渤海湾渤中C地区分流河道砂体油气富集规律及滚动开发实践

Enrichment Regulation of Distributary Channel Sandbody and Rolling Development Practice in Bozhong C Area of Bohai Bay

浅水三角洲分流河道砂体是渤海湾渤中C地区最具含油潜力的砂体类型,也是该区后期滚动挖潜的主要对象。以区域晚期成藏理论为指导,结合探井、开发井揭示的油气分布特征,以统计学为手段,弄清分流河道砂体的油气富集规律,对已开发或未开发分流河道砂体的潜力进行定量化分析,为滚动开发实践提供依据。结果表明:该区含油分流河道砂体平面上主要分布在渤中C地区主控断层平面距离5km以内的区域,纵向上主要集中在海拔-1 780^-1 650m之间;油气的富集程度平面上受控于构造背景和断砂的接触关系,位于面积大的圈闭内并与断层高角度接触的分流河道砂体油气相对富集,纵向上受控于各层位基准面旋回差异及分流河道砂体规模的大小,发育于基准面上升半旋回中晚期且在单一区块内面积小于5km2的分流河道砂体往往具有较高的面积充满度。实践证实,该成果较好指导了该区的滚动开发实践,有助于油田的高效开发评价,对类似区块的勘探及滚动开发评价具有重要的指导意义。

Distributary channel sandbody of shallow water delta is the most potential oil-bearing sandbody type and the main exploration and development target of Bozhong C area in Bohai Bay.According to the late-stage accumulation theory,combined with the characteristics of petroleum distribution revealed by the prospecting and development wells,the petroleum enrichment regulation of distributary channel sandbody was statistically discussed,and the potentials of developed and undeveloped distributary channel sandbodies were quantitatively analyzed in order to provide the basis for the practice of rolling development.The results show that the horizontal oil-bearing distributary channel sandbody mainly distributes in the area within 5km of primary faults in Bozhong C area on the plane,and the longitudinal oil-bearing distributary channel sandbody mainly concentrates in the altitude of-1 780--1 650 m;petroleum enrichment of distributary channel sandbody is horizontally controlled by the tectonic background and fault-sand contact relationship,and the petroleum is relatively enriched in the trap with large area and the distributary channel sandbody contacting with fault at high angle;petroleum enrichment isvertically controlled by the difference of base level cycle and the size of distributary channel sandbodies,and the distributary channel sandbodies in the single block with less than 5km2 have high area filling rate in the middle-late stage of the rise of base level semi-cycle.Practice proves that the results make a better guidance to the rolling development,and are helpful to the efficient development and evaluation in this area,and have reference for the exploration and rolling development practice of similar blocks in Bohai Bay.