A method for forming channels of high vaeskeledningsevne in formation parts around a borehole

摘要

A method for increasing the productivity of wells completed in soft acid-soluble producing formations, comprising the steps of: producing in such formation a fracture containing a viscous fluid; injecting an acid solution wherein the viscosity of the contained fluid is preferably at least 50 times greater than the acid solution into the formation to create acid etched fingering channels; injecting into the formation a fluid with a propping agent the viscosity of which is at least equal to the acid solution until propping agent is deposited in the fracture at least in those areas where channels have been etched; and lowering the pressure within the fracture to allow it to move towards a closed position. By controlling the viscosity ratios of viscous fluid to acid solution and carrying fluid to acid solution long fingering acid etched channels are created and propped such that the channel walls of the soft formation are propped open when the fluid pressure in the fracture is reduced.