长岭断陷龙凤山地区下白垩统地层压力特征及其对油气成藏的影响

长岭断陷龙凤山地区下白垩统油气资源丰富,油气分布受异常压力控制明显,研究地层压力特征及其对油气成藏的影响具有重要意义.利用实测地层压力和测井资料,对龙凤山地区下白垩统地层压力特征进行分析,探讨沙河子组超压成因;利用包裹体均一温度-盐度法并结合盆地模拟技术,恢复地层古压力演化过程,以明确地层压力演化对油气成藏的影响.结果...

Pressure Characteristics and Its Influence on Hydrocarbon Accumulation of Lower Cretaceous Formation in Longfengshan Area,Changling Faulted Depression

Longfengshan Area in Changling Faulted Depression is abundant in Lower Cretaceous hydrocarbon resources, and the hydrocarbon distribution is obviously controlled by abnormal pressure, so it is important to study the characteristics of formation pressure and its influence on hydrocarbon. The measured formation pressure and logging data were used to analyze the pressure characteristics of Lower Cretaceous Formation in Longfengshan Area and explore the causes of the overpressure in Shahezi Formation. The evolution of formation paleopressure was restored by the inclusion homogenization temperature-salinity method in combination with the basin modeling technology to determine the influence of formation pressure evolution on hydrocarbon accumulation. The results showed that the bottom-up pressure of Lower Cretaceous Formation in the study area was normal pressure, overpressure and normal pressure, and Shahezi Formation was under overpressure due to pressurization during hydrocarbon generation; the northern subsag belt was at the center of overpressure in the study area, and the formation pressure transited to normal pressure in all directions; the evolution of formation pressure experienced five stages: pressurization during early hydrocarbon generation, initial pressure release, pressurization during late hydrocarbon generation, secondary pressure release, and slow pressure accumulation; the overpressure generated in hydrocarbon generation of source rocks of Shahezi Formation was the main driving force of hydrocarbon migration, and the hydrocarbon migrated along the direction of the remaining formation pressure drop and mainly accumulated in the southeast gentle slope belt. The study results have a certain guiding significance for the in-depth exploration and development of Longfengshan area, Changling Faulted Depression.