页岩气水平井穿行层位优选

通过多年的勘探开发实践，我国在四川盆地及其周缘上奥陶统五峰组—下志留统龙马溪组实现了页岩气商业开发，认识到页岩气藏具有自生自储、低孔特低渗特征，属于“人工气藏”，其高产是由地质和工程两类因素共同控制。地质因素决定页岩气是否富集，工程因素则是决定页岩气是否高产的重要条件。准确识别“甜点层”，优选确定水平井穿行层位，是页岩气能否获得高产的关键。对涪陵页岩气田焦石坝区块水平井穿行层位优选实例的剖析表明，精细研究是准确优选水平井穿行层位的基础，地质、工程一体化紧密结合是准确优选水平井穿行层位的关键。根据各个地区具体地质条件，将地质、工程结合，优选水平井穿行层位，是页岩气勘探开发最终获得成功的重要保障。

Optimization of target layer selection in shale gas horizontal wells

Through several years of exploration and development practices, China has realized the commercial development of shale gas from the Upper Ordovician Wufeng and Lower Silurian Longmaxi formations in the Sichuan Basin and its periphery. It has been recognized that shale gas reservoirs are self-generating and self-preserving with low porosity and permeability, which can be identified as the “artificial gas reservoir” and its production is mainly controlled by geological and engineering factors. Geological factors determine the shale gas enrichment, and engineering factors play a major role in shale gas yield. The accurate identification of “sweet spots” and the optimization of target layer selection in horizontal wells are so significant that they decide the final production of each shale gas well. A case study of target layer selection in the Jiaoshiba block of Fuling Gas Field shows that detailed research is the basis for identifying the target window, and the integration of geological and engineering technologies is the key to accurately identify the target layers. According to the specific geological conditions in different regions, applying both geological and engineering knowledge to pinpoint the target layer is an important factor for the ultimate success of shale gas exploration and development.