石臼坨凸起东南斜坡带输导体系与油气运聚模式

Hydrocarbon translocation system and migration-accumulation patterns in southeastern
slope area, Shijiutuo Uplift

 姚城 张新涛 于海波 杨传超 陈丽祥 朱勇超

 （中海石油（中国）有限公司天津分公司，天津 300450）

 (Tianjin Branch of CNOOC Ltd., Tianjin 300450, China)

 通过生物标志化合物对比，断面精细刻画，并利用断层活动性、砂体的展布特征以及成藏综合分析等技术手段，厘清了石臼坨凸起东南斜坡带油气来源，刻画了油气优势运移路径，确定了油气的优势输导体系，最终建立了石臼坨凸起东南斜坡带油气运聚模式。研究结果表明：1）研究区油气主要来自渤中凹陷沙一二段烃源岩为低成熟—成熟原油，且表现出良好的运移效应。2）油气成藏期为2.1 Ma，与生烃高峰时间5.2 Ma相匹配，具有晚期、快速、高效生烃的特征。3）石南一号边界断层规模大、活动性强、断面形态起伏，控制油气从渤中凹陷深层到石臼坨凸起浅层的垂向运移，凸起上晚期断裂控制浅层油气的垂向运移和聚集。4）古近系近源扇体沿着边界断层呈裙边状发育，与烃源岩大面积接触，具有中转油气的作用。馆陶组砂砾岩是新近系油气横向输导层，油气趋于沿着构造脊向高部位运移。明下段极浅水三角洲砂体发育，与断层组合构成构造￣岩性圈闭，保存油气。5）在凸起斜坡带形成“断控源仓型”和“断裂直控型”油气运聚模式。

 Based on the integrating correlation of biomarker compounds, accurate description of fault plane, fault activity, distribution characteristics of sand body as well as comprehensive reservoir-forming analysis, the hydrocarbon migration-accumulation patterns in the southeastern slope of Shijiutuo Uplift, hydrocarbon source favorable migration pathway and translocation system were determined. The following results are drawn in our research: (1) the hydrocarbon of the study area is low mature-mature oil which comes from the source rock of the first and second Members of Shahejie Formation in Bozhong Sag, showing good migration effect. (2) the period of the hydrocarbon reservoir formation(2.1 Ma) is matched with the hydrocarbon generation peak(5.2 Ma), which is characterized by later period, speediness and efficiency. (3) Shinan No.1 Fault controls hydrocarbon vertical migration from the deep layers in Bozhong Sag to the shallow layers in Shijiutuo Uplift, while late-stage faults control hydrocarbon vertical migration and accumulation in Shijiutuo Uplift; near-source fans developed in Paleogene distribute as skirt-like type along Shinan No.1 Fault, which could absorb most of the hydrocarbon because of the large contact plane with the source rock and serve as a "transfer station". (4) the glutenite in Guantao Formation is a significant lateral transportation layer, where hydrocarbon migrated to the higher part along the structure ridges; extremely shallow delta sands developed in lower Minghuazhen Formation along with faults form structure-lithology traps to conserve hydrocarbon. (5) "source-fault-storage" and "fault-controlled" migration-accumulation patterns were established and this model can effectively guide the exploration in slope areas in Shijiutuo Uplift and other comparable regions in Bohai Basin.

10.6056/dkyqt201706005