塔河油田9区三叠系下油组沉积相研究

Study on the sedimentary phase of the lower triassic oil formation in Taher Oilfield Area 9

塔河油田9区三叠系下油组是非常重要的含油气层系,其沉积相类型及砂体展布等地质问题引起广泛关注。本文以9区三叠系下油组阿一段为研究对象,通过岩心观察、扫描电镜、粒度分析和物性分析等手段,对研究区的岩性、构造特征、沉积微相特征以及沉积展布进行了分析研究。通过分析结果显示:三叠系下油组砂岩储层为辫状河三角洲沉积产物,将其划分为三角洲平原和三角洲前缘两大亚相类,这两大亚相可识别出分流河道、河道侧缘、水下分流河道、水下河道侧缘、河口坝等多种微相,并根据沉积微相的划分原则和接触关系,建立了沉积微相平面展布图。

The Lower Triassic Oil Formation in Area 9 of Tahe Oilfield is a very important hydrocarbon-bearing formation, and its geological problems such as the type of sedimentary phases and the spreading of sand bodies have attracted widespread attention. In this paper, the lithology, tectonic characteristics, sedimentary micro-phase characteristics and sedimentary spreading of the study area were analyzed and studied by means of core observation, scanning electron microscopy, particle size analysis and physical analysis, taking the section of A section of the Lower Triassic Oil Formation in Area 9 as the research object. The results of the analysis show that the sandstone reservoir of the Lower Triassic Oil Formation is a product of braided river delta deposition, which is divided into two subphases: delta plain and delta front, and these two subphases can identify various microphases such as divergent river channel, river lateral margin, submerged divergent river channel, submerged river lateral margin, and estuarine dam, etc. According to the principle of sedimentary microphase division and contact relationship, a sedimentary microphase plan spreading map is established.