Sand (gravel) Rock Reservoir Flow Unit

The research of flow units is a kind of a application science or advancing edge subject, which widely describe fluid distribution and flowing process during development of a oilfield, it's include the moving difference between oil and water, efficiency differences for water-flood oil, and the distribution differences of the residual-oil-saturation, etc. Define flow units as the three-dimensional continues reservoirs, which have different grades from microcosmic to macroscopical, the lithological, physical and internal structure characteristics of a same unit are the same or similar, the property inside the flow unit is relative homogeneous, the obvious diversities of storage and permeability between the difference units, and there are good seal bounders or impermeable shields outer the flow unit.On the base of deeply analysis the theoretic of flow unit, we doing the systematic study of reservoir flow unit, it's including the classification of flow unit, the comprehensive evaluate flow unit, the relationship between flow unit and the development of oilfield. The article select the Shanan oilfield zero of shaqiu 5 doing the flow unit research.Using the scale analysis thinking in this article, first distinguish and contrast layer according to the " gyration contrast, control by thickness, discriminate in different facies", establish the stratum trellis which include layer, single sand layer, etc. Calibrate logging date by the results of core analysis and experiment, establish the explanation model of physical characteristics, then explain and statistic the parameters of reservoir.From quantitative research, classify the flow unit in the core segments by using probability statistics and systematically cluster analysis, the result of identification of the flow unit is 4 by using probability statistics. According to this method, selecting 6 parameters to characterize flow units which including available porosity, permeability, the ratio of pore volume and grain volume, the reservoir quality index and the flow zone index. Using the techniques of discriminant analysis, establish the estimation model of flow unit, classify the flow unit in uncored wells. General considerate the sediment model, the law of current distribution and the plane heterogeneous in all kinds of reservoir, describe the distribution of flow unit in plain, section and space.After analysis the classification result of flow unit, we find the factors influence the formation of flow unit are very complex, it's including sedimentation, diagenesis, tectonization, and the sedimentation is the most basic and importance factor. The seepage property inside the flow unit is relative homogeneous, the parameters of reservoir such as porosity, permeability variety in some range. The obvious diversities of storage and permeability between the difference units, and there are good seal bounders or impermeable shields outer the flow unit. The seal bounders or impermeable shields are the muddy intervals, and sealing faults. The muddy intervals and the belt of calcareous cementation are the mainly seal bounders.