JPS621071B2 - - Google Patents

Description

[Detailed description of the invention]

In oil recovery from oil-bearing reservoirs, it is usually only possible to recover a small portion of the crude oil on-site by so-called primary recovery methods, which utilize only natural forces in the reservoir. Various advanced recovery methods have been developed to increase the amount of oil recovered beyond the amount that can be recovered economically using such natural forces. One of the most widely used and advanced recovery techniques is the use of water flooding. Water is usually injected into the reservoir to push the crude oil toward the producing well. The amount of oil recovered by water flooding depends on factors such as the interfacial tension between the water and crude oil, the relative mobility between the crude oil and water, and the wetting properties of the oil-bearing rocks in the reservoir. be done. To increase the efficiency of water flooding, surfactants have been added to the water. The surfactant reduces the surface tension of the aqueous liquid and the interfacial tension between the aqueous liquid and the oil, increasing the water wettability of the oil and reducing capillary forces in the underground formation being treated. In this way, oil can be released from sand and rock formations in the earth. It has usually been advantageous to use aqueous compositions containing petroleum sulfonates together with a certain amount of NaCl.
Furthermore, in order to prevent the petroleum sulfonate surfactant from disappearing due to the crystal formation reaction with divalent cations, sodium carbonate and/or sodium tripolyphosphate may be added to the above composition as an adjuvant. Furthermore, it has been proposed to add thickeners to increase the efficiency of scraping off the flattening. Examples of water flooding include pre-flashing or conditioning slags to minimize the amount of divalent cations (e.g. Ca ²⁺ , Mg ²⁺ ), surface activity to loosen and dissociate oil from sand and rock. An agent-containing slug and a mobility buffering slug that can be used to push the surfactant system are used. The preflush or conditioning slug does not contain cations harmful to the surfactant, but may partially or fully contain solutions such as sodium carbonate, sodium tripolyphosphate, and the like. Optionally, additional NaCl brine can be injected to optimize the salt concentration to optimize surfactant performance. Sodium ion is
It also replaces calcium and magnesium ions. Strong acids can also be used to soften carbonate rock formations. After injecting the aqueous solution of surfactant, the mobility buffering slug is injected. Mobility buffers typically contain water-soluble polymers such as polyacrylamide or biopolymers (eg, natural rubber). After injection of the mobility buffer or conditioning slug, a driving fluid is injected into the sand or rock formation to displace the previously injected fluid. The nature of the driving fluid is not critical and may be, for example, locally available water.
However, the driving fluid must not be incompatible with the underground formations. In the above waterflooding method/embodiment using a pre-flooded slag, a surfactant slag and a mobility buffering slag, the surfactant slag is combined with a co-surfactant such as a petroleum sulfonate, an alcohol, and an electrolyte. , in the form of an aqueous microemulsion of oil. The present invention provides a method of treating underground formations that stimulates the flow of oil from the formation, as well as a surfactant composition for the treatment. More particularly, the present invention relates to a method of oil recovery from underground reservoirs comprising injecting an aqueous surfactant composition to release oil from the underground reservoir;
Here, the surfactant has the formula (1) R _f -Z _n -A-Q _o -R _HC (wherein R _f is a hydrophobic-oleophobic fluoroaliphatic group having 4 to 24 carbon atoms; , Z is a divalent bonding group, A is a divalent hydrophilic organic group, and Q is,
It is a divalent bonding group, R _HC is a hydrophobic-lipophilic aliphatic group having 6 to 24 carbon atoms, or an aromatic aliphatic group having 9 or more carbon atoms, and m and n are each independently 1 It is 2 to 2. ) is a compound of
The fluorochemical surfactant corresponds to the above formula and has a solubility in water at 30° C. of at least 0.01% by weight and a surface concentration of 30 dynes/cm or less at a concentration of 0.1% by weight in deionized water. and has an interfacial tension of less than 12 dynes/cm at a concentration of 0.1% by weight in deionized water relative to cyclohexane. Optionally, the aqueous surfactant composition also contains anionic, a mixture of anionic and nonionic, or a cationic non-fluorinated surfactant.
The solubility of a suitable surfactant in deionized water is:
For measurements of surface and interfacial tension, the concentration used (0.1% by weight in deionized water) or less may be used. In such cases, measurements are carried out in an aqueous saturated heterogeneous system containing 0.1% fluoroaliphatic surfactant in deionized water. The fluoroaliphatic surfactant preferably has a surface tension of about 16 to 28 dynes/cm at a 0.1% concentration in deionized water and less than or equal to 12 dynes/cm when measured against cyclohexane in deionized water, e.g. 4
It has an interfacial tension of ~10 dynes/cm. Fluoroaliphatic surfactants usually contain at least 2 to 50% by weight of fluorine, preferably 5 to 50% by weight of fluorine.
Contains 35% fluorine by weight. The R _f group may be a straight or branched perfluoroaliphatic group having 4 to 24 carbon atoms, optionally with oxygen attached in the chain. In a preferred embodiment, the R _f group is a straight-chain or branched fluoroalkyl of 4 to 20 carbon atoms, a straight-chain or branched perfluoroalkenyl of 4 to 20 carbon atoms, or a straight-chain or branched perfluoroalkyl of 4 to 20 carbon atoms.
straight-chain or branched perfluoroalkyl-polyperfluoroalkoxy-perfluoroalkylene. Suitable R _f groups include the following formula (2) C _o F _2o+1 (wherein n is 4 to 20); (3) C _o F _2o-1 (wherein n is 4 to 20); and (4) C _n F _2n+1 O(C _p F _2p −O) _q C _r F _2r (where m is 1 to 3, p is 2 to 4, and q is 0 to
6, and r is 1-10. However, m+p+
q+r is at least 4. ) is a group represented by A suitable R _f group in formula (2) is CF ₃ ( _{CF 3} )
3-19) and mixtures thereof and types of groups and mixtures thereof. A suitable R _f group in formula (3) is CF ₃ (CF ₂ ) _0~8 −CF=
CF (CF ₂ −) groups of types _{1 to 9} and mixtures thereof, as well as formulas It is a branched chain analogous group such as A typical R _f group of formula (4) is and types of groups as well as mixtures thereof. The R _f group may also contain substituents other than fluorine, such as chlorine and hydrogen. However, in order for this group to maintain its hydrophobic-oleophobic character, substituents other than fluorine must be present at less than 20%. Examples of suitable R _f groups containing such substituents other than fluorine include H(CF ₂ −) _5-20 ; and (In the formula, a is 0 to 8, and b is 0 to 8. However, (a+b) is 2 to 16.) When a divalent bonding group Z exists, its properties are as follows:
It is not critical as long as it fulfills its essential function of covalently bonding the fluoroaliphatic group R _f to the hydrophilic organic group A. Thus, Z can be, for example, the following groups: _-C1 - _C6 alkylene, -phenylene, -( _C1 - _C6 -alkylene) _-R1- ( _C1 - _C6 -alkylene)-, - ( _C1 - _C6 -alkylene) _-R1 '), _-R1- ( _C1 - _C6 -alkylene)-, _-R1- (C1 _{- C6} -alkylene- _R1 ')-, - R ₁ -, -R ₁ -phenylene- (C ₁ - _{C 6} -alkylene-
R ₁ ')-, -R ₁ -phenylene-, or -phenylene-R ₁ ', wherein in each case the alkylene and phenylene are independently hydroxy, halogen, nitro, carboxy, C ₁ ~
_C6 -alkoxy, _C1 - _C6 -alkanoyl, _C1-
Substituted with _C6 -carbalkoxy, _C1 - _C6 -alkanoyloxy or _C1 - _C6 -alkanoylamino, or unsubstituted. R ₁ and R′ ₁ are independently

