Three-dimensional gas extraction method by combining directional long drill holes with floor crossing drill holes

• Main Authors: TANG JUN, SHEN RUNSHENG, ZHANG GEQIANG, WEI MINTAO, LU ZHIJIE, GAO XIANGYANG, GAO YUAN, QIN BOTAO, CHENG ZIHUA, LI DONGFENG, ZHOU YOU, CHEN CHENGYU, CHEN HONGTAO
• Format: Patent
• Language: Chinese; English
• Published: 13.07.2021
• Subjects: EARTH DRILLING; EARTH DRILLING, e.g. DEEP DRILLING; FIXED CONSTRUCTIONS; MINING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR ASLURRY OF MINERALS FROM WELLS; SAFETY DEVICES, TRANSPORT, FILLING-UP, RESCUE, VENTILATION, ORDRAINING IN OR OF MINES OR TUNNELS

The invention discloses a three-dimensional gas extraction method by combining directional long drill holes with floor crossing drill holes. The three-dimensional gas extraction method comprises the following steps that directional crossing main drill holes are formed to a coal seam roof and floor through a coal seam floor rock roadway; crossing branch drill holes are formed at intervals of 20-30m, and hydraulic punching operation is carried out on each branch hole under the punching pressure of not less than 10MPa; and after all drilling construction and punching procedures are completed, a drainage pipe is connected to perform coal seam gas pre-drainage before mining, mining pressure relief gas extraction during working face tunneling and stoping and old goaf gas extraction after mining, and the whole process is served. According to the three-dimensional gas extraction method by combining the directional long drill holes with the floor crossing drill holes, coal seam top and bottom plate crossing directiona