五号桩—长堤地区沙河街组砂体储集性及控制因素研究

沙河街组是沾化凹陷东部五号桩-长堤地区重要的储油层系，主要目的层段为沙三段和沙二段。沙三段和沙二段主要发育有浊积扇、水下冲积扇和滩坝沉积体系，在浊积扇、水下冲积扇中发育辫状水道、扇中前缘、辫状水道间以及扇根、扇缘等沉积微相类型，其中辫状水道、扇中前缘砂体物性好，原生孔隙及次生孔隙均较发育，辫状水道间以及扇根砂体物性较差。其储集特征主要受岩性、沉积微相、成岩作用等因素控制，结合该地区实际情况，将沙二段、沙三段储集层划分为好、中、差3种类型。图4表1参7

Reservoir and controlling factors of sandbodies of the Shahejie Formation in Wuhaozhuang-Changdi Region

The sandbodies of the Shahejie Formation are one of the most important oil bearing systems in Wuhaozhuang Changdi Region in the eastern part of Zhanhua Sag. The Sha 3 and the Sha 2 members of the Shahejie Formation are the main reservoir beds. Based on the integrated analyses of geological, logging, seismic and chemical data, there are 3 types of sedimentary system developed in this area with the Sha 3 and the Sha 2 members, and they are turbidity fan, subsurface alluvial fan, and beach and dam. The subsurface alluvial fan and turbidity fan can be further divided into 3 types of sub facieses, i.e., root fan, middle fan and fan edge by conglomerate distribution, etc. The middle fan can be further divided into 3 micro facieses braided channels, spaces between channels, and front edge zone. Reservoir physical properties of the braided channel sandbody and front edge sandbody of the middle fan are good because the primary pores and secondary pores developed well. Reservoir physical properties of sandbody in root fan, fan edge and space between braided channels are poor in this area. The reservoir properties were controlled by lithology, sedimentary microfacies and diagenesis during the reservoir development. The reservoir of the Shahejie Formation can be divided into 3 types of good, medium and poor reservoirs.