Use of hexose oxidases to create hydrogen peroxide in aqueous well treatment fluids

摘要

A hydrocarbon-bearing subterranean formation may be treated with an aqueous well treatment fluid which contains a hexose oxidase, such as glucose oxidase, mannose oxidase or galactose oxidase. The aqueous well treatment fluid further may contain a viscosifying polymer and an aldohexose. The aldohexose reacts in-situ with the hexose oxidase and molecular oxygen to produce hydrogen peroxide. The hydrogen peroxide may then act as a breaker.

主权项

1. A method of treating a subterranean formation penetrated by a wellbore which comprises:
(a) pumping into the wellbore an aqueous well treatment fluid comprising (i) a viscosifying agent, a friction reducer or both a viscosifying agent and a friction reducer and (ii) a hexose oxidase and increasing the viscosity of the well treatment fluid in-situ; (b) producing hydrogen peroxide in-situ by reacting an aldohexose and oxygen, in the presence of the hexose oxidase, (c) reducing the viscosity of the well treatment fluid by reacting the hydrogen peroxide with the viscosifying agent, friction reducer or viscosifying agent and friction reducer.