Research on long hole hydraulic drilling with comb shaped directional drilling technology in coal mine

Abstract:

MWD comb directional drilling technology is mainly used in coal mine gas prevention and control, geological anomaly body detection and exploration & release of water and some other fields at present. However, this technology has not been combined with enhanced extraction technology by hydraulic fracturing permeability to apply in the field of coal seam gas prevention and control. Due to the special drilling requirement of enhanced extraction technology by hydraulic fracturing permeability, the breakthroughs should be made in drilling equipment, drilling design and hole completion. The results of this study combine the advantages of gas drainage technology by comb directional drilling and enhanced extraction technology by hydraulic fracturing permeability, a set of equipments and technological processes are formed, which is suitable to segmented hydraulic fracturing comb directional drilling construction, can meet the needs of long distance and regional permeability enhancing for the soft coal seam and solve the problems such as weak permeability of soft coal seam, poor gas extraction hole completion, short extraction distance and small extraction area.