Drilling slurry additive

Patent metadata

Field	Value
Publication number	US-2016200958-A1
Application number	US-201414912557-A
Country	US
Kind code	A1
Filing date	Aug 26, 2014
Priority date	Aug 30, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

To provide an additive for drilling mud, used in drilling for petroleum, natural gas, civil engineering, mines, etc., which has high heat resistance and high mechanical shear resistance, of which the viscous property does not degrade even under high-temperature and high-shear conditions; has high pseudoplastic flowability and therefore secures high flowability during discharging; and is a naturally-derived one and is therefore highly biodegradable and has least adverse impact on environment. An additive for drilling mud, which contains cellulose fibers having a number-average fiber diameter of from 2 to 500 nm and a fiber aspect ratio of 50 or more and having a cellulose I-type crystal structure.

First claim

1 . An additive for drilling mud, which comprises cellulose fibers having a number-average fiber diameter of from 2 to 500 nm and a fiber aspect ratio of 50 or more and having a cellulose I-type crystal structure.

2 . The additive for drilling mud according to claim 1 , wherein, in the cellulose fibers, a hydroxyl group on a surface of the cellulose fibers has been chemically modified.

3 . The additive for drilling mud according to claim 2 , wherein the cellulose fibers are cellulose fibers in which a hydroxyl group at C6-position in each glucose unit in their molecules has been selectively modified through oxidation into any of an aldehyde group, a ketone group and a carboxyl group, and a content of the carboxyl group falls within a range of from 1.2 to 2.5 mmol/g.

4 . The additive for drilling mud according to claim 3 , wherein a total content of the aldehyde group and the ketone group in the cellulose fibers is measured as 0.3 mmol/g or less according to a semicarbazide method.

5 . The additive for drilling mud according to claim 3 , wherein the cellulose fibers have been oxidized with a co-oxidizing agent in the presence of an N-oxyl compound and the aldehyde group and the ketone group formed through the oxidation reaction have been reduced with a reducing agent.

6 . The additive for drilling mud according to claim 5 , wherein the reduction with the reducing agent is carried out by sodium borohydride.

7 . A composition for drilling mud, which comprises the additive for drilling mud of claim 1 .

8 . The additive for drilling mud according to claim 4 , wherein the cellulose fibers have been oxidized with a co-oxidizing agent in the presence of an N-oxyl compound and the aldehyde group and the ketone group formed through the oxidation reaction have been reduced with a reducing agent.

9 . The additive for drilling mud according to claim 8 , wherein the reduction with the reducing agent is carried out by sodium borohydride.

10 . A composition for drilling mud, which comprises the additive for drilling mud of claim 2 .

11 . A composition for drilling mud, which comprises the additive for drilling mud of claim 3 .

12 . A composition for drilling mud, which comprises the additive for drilling mud of claim 4 .

13 . A composition for drilling mud, which comprises the additive for drilling mud of claim 5 .

14 . A composition for drilling mud, which comprises the additive for drilling mud of claim 6 .

15 . A composition for drilling mud, which comprises the additive for drilling mud of claim 8 .

16 . A composition for drilling mud, which comprises the additive for drilling mud of claim 9 .

Assignees

• Dai Ichi Kogyo Seiyaku Co Ltd

Inventors

• Goi Yousuke
• Sabi Mineo
• Jinno Kazuhito
• Noda Koji

Classifications

• C09K2208/08

  Fiber-containing well treatment fluids · CPC title

• C09K8/035 Primary

  Organic additives · CPC title