[Formula] −CO−, −NR ₂ CO−, −CONR ₂ ,

[Formula] - OCONR ₂ -, -O-, -S-, -SO-, -SO ₂ -, -
NR ₂ SO ₂ −, SO ₂ NR ₂ −, −NR ₂ CONR ₂ −, −NR ₂ −
SO ₂ −NR ₂ −,

【formula】

[Formula] −SO ₂ O−, −OSO ₂ −, −OSO ₂ O−,

【formula】 【formula】

【formula】

[Formula] or

Represents [formula]. R ₂ is hydrogen, C ₁ -C ₆ -alkyl or C ₁ -
C1 _-C6 -alkyl substituted by C6-alkoxy, halogen, hydroxy, carboxy, _C1 - _C6 -carbalkoxy, _{C1 - C6 -} alkanoyloxy or _C1 - _C6 -alkanoylamino. Furthermore, Z can also contain an alicyclic group or a heterocyclic group. Thus, for example, R ₁ can be further modified by the formula (wherein, R ₃ is -OR ₂ , -OM (M is defined below), or -NH ₂ ; R ₄ is -O- or

and R ₅ is hydrogen, halogen, C ₁ -C ₆ alkyl or C ₁ -C ₆ -alkoxy. )
and R ₁ can be expressed as or A suitable hydrophilic group A can be, for example, represented by the following formula: (wherein R ₆ is hydrogen; or a mixture of hydrogen and methyl, in which case hydrogen is predominant;

【formula】

[Formula] In the formula, R ₇ is hydrogen, lower alkyl or hydroxyethyl;

