裂谷盆地油气运移“中转站”模式的实践效果——以渤海油区第三系为例

Practical effect of the "transfer station" model for oil-gas migration in rift basin: A case study on the Tertiary in the Bohai oil province

断层是裂谷盆地重要的油气运移通道。对渤海油区大量成功与失利探井的深入分析表明,单纯断面的运移能力并不强,大断层只有与烃源岩内的"中转站"砂体配合,才能为上部圈闭提供充足的油源;凹陷内小断层根部无"中转站",只能形成小油藏;直立的走滑断层下部无"中转站",其上部无油藏。深入研究断层的运移能力,会大幅提高勘探成功率。

Oil-gas migration is regarded as one of the most difficult problems encountered in researches of petroleum geology in the world and currently a frontier subject as well.Faults are an important pathway for oil-gas migration in rift basins.A thorough analysis of the success or failure of many exploratory wells in the Bohai oil province demonstrated that oil-gas migration is inefficient simply depending on faults,only in concert with sand bodies within source rocks serving as an ＂oil-gas transfer station＂,can large faults provide traps above with an ample source of hydrocarbons.In sags,small faults without ＂oil-gas transfer station＂ at root can only form small oil reservoirs,while vertical strike-slip faults without ＂oil-gas transfer station＂ at root can not form oil reservoirs in upside.It will greatly improve the success ratio of exploration to make further studies on oil-gas migration capacity of faults.