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

A technology of coalbed methane and foam, which is applied in the field of underground self-generated CO2 foam huff and puff mining of coalbed methane, can solve the problems of smaller effective seepage pores, lower coal seam permeability, matrix expansion effect, etc., to achieve easy control of dosage and time, and convenient Relocation and transportation, the effect of improving permeability

CN105971573AActive Publication Date: 2016-09-28CHINA UNIV OF PETROLEUM (EAST CHINA)
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2016-09-28

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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.
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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...

Examples

Embodiment Construction

[0013] Such as figure 1 As shown, in the prior art, the coalbed methane well generally adopts the two-hole structure scheme, from the outside to the inside, followed by the well wall, the cement sheath between the surface casing and the well wall, the surface casing, the production casing and the well wall. Cementing cement sheath between well walls, production casing 1, annular space between production casing 1 and oil pipe and pump hanging tool 2, as well as oil pipe and pump hanging tool 2; the surface system of coalbed methane well includes: big four-way 3, Wellhead gas tree 4, gas-water separator 5, gathering and transportation device 6, water storage device 7 and related pipeline joints, data acquisition and control instrument tools.

[0014] The outlets on both sides of the large cross 3 are respectively externally connected to the casing pressure gauge 8 and the casing throttle valve 9, and the casing pressure gauge 8 is used to monitor the pressure change of the annul...