油气倒灌运移形式分布区预测方法及其应用

为了研究含油气盆地倒灌运移油气分布规律,在油气倒灌运移和常规油气运移对比的基础上,对油气倒灌运移形成所需条件和分布区预测方法进行了研究,结果表明:油气倒灌运移按运移方向可分为油气垂向和侧向倒灌运移形式两种,前者发生所需条件是油源断裂发育在一定压力差的紧邻源储区内,后者发生所需的条件是油源断裂发育在区域性盖层封闭区内。通过一定压力差的紧邻源储区和油源断裂叠合和区域性盖层封闭区和油源断裂分布叠合,分别建立了一套油气垂向和侧向倒灌运移形式分布区的预测方法,并将其分别应用于松辽盆地三肇凹陷青一段源岩生成的油向扶扬油层垂向倒灌运移形式分布区和渤海湾盆地南堡凹陷沿油源断裂运移天然气向东一段储层侧向倒灌运移形式分布区的预测中,其结果表明:三肇凹陷青一段源岩生成的油向下伏扶扬油层垂向倒灌运移形式分布区,除凹陷内和边部局部地区外,整个凹陷分布,南堡凹陷沿油源断裂运移的天然气向东一段源岩侧向倒灌运移形式分布区主要分布在凹陷西南地区。分别与三肇凹陷扶扬油层目前已发现的油藏分布和南堡凹陷东一段目前已发现的气藏分布相吻合,表明该二种方法分别用于预测油气垂向和侧向倒灌运移形式分布区是可行的。

Forecasting Method and Application of Oil and Gas Flowing Backward Migration Patterns in Range of Distribution

To study the oil and gas distribution regularities of downward migration in petroleum bearing basin , based on the correlation of oil and gas flowing backward migration and conventional oil and gas migration, we mainly researched the forming conditions of oil and gas flowing backward migration and distribution area forecasting method. It turned out that according to the direction of transportation, the oil and gas flowing backward migration can be divided into two forms of vertical migration and lateral migration. The former occurs when oil-migrating faults develop close to the source reservoir with a certain pressure difference, and the latter occurs as oil migrating faults develop in a regional caprock sealing area. Through a certain pressure difference between the adjacent source reservoir and oil source fracture overlap, and regional cap covered area and oil source fracture distribution overlap, we established a set of forecasting methods of oil and gas verticaland lateral flowing backward migration patterns in range of distribution, then use them in the forecasting of oil and gas vertical flowing backward migration patterns in range of distribution from oil generated in source of K1qn1 in Sanzhao depression of Songliao basin to Fuyang reservoir, and in the forecasting of gas lateral flowing backward migration patterns in range of distribution from Nanpu depression in Bohai Bay basin along oil migrating faults to Ed1 reservoir. The result shows that the vertical migration patterns ranges of distribution of oil generated from source of K1qn1 in Sanzhao depression flows backward to Fu Yang reservoirs, distributing in the depression except in local region and edge, and gas transporting to source of K1qn1 in Nanpu depression along oil migrating faults lateral flowing backward migration patterns in range of distribution mainly spreads in the southwest of the depression, separately consistent with found reservoir distribution of Fuyang reservoir in Sanzhao depression and discovered distribution of gas pools of Ed1 in Nanpu sag at present. It shows that it is feasible to apply two methods separately to predict oil and gas vertical and lateral flowing backward migration patterns in range of distribution.