Reversible oil-based mud

Patent metadata

Field	Value
Publication number	US-11639461-B2
Application number	US-201615999540-A
Country	US
Kind code	B2
Filing date	Feb 19, 2016
Priority date	Feb 19, 2016
Publication date	May 2, 2023
Grant date	May 2, 2023

Abstract

A wellbore fluid may include a non-oleaginous internal phase, an oleaginous external phase, and an emulsifier having a molecular weight of at least 700 daltons, whereby the emulsifier may include at least one tertiary amine. A method of completing a wellbore operation may include injecting a wellbore fluid downhole, the wellbore fluid including a non-oleaginous internal phase, an oleaginous external phase, and an emulsifier having a molecular weight of at least 700 daltons. The emulsifier may include at least one tertiary amine. The method may further include injecting a wash fluid comprising a protonating agent downhole.

First claim

What is claimed:

1. A wellbore fluid comprising:
a non-oleaginous liquid;
an oleaginous liquid; and
an amine emulsifier having a molecular weight of about 700 to 7,000 daltons, and present in an amount of about 0.1% to 10% by volume of the wellbore fluid,
wherein, when a majority of the tertiary fatty amines in the amine emulsifier is in an unprotonated form, the oleaginous liquid is a continuous phase and the non-oleaginous liquid is a discontinuous phase such that the amine emulsifier stabilizes a water-in-oil emulsion comprising the oleaginous liquid as the continuous phase and the non-oleaginous liquid as the discontinuous phase and, when a majority of the tertiary fatty amines is in a protonated form, the oleaginous liquid is the discontinuous phase and the non-oleaginous liquid is the continuous phase such that the water-in-oil emulsion converts to an oil-in-water emulsion comprising the non-oleaginous liquid as the continuous phase and the oleaginous liquid as the discontinuous phase;
wherein the amine emulsifier is according to Formula (I):

wherein R 1 and R 2 are independently selected from a linear or branched C 12 to C 22 alkyl group, alkenyl group, alkyl substituted cycloalkyl group, or mixtures thereof, A is independently selected from a monoester group, a diester group, a triester group, an ether group, an amide group, or a CH-substituted by a hydroxyl group; R′ is H, or a C 1 to C 3 alkyl; m is independently 1 or 2; x+y≥2; n is 2 to 12; D is either another [((CH 2 ) m CHR′A) x -(CH 2 ) m CHR′—NR 2 —((CH 2 ) m CHR′A) y ] n H group with the same limitations on A, m, x, y and n as described above, or D is a ((CH 2 ) m CHR′E) z H group, wherein m is independently 1 or 2; R′ is H, or a C 1 to C 3 alkyl; E is NH or O; and z is 1, 2, or 3.

2. The wellbore fluid of claim 1 , wherein at least one tertiary fatty amine of the tertiary fatty amines is substituted by a fatty hydrocarbon chain.

3. The wellbore fluid of claim 2 , wherein the amine emulsifier includes an electrophilic group in the fatty hydrocarbon chain.

4. The wellbore fluid of claim 1 , wherein, the amine emulsifier has a hydrophilic-lipophilic-balance (HLB) value between about 3 and 6.

5. The wellbore fluid of claim 1 , wherein the amount of oleaginous liquid is from about 30% to about 95% by volume of the wellbore fluid.

6. The wellbore fluid of claim 1 , wherein the amount of non-oleaginous liquid is from about 1% to about 70% by volume of the wellbore fluid.

7. The wellbore fluid of claim 1 , wherein the wellbore fluid has a density of about 9 to 21 pounds per gallon.

8. The wellbore fluid of claim 1 , further comprising:
at least one selected from the group of wetting agents, organophilic clays, viscosifiers, weighting agents, bridging agents and fluid loss control agents.

9. A method of completing a wellbore operation, the method comprising:
injecting the wellbore fluid of claim 1 downhole.

10. The method of claim 9 , further comprising:
injecting a wash fluid comprising a protonating agent downhole.

11. The method of claim 10 , wherein the protonating agent is at least one mineral acid selected from the group including hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid, and hydrobromic acid.

