【摘要】 长岭断陷SN109井地震层序地层表明断陷期主要存在三次较大规模的火山活动。烃源岩在3次热事件的长期作用过程中,有机质在沉积初期就处于较高的热演化环境中,加速了有机质的成熟过程。沙河子组—营城组烃源岩约在122Ma(登娄库组沉积末期)埋深1500m,Ro达到0.5%,烃源岩开始生烃,此时,还没有有效的盖层;119Ma时(泉头组沉积末期),烃源岩约埋深2000m,Ro大于1.3%,进入生气高峰和油裂解气阶段,泉二段盖层刚刚形成,天然气以散失为主,约95Ma(青山口组沉积末期)泉二段和青一、二段有效盖层形成,营城组烃源岩热演化Ro达到1.3～2%,油裂解气和高成熟天然气大量聚集,现今气藏中的天然气应以干气为主,勘探方向应加强盆地坳陷和斜坡区古构造,古气藏研究。更多还原

【Abstract】 The seismic stratigraphy of the well SN109 shows that the Changling fault depression has three relatively large volcanic activities during rift faulting.Under the three hot events,organic matters were in higher thermal evolution environment during the early stage of deposition,which speeded up maturation of source rocks.Shahezi and Yingcheng Fm.began to generate hydrocarbon in about 122Ma(late Denglou Fm.) at a burial depth of 1500m,and the Ro value reached 0.5%,but at that time,there were no effective caprocks.When the Ro value reached 1.3% in 119Ma(late Quantou Fm.) at a burial depth of 2600m,source rocks entered the peak of gas generation and pyrolysis gas stage.At the same time,the caprock of Quan-2 Member had just deposited,natural gas were primarily dispersion.When the Ro value reached 1.3%～2% at 95Ma(late Qingshankou Fm.),the caprock of Quan-2 and Qing-1,Qing-2 Member deposited,and a large quantity of pyrolysis gas and high maturity natural gas accumulated.Now the natural gases in the reservoir are mainly dry gas.The exploratory direction in this area should strengthen the study of paleostructure and gas reservoir at the basin depression and slope.更多还原