川中蓬莱地区须家河组须二段储层成岩相与优质储集层预测

Diagenetic Facies and Prediction of High Quality Reservoir of Member 2 of Xujiahe Formation in Penglai Area,Central Sichuan Basin

通过岩心观察并综合利用普通薄片、铸体薄片和扫描电镜分析等资料,对须二段储层岩石学特征、物性及孔隙结构特征、成岩作用、成岩矿物、成岩环境、所处成岩阶段和成岩演化序列等进行了研究。结果表明,须二段储层经历压实压溶、胶结、溶蚀和破裂等成岩作用,现今处于中成岩A期。根据成岩作用类型和强度、成岩矿物及其对储层物性的影响划分出3种成岩相:强压实自生矿物胶结相、强压实不稳定组分溶蚀相和破碎裂缝相。选取了对成岩相较敏感的声波时差、电阻率、自然伽马、密度和中子5条常规测井曲线和成像测井资料,通过岩心资料刻度测井建立了各成岩相的测井识别标准,将成岩相进行剖面展开和平面成图。再根据有利成岩相的平面展布规律,对蓬莱地区须二段优质储层发育带进行了预测,认为平面上的斜坡中部为主要的优质储集层发育区。

In order to find out distribution zones of high-quality reservoirs in Penglai area,based normal thin sections,casting thin sections,scanning electron microscope analysis data and core data,the reservoirs have been worked on lithological characteristics,reservoir property and pore structure,diagenesis,diagenetic minerals,diagenetic environment,diagenetic stage and diagenetic evolution sequence in Member 2of Xujiahe Formation.The results show that the reservoirs have experienced diagenesis such as compaction,cementation,corrosion,and fracture,it is now in the stage A of middle diagenetic stage.Three types of diagenetic facies are divided based on diagenesis,diagenetic minerals and their effect on the reservoir quality,these facies include high compaction-authentic minerals cementation facies,high compaction-corrosion of unstable components facies,and tectonic fracture facies.According to various well logging response characteristics,five normal logging curves and imaging logging data which are sensitive to the diagenetic facies are chosen to characterize diagenetic facies,which include compensated neutron logging（CNL）,density logging（DEN）,acoustic slowness（AC）,natural gamma ray（GR）,resistivity log（Rt）and EMI,different types of diagenetic facies has various response characteristics on various logging curve and their combination,and the vertical and plane distribution of diagenetic facies can be figured out with well logging data.The favorable diagenetic facies are used to optimize favorable regions of oil and gas bearing zones.The high quality reservoir distributed in the middle part of the slope on the plane surface.