The invention discloses a deep
coal bed gas and heat co-extraction method. The method comprises the steps that 1, a first vertical drilling well is constructed, a heat-preserving casing
pipe is adopted for carrying out gas sealing and heat isolating protection for a well hole; 2, construction of a layering horizontal well is carried out according to the thickness of a
coal bed, the layering numberK is determined according to the
coal bed real thickness M and the gas drainage
radius R, and K is equal to M / 2R; 3, a second vertical drilling well is constructed; 4, circumferential dispersing holes of the horizontal well are constructed, and then first extraction of gas is carried out; 5,
hydraulic fracturing is carried out on all the drilled holes, a three-dimensional fracture mesh is formed,and then second extraction of the gas is carried out; 6, the first vertical drilling well serves as a water injecting well, the second vertical drilling well serves as a steam output well, the wateris injected into the deep coal bed, the principle of
heat transfer is utilized for transferring
geothermal energy into the water steam, and the water steam is extracted and utilized. According to themethod, gas extraction and
geothermal energy exploitation can be carried out for the deep coal bed which is 1500-3000 meters, the geothermal extraction efficiency is improved, energy is saved, emission is reduced, and the geological environment problems of water and soil
pollution,
thermal pollution and the like are prevented.