渤海南部海域朵叶状浅水三角洲储层构型表征

渤海南部海域新近系明化镇组浅水三角洲储层呈朵叶状广泛分布,由于储层成因及结构复杂,常规的基于复合砂体储层表征精度较低,制约了油田开发中后期剩余油分布认识和挖潜。以渤海南部海域BZ28油田1167砂体为例,在浅水三角洲现代沉积演化模式指导下,综合应用高分辨率地震属性、测井相、水平井地质导向及生产动态等资料,由复合河道、分流砂坝、分流砂坝内部沉积朵体逐级次对砂体构型单元进行划分。研究表明:研究区浅水三角洲储层平面呈分流河道与分流砂坝相间沉积分布特征,其中,分流砂坝为储层沉积主体,由沉积朵体纵向叠加、低角度前积及溯流退积等方式拼接构成,分流河道为过水通道,储层厚度相对较薄。研究成果可有效指导在生产过程中对油层水淹特征的认识。

Lobate Shallow-Water Delta Reservoir Architecture Characterization in the Southern Bohai Sea

The Neogene shallow water delta reservoirs of the Minghuazhen Formation in the southern Bohai Sea show a wide lobate distribution. The complex reservoir genesis and architecture and relatively low conventional reservoir characterization accuracy based on composite sandbody limit the understanding of remaining oil distribution and recovery in the middle-late development stage. The Sandbody 1167 of BZ28 Oilfield in the southern Bohai Sea was taken to separate the configuration unit based on the modern sedimentary evolution mode of shallow water delta. High-resolution seismic attribute, logging facies, horizontal well geo-steering, production history and other data were comprehensively used to separate the sandbody configuration step by step from the sedimentary lobes in composite river channel, distributary channel and distributary bar. Research indicates that the lateral shallow water delta reservoir in the study area shows a alternate distribution of distributary channel and distributary bar. The reservoir sedimentation is dominated by distributary bar, which is composed of vertical stacking between sedimentary lobe, low angle frontal accumulation and backflow degeneration. The distributary channel is a water channel with relatively small reservoir thickness. This research could provide certain guidance for the understanding of water flooding in the production.