苏北盆地盐城组天然气藏成藏条件及控制因素探讨

苏北盆地天然气资源丰富,已经在盐城组发现两个气田———周庄气田和溪桥气田。盐城组天然气藏埋藏浅(<1000m),研究盐城组天然气的成藏条件及控制因素,对苏北盆地的下步勘探具有非常现实的指导意义。全面阐述了苏北盆地盐城组的成藏条件,探讨了其成藏的控制因素。通过研究,认为苏北盆地盐城组本身虽不具备生烃条件,但储盖条件较好,下部烃源岩生成的天然气沿断层向上运移,在盐城组圈闭配置理想的条件下形成气藏。天然气藏受气源、生气强度、断裂和盖层4个因素控制。

Pooling Conditions and Controlling Factors of Gas Pools in Yancheng Formation of Subei Basin

There is a great gas resource in Subei basin, represented by the Zhouzhuang and Xiqiao gas fields. The buried depth of the gas is shallow (<1 000 m). The authors discuss about the pooling conditions and controlling factors of the gas systematically. Through the study, Yancheng Formation can't generate hydrocarbon, but the reservoirs, caprocks and source rocks are in good condition. The hydrocarbon migrates upward along faults and accumulates in traps in the Formation. The gas pools are controlled by four factors, that is, source rock, fault, caprock and the intensity of gas generation.