胜利油田车镇凹陷沙河街组二、三段沉积相

车镇凹陷古近系沙河街组三段上亚段-二段下亚段是较为典型的深断陷型三级层序.层序的发育主要受控于幕式断陷作用,可进一步划分出低位体系域、湖侵体系域和高位体系域.通过岩心观察、薄片镜下鉴定、粒度分析、古生物及遗迹化石分析,并综合利用测井曲线和地震相特征,认为该时期主要发育有扇三角洲、三角洲、近岸水下扇、湖底扇、滨浅湖滩坝等骨架砂体相,以及滨浅湖、半深湖-深湖等沉积相及其亚相.综合考虑物源特征、沉积环境、沉积体系平面展布以及生、储、盖组合关系,认为有利的沉积相带主要是三角洲、扇三角洲前缘、湖底扇、近岸水下扇的中扇和外扇以及滨浅湖中发育的滩坝和砂坝.

Sedimentary facies in the second and third members of the Shahejie Formation in the Chezhen depression,Shengli Oil Field

The Chezhen depression as a fault basin is located in the northeastern part of the Bohaiwan Basin in Shandong. The upper submember of the third member and the lower submember of the second member of the Palaeogene Shahejie Formation are considered as the typical deeply faulted third-order sequences constrained by episodic faulting. These sequences may be divided into the lowstand, transgressive and highstand systems tracts. Sedimentary facies consist of fan delta, delta, nearshore submarine fan, sublacustrine fan, littoral-shallow lake beach and bar, as well as littoral-shallow lake, and semideep-deep lake facies and subfacies, of which the preferred sedimentary facies include delta, fan delta front, sublacustrine fan, midfan and outer fan of the nearshore submarine fan, and beach-bar facies developed in the littoral-shallow lake.