地层圈闭油气成藏有效性评价方法——以渤海湾盆地济阳坳陷为例

An Effective Evaluation Method for Stratigraphic Trap Hydrocarbon Accumulation:A Case Study of Jiyang Depression,Bohai Bay Basin

为了提高地层圈闭勘探成功率,以渤海湾盆地济阳坳陷为例,从已发现地层油藏解剖入手,结合地质风险要素分析及权重评价,开展了地层圈闭成藏有效性评价方法的建立。结果表明:济阳坳陷盆缘地层圈闭勘探风险评价主要包括运聚匹配条件、保存条件、圈闭条件及储层条件等4大地质条件10个地质要素;利用钻探成功率法和累计概率曲线法可以划分不同地质条件中地质要素的风险级别,利用成功率影响程度对比法可以确定不同地质要素的权重系数;最终利用地质风险概率法建立了济阳坳陷盆缘地层圈闭勘探评级分级标准和勘探风险评价方法,提高了地层圈闭含油性判识能力,完善和发展了勘探风险评价方法体系。该方法对于中国东部类似盆地地层油藏的勘探同样具有借鉴和指导意义。

To improve the success rate of stratigraphic trap exploration,Jiyang Depression of Bohai Bay Basin was taken as an example.First,the discovered stratigraphic reservoirs was analyzed.Second,the weight evaluation of geological risk factors was combined to establish the effective evaluation method of stratigraphic trap accumulation.Results show that the risk assessment of trap exploration in the basin margin of the Jiyang Depression revealed four types of geological conditions,i.e.,the operation and accumulation matching condition,preservation condition,trap condition,and reservoir condition,and 10 geological elements.The drilling success rate method and cumulative probability curve method were used to classify the risk levels of geological elements in different geological conditions.The weight coefficients of different geological elements could be determined by the method of comparing the influence degree of success rate.Finally,the grading standard and risk evaluation method for stratigraphic trap exploration in the basin margin of the Jiyang Depression were established,which enhanced the oil-bearing evaluation ability of stratigraphic trap and improved the risk evaluation method system for exploration.The new evaluation system can be used as reference and guidance to the exploration of similar basins in the eastern China.