Fracturing fluid having a delayed enzyme breaker

摘要

The invention is directed toward a breaker system for breaking fluids used to fracture subterranean formations. Specifically, the invention relates to a breaker system comprised of an enzyme component and a pH component. The enzyme component is active at only certain pH levels and, at those levels, is able to break the fluid. The fluid is not initially at a pH level at which the enzyme is active. The pH component controllably adjusts the pH of the fluid to a level such that the enzyme becomes active and can break the fluid at the desired time after the formation has been fractured.