of

the reservoir rock.

  Many surfactants have been proposed for enhanced oil recovery operations, particularly petroleum sulfonates, alkylsulfonates, alkylarylsulfonates, alkyl sulphates, alkylaryl sulphates, polyoxyethylated alkyl or alkylarylsulfates, alkylpyridinium salts, and the like. , quaternary ammonium salts, polyoxyethylated alcohols, polyoxyethylated alkylphenols, derivatives with betainic structure, etc. Many of these surfactants are satisfactory only in a few cases, particularly in formations with total salinity and ion concentration. divalents (in particular calcium and magnesium are relatively low, ie in general

  less than 10 g / l for total salinity, with a divalent ion concentration of less than 500 ppm.

  The major limitation to the use of most surfactants is their tendency to precipitate when exposed to high salt concentrations. In addition, their performance is impaired by the presence of salts, even when the concentration thereof is much lower than that causing their precipitation, by

example between 20 and 30 g / l.

  In the case of medium or high salinity, it has sometimes been recommended to use certain mixtures of anionic and nonionic surfactants, but the use of these mixtures poses certain problems: those resulting from selective adsorption of one of the two products. rather than the other and those associated with the tank temperature, the

  non-ionic derivative with decreasing solubility with temperature (cloud point).

  The present invention relates to a method of assisted oil recovery for use in formations whose salt concentrations may vary within wide limits. The surfactant is a mono or an α-sulfocarboxylic acid ester having one of the following general formulas:

R CH COO R '

1 ID

SQ M R CHC O -R "O -C -CH -R

  ## STR2 ## R is an alkyl or arylalkyl radical whose alkyl chain has from 5 to 25 carbon atoms; R 'an alkyl or arylalkyl radical whose alkyl chain has from 1 to 25 carbon atoms or a radical of the type - + (CH 2) x OZ, x being an integer capable of taking the values from 1 to 12, including an integer which can take the values from 1 to 50, Z the hydrogen atom or a methyl or ethyl radical; R "an alkylidene or arylalkylidene radical whose alkyl chain has 1 to 25 carbon atoms or a radical of the type + (CH 2) x O 3 y (CH 2) xx is an integer which can take the values of I at 12 and y an integer of from 1 to 50, and MB a metal cation (alkali or alkaline earth metal, particularly lithium, sodium, potassium, magnesium, calcium) or an ammonium ion such as ammonium, triethanolarcmonium, triethylammonium, pyridinium, etc. In the case of the alkaline earth metals M -cai 1 N 2 + (not equivalent), M represents in fact an half-cation M 2 However,

  M is most often a monovalent cation.

  By way of nonlimiting examples of esters which are suitable as surface-active agents for the enhanced recovery of the oil according to the invention, mention may be made of: α- (sodium sulfonate) methyl dodecanoate a- ( potassium sulfonate) Ethyl dodecanoate Sodium (sodium sulfonate) triethylene glycol mono-dodecanoate α, α '(sodium disulfonate) ethylene glycol didodecanoate O- (ammonium sulfonate) palmitate propyl α- (sodium sulfonate) butyl stearate α- (diethylamine sulfonate) isopropyl myristate triethanolanrimnium α-sulfonate) methyl stearate; a- (sodium sulfonate) methyl palmitate; and

  α- (sodium sulfonate) propylene glycol monopalmitate.

  The groups R, R 'and R "will be chosen according to the salt concentration of the water of the deposit to be treated. This family of α-sulfocarboxylic acid esters makes it possible to have a wide range of products, of synthesis easy, can be chosen "made to measure"

  depending on the characteristics of the underground reservoir.

  On the other hand, some products of this family of esters of asulfocarboxylic acids can be prepared from natural raw materials, animal or vegetable, belonging to the class of fats, oils and fats, such as tallow, oils of rapeseed, soybean, palm, coconut, etc. ie from raw materials whose production and price are

  relatively unaffected by fluctuations in the oil market.

