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.