四川盆地中西部须家河组储层特征与主控因素

Characteristics and major controlling factors of reservoirs in the Xujiahe Formation of the central and western Sichuan Basin

冯明石 刘家铎 孟万斌 王峻 张翔 冯艳红

Feng Mingshi Liu Jiaduo Meng Wanbin Wang Jun Zhang Xiang Feng Yanhong

运用铸体薄片镜下观察、物性分析、扫描电镜及X-衍射等分析手段,对四川盆地中西部须家河组的储层特征、沉积作用和成岩作用进行了研究。结果表明,研究区须家河组储层孔隙类型以残余原生粒间孔和粒内溶孔为主,平均孔隙度为5.83%,平均渗透率为0.283×10μm,为低孔-低渗型储层;控制储层发育的主要因素是沉积作用和成岩作用。三角洲前缘河口坝和水下分流河道沉积微相是储层发育的有利相带。压实作用是导致储层孔隙损失的主要因素,溶蚀作用是对储层发育贡献最大的建设性成岩作用,早期绿泥石环边胶结作用有利于保护剩余原生粒间孔隙。

In this paper,reservoir characteristics,sedimentation and diagenesis of the Xujiahe Formation in the central and western parts of the Sichuan Basin are studied through microscopy observation of cast thin sections,analysis of physical properties,scanning electron microscope and X-diffraction.The results show that pores in the Xujiahe Formation of the study area are mainly residual primary intergranular pores and intragranular dissolution pores.With an average porosity of 5.83% and average permeability of 0.283×10μm,the reservoirs are classified as low-porosity and low-permeability reservoirs.Sedimentation and diagenesis are the main factors controlling the development of reservoirs.Favorable facies belts for the development of reservoirs are river mouth bar and underwater distributary channel microfacies in the delta front.Compaction is the main influencing factor which led to the loss of porosity in the reservoirs.Early rim cementation of chlorites helped to protect the residual primary intergranular pores,and dissolution contributed the most to the development of reservoirs.

10.11743/ogg20090607