塔河油田奥陶系碳酸盐岩缝洞型油气藏的主要特征表现为油气藏高度远大于残丘圈闭幅度,油气分布受储集体发育程度控制,纵向上不连续,储集体主要为岩溶-构造作用所形成的缝洞,单个缝洞储集体为独立的油水系统等.运用油藏压力降落法、类干扰试井法和流体性质变化法等方法将塔河油田主体开发区划分出10个连通储渗单元和20个孤立或相对定容封闭体,对这些缝洞单元的特点作了描述.塔河油田整体上不具统一的底水;各油气藏流体性质变化较大.

Tahe Oilfield is located in the southern Ackulie Arch of Xayar Uplift in northern Tarim Basin. The Ordovician limestone reservoir is a unique kind of composite one with multi-units of fractures and/or vugs (or caverns) so it is similar with neither fractural one nor buried-hill one. The height of the reservoir is much larger than the relief of residual trap. Distribution of hydrocarbon is under the control of developing reservoir. Reservoir bodies are composed of fractures and vugs formed by karstification and tectonization, which are not continuous in longitudinal, and usually a single fractured-vuggy reservoir body is an isolated oil/water system. 10 connecting permeable-stored units and 20 isolated or constant-volume sealed bodies of the reservoir are subdivided and described in feature. The whole oilfield has not unitive basal groundwater and quite different quality of fluids exists in different reservoir bodies.