Apparatus and method for in-situ permeability enhancement of reservoir rock

Abstract

A method of in-situ rock permeability enhancement involves penetration of a target formation by a well, downhole injection of a fluid, action on the fluid by static pressure and shock waves of a specific pattern transmitted downhole along a fluid waveguide and directed to the target formation from a wave reflector, thereby generating dilatant decompaction of the rock. The action on the fluid by static pressure and by shock waves occurs simultaneously, so that static pressure exceeds the capillary pressure in pores of the most common size in the decompacting rock by no less than 1.3 times. The selected shock wave amplitude is equal to or greater than the compressive or tensile stress necessary for dilatant decompaction of the rock. The proposed technical solution will make it possible to improve the efficiency of the in-situ permeability enhancement and rock decompaction process while reducing energy consumption and operating costs.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to mining activity and may be used to recover subsoil resources through conventional or purpose-drilled wells.[0002]An essential factor in the extraction of subsoil resources is rock permeability, which determines the effectiveness of the technology employed. Depending on rock type, the process of permeability enhancement directly affects productivity, energy consumption and equipment wear. Various permeability enhancement methods are currently available.[0003]One documented method of rock permeability enhancement (USSR Certificate of Authorship No. 1030540 IPC3, 1980) is based on focusing directed wave energy on rocks at their depths of occurrence and involves penetration of the target formation by a well, downhole injection of fluid, and in-situ application of pulse-pattern wavefield energy emitted from a downhole transmission source. Rocks are impacted by emitted pulses with periodic waveforms and an asymmetrical dist...

AI Technical Summary

Benefits of technology

The invention presents a method to improve the permeability of a certain area without increasing energy consumption or operating costs. This method minimizes the loss of wave energy, making it more effective.

Problems solved by technology

Depending on rock type, the process of permeability enhancement directly affects productivity, energy consumption and equipment wear.

A drawback of this method is that the efficiency of the process is low, since losses of the energy transmitted to the target formation are substantial, resulting in a failure to generate adequate rock permeability.

A deficiency of this method is that while energy intensive, it yields inadequate permeability enhancement owing to the lack of alignment between static pressure in the fluid and pore pressure in the rock coupled with significant losses of wave energy transmitted to the formation.

The disadvantage of the known device is that it does not provide sufficient rock permeability and also has high energy consumption and short operational life due to high vibration of the wave generator.

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