Protected seam bottom plate upward comb-shaped drilled hole gas extraction method

One kind is disclosed in the present invention to protect the drainage layer on the comb base gas drilling method, the protective layer by the base plate directional drilling, the whipstock from the packer bore special mention after drilling, the use of small diameter large angled downhole motor is upwardly and outwardly from the inside construction of the branch borehole is drilled to form a bundle of a comb plate on the protective layer, until the end of all the boring construction, sealing and gas drainage line access conduct gas drainage. A protective layer of gas drainage in mining technology, having "a multi-hole" feature, can be pre-evacuated protective layer before the protective layer of gas extraction to achieve the protective layer of the pressure relief gas drainage in mining after the protective layer, low construction cost, short cycle.