Simulation The Fluid Potential Of Baiyun Sag In The Pear River Mouth Basin

In this paper,the fluid potential of Baiyun sag is the main study object,and the fluid potential and hydrocarbon migration characteristics of Enping and Zhuhai Formation are divided into three periods to simulate separately.The burial history and thermal evolution history are simulated and the characteristic of hydrocarbon generation of every source rocks analyzed before doing the fluid potential simulation.Based on the analysis of the ancient water depth variation of Baiyun sag,we apply the technology of the formation back-stripping and use the basin simulation software of BasinMod to simulate the burial history of the BY-1 well and BY-3 well in the study area.According to the burial curves and depositon rate curve and combined with the tectonic evolution recovery results,we could know that the burial history of Baiyun sag can be divided into the faulted period which from Eocene to early Oligocene,transition period of faulted and depression in late Oligocene,depression phase which from early Miocene to middle Miocene and thermal subsidence period since late Miocene.In the condition of present geothermal field analysis,we utilize the instantaneous heat flow method and the dynamic model of Easy%Ro and use the basin simulation software of BasinMod to simulate the thermal evolution history of the BY-1 well,BY-2 well,BY-3 well,BY-4 well.The results show that the geothermal gradient of the study area is highest in Eocene,decrease in Oligocene,then increase until now.At the same time,the thermal evolution degree of the source rocks has obvious temporal and spatial features.Based on the simulations of the burial history,thermal evolution history and the hydrocarbon generation analysis,we apply the Basin View software and Basin Flow software to simulate the hydrocarbon potential of the Enping upper part and the Zhuhai middle part in three periods.The results show that the high hydrocarbon potential of the two groups mainly located in the primary depression of Baiyun sag,and the hydrocarbon potential is increasing with the geologic time from ancient to now.However,the distribution location of the high potential area was relatively constant.The analysis on the plane migration and accumulation of oil-gas potential shows that the hydrocarbon migration and accumulation units of Baiyun sag can be divided into the northern migration and accumulation unit,northeast migration and accumulation unit,eastern migration and accumulation unit,southeast migration and accumulation unit and southern migration and accumulation unit.Based on the analysis of the preferred conditions of the favorable area such as the hydrocarbon generation conditions,regional tectonic conditions and the direction of the hydrocarbon migration,we found that the northern migration and accumulation unit is best exploration area,the southeast of migration and accumulation unit is more favorable exploration area,the eastern migration and accumulation unit is favorable exploration area,the northeast and southern migration and accumulation units are the general region,and their exploration potential is minimum.