Additive for slurry, drilling mud, and cement slurry

Patent metadata

Field	Value
Publication number	US-10563109-B2
Application number	US-201515300649-A
Country	US
Kind code	B2
Filing date	Mar 23, 2015
Priority date	Mar 31, 2014
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

Provided by the present invention is an additive for a slurry being capable of inhibiting viscosity elevation and dehydration at high temperatures at low cost, through use for a slurry for civil engineering and construction (for example, a drilling mud and a drilling cement slurry for use in well drilling. etc.), and the like. A powdery additive for a slurry, the powdery additive containing a vinyl alcohol polymer, which has: a solubility of 25% or less when immersed in hot water at 60° C. for 3 hours; a degree of saponification of at least 99.5 mol %; an average degree of polymerization of at least 1,500 and 4,500 or less; and the amount of 1,2-glycol linkage of 1.8 mol % or less, the powdery additive being capable of passing through a sieve having a nominal mesh opening size of 1.00 mm.

First claim

The invention claimed is:

1. A powdery additive comprising a vinyl alcohol polymer, wherein
the vinyl alcohol polymer has:
a solubility of 25% or less when immersed in hot water at 60° C. for 3 hours; a degree of saponification of at least 99.5 mol %; an average degree of polymerization of 1,500 to 4,500; and an amount of 1,2-glycol linkage of 1.8 mol % or less, and the powdery additive is capable of passing through a sieve having a nominal mesh opening size of 1.00 mm,
wherein the solubility is represented by the following formula:
solubility=(4 g weight of vinyl alcohol polymer powder charged into 100 g of the hot water−weight of undissolved vinyl alcohol polymer powder separated by using a wire mesh having a nominal mesh opening size of 75 micron measured after drying with a heating dryer at 105° C. for 3 hours)/(4 g weight of vinyl alcohol polymer powder charged into 100 g of the hot water), wherein a proportion of an ethylene unit with respect to total structural units in the vinyl alcohol polymer is less than 10 mol %.

2. The powdery additive according to claim 1 , which is suitable as an additive for a slurry for civil engineering and construction.

3. The powdery additive according to claim 2 , is suitable as an additive for a drilling mud.

4. The powdery additive according to claim 1 , which is capable of passing through a sieve having a nominal mesh opening size of 500 um.

5. The powdery additive according to claim 2 , is suitable as an additive for a cement slurry.

6. The powdery additive according to claim 1 , which is capable of passing through a sieve having a nominal mesh opening size of 250 um.

7. A drilling mud comprising the powdery additive according to claim 1 .

8. A method of producing a drilling mud, comprising mixing: the powdery additive according to claim 1 ; water; and a muddy material.

9. A cement slurry comprising the powdery additive according to claim 1 .

10. A method of producing a cement slurry, comprising mixing: the powdery additive according to claim 1 ; a liquid; and a hardening powder.

Assignees

• Kuraray Co

Inventors

• Kumaki Yosuke
• Saito yasutomo

Classifications

• C09K8/5083

  obtained by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C09K8/487

  Fluid loss control additives; Additives for reducing or preventing circulation loss · CPC title

• C04B28/02

  containing hydraulic cements other than calcium sulfates · CPC title

• C04B2111/70

  Grouts, e.g. injection mixtures for cables for prestressed concrete · CPC title

• C04B40/0042

  Powdery mixtures · CPC title