砂质辫状河砂体构型及剩余油分布模式

针对砂质辫状河内部不同级次的砂体构型模式及其内部夹层、韵律特征影响油田开发中后期剩余油分布的问题,基于野外露头岩性、沉积构造等特征研究,对山西大同铁路桥剖面中侏罗统云岗组砂质辫状河砂体进行精细解剖和岩相分析。结果表明:研究区可识别出9个岩相类型,确定出河道砂体、心滩砂体和边滩砂体等3种成因砂体,通过精细解剖剖面砂体和详细研究现代河流沉积特征,将边滩砂归入辫状河河道主要成因砂体中;同时结合砂体4、5级构型界面特征及注采井网部署情况,建立了9种剩余油富集模式。研究结果可对云岗组砂质辫状河储层进一步挖潜剩余油及提高采收率提供可靠依据。

Sandy Braided River Sandbody Configuration and Remaining Oil Distribution Pattern

In order to identify the effects of different-order sandbody configuration patterns, internal interlayer and rhythm within braided-river on the remaining oil distribution in the middle-late development stage, The braided river and lithofacies of the middle Jurassic Yungang Formation in the Tieluqiao profile of Shanxi Datong were detailed characterized and analyzed based on the field outcrop lithology and sedimentary structure. Result indicates that there are nine lithofacies categories can be identified and three genetic sandbody categories, including channel sandbody, channel bar sandbody and point-bar sandbody. The point-bar sandbody is classified into the major genesis sandbody in the braided river channel from fine dissection of longitudinal sandbodies and detailed modern river sedimentation. In addition, 9 remaining oil enrichment patterns were established by combining with the fourth-order and fifth-order configuration interfaces and the deployment of injection-production well pattern. This research could provide a reliable reference for further remaining oil recovery and enhancing oil recovery for the sandy braided-river reservoirs in the Yungang Formation.