Distributed structure of horizontal section of multi-branch horizontal coal bed methane well

Abstract

The invention provides a distributed structure of a horizontal section of a multi-branch horizontal coal bed methane well, which comprises a main borehole, and branch boreholes connected to the main borehole. The main borehole comprises a first main borehole and at least one second main borehole; the second main borehole is a branch of the first main borehole; and in the first main borehole and the at least one second main borehole, the outer sides of two branch main boreholes positioned on the outermost parts are respectively provided with a group of branch boreholes. In the distributed structure of the horizontal section of the multi-branch horizontal coal bed methane well, by increasing the number of the main boreholes, the branch boreholes originally connected to the two sides of the same main borehole are distributed to the two sides of the two main boreholes, the pressure of the main boreholes serving as drainage and pressure release channels is reduced, and the footage of the main boreholes per se is fully utilized. Meanwhile, the risk that the main boreholes are damaged, complicated or blocked is dispersed. The footage of the tail end of the horizontal section of the horizontal well is relatively reduced, and the probability that the footage of the tail end of the horizontal section of the horizontal well is actually invalid when the main boreholes are declined due to terrain declination is reduced.

Description

technical field [0001] The invention relates to the field of coal-bed methane exploitation, in particular to a distribution structure of horizontal sections of multi-branched horizontal wells of coal-bed methane. Background technique [0002] Coalbed methane is unconventional natural gas that is self-generated and self-storage in coal seams, mainly containing 90% CH4. Under the situation of tightening international energy situation, coalbed methane, as a high-quality, efficient and clean energy, has very broad development prospects. Coalbed methane can be used as fuel for power generation, industrial fuel and residential fuel, and can also be used as automobile fuel after liquefaction. It can also be widely used in the production of synthetic ammonia, formaldehyde, methanol, carbon black, etc. [0003] The mining area and mining effect of coalbed methane are directly related to the arrangement structure of horizontal wells and horizontal sections in the coal seam. The larg...

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Problems solved by technology

[0009] The purpose of the present invention is to provide an arrangement structure of horizontal sections of multi-branched horizontal wells of coalbed methane to solve the unreasonable and too tight distribution of existing horizontal wellbores in coal seams. Once the main wellbore is partially blocked, it will lead to The complexity of the drilling construction stage and the risk of pipe sticking accidents. In the production stage, the footage after the blockage section is invalid due to blockage, and the productivity of the well drops sharply.

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