Abstract:

Pre-Cenozoic marine strata widely developed in China.These strata have rich potential hydrocarbon reserves but their exploration degree and success ratio are low since they underwent multi-stage reformation and have the feature of residul basin.The reformation includes erosion,structural deformation and deep burial etc.However,the ways of reformation,such as being superposed by foreland basin or rift basin,being uplifted as a plateau or highland,being transformed from thrust folds into fault-fold belt or even orogenic zone,etc.Marine residual basins have complex hydrocarbon pool-forming dynamics.The most important hydrocarbon pool-forming properties are:(1)multi-stage hydrocarbon accumulation resulted in the formation of complex oil and gas systems with dispersed oil and gas pools;(2)late-stage pool-forming controlled by Himalayan movement.Therefor,the key problem of petroleum exploration in residual basins is to understand and describe their heterogeneity of geological characters,graps the dynamic process of hydrocarbon generation,migration,dispersion and accumulation,study the evolution history of various geological factors.In short,marine reformed residual basins bear bright prospects in oil and gas exploration,amd they bound to be the main targets of China's oil and gas exploration in the 21st century.

Key words: reformed-residual basin, marine strata, hydrocarbon-forming process pool-forming dynamics, Himalayan stage