琼东南盆地深水区宝岛凹陷3D输导体系评价

Evaluation of 3D Hydrocarbon Migration System in Baodao Sag in the Deep-water Area of Qiongdongnan Basin

为查明宝岛凹陷优势运移通道和运移方向,以钻井和地震资料为基础,采用地震解释、古构造恢复、油气运聚模拟、3D地质建模等技术手段,在宝岛凹陷识别出了4级4组断裂、4套骨架砂体和4条主构造脊,建立了宝岛凹陷烃源岩—输导体系—储层—圈闭空间格架,划分了T型、阶梯型、受限网毯型3种输导体系,南部断阶带和东北断阶带为阶梯型输导体系,松南低凸起和北部斜坡带为受限网毯型输导体系。运移模拟表明南部断阶带、东北断阶带、松南低凸起前排构造带都是优势的运移方向,垂向+侧向运移为主。区带优选表明南部断阶带为最有利区带,具有"近源、断—砂—脊阶梯型输导、海底扇和扇三角洲储集、断块-岩性圈闭"配置特征。

The dominant migration path and migration direction of the Baodao Sag,were identified based on drilling and seismic data using seismic interpretation,paleostructure restoration,oil and gas migration and accumulation modeling,3D geological modeling,and other technological approaches.Four faults with four levels,four sets of framework sand bodies,and four main structure ridges were identified in the Baodao Sag.The system of source rock-migration system-reservoir-trap in the Baodao Sag has been established,and the migration systems have been classified into three types:the T type,ladder type,and restricted meshwork-carpet type.The southern and northeastern step-fault zones are characterized by ladder type migration systems,while the Songnan low uplift and northern slope zones are characterized by restricted meshwork-carpet type systems.The migration simulation shows that the southern step-fault zone,northeastern step-fault zone,and Songnan low uplift front tectonic zone are the dominant migration directions,which are mainly characterized by vertical and lateral migration.The selection of favorable zones indicates that the southern step-fault zone is the most favorable zone,which has the configuration features of“near source,fault-sand-ridge ladder type migration,submarine fan and fan delta reservoir,and fault block-lithologic trap.”