Coalbed Methane Enhancement in Low-Permeability Reservoirs by Hydraulic Fracturing with Coated Ceramsite

The overall fracturing stimulation effect using quartzsand asa proppant is poor, resulting in no breakthrough in the productionof coalbed methane (CBM) wells in the low permeability coal reservoirof Lu'an Mining Area. In this study, the mixed coated ceramsiteof three particle sizes (40-60, 16-40, and 12-20mesh) was selected as a proppant to conduct a hydraulic fracturingfield experiment on CBM wells, located near the three wells fracturedwith quartz sand in the study area. The drainage and production effectsof mixed particle size-coated ceramsite and quartz sand fracturedwells in the area were compared. The results show that the cumulativegas production from the coated ceramsite fractured CBM well was approximately93,004 m(3) in 238 days of gas production, with a maximumdaily gas production of 825 m(3)/d, approximately 3.3 timesthat of the quartz sand fractured wells. After 400 days of gas production,the two types of proppant-fractured CBM wells differed notably, thedaily gas production of the coated ceramsite-fractured well being450-825 m(3)/d and that of the quartz sand-fracturedwells being only 150-250 m(3)/d. In the stable productionstage, the coated ceramsite-fractured well displayed a better gasproduction potential. Therefore, in view of the low permeability ofthe coal reservoir, the use of coated ceramsite to fracture CBM wellscan achieve a more satisfactory production enhancement effect. Theresearch findings can provide a reference for fracturing-induced productionenhancement of low-permeability reservoirs.