Thermally stable surfactants for oil based drilling fluids

Patent metadata

Field	Value
Publication number	US-10876039-B2
Application number	US-201816055890-A
Country	US
Kind code	B2
Filing date	Aug 6, 2018
Priority date	Aug 15, 2017
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

Embodiments for an oil-based drilling fluid and methods of making the oil-based drilling fluid are provided, in which the oil-based drilling fluid comprising: an oil phase; an aqueous phase; at least one surfactant, in which at least one surfactant comprises a carboxylic acid having 10 or more glycol repeating units; and optionally, at least one emulsifying agent.

First claim

What is claimed is:

1. A oil-based drilling fluid comprising:
an oil phase;
an aqueous phase;
at least one wetting agent, in which at least one wetting agent comprises a polyethylene glycol carboxylic acid surfactant having 10 or more than 10 glycol repeating units; and
optionally, at least one emulsifying agent,

wherein the wetting agent comprises a polyethylene glycol carboxylic acid surfactant according to formula (V):

where:
R 1b is a —H, alkyl, aryl, alkyl substituted aryl, or aryl substituted alkyl; and x is an integer from 21 to 453.

2. The oil-based drilling fluid according to claim 1 , in which x is from 21 to 200.

3. The oil-based drilling fluid according to claim 1 , in which R 1b a linear or branched (C 1 -C 12 )alkyl chosen from methyl, ethyl, 1-methylethyl, propyl, butyl, 1,1-dimethylethyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, duodecyl.

4. The oil-based drilling fluid according to claim 1 , in which R 1b is a radical —CH 2 COOH and the wetting agent comprises a polyethylene glycol carboxylic acid surfactant according to formula (VI):

where x is from 21 to 200.

5. The oil-based drilling fluid according to claim 1 , in which x is between 30 and 40.

6. The oil-based drilling fluid according to claim 1 , comprising based on the total weight of the oil-based drilling fluids from 10% by weight to 20% by weight base oil.

7. The oil-based drilling fluid according to claim 1 , comprising based on the total weight of the oil-based drilling fluids from 0.1% by weight to 2.0% by weight wetting agent.

8. The oil-based drilling fluid according to claim 1 , comprising based on the total weight of the oil-based drilling fluids from 0.05% by weight to 5.0% by weight emulsifier.

9. The oil-based drilling fluid according to claim 1 , further comprising based on the total weight of the oil-based drilling fluids from 0.1% by weight to 2.0% by weight rheology modifier.

10. The oil-based drilling fluid according to claim 9 in which the rheology modifier is magnesium aluminum carbonate.

11. The oil-based drilling fluid according to claim 1 , further comprising based on the total weight of the oil-based drilling fluids from 0.5% by weight to 2.0% by weight fluid-loss control additive.

12. A method for making an oil-based drilling fluid comprising:
mixing a base oil, at least one emulsifier, and at least one wetting agent to form a first mixture, the wetting agent comprises a polyethylene glycol carboxylic acid surfactant having 10 or more than 10 glycol repeating units to form a base oil mixture,
wherein the wetting agent comprises a polyethylene glycol carboxylic acid surfactant according to formula (V):

where:
R 1b is a —H, alkyl, aryl, alkyl substituted aryl, or aryl substituted alkyl; and x is an integer from 21 to 453;

optionally, mixing at least one rheology modifier, a viscosifier, and an alkalinity control agent into the base oil mixture
optionally, mixing at least one fluid-loss control additive into the base oil mixture;
mixing a brine solution into the base oil to form a second mixture; and
mixing a weighting additive into the second mixture to form the high pressure high temperature oil-base drilling fluid.

13. The method of claim 12 , in which x is from 21 to 200.

14. The method according to claim 12 , in which R 1b is a linear or branched (C 1 -C 12 )alkyl chosen from methyl, ethyl, 1-methylethyl, propyl, butyl, 1,1-dimethylethyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl.

15. The method according to claim 12 , in which R 1b is a radical —CH 2 COOH and the wetting agent comprises a polyethylene glycol carboxylic acid surfactant according to formula (VI):

where x is defined in formula (V).

16. The method according to claim 12 , in which x is between 30 and 40.

17. A method for drilling in a subterranean formation, the method comprising:
providing an oil-based drilling fluid composition; and
introducing the oil-based drilling fluid composition into a wellbore;
wherein the oil-based drilling fluid composition comprises:
an oil phase;
an aqueous phase;
at least one wetting agent, in which at least one wetting agent comprises a polyethylene glycol carboxylic acid surfactant having 10 or more than 10 glycol repeating units; and

optionally, at least one emulsifying agent,

wherein the wetting agent comprises a polyethylene glycol carboxylic acid surfactant according to formula (V):

where:
R 1b is a —H, alkyl, aryl, alkyl substituted aryl, or aryl substituted alkyl; and x is an integer from 21 to 453.

18. The method of claim 17 , where the wellbore comprises a wellbore temperature greater than 300° F. and a wellbore pressure greater than 10,000 psi.

Assignees

• Saudi Arabian Oil Co
• Univ Durham
• M I Drilling Fluids Uk Ltd

Inventors

• Mohammed Musarrat Halima
• Whiting Andrew
• Greenwell Hugh Christopher
• Al Batal Mona
• Hall John Adrian
• Alabedi Gasan Selman
• Hodder Michael Hayward

Classifications

• C09K8/32

  Non-aqueous well-drilling compositions, e.g. oil-based · CPC title

• C09K8/506

  containing organic compounds · CPC title

• C09K8/035 Primary

  Organic additives · CPC title

• C09K8/36 Primary

  Water-in-oil emulsions · CPC title

• C09K8/032

  Inorganic additives · CPC title