海拉尔盆地贝尔凹陷油源及油气运移研究

海拉尔盆地贝尔凹陷南屯组源岩有机质丰度高、类型好且已成熟,为本区的主要生油岩。大磨拐河组一段为次要生油岩。贝尔凹陷烃源岩灶主要分布在贝西洼陷和贝中的敖脑海洼陷中。油油对比显示出各构造带上的原油具有相似的生物标志化合物分布,表明来源于相同源岩。油岩对比指示原油主要来自于南屯组生油岩。苏德尔特构造带原油沿断裂带由西向东运移,呼和诺仁构造带原油由贝西洼陷北部源岩灶运移而来,纵向上原油显示出从下向上的运移特点。贝尔凹陷油气运移通道主要是断裂或不整合面,通源断裂两侧为油气勘探的有利部位。

Study on the Source and Migration of Oil and Gases in the Beier Depression in the Hailaer Basin

Being hydrogen-rich(mainly type II) and mature,the mudstone in the Nantun Member in the Beier depression served as the main source rock for oil and gases in the area while the Damoguaihe Member is the secondary source rock.These source rocks are mainly distributed in the western Beier sag and the central Aonaohai sag.Comparison of the crude oils in the Beier depression reveals their similar bio-markers and other features,indicating their similar sources.The correlation of oil to rock shows that the oil was mainly generated from the source rock in the Nantun Member.Hydrocarbon migration direction is studied using the maturity parameters of the biomarkers and the indexes of the pyrrolic nitrogen compounds.The migration of oil in the Suderte tectonic belt was from west to east,the oil in the Huhenuoren tectonic belt came from the source rock in the north of the west Beier sag.Vertically oil migrated from the lower to the upper levels.The migration channels in the Beier depression are mainly unconformities and faults.Both sides of the faults are favorable area for exploration.