东营凹陷岩性圈闭含油性定量预测

Quantitative prediction of oil - bearing probability in lithological trap of Dongying Sag

依据东营凹陷岩性油气藏勘探实践,其成藏主控因素概括为烃源岩、输导体系和成藏动力。以油气成藏动力为主线,从油气运聚的动力和阻力2个方面入手,将主控因素定量化,成藏动力为油气排出初始压力减去运移路径的压力衰减、储层静水压力和砂体毛细管压力。回归东营凹陷48个岩性圈闭的成藏动力与油气充满度的关系,建立了砂体含油性成藏动力定量预测公式。采用先确定烃源岩、输导体系和储层物性,最后计算成藏动力的方法,在对砂体钻预探井之前定量预测其含油性,从而降低勘探风险,提高勘探成功率。

According to oil - gas exploration practice in Dongying Sag, major controlling factors of reservoir - forming are source rocks, transporting - conducting system and reservoir - forming dynamic. Setting about dynamic and resistance of oil - gas migration and accumulation, reservoir - forming dynamic being principal line,the major controlling factors were quantitatively determined, reservoir - forming dynamic of lithological trap equals to remnant which is initial pressure of oil - gas draining from source rocks minus pressure reduction along oil - gas migration path, static water pressure in reservoir and capillary pressure of sandstone. Based on regressed relationship between oil - gas filling degree and reservoir - forming dynamic of 48 lithological traps in Dongying Sag, the quantitative prediction formula of reservoir -forming dynamic of sandbody oil - bearing was established. The method first determined source rocks, transporting - conducting system and reservoir property, then calculated reservoir - forming dynamic. This method quantitatively predicted its oil - bearing before drilling, so exploration risk will decrease and exploration efficiency will increase.