[Formula] In the formula, R ₇ is hydrogen or hydroxyethyl; In the formula, t is 1 to 3 and R ₈ is lower alkyl,
Hydroxy _- lower alkyl or ( _CH2CH2O ) _s
H; In the formula, t is 1 to 3, T is -SO ₃ M, -COOM,
−PO ₃ M, −OSO ₃ M or −OPO ₃ M ₂ , and M
is ammonium hydrogen or an alkali metal cation; or where R ₉ , R ₁₀ and R ₁₁ are independently hydrogen; C ₁
~ _C4 -alkyl or _hydroxy , C1- _C4-
alkoxy or hydroxy-C ₂ -C ₄ -alkoxy; and one of R ₉ and R ₁₀ further represents benzyl; u is 0 or 1; R ₁₁ is C ₁ - further substituted with sulfone or carboxy _C6 alkylene; when u is 1 and _R11 is other than the above _C1 - _C6 -alkylene, X is acetate, halo, methosulfate or hydroxyl anion; and s is 1-3. ). In each of the above formulas, S is preferably 2 to 60,
5 to 25. Mixtures of the above hydrophilic groups can also be used. Furthermore, at least a portion of the hydrophilic character is expressed by the following formula: i.e. In the formula, n ₁ is 0 to 20 and n ₂ is 1 to 20; In the formula, n ₁ and n ₃ are independently 0 to 20, and n ₂ and n ₄ are independently 1 to 20; In the formula, n ₅ is independently 2 to 20, and n ₆ is independently 1
~10; or In the formula, _R14 is hydrogen, _C1 - _C4 alkyl, or ( _{OCH2CH2 ) o4OH} ; _y1 and _y2 are independently 0
Hydrophilic divalent groups can also be used, such as those due to pendant divalent groups such as -4; y ₃ is 1 to 8; and n ₄ is independently 1 to 20. Q is a divalent bonding group, and like Z, it is not critically important as long as it fulfills the essential function of covalently bonding the hydrophilic organic group A to the hydrophobic-lipophilic group _RHC . do not have. Thus, the linking group Q can be independently selected from among the groups described above for Z, with the proviso that R ₁ or R ₁ ' is directly bonded to A and the terminal end of A is an oxy or amino ligand. and R ₁ ′ at the above position is

