摘要
压裂改造甜点的准确识别是页岩气储层水力压裂实现经济产能的关键之一.以四川盆地奥陶系五峰组—志留系龙马溪组一段页岩为研究对象,考虑储层成层性、脆性矿物和天然弱面发育特征等压裂改造关键影响因素,引入综合脆性指数、储层层理与裂缝指数和缝网扩展指数,整合为缝网压裂甜点指数,建立四川盆地龙马溪组页岩气缝网压裂改造甜点识别方法.研究表明:储层层理与裂缝指数介于0.5~0.6之间,综合脆性指数介于0.55~0.6之间,缝网扩展指数大于0.6,缝网压裂甜点指数大于0.55的储层,层理发育明显、基质碳酸盐矿物较多、天然裂缝发育适度且充填程度高的页岩可获得较好压裂改造效果,最具改造潜力,能有效改造储层实现缝网压裂,是体积压裂改造的甜点.研究成果与矿场微地震监测和产气剖面解释结果较为一致,对储层压裂改造的选层选段和压裂方案设计具有理论支撑和现场指导意义.
The key to obtain economic productivity on shale gas reservoir stimulation is to identify the fracturing sweet spots.Considered some factors on stimulation such as layered property,brittle minerals contents and natural weak plane feature which are in Wufeng Formation to Longmaxi Formation in Sichuan Basin,layered index,brittleness index and fracture network probability index had been proposed to establish the network-fracturing sweet spot index and a method to identify fracturing sweet spot based on shale facies.It was concluded that shale reservoir,with layered index between 0.5 and 0.6,brittleness index between 0.55 and 0.6,fracture network probability index between 0.6 and 1.0,network-fracturing sweet spot index between 0.55 and 1.0,as the fracturing sweet spot,has preponderant stimulation potential and efficient network-fracturing due to visible layered property,and high proportion of carbonate.Moderate development of packed fractures could obtain better stimulation.The conclusions agree with the result of microseismic monitoring and production profile.The method could be a theoretical foundation and live guidance for providing strategy and design scheme for fracturing.
作者
沈骋
赵金洲
任岚
范宇
Shen Cheng;Zhao Jin-Zhou;Ren Lan;Fan Yu(Shale Gas Research Institute iPetroChiiia Southwest Oil & Gas Field Compuny Chengdu 610051,China;State Key Laboratory of Oil and Gas Reservoir Geology and Ex ploration,Southwest Petroleum University,Chengdu 610500,china)
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2019年第7期937-945,共9页
Natural Gas Geoscience
基金
国家自然科学基金项目“页岩地层动态随机裂缝控制机理与无水压裂理论”(编号:51490653)资助
