临兴地区下石盒子组致密砂岩储层成岩作用及有利成岩相研究

Diagenesis and Favorable Diageneticfacies Analysis on the Tight Sand Stone Reservoirs of the Lower Shihezi Formation in Linxing Area

根据铸体薄片、扫描电镜、X-射线衍射、高压压汞、物性分析等资料,对临兴地区下石盒子组致密砂岩储层成岩作用和成岩相进行了研究,用定量指标划分了该区成岩相类型,建立了其与测井响应的特征关系。研究区下石盒子组致密砂岩储层主要经历了压实、胶结和溶蚀作用,其中压实作用和胶结作用是该区砂岩致密化的主要原因,溶蚀作用在一定程度上改善了储层物性。成岩相类型可划分为中压实中溶解相、中压实弱溶解相、强压实中溶解相、强压实弱溶解相、中压实强胶结相、强压实强胶结相和极强压实相7种成岩相带。相对优质储集层主要集中在中压实中溶解相和中压实弱溶解相,优质成岩相带主要受沉积环境控制,主要集中在曲流河河道砂体中,在平面上呈带状展布。

Employing experimental methods ofcasting slice,scanning electron microscope,X- raydiffraction, high pressure injection, physical properties and other analytical testing information, thepresent paper comprehensively investigated the diagenesis and diageneticfaciesof the tight sand stonereservoirs of the lower Shihezi formation in LinxingArea,distinguished the types of diageneticfacies withthe aspect of quantitative index , and established the relationship with the logging responsecharacteristics.The tight sandstonereservoir of Lower ShiheziFormation have mainlyexperiencedcompaction, cementation and dissolution.Decrease of sandstone porosity is mainly caused by compactionand cementation.Secondry pores resulted from dissolution improved the property of reservoir to someextent. The reservoir could be divided into seven types of diageneticfacics,including medium compactionwith medium dissolution facics,medium compaction with weak dissolution facics, strong compaction withmedium dissolution facics, strong compaction with weak dissolution facics, medium compaction with strong cementation facics, strong compaction with strong cementation facics and extremely strongcompactionfacics. Relatively high quality reservoir mainly concentrated in the medium compaction withmedium dissolution facics and medium compaction with weak dissolution facics.The quality ofdiageneticfacies are mainly controlled by sedimentary environment. The relatively high qualityformationmainlyconcentrated in the sandbodyof in the meandering river channel,and horizontally, the distributionof relatively high qualityformation mainly shaped in ribbon .