大民屯凹陷西陡坡砂砾岩体勘探技术初探

Preliminary Study of Exploration Technology for Glutenite Body in Western Steep Slope of Damintun Sag

大民屯凹陷西陡坡沙河街组沙四段发育砂砾岩沉积,累计资源潜力超过2×10~8t。勘探实践证明,砂砾岩体具有纵向厚度大、相带及岩性变化快、储层物性差异大、地震识别描述难度大的特点。自2014年以来,针对大民屯凹陷砂砾岩体多期叠置、非均质性强的特征,从储量上报升级、探井部署质量和有效储层开发等方面开展一体化联合攻关,探索建立了厚层砂砾岩体期次划分、复杂岩性储层识别以及非均质性砂砾岩有效储层地震预测等砂砾岩体勘探技术系列,并获得了"陡岸控砂、相带控储、物性控藏"的地质认识。通过大民屯凹陷西陡坡沙四段砂砾岩体的勘探,顺利完成了对平安堡-安福屯扇体的井位部署工作及储量上报,新部署实施探井4口,3口井获得工业油流;实施4口老井试油,试油符合率达到80%以上;2015年新增含油面积35km^2,上报各级储量超过5000×10~4t。

Glutenites of Es4 of Shahejie formation in western steep slope of Damintun sag developed well,whose cumulative resource potential was predicted above two hundred million tons.Petroleum exploration practice shows that the glutenite body has the features of large longitudinal thickness,fast facies belt and lithology alteration,various physical properties of reservoirs and great difficulty in seismic identification and description.Since 2014,based on the reservoir characters of multi-stage overlay and strong heterogeneity,technical breakthrough including reserve reporting and upgrading,exploratory well deployment and effective reservoir development was researched together.A set of exploration techniques,stage division in thick glutenites body,complex-lithology reservoir identification,and seismic prediction of effective reservoir in heterogeneous glutenites,were established.In the end geological understanding was formed as sand control by steep slope,reserves control by facies belt,and oil reservoir control by physical properties.Based on the exploration,well deployment and reserves report was done in Pinan-pu-Anfutun fan smoothly.Four exploration wells were deployed newly and three of them obtained the industrial oil flow.Successful rate of testing for oil in 4 old wells is over 80 percent.Newly increased oil-bearing area in 2015 was 35km^2 and the reported reserves were more than fifty million tons.