济阳坳陷青东凹陷沙河街组储层特征

Reservoir characteristics of Shahejie Formation in Qingdong Sag,Jiyang Depression

济阳坳陷青东凹陷勘探程度很低,沉积储层等基础地质条件研究显得尤为重要。沙河街组是青东凹陷主要的含油层系。综合岩心、薄片、物性分析等资料,对该区储层特征进行了系统研究。沙河街组储层储集空间以原生粒间孔隙、粒间溶蚀孔和粒内溶孔为主。沙四段主要处于早成岩B期—晚成岩A期,非均质性较强;沙三段主要处于早成岩B期,整体物性表现为高孔、高渗透的特征。沉积微相和成岩作用是研究区储层物性的主要影响因素。溶蚀作用的发生与有机质排烃伴生的有机酸有关,使储层物性得以改善;胶结作用和压实作用使储层孔渗性变差。

The exploration degree of the Qingdong Sag of the Jiyang Depression is very low, so it is necessary to carry out studies of basic geological conditions such as sedimentary reservoir. The Shahejie Formation is the main oil-bearing sequence in the Qingdong Sag. Based on core, thin section and physical property analyses, the reser- voir characteristics in the study area have been systematically researched. Pores in the Shahejie Formation are mainly primary intergranular, intergranular dissolved and intragranular dissolved ones. The 4th member of the Shahejie Formation is from the early diagenesis stage B to the late diagenetic stage A, and has strong heterogenei- ty. The 3rd member of the Shahejie Formation is during the early diagenesis stage B, and has high porosity and high permeability. Sedimentary microfacies and diagenesis are the main influencing factors for reservoir property in the study area. Corrosion happens when organic acid generates as organic matter expulsing, which improving reservoir property. Cementation and compaction make the reservoir porosity and permeability become worse.