A preferred novel breaker-crosslinker-polymer complex and a method for using the complex in a fracturing fluid to fracture a subterranean formation that surrounds a well bore by pumping the fluid to a desired location within the well bore under sufficient pressure to fracture the surrounding subterranean formation. The complex may be maintained in a substantially non-reactive state by maintaining specific conditions of pH and temperature, until a time at which the fluid is in place in the well bore and the desired fracture is completed. Once the fracture is completed, the specific conditions at which the complex is inactive are no longer maintained. When the conditions change sufficiently, the complex becomes active and the breaker begins to catalyze polymer degradation causing the fracturing fluid to become sufficiently fluid to be pumped from the subterranean formation to the well surface.
A preferred novel breaker-crosslinker-polymer complex and a method for using the complex in a fracturing fluid to fracture a subterranean formation that surrounds a well bore by pumping the fluid to a desired location within the well bore under sufficient pressure to fracture the surrounding subterranean formation. The complex may be maintained in a substantially non-reactive state by maintaining specific conditions of pH and temperature, until a time at which the fluid is in place in the well bore and the desired fracture is completed. Once the fracture is completed, the specific conditions at which the complex is inactive are no longer maintained. When the conditions change sufficiently, the complex becomes active and the breaker begins to catalyze polymer degradation causing the fracturing fluid to become sufficiently fluid to be pumped from the subterranean formation to the well surface.
An encapsulated breaker slurry composition for reducing the viscosity of a fracturing fluid. The slurry has a flashpoint above 93.degree. C., and the liquid of the slurry does not facilitate release of the breaker from the coating. Methods of using the slurry composition are also described.
The present Invention relates to hydrocarbon well stimulation, and more particularly to methods and compositions to remove (or more generally to transfer) fluid introduced into the subsurface. For instance, preferred methods involve creating then exploiting a capillary pressure gradient at the fracture face to induce fluid flow from the fracture into the formation thereby increasing effective fracture length, and then improving fracture conductivity.
The present invention relates to methods of treating subterranean formations and viscosified aqueous well treating compositions which break into thin fluids at temperatures in the range of from about 100.degree. F., to about 300.degree. F. A breaker system is included in the compositions comprised of an alkali metal chlorite or hypochlorite breaker and a breaker activator comprised of copper II ion or an amine, or both.
Methods of treating subterranean zones and viscous aqueous fluids containing xanthan biopolymer gelling agent and a combination crosslinker and delayed breaker are provided. A viscous cross-linked aqueous treating fluid of the invention comprises water, a xanthan polymer gelling agent, and a combination cross-linker and delayed breaker for said xanthan biopolymer gelling agent.
