二连盆地乌里雅斯太凹陷H区阿尔善油层组储层特征及影响因素

Reservoir Characteristics and Influential Factors of Aershan Reservoir of the Wuliyasitai Depression in H Area,Erlian Basin

为了研究二连盆地乌里雅斯太凹陷H区阿尔善油层组储层特征及影响因素,采用储层岩心观察、铸体薄片、扫描电镜、常规压汞等测试资料,对储层岩石学特征、孔隙特征、物性特征、沉积作用和成岩作用进行了分析,结果表明阿尔善油层组为近源、快速堆积,砂岩类型主要是长石质岩屑砂岩和岩屑质长石砂岩,表现为胶结物含量高、结构成熟度低和成分成熟度低的"一高两低"特点。储层受碎屑粒径、压实程度、碳酸盐含量的影响,主要发育中-细喉道,储集空间以残余粒间孔和粒间溶孔为主,物性分析判断为低孔-低渗储层。研究区最好的储层为扇三角洲前缘水下分流河道砂,其次为远端席状砂和河口坝砂。研究区目的层原始孔渗分布主要受沉积作用控制;成岩作用中胶结作用对储层既有部分破坏作用又有部分改善作用,压实作用主要起破坏作用,溶解作用主要起改善作用。

In order to research the reservoir characteristics and influential factors of Aershan reservoir ofthe Wuliyasitai Depression in H area,this study core,utilizes casting thin sections,scanning electron microscopy analysis of the test data,etc.to determine the reservoir rocks,pore characteristics,physical characteristics,sedimentation and diagenesis of the reservoir.The results show that the sand-bodies of Aershan reservoir consist of feldspathic lit arenite and lithic feldspar with high cement content,low compositional maturity and low maturity structure,which are originated from proximal and rapid accumulation.The reservoir is of ultra-low porosity and permeability reservoir type.Big-middle throats are well developed and the reservoir spaces are dominated by residual intergranular pores and dissolved intergranular pores,and their development are controlled by particle size,compaction,cementation,and content of carbonates.The favorable reservoir is mainly distributed in the sandstones of the subaqueous distributary channel of fan delta front,followed by fine sandstones in sand sheet and estuarine deposit.Diagenesis has an important influence on the reservoir characteristics.The sedimentary action of the study area controls the original pores and seepage distribution of the reservoir.Diagenesis can destroy and improve the reservoir.Compaction mainly destroys the reservoir,while the dissolution is the key factor to improve the quality of reservoir.Cementation has double action to reform the reservoir.