[Formula] -S-,

【formula】

[Formula] −OSO ₂ −, −OSO ₃ −,

【formula】

[Formula] or other than -O-. R _HC is a hydrophilic-lipophilic aliphatic or araliphatic monovalent group. Hydrophobic-lipophilic higher alkyl or alkenyl having from 6 to 24 carbon atoms as suitable R _HC groups, chloro, bromo, alkoxy having up to 18 carbon atoms, nitro, alkanoyl having up to 18 carbon atoms, Includes those substituted with alkylmercapto of up to 18 carbon atoms, amino, _C1 - _C18 -alkylamino or di- _C1 - _C18 -alkylamino, or unsubstituted. R _HC is preferably an alkyl or alkenyl as defined above of at least 8 carbon atoms. The alkyl and alkenyl groups may be straight or branched. Mixtures thereof can also be used. Furthermore, the R _HC group has the formula (wherein R ₅ is C ₁ -C ₆ -alkyl, n ₇ is 5-20 and R ₆ is hydrogen or alkyl having up to 24 carbon atoms). Furthermore, the R _HC group may also be a hydrophobic-lipophilic aromatic aliphatic group having at least 9 carbon atoms. An example of a suitable group is the formula (In the formula, _n8 is 0 to 1; _R15 is alkyl having up to 20 carbon atoms, alkoxy having up to 20 carbon atoms, alkanoyl having up to 20 carbon atoms, mono- or dialkylamino having up to 20 carbon atoms. , carbon atom 20
alkylmercapto, alkanoyloxy of up to 20 carbon atoms, or carbalkoxy of up to 20 carbon atoms; and R ₁₆ is hydrogen, halogen,
Nitro or _R15 . ) can be given. Also expression (In the formula, n ₈ , R ₁₅ and R ₁₆ are defined as above.) A hydrophobic-lipophilic group represented by the formula can be cited as an example. Furthermore, the -Q _o -R _HC group (in the formula, n is 1) has the formula (wherein R ₁₇ and R ₁₈ are independently carbon atoms 6 to 24
is a higher alkyl group having 5 carbon atoms. )
group or formula of (wherein R ₁₉ and R ₂₀ are higher alkyl having 6 to 24 carbon atoms). Preferred compounds are substantially nonionic compounds;
That is, it is free of strong acid groups such as -SO ₃ H and -PO ₃ H, and is free of strong basic quaternary ammonium groups. Of particular interest among these preferred substantially nonionic surfactants are
Surface tension at 0.1% concentration is approximately 16-28 dynes/
cm, the solubility in water is at least 0.01% by weight, and at a concentration of 0.1% by weight in deionized water,
_{The apparent} HLB (hydrophilic -
lipophilic balance) is in the range of about 5 to 24, preferably in the range of about 12 to 18. Substantially nonionic hydrocarbon surfactant
HLB is the percentage weight of the hydrophilic portion of the nonionic hydrocarbon surfactant molecule.
[See, for example, Industrial and Engineering Chemistry, Analytical Edition 18, page 500, 1946 (Ind. and Eng. Chem, Anal. Ed.
Vol. 18, Page 500 (1946)]. A particularly preferred class of fluorochemical surfactants has the formula (5) R _f -Z _n (CH ₂ CH ₂ O) _s Q _o -R _HC where R _f has 4 to 20 carbon atoms, especially 4 straight-chain or branched perfluoroalkyl having ~12 carbon atoms, R _HC is alkyl having 6 to 24 carbon atoms, preferably 12 to 18 carbon atoms, or (In the formula, R ₂₁ has 3 to 20 carbon atoms, preferably,
6-12 alkyl, _R22 is hydrogen, halogen (chloro, bromo, fluoro), nitro or _R21 ; m is 0 or 1; s is 5-30; Z is -
COO-, _SO3 , -O-, _-C1 - _C4 -alkylene-
COO, _-C1 - _C4 -alkylene- _SO3 , or n is 0 or 1; and Q is -CO or _-SO2
− is. ). Among the compounds of formula (5), preferred are R _f ,
R _HC and s have the abovementioned meanings, m and n
is zero. Among the compounds of formula (5), preferred ones also include Z
However, equation (6) like Alternatively, Z is the formula (7) (wherein R _f , R _HC and s have the same meanings as above) It is something that is. The fluorochemical surfactants used according to the invention can be obtained by conventional methods. The fluorochemical surfactant is, for example, a known hydrocarbon surfactant of the formula R _HC -Q _o -A-OH or R _HC -Q _o -A-NHR ₂ mixed with a fluorofatty acid halide in an inert solvent. Obtained by reacting with For example, CF ₃ (CF ₂ ) ₇ SO ₂ F obtained according to US Pat.
(OCH ₂ CH ₂ ) _5-20 N(stearyl) ₂ to give the corresponding ester of formula CF ₃ (CF ₂ ) ₇ SO ₂ (OCH ₂ CH ₂ ) ₂₀ N(stearyl) ₂ can. Similarly, n-C ₃ F ₇ OCF (CF ₃ ) COF as disclosed in Canadian Patent No. 725,740 was prepared from octyl fluoride with an average molecular weight of 514 to 778 in the presence of diethyl ether and pyridine as the acid acceptor. The corresponding ester can be obtained by reaction with enoxy-poly(ethyleneoxy)ethanol. Alternatively, the formula C _o F ₂ n _-1 (where n is 6 to
20) in an inert solvent such as methyl ethyl ketone or acetone at a temperature of 20 to 70 °C in the presence of potassium carbonate with the formula R _HC -Q