12. The method of claim 10 , wherein the protonating agent is at least one organic acid or compound that generates acid upon dissolution in water selected from the group including formic acid, citric acid, tartaric acid, acetic acid, propionic acid, glycolic acid, lactic acid, halogenated acetic acids, butyric acid, organosulfonic acids, organophosphoric acids, acetic anhydride, hydrolyzable esters, hydrolyzable organosulfonic acid derivatives, hydrolyzable organophosphoric acid derivatives, phosphorus trihalide, phosphorous oxyhalide, anhydrous metal halides, sulfur dioxide, nitrogen oxides, and carbon dioxide.

13. The method of claim 10 , further comprising:
withdrawing a substantial portion of the wellbore fluid from downhole prior to injecting the wash fluid downhole.

14. The method of claim 9 , wherein at least one tertiary fatty amine of the tertiary fatty amines is substituted by a fatty hydrocarbon chain.

15. The method of claim 14 , wherein the emulsifier includes an electrophilic group in the fatty hydrocarbon chain.

16. A wellbore fluid comprising:
a non-oleaginous liquid;
an oleaginous liquid; and
an amine emulsifier having a molecular weight of about 700 to 7,000 daltons and comprising tertiary fatty amines,

wherein, when a majority of the tertiary fatty amines in the amine emulsifier is in an unprotonated form, the amine emulsifier has a first hydrophilic-lipophilic-balance (HLB) value between about 3 and 6 and, when a majority of the tertiary fatty amines in the amine emulsifier is in a protonated form, the amine emulsifier has a second HLB value of 9 to 20; wherein the amine emulsifier is according to Formula (I):

wherein R 1 and R 2 are independently selected from a linear or branched C 12 to C 22 alkyl group, alkenyl group, alkyl substituted cycloalkyl group, or mixtures thereof; A is independently selected from a monoester group, a diester group, a triester group, an ether group, an amide group, or a CH-substituted by a hydroxyl group; R′ is H, or a C 1 to C 3 alkyl; m is independently 1 or 2; x+y≥2; n is 2 to 12; D is either another [((CH 2 ) m CHR′A) x -(CH 2 ) m CHR′—NR 2 —((CH 2 ) m CHR′A) y ] n H group with the same limitations on A, m, x, y and n as described above, or D is a ((CH 2 ) m CHR′E) z H group, wherein m is independently 1 or 2; R′ is H, or a C 1 to C 3 alkyl; E is NH or O; and z is 1, 2, or 3.

17. A wellbore fluid comprising:
an invert emulsion that is reversible from a water-in-oil emulsion to an oil-in-water emulsion, wherein the invert emulsion comprises:
a non-oleaginous liquid;
an oleaginous liquid; and
an amine emulsifier having a molecular weight of about 700 to 7,000 daltons; wherein the amine emulsifier is according to Formula (I):

wherein R 1 and R 2 are independently selected from a linear or branched C 12 to C 22 alkyl group, alkenyl group, alkyl substituted cycloalkyl group, or mixtures thereof, A is independently selected from a monoester group, a diester group, a triester group, an ether group, an amide group, or a CH-substituted by a hydroxyl group; R′ is H, or a C 1 to C 3 alkyl; m is independently 1 or 2; x+y≥2; n is 2 to 12; D is either another [((CH 2 ) m CHR′A) x -(CH 2 ) m CHR′—NR 2 —((CH 2 ) m CHR′A) y ] n H group with the same limitations on A, m, x, y and n as described above, or D is a ((CH 2 ) m CHR′E) z H group, wherein m is independently 1 or 2; R′ is H, or a C 1 to C 3 alkyl; E is NH or O; and z is 1, 2, or 3.

Assignees

• M I L L C [
• Schlumberger Technology Corp

Inventors

• Chinwangso Pawilai
• Zhang Hui
• Sui Changping
• Pauferro Jr Paulo

Classifications

• C09K8/36 Primary

  Water-in-oil emulsions · CPC title

• C09K8/502

  Oil-based compositions · CPC title