基于源断盖空间配置的油气侧向分流运聚有利区预测方法及其应用

Prediction methods of favorable area for laterally migrated and accumulated oil and gas based on source-fault-caprock spatial configuration and their application

为了有效地指导含油气盆地内下源上储式油气勘探,以源断盖空间配置油气侧向分流运聚机制及其所需条件为研究基础,通过厘定源岩成熟区、油源断裂分布区和盖层封闭区,研究出一套基于源断盖空间配置的油气侧向分流运聚有利区的预测方法,并用其对渤海湾盆地南堡凹陷东一段源断盖空间配置天然气运聚有利区进行了预测。结果表明:渤海湾盆地南堡凹陷东一段源断盖空间配置天然气侧向分流运聚有利区仅在凹陷西南局部区域分布且分布面积较小,底部源岩生成的天然气由此区向上覆层位发生侧向分流运聚成藏,这符合目前研究区内已发现天然气的分布特征,证明了用该方法对源断盖空间配置的油气侧向分流运聚有利区预测的有效性。

In order to effectively guide the exploration of oil and gas in combination of lower source rock and upper reservoir in petroliferous basins, on the basis of the studies on lateral migration-accumulation mechanisms of oil and gas in source-fault-caprock spatial configuration and their necessary conditions, through determining the mature area of source rock, the distribution area of oil source fault and the sealed area of caprock, a set of prediction methods is established for the favorable area of oil and gas lateral migration and accumulation based on source-fault-caprock spatial configuration, and is applied to predict the favorable area for the natural gas migration and accumulation in source-fault-caprock spatial configuration in Member Ed_(1) of Nanpu Sag, Bohai Bay Basin. The results show that the favorable area of natural gas migration and accumulation in source-fault-caprock spatial configuration in Member Ed1 of Nanpu Sag is only distributed in the southwestern part of the sag, and the area is relatively small;the natural gas generated from the bottom source rock undergoes lateral migration and accumulation in the overlying layer in this area, which is coincident with the distribution characteristics of the natural gas currently discovered in the study area. All the achievements prove the effectiveness of using this method to predict the favorable area of oil and gas lateral migration and accumulation in the source-fault-caprock spatial configuration.