_o -A-OH can be reacted with a hydrocarbon surfactant to give the corresponding fluorofatty acid ether. For example, oleic acid-ethylene oxide condensate (molecular weight approximately 680) is reacted with tetrafluoroethylene pentanamer in the presence of potassium carbonate in acetone to form the formula C ₁₀ F ₁₉ O(CH ₂ CH ₂ O) ₁₀ COC ₁₅ H ₂₉ can get things. Using _a mixture of cetyl/oleyl-ethylene oxide condensates (molecular weight approximately 550) it is possible to obtain the corresponding _cetyl /oleyl ether product of formula _{C10F19O ( CH2CH2O} ) _10C16H31 / _{33 .} can. Such above-mentioned compounds and methods for their preparation are disclosed in the specification of GB 1371054. Alternatively, also fluoroaliphatic isocyanates and carbamic acid halides of the formula R _HC -Q _o
-A-OH or R _HC -Q _o -A-NHR ₂ by reacting with a hydrocarbon surfactant, respectively.
Corresponding urethanes and ureas can be obtained. The reaction is preferably carried out in the presence of an inert medium at a temperature of 20-50°C. When a fluoroaliphatic carbamic acid halide is a reactant, a tertiary amine such as triethylamine or pyridine may be added to accelerate the reaction and remove the hydrogen halide formed. For example, 1,1-dihydroperfluorooctylcarbamyl chloride of the formula C ₇ F ₁₅ CH ₂ NHCOCl obtained according to German Patent No. 1 145 606 is dissolved in diethyl ether with stirring in the presence of triethylamine as HCl removing agent. (15
mol) gradually added to the cocoa fatty acids. The product is
_It has the _{formula C7F15CH2NHCOO-} ( _{CH2CH2 -} O) _15CORHC , where _RHC is _a cocoa fatty acid hydrocarbon residue. Similarly, CF ₃ (CF ₂ ) ₆ NCO obtained according to US Pat. No. 2,617,817 is diluted with stearic acid or lauric acid as described in US Pat. No. 2,163,807 in an inert diluent. Reacting with an amide-ethyleneimine (4-6 moles) condensate gives the formula _CF3 ( _CF2 ) _6NHCO
The product (NHCH ₂ CH ₂ ) _4-6 NHCO-R _HC where R _HC is a hydrocarbon residue of stearic or lauric acid is obtained. This product can be neutralized with an aqueous solution of hydrochloric or sulfuric acid to give the corresponding salt, or alkylated with a methyl halide such as dimethyl sulfate or methyl bromide to provide its tertiary and quaternary Ammonium derivatives can also be obtained. Alternatively, the above product can be reacted in the presence of an HCl catalyst, for example with 4 to 15 moles of ethylene oxide per mole of product, to obtain its ethoxylated derivative. Similarly, reaction with nonionic hydrocarbon surfactants of the phosgene formula R _HC -Q _o -A-OH gives the corresponding chloroformates, and reaction of acid chlorides with fluoroaliphatic alcohols or amines, respectively The corresponding carbonates or urethanes are obtained. The reaction is preferably carried out in the presence of a tertiary amine such as triethylamine and an inert diluent. For example, reaction _{of C12H25S} ( _CH2CH2O ) _-10H with phosgene in the presence of _{triethylamine} yields _the corresponding acid chloride _C12H25S ( _OH22CH2O ) _10COCl , _which The acid chloride was then dissolved in diethyl ether in the presence of triethylamine in U.S. Pat.
(CF ₃ ) ₂ CFO disclosed in specification No. 3697564
−CF ₂ CF ₂ −CH ₂ CH ₂ CONH When reacted with a fluoroaliphatic alcohol such as (CH ₂ ) ₃ OH, the formula (CF ₃ ) ₂ CFO−CF ₂ CF ₂ CH ₂ CH ₂ CONH
_A product _of ( _CH2 ) _3OCO ( _OCH2CH2 ) _-10 -S- _C12H25 is obtained. Similarly, UK Patent Nos. 1130822 and 1270662
Reaction of the C ₁₀ F ₁₉ OC ₆ H ₄ SO ₂ Cl described in the specification with polyoxyethylene 20 sorbitan monolaurate in the presence of triethylamine in an inert diluent gives the corresponding ester. The fluorochemical surfactant preferably comprises:
A hydrocarbon surfactant of the formula R _HC -Q _o -A-OH is reacted with an equimolar amount of toluene diisocyanate to form its 1:1 urethane adduct, and the urethane monoisocyanate is reacted with a polyfluoroaliphatic amine or alcohol. You can get it. Thus, reacting nonylphenoxypolyethoxyethanol with an average of 4 moles of ethylene oxide with 1 mole of toluene diisomanate gives the corresponding 1:1 adduct, which is then described in U.S. Pat. No. 3,257,407. Reaction with a perfluoroalkylalkylamine of formula C ₈ F ₁₇ (CH ₂ ) ₅ NH ₂ obtained according to gives the corresponding urea derivative. Similarly, many fluorochemical surfactants of the formula R _f -Z _o -A-OH can be reacted with appropriate aliphatic or araliphatic acid halides, isocyanates, etc. to form suitable fluorochemical surfactants for use in the present invention. A chemical surfactant is obtained. For example, it was disclosed in US Pat. No. 2,915,554. C ₈ F ₁₇ SO ₂ N (C ₂ H ₅ )−CH ₂ CH ₂ (OCH ₂ CH ₂ ) ₁₀
