Fracturing fluid viscosity-controlling agent to be used in hydraulic fracturing

Patent metadata

Field	Value
Publication number	US-2016115374-A1
Application number	US-201414897340-A
Country	US
Kind code	A1
Filing date	Jun 9, 2014
Priority date	Jun 10, 2013
Publication date	Apr 28, 2016
Grant date	—

Abstract

A fracturing fluid viscosity-controlling agent is described. The fracturing fluid viscosity-controlling agent is capable of maintaining the high viscosity of the fracturing fluid during fracture formation in hydraulic fracturing and of reducing the viscosity during recovery of the fracturing fluid. A fracturing fluid which includes the viscosity-controlling agent is provided as well as a crude oil or natural gas drilling method using the fracturing fluid with the viscosity-controlling agent. This viscosity-controlling agent contains polyalkylene oxide and a viscosity-reducing agent and is in the form of a tablet.

First claim

1 . A viscosity controlling agent for controlling a change in viscosity of a fracturing fluid to be used in hydraulic fracturing,
wherein the viscosity controlling agent comprises a polyalkylene oxide and a viscosity reducing agent and being in the form of a tablet.

2 . The viscosity controlling agent according to claim 1 , wherein the ratio of the polyalkylene oxide in the viscosity controlling agent is 30 to 99.99% by mass.

3 . The viscosity controlling agent according to claim 1 , wherein the mass of the tablet is 0.2 g or more.

4 . The viscosity controlling agent according to claim 1 , wherein the polyalkylene oxide has a viscosity of 20 to 1,500 mPa·s in the form of a 0.5 mass % aqueous solution at 25° C., or a viscosity of 50 to 80,000 mPa·s in the form of a 5 mass % aqueous solution at 25° C.

5 . The viscosity controlling agent according to claim 1 , wherein the viscosity reducing agent is at least one selected from the group consisting of a radical generator, an acid and an enzyme.

6 . The viscosity controlling agent according to claim 1 , wherein the carbon number of a monomer unit that forms the polyalkylene oxide is 2 to 4.

7 . The viscosity controlling agent according to claim 1 , wherein the polyalkylene oxide contains at least one monomer unit selected from the group consisting of an ethylene oxide unit, a propylene oxide unit and a butylene oxide unit.

8 . The viscosity controlling agent according to claim 1 , wherein the polyalkylene oxide is at least one selected from the group consisting of a polyethylene oxide, a polypropylene oxide, a polybutylene oxide, an ethylene oxide-propylene oxide copolymer, an ethylene oxide-butylene oxide copolymer and a propylene oxide-butylene oxide copolymer.

9 . Use of a tablet containing a polyalkylene oxide and a viscosity reducing agent for controlling a change in viscosity of a fracturing fluid to be used in hydraulic fracturing.

10 . A method for controlling a change in viscosity of a fracturing fluid to be used in hydraulic fracturing, the method comprising adding a tablet comprising a polyalkylene oxide and a viscosity reducing agent to the fracturing fluid.

11 . A fracturing fluid which is used in hydraulic fracturing, the fracturing fluid comprising the viscosity controlling agent according to claim 1 , water, a support material and a gelling agent.

12 . A method for mining crude oil or natural gas, the method comprising the steps of:
forming a mining hole in a stratum; introducing the fracturing fluid according to claim 11 into the mining hole to form a fracture in a part of the stratum; and mining crude oil or natural gas from the mining hole.

Assignees

• Sumitomo Seika Chemicals

Inventors

• Ido Toru
• Yamaguchi Noboru

Classifications

• C09K8/885

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

• C09K8/88

  macromolecular compounds · CPC title

• C09K8/725

  Compositions containing polymers · CPC title

• C09K2208/26

  Gel breakers other than bacteria or enzymes · CPC title

• C09K8/70 Primary

  characterised by their form or by the form of their components, e.g. foams · CPC title