Thinner for oil-based drilling fluids

Patent metadata

Field	Value
Publication number	US-2017145281-A1
Application number	US-201615061175-A
Country	US
Kind code	A1
Filing date	Mar 4, 2016
Priority date	Nov 19, 2015
Publication date	May 25, 2017
Grant date	—

Abstract

A thinner that is a poly fatty amide reacted with maleic acid to form a product, and diluting the product with a compound selected from the group consisting of oleyl alcohol, fatty acid, and poly condensed fatty 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 produced by reacting a poly fatty amide with maleic acid to form a product, and diluting the product with a compound selected from the group consisting of oleyl alcohol, fatty acid, and poly condensed fatty 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 the oil-based drilling fluid composition is reusable after being retrieved from the wellbore.

3 . The method of claim 1 wherein the thinner is present in a range of 0.03 -1.6%.

4 . The method of claim 1 wherein the poly fatty amide is made from fatty acid or oil reacted with polyamines at a temperature range of 100-200° C.

5 . The method of claim 1 wherein the poly fatty amide is reacted with maleic acid at a temperature range of between about 80-150° C.

6 . The method of claim 1 wherein the oleyl alcohol, fatty acid, and poly condensed fatty acid are in the range of about 40% to 100%.

7 . The method of claim 1 wherein the temperature of the wellbore is between about 220-250° C.

8 . 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.

9 . The method of claim 1 wherein the oil-based drilling fluid composition has a density as high as 2.8 specific gravity.

10 . A oil-based drilling fluid composition comprising a thinner; wherein the thinner is produced by reacting a poly fatty amide with maleic acid, and diluting with a compound selected from the group consisting of oleyl alcohol, fatty acid, and poly condensed fatty acid; wherein the thinner is present at a concentration effective to decrease by up to 25% of the yield point in comparison to the viscosity of the oil-based drilling fluid before addition of the thinner; and
wherein the oil-based drilling fluid composition is reusable after being retrieved from a wellbore.

11 . The oil-based drilling fluid composition of claim 10 wherein the thinner is present in a range of 0.03 -1.6%.

12 . The oil-based drilling fluid composition of claim 10 wherein the poly fatty amide is made from fatty acid or oil reacted with polyamines at a temperature range of 100-200° C.

13 . The oil-based drilling fluid composition of claim 10 wherein the poly fatty amide is reacted with maleic acid at a temperature range of between about 80-150° C.

14 . The oil-based drilling fluid composition of claim 10 wherein the oleyl alcohol, fatty acid, and poly condensed fatty acid are in the range of about 40% to 100%.

15 . The oil-based drilling fluid composition of claim 10 wherein the temperature of the wellbore is between about 220-250° C.

16 . The oil-based drilling fluid composition of claim 10 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.

17 . The oil-based drilling fluid composition of claim 10 wherein the oil-based drilling fluid composition has a density as high as 2.8 specific gravity.

18 . A wellbore comprising an oil-based drilling fluid composition comprising a thinner produced by reacting a poly fatty amide with maleic acid, and diluting with a compound selected from the group consisting of oleyl alcohol, fatty acid, and poly condensed fatty acid;
wherein the thinner is present at a concentration effective to decrease by up to 25% of the yield point in comparison to the viscosity of the oil-based drilling fluid before addition of the thinner; and wherein the oil-based drilling fluid composition is reusable after being retrieved from a wellbore.

19 . The wellbore of claim 18 wherein the temperature of the wellbore is between about 220-250° C.

20 . The wellbore of claim 18 wherein the oil-based drilling fluid composition has a density as high as 2.8 specific gravity.

Assignees

• Cnpc Usa Corp

Inventors

• Zhou Chun
• Li Jiancheng
• Hoxha Burhan
• Yu Stephanie

Classifications

• C09K8/035 Primary

  Organic additives · CPC title

• E21B7/00

  Special methods or apparatus for drilling · CPC title

• E21B21/065

  Separating solids from drilling fluids · CPC title

• C09K8/32 Primary

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

• C09K8/34

  Organic liquids · CPC title