Reaction of -OH with dodecylbenzenesulfonyl chloride in diethyl ether in the presence of triethylamine gives the corresponding sulfonate ester. Useful surfactants for use in the present invention include reacting a fluoroaliphatic thiol with an ethylenically unsaturated dicarboxylic acid anhydride and then converting the resulting anhydride condensate into a compound of the formula R _HC -Q _o -A-OH or R _HC - Q _o -A-
It can also be obtained by reacting NH ₂ with an equimolar amount of a hydrocarbon surfactant to form a half-ester or half-amide, respectively. or,
Furthermore, ethylenically unsaturated dicarboxylic acid anhydrides can be expressed by formulas R _HC -Q _o -A-OH or R _HC -Q-A-
NH ₂ may be reacted with an equimolar amount of a hydrocarbon surfactant and the reaction product then reacted with a fluoroaliphatic thiol. For example, by reacting dodecylphenoxypolyethoxyethanol (containing 9 moles of ethylene oxide) with an equimolar amount of maleic anhydride in the presence of an inert diluent such as sulfolane, formula (8) can be obtained. The half ester of is obtained. This half ester was then converted into a
Obtained according to specifications No. 3172910 and No. 3088849
React with a fluoroaliphatic thiol such as C ₉ F ₁₉ C ₂ H ₄ SH. The reaction is preferably carried out in substantially stoichiometric amounts in aqueous ethanol in the presence of a small amount of caustic soda and a tertiary amine such as piperazine at a temperature between 20 and 75°C, e.g. of the product can be obtained. The formula also obtained according to US Pat. No. 3,471,518 The compound of formula (11) disclosed in U.S. Pat. No. 2,341,846 was prepared in equimolar amounts in dioxane under reflux. The corresponding half ester is obtained when reacted with the compound . Similarly, equation (12) (wherein R _f is the combination of norbornane anhydride and R _f in the presence of a small amount of azobutyronitrile as a catalyst)
It is a mixture of _{C6 to C10} perfluoroalkyl obtained by reacting with _CH2CH2SH . ) with an equimolar amount of 3-(n-dodecylamino)propylamine in an inert diluent such as toluene at a temperature between 20 and 50°C, and the product is dehydrated by azeotropic distillation of water. to give the corresponding imine, which is then ethoxylated with 10 moles of ethylene oxide in an aqueous acidic medium to give formula (13). of product is obtained. Fluorochemical surfactants that can be used in accordance with the present invention also include known compounds. Suitable fluorochemical surfactants as defined above and which may be used in the present invention include those defined above,
And also, as explained in the examples below,
It can be easily obtained from known starting materials by conventional methods. Fluorochemical surfactants may be used alone in aqueous systems or in combination with conventional flattening surfactants. Such surfactants for advanced oil recovery are well known and include, for example, petroleum sulfonates, anionic surfactants such as synthetic alkylaryl sulfonates, U.S. Pat. Mention may be made of anionic-nonionic surfactant systems and cationic surfactant systems as disclosed in US Pat. No. 4,005,749. Mixtures of cationic and anionic surfactants are typically not used because they interact and become incompatible. The total amount of surfactant for the aqueous medium ranges from 0.01 to
40% by weight, which can typically vary from 0.05 to 20% by weight. When using a mixture of the fluorochemical surfactant of the present invention and a conventional floating surfactant, the fluorochemical surfactant is at least 1% based on the amount of non-fluorochemical surfactant; Preferably at least 4%
It is normal for it to exist. The aqueous surfactant slug preferably contains 10% of the solution.
Suitable common surfactants such as aliphatic or alkylaryl alcohols having a molecular weight of 40 to 220 may be included in amounts up to % by volume. Monovalent salts may also be present in the aqueous medium in an amount of 5% by weight or less based on the aqueous medium for salinity control. Various thickening agents such as guar gum or polysaccharides and sacrificial agents such as inorganic polyphosphates or alkali metal carbonates.
