HYDRAULIC FRACTURING OF SUBTERRANEAN FORMATIONS

摘要

Methods of hydraulically fracturing subterranean coal seams and formations resulting in improved permeability to stimulate coalbed methane. In one method, the coal seam is fractured using a proppant-containing fracturing fluid in alternating stages with an aqueous base solution configured to etch the fracture faces of the coal and thereby create channels for fluid flow. In another method, the coal seam is fractured using a fracturing fluid without propping agents in alternating stages with an aqueous oxidizing solution that is pumped at a pressure sufficient to maintain the fractures in an open position thereby etching the fracture faces to create channels for fluid flow. In yet another embodiment, the aqueous oxidizing agent solution is pumped into the formation at a pressure sufficient to create fractures therein and simultaneously etch the faces of the open fractures to thereby form channels in the faces for increased fluid flow.