通过岩心观察、薄片分析,结合测井和录井资料及粒度分析等化验资料,对柴达木盆地北缘马北地区古近系下干柴沟组下段砂砾岩的沉积环境和沉积序列进行了深入研究,认为该区古近系主要为辫状河沉积,并详细讨论了研究区辫状河各微相特征。研究区古近系岩性主要以砾岩、砂岩和泥岩沉积为主,砾岩所占比例不高,具有正旋回沉积序列特征。根据辫状河沉积环境特征和沉积序列建立了研究区辫状河沉积模式。通过对研究区储层物性和沉积微相的关系分析,认为沉积微相为研究区储层的主控因素。 The sedimentary environment and sedimentary sequence of the glutenite in the Lower Paleogene of the Lower Ganchaigou Formation of the Paleogene in the northern margin of the Qaidam Basin were analyzed by core observation, thin-slice analysis, combined with laboratory and log data such as logging and well logging data and grain size analysis In-depth study, that the Paleogene is mainly braided river deposition, and discussed in detail the study of braided river microfacies characteristics. The Paleogene lithology in the study area mainly consists of conglomerate, sandstone and mudstone, and conglomerate accounts for a small proportion of the lithofacies. Based on the characteristics of sedimentary environment and depositional sequence of braided river, the depositional pattern of braided river in the study area was established. By analyzing the relationship between reservoir physical properties and sedimentary microfacies in the study area, it is considered that the sedimentary microfacies are the main controlling factors of the reservoir in the study area.