Thinner for oil-based drilling fluids

Patent metadata

Field	Value
Publication number	US-2017145286-A1
Application number	US-201514945697-A
Country	US
Kind code	A1
Filing date	Nov 19, 2015
Priority date	Nov 19, 2015
Publication date	May 25, 2017
Grant date	—

Abstract

A thinner that is a polycondensed fatty acid that is selected from the group consisting of 12-hydroxystearic acid, 12-hydroxyoctadecanoic acid, polyhydroxystearic acid, reaction products with stearic acid, octadecanoate, octadecanoic acid, and homopolymers of stearic acid is able to reduce the viscosity of oil-based drilling fluid, thus allowing for reuse of the oil-based drilling fluid.

First claim

What is claimed is:

1 . A method of decreasing viscosity of an oil-based drilling fluid composition comprising
a) adding a thinner to the oil-based drilling fluid to form an oil-based drilling fluid composition; wherein the thinner is 0.03-0.2% of a polycondensed fatty acid that is selected from the group consisting of 12-hydroxystearic acid, 12-hydroxyoctadecanoic acid, polyhydroxystearic acid, reaction products with stearic acid, octadecanoate, octadecanoic acid, and homopolymers of stearic acid; b) injecting the oil-based drilling fluid composition into a wellbore; and c) retrieving the oil-based drilling fluid composition as it returns to the surface.

2 . The method of claim 1 wherein steps a)-c) are repeated.

3 . The method of claim 1 wherein the temperature of the wellbore is 180 degrees C. or less.

4 . The method of claim 1 wherein the temperature of the wellbore is 130 degrees C. or less.

5 . The method of claim 1 wherein the temperature of the wellbore is 22 degrees C. or above.

6 . The method of claim 1 wherein viscosity of the oil-based drilling fluid composition after addition of the thinner is decreased by up to 75% of the yield point in comparison to viscosity of the oil-based drilling fluid before addition of the thinner.

7 . The method of claim 1 wherein viscosity of the oil-based drilling fluid composition after addition of the thinner is decreased by up to 50% of the yield point in comparison to viscosity of the oil-based drilling fluid before addition of the thinner.

8 . The method of claim 1 wherein the oil-based drilling fluid comprises
50-100% oil;
1-5% viscosifier;
20-70% weighting agent;
5-10% fluid loss additives;
0-5% lime;
0-30% brine; and
0.3-10% emulsifiers.

9 . A oil-based drilling fluid composition comprising 0.03-0.2% of a polycondensed fatty acid that is selected from the group consisting of 12-hydroxystearic acid, 12-hydroxyoctadecanoic acid, polyhydroxystearic acid, reaction products with stearic acid, octadecanoate, octadecanoic acid, and homopolymers of stearic acid;
wherein the oil-based drilling fluid composition comprises a concentration of a polycondensed fatty acid that is selected from the group consisting of 12-hydroxystearic acid, 12-hydroxyoctadecanoic acid, polyhydroxystearic acid, reaction products with stearic acid, octadecanoate, octadecanoic acid, and homopolymers of stearic acid effective to act as a thinner; and wherein the oil-based drilling fluid composition is reusable.

10 . The oil-based drilling fluid composition of claim 9 wherein the temperature of the wellbore is between 130-180 degrees C.

11 . The oil-based drilling fluid composition of claim 9 wherein the temperature of the wellbore is 130 degrees C. or less.

12 . The oil-based drilling fluid composition of claim 9 wherein viscosity of the oil-based drilling fluid composition after addition of the thinner is decreased by up to 75% of the yield point in comparison to viscosity of the oil-based drilling fluid before addition of the thinner.

13 . The oil-based drilling fluid composition of claim 9 wherein viscosity of the oil-based drilling fluid composition after addition of the thinner is decreased by up to 50% of the yield point in comparison to viscosity of the oil-based drilling fluid before addition of the thinner.

14 . The oil-based drilling fluid of claim 9 wherein the oil-based drilling fluid comprises
50-100% oil;
1-5% viscosifier;
20-70% weighting agent;
5-10% fluid loss additives;
0-5% lime;
0-30% brine; and
0.3-10% emulsifiers.

15 . A wellbore comprising an oil-based drilling fluid composition comprising 0.03-0.2% of a polycondensed fatty acid that is selected from the group consisting of 12-hydroxystearic acid, 12-hydroxyoctadecanoic acid, polyhydroxystearic acid, reaction products with stearic acid, octadecanoate, octadecanoic acid, and homopolymers of stearic acid;
wherein the oil-based drilling fluid composition comprises a concentration of a polycondensed fatty acid that is selected from the group consisting of 12-hydroxystearic acid, 12-hydroxyoctadecanoic acid, polyhydroxystearic acid, reaction products with stearic acid, octadecanoate, octadecanoic acid, and homopolymers of stearic acid effective to act as a thinner; and wherein the oil-based drilling fluid composition is reusable.

16 . The wellbore of claim 15 wherein the temperature of the wellbore is 180 degrees C. or less.

17 . The wellbore of claim 15 wherein the temperature of the wellbore is 130 degrees C. or less.

18 . The wellbore of claim 15 wherein viscosity of the oil-based drilling fluid composition after addition of the thinner is decreased by up to 75% of the yield point in comparison to viscosity of the oil-based drilling fluid before addition of the thinner.

19 . The wellbore of claim 15 wherein viscosity of the oil-based drilling fluid composition after addition of the thinner is decreased by up to 50% of the yield point in comparison to viscosity of the oil-based drilling fluid before addition of the thinner.

20 . The wellbore of claim 15 wherein the oil-based drilling fluid comprises
50-100% oil;
1-5% viscosifier;
20-70% weighting agent;
5-10% fluid loss additives;
0-5% lime;
0-30% brine; and
0.3-10% emulsifiers.

Assignees

• Cnpc Usa Corp

Inventors

• Zhou Chun
• Liu Fuchen
• Hoxha Burhan

Classifications

• C09K8/32 Primary

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

• E21B21/062

  by mixing components · CPC title

• C09K2208/28

  Friction or drag reducing additives · CPC title

• C09K8/035 Primary

  Organic additives · CPC title

• C09K8/36

  Water-in-oil emulsions · CPC title