agents) may be present. In one embodiment of the invention, the surfactant slag may be in the form of an aqueous petroleum emulsion containing from 0.5 to 40% by weight of oil, relative to the weight of the aqueous phase. Further, in embodiments of the invention, the last portion of the aqueous surfactant slag or aqueous petroleum emulsion has a lower concentration of non-aqueous components than the first portion injected into the reservoir from which oil is recovered. By using such concentrations, the total amount of surfactant required for oil recovery operations can be reduced. The following examples are merely illustrative of the invention and are not intended to limit its scope. Unless otherwise specified, all parts are parts by weight. Example 1 Having a thermometer, stirrer and nitrogen inlet
84.2 g of polyethoxylated cetyl alcohol having an average of 20 ethoxy units and having _{the formula (101) C16H33(-OCH2CH2)-20OH in a 500ml} container _.
(0.075 mol) in a nitrogen atmosphere at 50-55℃.
It was stirred with Diethyl ether complex salt (BF ₃ 47.3
0.4 g of boron trifluoride in the form of %) was added. 6.1 g of epichlorohydrin was then added to this mixture over a period of approximately 10 minutes while maintaining the temperature at 50-60°C.
(0.066 mol) was added gradually. The reaction mixture was then stirred for an additional 30 minutes at a temperature of 50-60°C.
The resulting product has the formula It can be expressed as Then, 140.3 g of anhydrous isopropyl alcohol and R _f CH ₂ CH ₂ SH (in the formula,
R _f is a straight chain perfluoroalkyl, and R _f is as follows:
It has a distribution. i.e. _{C4F9 −0.9 %} , _C6F13
-32.9%, _C8F17 -37.5%, _{C10F21 -22.99} % and _{C12F25 -5.3} %) (average molecular weight approximately 465) _.
was added and the mixture was stirred at 50°C. Then, 5.4 g (0.0672 mol) of 50% NaOH aqueous solution was added slowly at a rate such that the reaction mixture was maintained at 50-60°C. An autochromic precipitate of NaCl was produced. When this mixture was further stirred at 50-55°C for 1 hour, the color changed from colorless to pale yellow. The solution was filtered to remove by-product NaCl. 73.6g of dried product
(yield about 70%). The product has the formula It can be expressed as Example 2 By the method of Example 1, the formula 54.69 g (0.063 mol) of polyethoxylated stearylamine (wherein q+r is 15) was reacted with 5.09 g (0.055 mol) of epichlorohydrin in the presence of BF ₃ ; diethyl ether complex salt 0.3 g, and the resulting reaction product 50% in 98.85g of isopropanol
R _f of Example 1 in the presence of 4.48 g of NaOH aqueous solution
It was reacted with 23.25 g of CH ₂ CH ₂ SH. The reaction product was stirred for 2 hours before being filtered, yielding 151.47 g of an amber cloudy solution. Filtration gave 142.01 g of a clear amber solution. dry and formula 46.43 g of a product of the following formula was obtained. Example 3 Using the method of Example 1, the formula 264.0 g of ethoxylated (15) p-nonylphenol represented by BF ₃ ; 1.6 g of diethyl ether complex salt
The product was then treated with 21.50 g of 50% caustic soda.
g and 460.4 g of isopropyl alcohol, R _f having the same R _f distribution as in Example 1.
It was reacted with 111.6 g of CH ₂ CH ₂ SH. The resulting reaction product has the formula It can be expressed as Example 4 2.55 g of maleic anhydride and 2.55 g of sulfone as a solvent were combined into the formula Add to 36.45 g of dinonyl polyethoxylated (24) phenol represented by the formula and stir at 60°C for 20 hours to obtain the formula A reaction mixture was obtained containing the half ester of . To this reaction mixture, under a nitrogen atmosphere, 0.1 g of triethylamine and 11.63 g of R _f CH ₂ CH ₂ SH having the same R _f distribution as in Example 1 were added.
The mixture was stirred at 60°C for 7 hours. The product is the formula It is expressed as Example 5 The following screening technique was used to determine the efficacy of fluorochemical surfactants to release oil from underground oil-bearing formations by increasing the effectiveness of the aqueous medium. Procedure: 20 g of sand-oil mixture (10% of ASTM Oil No. 3 and 90% of Ottawa Standard Sand 20-30 mesh)
It was placed in a 25 x 15 mm test tube. The test solution (25 ml of sample in 0.1% actives in deionized water) was carefully poured over the sand-oil mixture.
The system was then left undisturbed for 18-20 hours. The oil to be percoated on the surface was sampled with a pipette and weighed. Results are expressed as percent recovered (ie, weight of oil recovered compared to the theoretical maximum amount of oil in the test tube, 2.0 g). 3-5 experiments were performed for each sample to obtain one average value. In the table below, compounds were screened in 0.1% actives in deionized water and surface tension and interfacial tension relative to cyclohexane were measured. Unless otherwise indicated,
The R _f distribution in the perfluoroalkyl surfactant was as follows. i.e. C ₄ F ₉ −0.9%, C ₆ F ₁₃
-32.9%, _C8F17 -37.5%, _{C10F21 -22.9} %, and _{C12F25 -5.3 %} .

