江汉盆地白垩系油气藏特征与勘探潜力

江汉地区白垩系广泛分布于盆地周缘露头和盆地内,以红色砂泥岩为主,缺乏生烃潜力,但白垩系下伏古生代海相地层,上覆第三纪断陷层,为其油气聚集提供了丰富的油源条件,具有良好勘探潜力,并被最近的勘探证实。通过对江汉盆地西南缘白垩系油气藏的研究发现,该地区白垩系油气藏的油源来自邻近第三系烃源岩,由于白垩系储层与第三系烃源岩通过断层沟通、油气沿断层运移到白垩系形成新生古储油气藏。同时在沔阳凹陷还发现白垩系下伏古生代海相地层也具有生烃潜力,生成的油气运移至上覆白垩系形成古生新储油气藏。

Characteristics and Exploration Potential of Cretaceous Reservoirs in Jianghan Basin

The Cretaceous, which is mainly integrated with a set of red sandstones and mudstones, is widely distributed in Jianghan Basin and outcrop around Jianghan Basin, it lacks hydrocarbon generation potential. But the palaeozoic marine stratum under it and tertiary rifted stratum above it have great exploration potential and can be the oil source of the Cretaceous system. This has been approved by the recent exploration practice. The research indicates that the Cretaceous reservoirs in southwest of Jianghan Basin are from the tertiary source rocks. As the Cretaceous reservoirs are connected with tertiary source rocks by faults, so the oil and gas migrate to the Cretaceous reservoirs along the fault and forms a newly generated palaeo-reservoir. Meanwhile, the palaeozoic marine stratum under the Cretaceous in Mianyang Depression has hydrocarbon generation potential and forms a palaeozoic new reservoir in Cretaceous.