KEY TECHNOLOGY FOR EXPLORATION OF COMPLEX PRESALT TRAPS IN THE DEEP WATERS OF GABON BASIN, WEST AFRICA

In recent years, global deepwater oil and gas exploration, as demonstrated by West Africa and the Gulf of Mexico, has become increasingly active. Verification of structures is always the key problem in salt basin exploration. Therefore, it really is a great need to develop a set of technology for trap identification to support the exploration of oil and gas under salt cap in the deep water of Gabon Basin. Based on the studies of the mechanisms of salt rock deformation and its impacts on seismic imaging, a set of key technology is proposed in this paper. It includes: ①Establishment of interpretation models for structures based on the mechanism of salt rock deformation; ②Introducing the technique for pre-salt seismic horizon interpretation based on the fine recognition of dirty salt bodies; ③Integration of gravity, magnetic and seismic data for multiscale comprehensive interpretation of pre-salt faults; ④Adoption of the method for distinguishing false images from the real based on wave equation forward modeling. Using the method, a series of pre-salt traps are effectively identified in the research area, and drilling proves that the M trap is a large pre-salt gas field. It is concluded that the technical system proposed can help solve the problem of the verification of pre-salt structures, which can be used as a reference for similar oil fields in West Africa and other regions.