【table】

[Table] Example 6 Blends of various hydrocarbon surfactants with representative fluorochemical surfactants and Example 5
The efficacy of these formulations in liberating oil by the method described in Table 1 is shown in the following table. In the following table, hydrocarbon surfactants are defined as commercially available anionic sulfate surfactants [Conco EL
-30: Trademark]; the hydrocarbon surfactant is polyethoxylated nonylphenol, a nonionic surfactant [Igepal CO-710: Trademark]; and the surfactant is a petroleum sulfonate anionic surfactant [Petronate]; L (Petronate L);
Trademark].

【table】

【table】

[Table] The results shown in the above table show that it is advantageous to use a blend of a conventional hydrocarbon surfactant and a fluorochemical surfactant in tertiary oil recovery.

Claims (1)

[Scope of Claims] 1. A method for recovering oil from an underground oil reservoir by injecting an aqueous surfactant composition to expel oil from an underground oil reservoir, wherein the surfactant has the formula R _f - Z _n -A-Q _o -R _HC (wherein R _f is a hydrophobic-oleophobic fluoroaliphatic group having 4 to 24 carbon atoms, Z is a divalent bonding group, A is a divalent hydrophilic organic group, Q is a divalent linking group, and R _HC is a hydrophobic-lipophilic aliphatic group having 6 to 24 carbon atoms, or at least 9 carbon atoms. an araliphatic group having an atom, m and n are independently 0 or 1), wherein the fluorochemical surfactant contains at least 0.01% by weight of water at 30°C. It has a solubility of 30 dynes/cm or less in deionized water at a concentration of 0.1% by weight, and an interfacial tension of 12 dynes/cm or less at a concentration of 0.1% by weight in deionized water with respect to cyclohexane. A method for recovering oil from an underground oil reservoir characterized by the following. 2. The aqueous surfactant composition further comprises an anionic surfactant, a mixture of anionic and nonionic surfactants, or a non-fluorinated surfactant of a cationic surfactant. The method described in Section 1. 3. The fluorochemical surfactant has a concentration of about 16 to 28 dynes/cm in deionized water at a concentration of 0.1%.
2. The method of claim 1, wherein the method has a surface tension of less than 12 dynes/cm and an interfacial tension relative to cyclohexane of less than or equal to 12 dynes/cm. 4. The method of claim 3, wherein the fluorochemical surfactant is nonionic in nature. 5 The fluorochemical surfactant R _f −Z _n −
A-Q _o -R Surfactant HO-A-Q corresponding to _HC
5. The method of claim 4, wherein _o -R _HC has an apparent hydrophilic-lipophilic balance in the range of about 4-24. 6 The surfactant HO-A-Q _o -R _HC is about 12 to
6. The method of claim 5 having an apparent hydrophilic-lipophilic balance in the range of 18. 7 The fluorochemical surfactant has the formula R _f −Z _n (CH ₂ CH ₂ O) _s Q _o- R _HC [wherein R _f is a straight chain or branched chain perfluoroalkyl, R
_HC is alkyl having 6 to 24 carbon atoms or (Here, R ₂₁ is alkyl of 3 to 20 carbon atoms,
_R22 is hydrogen, halogen, nitro or _R21 . ); m is 0 or 1; s is 5 to 25; Z is -
COO-, _-SO3- , -O-, _{-C1- C4} -alkylene-COO-, -C1 _{- C4} -alkylene- _SO3 , _-C1-
C ₄ -Alkylene [Formula] or -C ₁ -C ₄ -Alkylene [Formula] n is 0 or 1, and Q is -CO- or -SO ₂ -. ] The method according to claim 5, which is represented by: 8 R _f is a straight chain or branched perfluoroalkyl of 4 to 20 carbon atoms, and R _HC is an alkyl of 6 to 24 carbon atoms or is a group represented by; m and n are 0,
8. The method of claim 7, wherein s, R ₂₁ and R ₂₂ are as defined in claim 7. 9 The fluorochemical surfactant has the formula or (In the formula, R _f , R _HC and s are
8. The method according to claim 7, wherein the method is as described in paragraph 7. 10 Formula R _f -Z _n -A-Q _o -R _HC (wherein R _f is a hydrophobic-oleophobic fluoroaliphatic group having 4 to 24 carbon atoms, and Z is a divalent bond group, where A is a divalent hydrophilic organic group, Q is a divalent bonding group, and R _HC is a hydrophobic-lipophilic aliphatic group having 6 to 24 carbon atoms, or both are aromatic aliphatic groups having 9 carbon atoms, m and n are independently 0 or 1), and have a solubility of at least 0.01% by weight in water at 30°C. 30 dynes/cm at a concentration of 0.1% by weight in deionized water
0.01 to 4% by weight of a fluorochemical surfactant having a surface tension of less than or equal to 12 dynes/cm at a concentration of 0.1% by weight relative to cyclohexane in deionized water and, optionally,
An aqueous surfactant composition for oil recovery from underground oil reservoirs, characterized in that it contains a conventional non-fluorochemical surfactant for flattening. 11. The composition of claim 10, wherein the non-fluorochemical surfactant is an anionic surfactant, a mixture of anionic and nonionic surfactants, or a cationic surfactant. 12 The fluorochemical surfactant has a concentration of about 16 to 28 dynes/dyne/dyne in deionized water at a concentration of 0.1%.
11. The composition of claim 10, having a surface tension of 12 dynes/cm and an interfacial tension with respect to cyclohexane of less than 12 dynes/cm. 13. The composition of claim 12, wherein the fluorochemical surfactant is nonionic in nature. 14 The fluorochemical surfactant R _f −Z _n
-A-Q _o -R Surfactant HO-A- corresponding to _HC
Q _o - Apparent hydrophilicity with R _HC ranging from about 4 to 24 -
14. A composition according to claim 13 having a lipophilic balance. 15 The surfactant HO-A-Q _o -R _HC is about 12
15. The composition of claim 14 having an apparent hydrophilic-lipophilic balance in the range of .about.18. 16 The fluorochemical surfactant has the formula R _f −Z _n (CH ₂ CH ₂ O) _s Q _o −R _HC [wherein R _f is a straight chain or branched chain having 4 to 20 carbon atoms] chain perfluoroalkyl, R
_HC is alkyl having 6 to 24 carbon atoms or (Here, R ₂₁ is alkyl of 3 to 20 carbon atoms,
_R22 is hydrogen, halogen, nitro or _R21 . ); m is 0 or 1; s is 5 to 25; Z is -
COO-, _-SO3- , -O-, _{-C1- C4} -alkylene-COO-, -C1 _{- C4} -alkylene- _SO3 , _-C1-
C ₄ -Alkylene [Formula] or -C ₁ -C ₄ -Alkylene [Formula] n is 0 or 1, and Q is -CO- or -SO ₂ -. ] The composition according to claim 14, which is represented by: 17 R _f is a linear or branched perfluoroalkyl of 4 to 20 carbon atoms, and R _HC is an alkyl of 6 to 24 carbon atoms or is a group represented by; m and n are 0,
17. The composition of claim 16, wherein s, R ₂₁ and R ₂₂ are as defined in claim 16. 18 The fluorochemical surfactant has the formula or (In the formula, R _f , R _HC and s are
17. The composition according to claim 16, which is represented by the formula (as described in item 6). 19. The composition of claim 10 containing at least 1% by weight of fluorochemical surfactant, based on the weight of non-fluorochemical surfactant. 20 formula [Wherein, R _f is a hydrophobic-oleophobic fluorinated aliphatic group having 4 to 20 carbon atoms, s is 5-30, R _HC is a hydrophobic-lipophilic aliphatic group or a formula (In the formula, R ₂₁ is alkyl having 3 to 20 carbon atoms, and R ₂₂
is hydrogen, halogen, nitro or _R21 . ). ] A compound represented by 21 R _f is perfluoroalkyl having 6 to 20 carbon atoms, and R _HC is alkyl having 6 to 24 carbon atoms or the formula 21. The compound according to claim 20, which is a group represented by the formula (wherein _R21 is alkyl having 6 to 12 carbon atoms, and _R22 is hydrogen or _R21 ).