Formation fracturing technique using liquid proppant carrier followed by foam

摘要

A hydraulic fracturing process includes the step of pumping into the well a fracturing liquid containing a proppant for fracturing the formation and delivering the proppant into the fracture. At or near the end of the fracturing operation, a foam slug is pumped into the well. The pressure in the fracture is reduced and the fracture is closed on the proppant by backflowing the foam slug from the well to the surface.