Analysis of coalbed methane reservoir characteristics and reconstruction process in Shuicheng Mining Area
BI Caiqin;CHI Huanpeng;SHAN Yansheng;WANG Fuguo;XU Yinbo;ZHANG Jiaqiang;LI Zhao;Oil and Gas Survey,China Geological Survey;China Coal Geology Engineering Corporation;
In order to promote the coalbed methane development of Shuicheng Mining Area in Liupanshui Coalfield,coal reservoir characteristics and geological conditions were analyzed based on materials of three coalbed methane wells. Coal reservoir reconstruction and multi-layer drainage process match with thin and medium thickness coal seams condition were developed from engineering practices.The results showed that No.5-2,7 and 13-2coals of Longtan Formation were main coalbed methane development layers with characteristics of large single layer thickness,stable distribution,complete coal structure,high gas content and high resource abundance. Under normal-overpressure reservoir pressure,these coal seams which have high gas saturation and good permeability are suitable for coalbed methane development after reservoir reconstruction. Coal reservoir reconstruction effect can be improved by using active water and finemedium grain quartz sand as fracturing fluid and proppant for layered perforation process,using light casing pump injection combined with drillable bridge plug as sealing method,using large flow rate,stepwise sand add,multi-stage slug duringmulti-layer hydraulic fracturing processes.