| Deep Water Gulf of Mexico(DWGOM),passive continental margin basin,is one of the famous "Gold Triangle Deep Water" areas in the world.Thick salt was developed in transitional period and its plastic deformation influenced the hydrocarbon accumulation elements.The study on the controlling factor of hydrocarbon accumulation is still the weakest research field,and the accumulation regulations limit the exploration potential evaluation.This thesis employed the plate sepration and salt structure restoration techniques to describe the salt evolution process,salt structure characteristics and salt-related trap types.And this technology was used to discuss the influence of source rock,reservoir and hydrocarbon migration and accumulation during the deformation process of salt,and to study the main controlling factors of the different plays,and to set up the salt related hydrocarbon accumulation mode.The plate separation and the sedimentary loading is the dominant mechanism of salt deformation.Louann salt has experienced 3 main stages of evolution and deformation,and formed two types of Mini-basin.The fold was formed in the initial salt deformation period,and then the salt diapir and salt stock were developed by the salt withdrawal in the middle period,and finally the salt canopy and complicated salt diapir were developed by the lateral flow of salt in the late period.Continuous sediments deposited in the type I Mini-basin among the salt diapirs or salt stocks during late Jurassic-Oligocene period,and Miocene-Pleistocene sediments deposited in the type II Mini-basin above salt canopy.Three hydrocarbon migration modes improve the efficiency of hydrocarbon migration and complement the migration theory in salt-bearing basins,which includes the vertical migration path by salt related fault and growing salt stock flanks,the lateral migration path by the salt lateral movement,and the 'temporary warehousing'of thick sandstone reservoir lateral distribution.Three-dimensional oil&gas migration network was formed comprehensively by salt arch related fault or fracture system,salt withdrawal related fault system,migration path of growing salt stock flanks and base of the salt canopy,Wilcox sandstone 'temporary warehousing' and 'salt window' in the base of type ? Mini-basin.Hydrocarbon discoveries in the deep water of the basin have been made in three sands,including the Upper Jurassic Norphlet eolian,Paleocene-Eocene Wilcox submarine fan and Miocene-Pleistocene turbidite channel.The distribution of these sands is under the control of salt tectonic belt distribution and the sediment provenance.Salt-related traps are well developed in the inner belt based on type ?Mini-basin development.Three-way traps against salt body or salt weld are the main trap style.The Miocene-Pliocene turbidite channel sand reservoir restricted by salt is the main reservoir,and the main controlling factors of oil accumulation are the reservoir and migration.Salt-related traps also develop in the outer belt based on type I Mini-basin development,including salt cored anticline,thrust anticline and 3-way traps against salt body or weld.The Paleocene Wilcox sands are the main reservoir,and the main controlling factor of oil accumulation is the effectiveness of the top seal.According to salt movement,salt structure distribution and the development of three sets of sand bodies,3D network migration mode was set up in Minibasins.Three hydrocarbon accumulation modes were set up including the Jurassic 'adjacent generation and lateral storage' mode,the Wilcox 'upper generation and lower storage'mode in the outer belt and the Miocene 'upper generation and lower storage' mode in the inner belt.Rapid evaluation method was made on deep water salt-related structures,and favorable areas were predicted that the Kealthy fold belt,GB and GC area inner belt have the huge potential for the future exploration.The research finding in this thesis can also give some reference for the oil&gas exploration in the salt basin of domestic or abroad. |
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