Design of High Level Directional Long Borehole Extraction in High Gas Spontaneous Combustion Coal Seams and Its Impact on Coal Spontaneous Combustion
There is a contradiction between gas control and coal spontaneous combustion prevention in goaf of high gas spontaneous combustion coal seam.Directional long drilling has a significant effect on improving gas extraction efficiency in goaf and preventing excessive gas in the upper corner of the working face.However,its impact on coal spontaneous combustion cannot be ignored.This article studies the development law of overlying rock fractures in high gas spontaneous combustion coal seams,and proposes a reasonable directional long borehole layout plan.The analysis data of single borehole flow rate and single borehole gas composition show that directional long boreholes maintain a low oxygen volume fraction in the gas extraction hole while efficiently extracting gas from the fracture zone.The volume fraction of carbon monoxide in the extraction hole is relatively stable and controllable,ensuring that the remaining coal in the goaf is always in a slow oxidation state and ensuring safe recovery.
High gasSpontaneous combustionGoafDirectional long drillingGas
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