关键词: 构造应力, 平均应力, 油气运移, 连续体力学, 有限元法, 辽河油田

Abstract: Continuous media mechanic theory and Finite Element Method are introduced to solve the problems concerning hydrocarbon migration driven by tectonic stress field through an example of Liaohe Oilfield.Both in order to gain the flow velocity of pore-fluid,the fluid pressure and the solid tectonic stress were studied.Three cases of tectonic forces imposed on the basin:1.only under the action of tectonic boundary force;2.only being loaded by temperature differences;3.under the actions of tectonic forces and temperature loads.The numerical calculation showed that the tectonic pressing stress played a dominant role in driving pore-fluid from the high-stress area to the low one.Hydrocarbons tend to be driven into the basin where the main structural belts are located.The effects of thermal stress caused by difference of temperature are equivalent to pore-pressure in the basin.Thermal stresses have regional effects on oil-gas migration.The phenomena that the generated hydrocarbons in depth of basin always migrated upward to the relative higher points of the basin could be simulated.So the temperature differenceis is also an important factor for oil migration.The distribution patterns of oil resources of the basin may be better recognized by knowing the driving effects on oil from both the tectonic stress and thermal stress,which is of importance in predicting favorable areas for oil accumulation.

Key words: tectonic stress field, average stress, hydrocarbon migration, continuous mechanics, Finite Element Method, Liaohe Oilfield