Coal-bed gas thermal cavity completion method

Abstract

The invention belongs to the field of coal-bed gas exploration and development, and in particular relates to a coal-bed gas thermal cavity completion method, which comprises the following steps of: (1) performing high temperature resistant cement casing cementation on the top of a coal bed; (2) drilling to a position 50 to 80 meters lower than the coal bed, and performing hole enlargement completion on a coal bed section; (3) removing coal dust from a shaft; (4) descending a thermal completion combination stem to the middle of a cavity; (5) injecting silane and oxygen, beginning combusting on the cavity part, and heating the coal bed; (6) when the temperature is higher than 600DEG C, determining whether to stop supplying the silane according to a component detection result of flow-back gas; and (7) when the temperature is raised to 1,500DEG C, stopping supplying the oxygen. By the method, the cavity completion is performed under the thermal condition, the coal bed around the shaft is stable and difficult to collapse, the ignition is simple and easy to control, and the method can be used for blind hole type underground coal gasification.

Description

technical field [0001] The invention belongs to the field of exploration and development of coalbed methane, and in particular relates to a coalbed methane cave thermal well completion method. Background technique [0002] Cavern completion is a major CBM completion technology. PetroChina, China United Coal and BP have tested it in the Shenbei area and BP in Turpan. The initial effect is good. However, during the drainage period, the exposed coal seam is prone to collapse, which leads to sand dredging in the wellbore. High operating frequency and even wellbore damage. Contents of the invention [0003] The present invention aims to overcome the deficiencies of the prior art and provide a kind of coalbed methane that can be used for blind-hole underground coal gasification when the cave is completed under thermal conditions. Cave thermal well completion method. [0004] To achieve the above object, the present invention is achieved in that: [0005] The coalbed methane c...

AI Technical Summary

Problems solved by technology

[0002] Cavern completion is a major CBM completion technology. PetroChina, China United Coal and BP have tested it in the Shenbei area and BP in Turpan. The initial effect is good. However, during the drainage period, the exposed coal seam is prone to collapse, which leads to sand dredging in the wellbore. High operating frequency and even wellbore damage

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