Physical Simulation Experiment Study Of Neogene Petroleum Migration And Accumulation In Chengdao Area

The Neogene is the most important oil-bearing strata in Chengdao.The Neogene has developed multi-level faults,sand bodies with different pore permeability,and a variety of reservoir-seal assemblage.The factors influencing the migration and accumulation of Neogene petroleum are not yet clear.The paper takes the Neogene reservoir as the research object.Based on the geological data of the area,the author studies the anatomy of the key reservoir and propose the main influencing factors of oil accumulation.The physical simulation experiments are designed to study the influence and the mechanism.The results show that:(1)The main controlling factors of petroleum migration and accumulation includes the character of the main oil source fault and the sand bodies.(2)When the main oil source fault is strong in transmission,the tilt angle is large,or the fault connects to the source rock which generates and expulses hydrocarbon continuously,the oil preferentially migrates upward along the fault,accumulates in the sand body at the high part and inhibit the accumulation at the low parts.(3)In the sand bodies communicated by main oil source faults,when the tilt angle of the sand body increases,the oil is promoted to migrate in that side of the fault.Better sand body connectivity promotes oil migration within the sand body;poor sand body connectivity promotes oil migration and accumulation in other sand bodies The sand bodies with better properties are likely to become dominant migration channels and accumulates oil.When multiple sets of sand bodies are stacked,the physical properties of the middle sand bodies are more conducive to the promotion of petroleum migration and accumulation.(4)Summarize two types of reservoir formation modes: Fault-sand body episodic petroleum accumulation mode and Fault-sand body continuous petroleum accumulation mode.