Method of mineral oil production

Patent metadata

Field	Value
Publication number	US-10266751-B2
Application number	US-201515527249-A
Country	US
Kind code	B2
Filing date	Nov 17, 2015
Priority date	Nov 18, 2014
Publication date	Apr 23, 2019
Grant date	Apr 23, 2019

Abstract

The present invention relates to a method for producing mineral oil from underground mineral oil deposits, in which an aqueous formulation comprising at least a mixture of alkyl ether carboxylate and corresponding alkyl ether alcohol, where the alkyl ether carboxylate has been prepared from the alkyl ether alcohol and the molar ratio in the mixture of alkyl ether carboxylate:alkyl ether alcohol is from 51:49 to 92:8, is injected through at least one injection well into a mineral oil deposit, where the deposit has a deposit temperature of 55° C. to 150° C., a crude oil having more than 20° API and a deposit water having more than 100 ppm of divalent cations, and crude oil is withdrawn through at least one production well from the deposit. The invention further relates to the preparation of the mixture and to a concentrate comprising the mixture.

First claim

The invention claimed is:

1. A method for producing mineral oil from underground mineral oil deposits, in which an aqueous saline surfactant formulation comprising a surfactant mixture, for the purpose of lowering the interfacial tension between oil and water to <0.1 mN/m at deposit temperature, is injected through at least one injection well into a mineral oil deposit and crude oil is withdrawn through at least one production well from the deposit, wherein
a) the mineral oil deposit has a deposit temperature of 55° C. to 150° C., a crude oil having more than 20° API and a deposit water having more than 100 ppm of divalent cations; and
b) the surfactant mixture comprises at least one anionic surfactant (A) of the general formula (I)
R 1 —O—(CH 2 C(R 2 )HO) x -(CH 2 C(CH 3 )HO) y —(CH 2 CH 2 O) z -CH 2 CO 2 M  (I)

and at least one nonionic surfactant (B) of the general formula (II)
R 1 —O—(CH 2 C(R 2 )HO) x —(CH 2 C(CH 3 )HO) y —(CH 2 CH 2 O) z —H,  (II)

where a molar ratio of anionic surfactant (A) to nonionic surfactant (B) of 51:49 to 92:8 is present in the surfactant mixture on injection and the nonionic surfactant (B) serves as starting material for the anionic surfactant (A), where said starting material means that nonionic surfactant (B) has the same definitions of the variables R 1 , R 2 , x, y, z as a nionic surfactant (A) and that nonionic surfactant (B) serves as a reactant for the preparation of anionic surfactant (A)
where
R 1 is a primary linear or branched, saturated or unsaturated, aliphatic hydrocarbyl radical having 10 to 36 carbon atoms; and
R 2 is a linear saturated aliphatic hydrocarbyl radical having 2 to 14 carbon atoms; and
M is H, Na, K or NH 4 ; and x is a number from 0 to 10; and
y is a number from 0 to 50; and
z is a number from 1 to 35;
where the sum total of x+y+z is a number from 3 to 80 and the x+y+z alkoxylate groups may be arranged in random distribution, in alternation or in blocks; and where the sum total of x+y is a number >0 if R 1 is a primary linear, saturated or unsaturated, aliphatic hydrocarbyl radical having 10 to 36 carbon atoms; and
c) the concentration of all the surfactants together is 0.05% to 0.49% by weight, based on the total amount of the aqueous saline surfactant formulation.

2. The method according to claim 1 , wherein a molar ratio of anionic surfactant (A) to nonionic surfactant (B) of 60:40 to 92:8 is present in the surfactant mixture on injection and the nonionic surfactant (B) serves as starting material for the anionic surfactant (A).

3. The method according to claim 1 , wherein a molar ratio of anionic surfactant (A) to nonionic surfactant (B) of 60:40 to 92:8 is present in the surfactant mixture on injection, the nonionic surfactant (B) serves as starting material for the anionic surfactant (A), and the interfacial tension between oil and water is lowered to <0.05 mN/m at deposit temperature.

4. The method according to claim 3 , wherein a molar ratio of anionic surfactant (A) to nonionic surfactant (B) of 70:30 to 89:11 is present in the surfactant mixture on injection, the nonionic surfactant (B) serves as starting material for the anionic surfactant (A), and the interfacial tension between oil and water is lowered to <0.01 mN/m.

5. The method according to claim 1 , wherein
R 1 is a primary linear or branched, saturated or unsaturated, aliphatic hydrocarbyl radical having 10 to 36 carbon atoms; and
R 2 is a linear saturated aliphatic hydrocarbyl radical having 2 to 14 carbon atoms; and
M is H, Na, K or NH 4 ; and
x is a number from 1 to 10; and
y is a number from 0 to 50; and
z is a number from 3 to 35;
where the sum total of x+y+z is a number from 4 to 80.