  The technology for making these sulfonated fatty acid esters has already been the subject of numerous publications (AJ STIRTON, The Journal of the Amer, Oil Chemists', Vol 39, Nov. 1962, 490-496 W STEIN and H BAUMAN, same ref Vol 52, Sept 1975, p 323-329 BL KAPUR, JM SOLOMON and BR BLUESTEIN, same ref, Vol 55, June 1978, p 549-557) and some products are already commercialized. These α-sulfocarboxylic acid esters are, unexpectedly, extremely resistant to hydrolysis, compared to the acid esters.

  fat, and this over a range of p H ranging from 3.5 to 9.5 and at temperatures that can reach and even exceed 80 C.

  In the context of the present invention, these surfactants of the family of m-sulfocarboxylic esters may be used according to several techniques and be used alone or in mixtures, including with other anionic surfactants (petroleum sulfonates,

  olefin sulfonates, etc.) or nonionic (polyoxyethylated alkylphenols, polyoxyethylated alcohols, etc.).

  A first implementation technique consists in using an aqueous solution of the surfactant at concentrations, preferably of the order of 0.5 to 10% by weight of active product, the injected volumes preferably representing 20 to 30% by weight. % of the pore volume, the rheological properties of the system being possibly adjusted by the incorporation into the solution of a water-soluble polymer A second technique consists in injecting a smaller volume of a solution which may preferably contain up to 30 % by weight of surfactant, counted in active material, and contents of water, hydrocarbon oil and potential cotensioactif variable, which amounts to

use mioroemulsions.

  In the more particular context of using the surfactants of the invention in the microemulsion form, the surfactant coagent 30 may be chosen from those of the known art, especially from

  different aliphatic, alicyclic, aromatic mono alcohols -

  aliphatic alcohols, such as, for example, isopropyl, butyric, isobutyl, amyl, isoamyl, hexyl, heptyl, octyl, cyclohexanol and benzyl alcohol alcohols or, for example, monobutyl ether of ethylene glycol, this enumeration being given for illustrative purposes without

  no limitation The proportions of coagent surfactant are well known in the art; in general, 50 to 150 parts by weight of alcohol are advantageously employed with 100 parts of surfactant.

  On the other hand, the nature of the hydrocarbon and the possible salinity of the water control the proportions of surfactant to be used to remain within the stability limits of the miorcemulsion. It can simply be said that this quantity is most often, in particular for the mioroemulsions of salt water with paraffinic hydrocarbons, from about 1 to 30 parts by weight per 100 parts of microemulsified mixture; this proportion is in general of the order of 1 to 15 parts per 100 of the mioroemulsion, when

  the hydrocarbon and the water are in substantially equal amounts.

  The invention is illustrated by the following nonlimiting examples. These examples indicate for various elements of the α-sulfocarboxylic ester family the optimum salinity and the parameters.

solubilization.

EXAMPLES 1 to 8

  The principle consists in preparing multiphase mixtures describing the transitions I III II (WINSOR notation) by increasing the salinity of the water. The quantities of oil and water solubilized by the micellar phase are determined. the equality of these quantities is arbitrarily defined as the

optimal salinity (S O).

  The solubilization parameters (PS) are calculated as follows: PS water = weight initial water weight water excess weight initial water PS oil = weight initial oil weight oil excess weight initial oil The following formulation is prepared: n-dodecane surfactant n-butanol brine 4.5 g 0.25 g 0.25 g 4.5 g The brine consists of water, NaCl and Ca C 12 in the

  proportion of 9 parts Na Cl for 1 part of Ca C 12.

  In the following table, the nature of the acid ester has been indicated.

  α-sulfocarboxylic acid as surfactant and the values obtained for optimum salinity (S 0) and solubilization parameters (P S), at the indicated temperatures.

