二连盆地盖层条件与油气保存

Cap Rock Condition and Hydrocarbon Conservation in Erlian Basin

研究二连盆地盖层封盖条件 ,寻找有利的储盖组合发育对二连盆地的油气勘探意义重大 .二连盆地是在海西期褶皱基底上发育起来的 ,在其构造和沉积演化过程中 ,形成了众多的彼此分割、相互独立的断陷湖盆 ,每个湖盆都有各自独立的沉积体系 ,接受了下白垩统巴彦花群一套粗 -细 -粗完整的正旋回沉积 ,暗色泥岩较为发育 ,以腾格尔组和阿尔善组最为发育 ,是 2套主力烃源层 ,同时 ,在与构造和储层相配置的有利区 ,又为油气藏的形成提供了良好的封盖条件 .

Erlian Basin developed on Hercynian fold basement. Many rift subsidence lake basins, which are separated and independent each other, are formed in the process of structure and deposition evolution. Each lake basin has independent depositional system, accepting a set of coarse fine coarse positive cycle of Bayanhua Group, Lower Cretaceous. Dark mudstone is more developed, and especially in Tengeer Formation and Aershan Formation, which are two major source rock formations. At the same time, the dark mudstone provide good cap rock condition for the generation of the oil and gas reservoirs if the favorable areas with the suitable matching of structure and reservoir. Therefore, the study on the sealing condition of cap rock is helpful to finding the areas of favorable reservoir cap combination, which is significant to hydrocarbon exploration in Erlian Basin.