Abstract: The primary migration mechanism of oil and gas in Fuyang oil layer showed that gas and oil migrated to Fuyang oil layer along the fault and fracture under the abnormal pressure in the source rocks.According to the acoustic logging data of hundreds of wells,the overpressure of K₁qn₁ mudstone under the most buried depth was resumed by using balancing depth method.The dynamic force and direction of primary migration of oil and gas were discussed.The ancient fluid potential from K₁n₁ to nowadays was resumed by using numerical simulation.The distribution characteristics of fluid potential and secondary migration direction of oil and gas at the critical time of K₁m₂ were analyzed.On the basis of the distribution of ancient fluid potential,the beneficial hydrocarbon regions in Fuyang oil layer were predicted by combining the characteristics of hydrocarbon-generation and hydrocarbon-expulsion,transforming system,and development of cap formation and trap.

Key words: Songliao Basin, Daqing placanticline area, Fuyang oil layer, hydrocarbon migration, ancient fluid potential, balancing depth method, numerical simulation

摘要： 对松辽盆地大庆长垣及其以西地区扶杨油层油气初次运移机理的分析表明,油气是在烃源层中超压的作用下沿着断层和裂缝运移到扶杨油层。根据约130口井声波测井资料,采用平衡深度法,恢复了青一段泥岩在最大埋深时期的过剩压力,探讨了油气初次运移的动力和方向。在此基础上,采用数值模拟的方法恢复了扶杨油层从嫩江组沉积末到现今的古流体势,并以明水组沉积末期为例,对流体势分布特征及油气二次运移方向进行了分析。以古流体势的分布为主要依据,综合生烃和排烃、输导体展布及盖层、圈闭发育特点等因素,预测出了扶杨油层的有利含油气区带。

关键词: 松辽盆地, 大庆长垣地区, 扶杨油层, 油气运移, 古流体势, 平衡深度法, 数值模拟