河套盆地纳林湖构造带油气富集主控因素分析

Analysis of main controlling factors of hydrocarbon enrichment in Nalinhu structural belt,Hetao Basin

河套盆地纳林湖构造带被两条断层分割形成“两洼夹一垒”的结构特征,目前已在古近系临河组、乌拉特组和白垩系固阳组发现了三套含油气层系。该构造带为多油源、多层系含油、多类型油藏共生的复式油气聚集,具有较大的勘探潜力。通过分析该构造带的油气成藏条件,结合已钻井分析,认为近油源、晚期弱构造、晚期地层反转是该地区油气富集的主控因素。研究结果为下步勘探提供了方向。

The Nalinhu tectonic zone in the Hetao Basin is divided by two faults to form a structural feature of“two depressions sandwiching one base”.Three sets of oil and gas-bearing formations have been discovered in the Paleogene Linhe Formation,the Wulate Formation,and the Cretaceous Guyang Formation.This tectonic zone is a complex oil and gas accumulation with multiple oil sources,multiple oil-bearing layers,and multiple types of reservoirs coexisting,which has a large exploration potential.By analyzing the hydrocarbon formation conditions in this tectonic zone,combined with the analysis of drilled wells,it is concluded that the near oil source,late weak tectonics,and late stratigraphic inversion are the main controlling factors of hydrocarbon enrichment in this area.The results of the study provide directions for the next step of exploration.