Method for cooperatively and progressively extracting gas from top and bottom of extra-thick coal seam well

• Main Authors: ZHAO WENHUA, LIU JUN, JIA LIGANG, LIN FUJIN, LI DAYONG, HE YUNWEN, LIU BO, RAN QINGLEI, FENG NING, HUANG GUANGLI, WANG ZHEN, MA ZHIYONG, LI ZHIHENG, MA PINGHAI, MA WANGLONG
• Format: Patent
• Language: Chinese; English
• Published: 18.08.2023
• 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 belongs to the technical field of coal mine gas extraction. The coal mine coal face area gas advanced extraction method comprises the steps of S1, advanced pre-extraction of a ground well hydraulic fracturing area, S2, intensified extraction of an underground directional drilling segmented hydraulic fracturing area, and S3, bottom plate crossing drilling supplementary extraction. According to the method, the coal seam hydraulic fracturing permeability increasing technology serves as a basic means, and the problems that the original gas content of the extra-thick coal seam is high, the coal seam permeability is low, and the gas extraction standard reaching extraction period is long are effectively solved through three-stage cooperative progressive extraction such as ground well area advanced pre-extraction, underground directional drilling reinforced extraction and bottom plate crossing drilling supplementary extraction; therefore, efficient gas extraction of the extra-thick high-gas coal seam is