Coal seam reconstruction method for coalbed methane horizontal well

Abstract

The invention discloses a coal bed gas horizontal well coal bed transformation method, and belongs to the technical field of coal bed gas mining. The method comprises the steps of drilling a horizontal well; inserting a sieve pipe into a preset position of the coal bed horizontal section, and hanging the sieve pipe in an upper layer casing pipe, sieve holes being formed in the side face of the sieve pipe; performing pressurization and pressure relief on the coal bed horizontal section of the coal bed gas horizontal well; enabling the coal bed around the sieve pipe to generate cracks; forming pressure fluctuation collapse zones and pressure fluctuation extending zones; enabling coal dust or coal ash generated when the coal bed around the sieve pipe forms the pressure fluctuation collapse zones and the pressure fluctuation extending zones to enter the sieve pipe through the sieve holes formed in the side face of the sieve pipe; and performing well flushing by using a water jet flow drilling tool combination, flushing the coal bed around the sieve pipe, and bringing out the coal dust or coal ash in the sieve pipe out of a well head. The method provided by the invention has the advantages that the problem of complicated steps of coal bed gas mining and low coal bed transformation success ratio are solved; the coal bed gas mining steps are simplified; the coal bed transformation effects are improved; and the method is used for coal bed gas mining.

Description

technical field [0001] The invention relates to the technical field of coalbed methane exploitation, in particular to a method for reforming a coalbed methane horizontal well coal seam. Background technique [0002] Coalbed methane is an unconventional natural gas resource. A conventional horizontal well for coalbed methane refers to a directional well in which the inclination angle of the well in the coal reservoir is greater than or equal to 86°, and a certain length of horizontal section is drilled while maintaining this angle. Due to the poor physical properties of the usual coal seams, the use of horizontal wells for coalbed methane mining generally has problems such as low single-well production and poor development effects. Therefore, it is necessary to increase the production of coalbed methane. [0003] In the prior art, in order to increase the output of coalbed methane, hydraulic fracturing technology is mainly used. Specifically, liquid can be injected into the ...

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Problems solved by technology

[0005] In order to solve the problem that the mining steps of coalbed methane are cumbersome and the effect of coalbed transformation is poor, the invention provides a method for coalbed transformation of coalbed methane horizontal wells

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