Electric pulse coal rock fracturing and permeation enhancing experimental system and experimental method under air environment

Abstract

The invention discloses an electric pulse coal rock fracturing and permeation enhancing experimental system under an air environment. The system comprises an electric hoist, an electric pulse generation device, a sample fixing bracket, a steel tank, a power control cabinet and two groups of shock wave pressure test devices, wherein the steel tank is of a cylindrical structure provided with an opening in the top; the bottom of the left side of the steel tank is connected with the ground through a ground wire. The experimental device aims to develop visual and dynamic monitoring for a crack extension and evolution process under the action of an electric pulse, and the visual and continuous monitoring process cannot be implemented under the condition of confining pressure, which is also the reason and objective to set the experimental device under the air environment condition. An extension direction and an extension mode of a crack and an evolution law of the length, the width and the density of the crack are analyzed by comparing features of the crack of a coal sample under different impact numbers of times; a fractal theory is used for quantitatively researching a crack extension and evolution process; finally, in combination with related theories of fracture mechanics and damage mechanics, the extension and evolution law of the crack of coal rock under the action of the electric pulse can be disclosed.

Description

technical field [0001] The invention belongs to the technical field of coal bed methane development, and in particular relates to an experimental system and an experimental method for electric pulse coal-rock fracturing and seepage enhancement in an air environment. Background technique [0002] At present, the low average single well production of coalbed methane has become the main bottleneck restricting the development of my country's coalbed methane industry. In addition to the impact and influence of shale gas development heat in recent years, the development of coalbed methane has a tendency to be marginalized, and it is imminent to increase the single well production of coalbed methane . Existing hydraulic fracturing-based coalbed methane stimulation technologies have many problems such as water sensitivity, reservoir pollution, and excessive coal output, and the effect of coal seam permeability modification is often not significant enough. Therefore, it is necessary t...

AI Technical Summary

Problems solved by technology

[0004] Although some knowledge about the mechanism of electric pulse permeation enhancement has been obtained in the early stage of engineering exploration, which roughly includes three aspects: fracture creation, plugging removal and desorption promotion, these understandings are generally superficial, and the deeper and more detailed mechanism of electric pulse permeation enhancement The cognition needs to be further explored, especially the expansion and evolution law of coal and rock fractures under the action of electric pulse is very little known, but there is no experimental device that can be directly used or referenced to conduct in-depth research on the expansion and evolution law of coal and rock cracks under the action of electric pulse , resulting in a lack of theoretical guidance for the field application of electric pulse permeation enhancement technology, which to a certain extent restricts the deepening of research and development, effect improvement and popularization and application of this technology

Images