6. The method according to claim 1 , wherein
R 1 is a primary branched saturated aliphatic hydrocarbyl radical having 10 to 36 carbon atoms; and
R 2 is a linear saturated aliphatic hydrocarbyl radical having 2 to 14 carbon atoms; and
M is H, Na, K or NH 4 ; and
x is a number from 0 to 10; and
y is the number 0; and
z is a number from 3 to 35;
where the sum total of x+y+z is a number from 3 to 45.

7. The method according to claim 1 , wherein
R 1 is a primary branched saturated aliphatic hydrocarbyl radi cal having 16 to 20 carbon atoms, selected from the group consisting of 2-hexyldecyl, 2-octyldecyl, 2-hexyldodecyl, 2-octyldodecyl and a mixture of the hydrocarbyl radicals mentioned; and
x is the number 0.

8. The method according to claim 1 , wherein
R 1 is a primary branched saturated aliphatic hydrocarbyl radical having 24 to 28 carbon atoms, being 2-decyltetradecyl, 2-dodecylhexadecyl, 2-decylhexadecyl or 2-dodecyltetradecyl or a mixture of the hydrocarbyl radicals mentioned; and
x is number 0.

9. The method according to claim 1 , wherein
R 1 is a primary linear or branched, saturated or unsaturated, aliphatic hydrocarbyl radical having 10 to 36 carbon atoms; and
x is the number 0; and
y is a number from 3 to 25; and
z is a number from 3 to 30;
and the sum total of x+y+z is a number from 6 to 55.

10. The process as claimed in claim 9 , wherein
x is the number 0; and
y is a number from 3 to 10; and
z is a number from 4 to 15;
and the sum total of x+y+z is a number from 7 to 25.

11. The method according to claim 1 , wherein
R 1 is a primary linear or branched, saturated or unsaturated, aliphatic hydrocarbyl radical having 13 to 20 carbon atoms.

12. The method according to claim 1 , wherein
R 1 is a primary linear saturated aliphatic hydrocarbyl radical having 16 to 18 carbon atoms.

13. The method according to claim 1 , wherein the sum total of x+y+z is a number from 7 to 24.

14. The method according to claim 1 , wherein the aqueous surfactant formulation comprises a thickening polymer from the group of the biopolymers or from the group of the copolymers based on acrylamide.

15. The method according to claim 1 , wherein the mixture of anionic surfactant (A) of the general formula (I) and nonionic surfactant (B) of the general formula (II) is provided in the form of a concentrate comprising 20% by weight to 70% by weight of the surfactant mixture, 10% by weight to 40% by weight of water and 10% by weight to 40% by weight of a cosolvent, based on the total amount of the concentrate, where
a) the cosolvent is selected from the group of the aliphatic alcohols having 3 to 8 carbon atoms or from the group of the alkyl monoethylene glycols, the alkyl diethylene glycols or the alkyl triethylene glycols, where the alkyl radical is an aliphatic hydrocarbyl radical having 3 to 6 carbon atoms;
and/or
b) the concentrate is free-flowing at 20° C. and has a viscosity at 40° C. of <1500 mPas at 200 Hz.

16. The method according to claim 15 , wherein the concentrate comprises 0.5% to 15% by weight of a mixture comprising NaCl and diglycolic acid disodium salt, where NaCl is present in excess relative to diglycolic acid disodium salt.

17. The method according to claim 15 , wherein the concentrate comprises butyl diethylene glycol as cosolvent.

18. The method according to claim 1 , wherein the aqueous saline surfactant formulation comprises, as well as the anionic surfactant (A) of the general formula (I) and the nonionic surfactant (B) of the general formula (II), also further surfactants (C) which
a) are not identical to the surfactants (A) or (B);
and
b) are from the group of the alkylbenzenesulfonates, alpha-olefinsulfonates, internal olefinsulfonates, paraffinsulfonates, where the surfactants have 14 to 28 carbon atoms;
and/or
c) are selected from the group

Assignees

• Basf Se

Inventors

• Bittner Christian
• OETTER Günter
• Weiβe Sebastian Alexander
• Raths Hans-Christian
• Tinsley Jack
• Kienle Marcel

Classifications

• C09K8/60

  Compositions for stimulating production by acting on the underground formation · CPC title

• E21B43/20

  Displacing by water · CPC title

• C09K8/584 Primary

  characterised by the use of specific surfactants · CPC title

• C09K8/524

  organic depositions, e.g. paraffins or asphaltenes · CPC title

• C09K8/86

  containing organic compounds · CPC title