贝尔凹陷优质烃源岩的发现及其地质意义

摘要

贝尔凹陷是海拉尔盆地南部最富油的凹陷之一.通过对贝尔凹陷烃源岩特征的研究,发现下白垩统南屯组第一段存在优质烃源岩.该烃源岩为暗色泥岩、泥灰岩、油页岩和含钙泥岩的互层,有机质丰度高,有机质类型好,生烃潜力大,排烃效率高,是形成大规模油气聚集的物质基础.该层段代表了白垩纪早期的缺氧事件,是贝尔凹陷重要的地层对比标志层.南屯组第一段优质烃源岩范围控制了贝尔凹陷油气的平面分布,优质烃源岩层上下油气最为富集.%The Bei'er sag is one of the most rich oil sags in the south of Hailaer Basin in China.The author of the paper focuses on the research of the source rock feature of the Bei'er sag,and finds that there are high-quality source rock in Member 1 of Lower Cretaceous Nantun Formation of the sag.This source rock is the alternating beds of the dark peat,muddy limestone,oil shale and calcium shale,and the source rock has the high abundance of organic matter,good organic matter type,high hydrocarbon-generating potential and high hydrocarbon-exhausting efficiency.All of these are the material base to form the large scale oil and gas accumulation.The formation represents the anoxic event early in Cretaceous period and is the significant stratigraphic correlation marker bed of the Bei'er sag.In Member 1 of Nantun Formation,the high-quality source rock controls the plane distribution of the oil and gas.Above and below the high-quality source rock bed,the oil and gas are very rich.