渤海湾盆地垦利10-4油田沙三上段砂体富集模式

Sandbody enrichment model for upper 3rd Member of Shahejie Formation of KL 10-4 Oilfield, Bohai Bay Basin

赵汉卿

ZHAO Hanqing

中海石油（中国）有限公司天津分公司，天津 300459

Tianjin Branch of CNOOC Ltd., Tianjin 300459, China

古近系沙三上段辫状河三角洲沉积是渤海湾盆地莱州湾凹陷的重要储层，综合利用岩心、测井、录井、地震等资料，统计砂地比等数据，并结合经典层序地层学原理，详细分析了垦利10￣4油田沙三上段辫状河三角洲砂体叠置类型及砂体富集规律。研究结果表明：沙三上段为一套完整的三级层序，其内部依次为低水位体系域（LST）、水进体系域（TST）和高水位体系域（HST）。井间对比剖面显示，LST时期砂体以Ⅰ型河道为主，河道切割叠置特征明显；TST时期砂体以Ⅱ型河道为主，河道呈叠置特征，切割作用不明显；HST时期砂体以Ⅲ型河道为主，几乎不存在切割叠置特征，河道间相互分离。叠置特征和富砂规律主要受湖平面变化和沉积物供给速率控制。研究其富砂规律对莱州湾凹陷油气勘探开发具有借鉴意义。

The braided river delta deposit in the upper 3rd Member of Shahejie Formation is an important reservoir of the Laizhou Bay Sag, Bohai Bay Basin. Comprehensive use of core, logging, seismic materials, statistics of sand ratio data, combined with the classical sequence stratigraphy principle, the sandbody superimposed types and sandbody enrichment law of braided river delta in the upper 3rd Member of Shahejie Formation in Kenli 10-4 Oilfield were analyzed in detail. The results show that the upper 3rd Member of Shahejie Formation in Kenli 10-4 Oilfield is a complete third-order sequence, which is divided into lowstand systems tract (LST), transgressive systems tract (TST) and highstand systems tract (HST) from bottom to top. Inter-well correlation shows that the sand body in the LST is dominated by the type I channels, and the channel cutting features are obvious; the sand body in the TST is dominated by the type II channels, and the channel is characterized by vertical or lateral superposition; the sand body in the HST is dominated by type III channels, and the channels are separated from each other. The sand-rich law is mainly controlled by the elevation of the lake level and the rate of sediment supply. Studying the law of sand enrichment has reference significance for oil and gas exploration and development in Laizhou Bay Sag.

10.6056/dkyqt201904011