Abstract: Traditional concept suggests that an oil-gas field is in static equilibrium for single-stage charging, and the more producing, the lessremained for amount of hydrocarbons, being accordant with subtraction rule in mathematics. However, exceptions are found by the proofs ofw ithdrawals much more than estimated reserves in some fields such as Romaskino and Groznei oilfields in Russia, and Daqing oilfield in whichH,S occurred in high-water cut stage of development. The facts show that hydrocarbons regenerated and from deep crust could be recharged intothe oil-gas fields rather than oil-gas fields is merely in static equilibrium for single-stage charging. The present crust movement can providepower for displacement and also passages for recharging oil-gas into related reservoirs. The domestic trace element analysis suggests that thetrace element content in crude is generally higher than the mean trace element content in continental crust, including the higher density. Underthese circumstances, it is not suitable for most oil-gas fields to adopt EOR technologies taking water injection as medium or supporter, but toapply gas injection (CO, N2, and H,S) for petroleum development.

Key words: oil-gas field, multi-stage charging, present crust movement, new material, EOR, IOR