System and method for automatically generating CO2 foam and exploiting coalbed methane in huff-puff mode underground

Abstract

The invention belongs to the field of oil-gas field development engineering, and particularly relates to a system and method for automatically generating CO2 foam and exploiting coalbed methane in a huff-puff mode underground. The system comprises a water storage device, a prying installation type sewage treatment device, a chemical mixing device, a chemical storage tank, intelligent dosing equipment and a prying installation type water injection device; the water storage device, the prying installation type sewage treatment device, the chemical mixing device, the prying installation type water injection device and an oil nozzle connector of a well mouth gas exploitation tree are sequentially connected through pipelines; the chemical storage tank, the intelligent dosing equipment and a chemical inlet of the chemical mixing device are sequentially connected through chemical supply pipelines. The system is easy and convenient to operate, the method is easy to implement, a gas generating agent solution system, an active water system and a gas releasing agent solution system slug are sequentially injected into a target coalbed by the well mouth gas exploitation tree, an oil pipe and a pump hanging tool through the prying installation type water injection device, a CO2 foam system is automatically generated underground, and the coalbed methane desorption and exploitation speed can be effectively increased.

Description

technical field [0001] The invention belongs to the field of oil and gas field development engineering, and in particular relates to an underground self-generated CO 2 A system and method for mining coalbed methane by foam huff and puff. Background technique [0002] Restricted by the complex coal structure conditions and the ubiquitous "three low" unfavorable factors such as low pressure, ultra-low permeability and low saturation, most coalbed methane production wells in my country currently have low production or even no gas production. Therefore, how to effectively and substantially increase the The recovery rate of coalbed methane wells is the main problem facing the development of coalbed methane in my country at present. At present, the commonly used coalbed methane stimulation technologies mainly include hydraulic fracturing technology, heat injection stimulation technology, and gas injection displacement coalbed methane technology, among which gas injection displacem...

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Problems solved by technology

[0004] The above existing methods have better solved the problem that the gas source required for the gas injection displacement CBM technology is difficult to obtain, and some methods effectively combine the effects of gas injection displacement and heat injection stimulation. In this case, the injected gas is mainly adsorbed and accumulated near the wellbore, and the matrix expansion effect is likely to occur after a large amount of injected gas is adsorbed in the near-wellbore coal seam, resulting in smaller effective seepage pores, reducing the permeability of the coal seam, and making subsequent injection difficult. Low-permeability coal reservoirs are particularly serious

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