  EX α-sulfo acid ester SO (g / l) P S. carboxylic acid at 25 ° C to 80 ° C at 250 ° C to 800 ° C 1 a (sodium sulfonate) methyl palmitate 180 0.18 2 a (sulfonate of sodium) ethyl palmitate 135 120 0.16 0.153 a (sodium sulfonate) isopropyl palmitate 75 75 0.17 0.16 4 a (sodium sulfonate) n-butyl palmitate 30 0.18 0, 18 sodium alsulfonate) methyl stearate 150 120 0.28 0.27 8 - α-sulfo acid ester SO lg / 1) P S. EX carboxylic acid

  at 25 C to 80 C 1 at 25 C to 80 C

  6a (sodium sulfonate) propyl stearate 45 30 0.21 0.26 7 sodium acsulfonate) n-butyl stearate 22 18 0.33 0.32 8a (sodium sulfonate)

methyl tallowate "180 0.19 -

  At 80 ° C., a three-phase system is obtained for saline concentrations ranging from 150 to 200 g / l.

c O Mixture of tallow fatty acids.

Claims (10)

  A process for recovering oil, in which a liquid containing a surfactant compound is injected into a deposit, characterized in that said surfactant compound consists of at least one anionic surfactant chosen from among the acid esters. c-sulfo5 carboxylic compounds corresponding to one of the general formulas R-CH-COO-R ' SO 3 M 038 M and R CH-COO-R "-OCO -CH -R l Iu SO 3 M SO 3 M   in which R represents an alkyl or arylalkyl radical whose alkyl chain contains from 5 to 25 carbon atoms; R 'represents an alkyl or arylalkyl radical whose alkyl chain contains from 1 to 25 carbon atoms or a group - * (CH 2) x O 4 -Z, where Z represents the hydrogen atom, a methyl radical or an ethyl radical, x is an integer from 1 to 12 and y an integer from 1 to 50; R "represents an alkylidene or arylalkylidene radical whose alkyl chain contains from 1 to 25 carbon atoms or a - (CH 2) O group (t CH 2 1 x 2 xy 2 xox is an integer from 1 to 12 and y whole number of   1 to 50; and MB represents an alkali metal cation, an alkaline earth metal halide or an ammonium ion.   Process according to Claim 1, characterized in that the α-sulphocarboxylic acid ester is chosen from: methyl t-(sodium sulphonate) dodecanate; potassium α-sulfonate) ethyl dodecancate sodium α- (sodium sulfonate) triethylneglycol mono-dodecanoate; a, o '(sodium disulfonate) ethylene glycol didodecanoate; a- (ammonium sulfonate) propyl palmitate a- (sodium sulfonate) butyl stearate diethylamine α-lsul-fonate) isopropyl myristate a (triethanolammonium sulfonate) methyl stearate sodium α-sulfonate) methyl palmitate; and   t- (sodium sulfonate) propylene glycol monopalmitate.   3. Method according to one of claims i and 2, characterized in   the so-called α-sulfocarboxylic acid ester is used in the form of an aqueous solution. 4. Process according to claim 3, characterized in that the concentration of the so-called asulfocarboxylic acid ester in said   aqueous solution is 0.5 to 10% by weight.   Process according to one of Claims 1 and 2, characterized in that   that said α-sulfocarboxylic acid ester is used in the form of a mioroemulsion additionally containing water, an oil   hydrocarbon and optionally a co-surfactant.   6. Process according to claim 5, characterized in that said co-surfactant consists of an aliphatic aliphatic aliphatic aliphatic or aliphatic aromatic mono-ether or a Kieselglycol allyl mono-ether, and is used in a proportion of 50 to   parts by weight per 100 parts by weight of α-sulfocarboxylic ester. ? 549524   Process according to one of Claims 5 and 6, characterized in that the proportion of surfactant is from 1 to 30 parts by weight.   weight per 100 parts by weight of said microemulsion.   Process according to one of Claims 5 to 7, characterized in   what in the so-called microemulsion, the proportions of water and oil   hydrocarbon are substantially equal.   9 Microemulsion for use in enhanced oil recovery, characterized in that it is defined as in one Claims 5 to 8.