利用流动单元圈定含油有利区

Locating favorable oil-bearing areas by flow units

针对陕北斜坡中部特低渗透储层受沉积环境、成岩作用、构造等因素影响,储层宏观物性和微观孔隙类型多样、储集性能和渗流结构差异较大、流动层带复杂的特点,选用反映多孔介质地质特征的流动层带指标、储能参数、成岩综合系数、单渗砂层厚度、砂地比、渗透率、孔隙度、泥质含量、夹层分布频率和夹层分布密度等参数,把储层流动单元按渗流能力和储集能力分为好、较好、一般和差4类,建立综合评价指标体系。利用Ⅰ类和Ⅱ类有利流动单元有效地圈定出含油有利区位置及分布范围,为研究区特低渗透油田增储上产提供有利目标和重点层位。

Since extra-low permeability reservoirs in middle of Shanbei Slope were influenced by sedimentary environment, diagenesis, structure and some other factors, macroscopic physical properties and micro-pore types are various, and the reservoir accumulation behavior and percolation structure are variable with complex flow zones in this area. Reservoir flow unit was divided into four types according to the flow capability and storage using various parameters which could reflect geologic features of porous medium including flow zone indicators, energy storage parameters, diagenetic synthetic coefficient, thickness of single permeability sands, sand-land ratio, permeability, porosity, shale content, and frequency and density of interlayer distribution etc. Comprehensive evaluation index system was established. The Location and distribution range of favorable oil-bearing areas were exactly identified according to Type I and H favorable flow units. The results can offer favorable target, major stratigraphic positions and well field for increasing reserves and raising yield in the extra-low permeability reservoirs of this area.