Application of statistical methods for 'flow unit' identification and characterization of a reservoir using well log and core data.

摘要

A flow unit is a stratigraphically continuous interval of similar reservoir process speed that maintains the geologic framework and characteristics of rock types. Permeability and porosity of the reservoir rock has always been considered as two of the most important parameters to identify flow unit for formation evaluation, reservoir description, and characterization. Beyond evaluating permeability and porosity, one can also use combinations of two or more rock properties to gain insight into the character of two through porous media. Porosity is commonly evaluated from the well log data, which are usually available from the most wells in the reservoir. But permeability values, which are generally determined from the core analysis, are not usually available. The need for permeability values significantly limits the identification of Flow Units in reservoirs where core analysis is not abundant.; In this study, in a complex reservoir in West Virginia was successfully characterized using Flow Unit modeling. A linear relationship established between the log density and core permeability data in the cored wells was used to predict the permeability of the uncored wells, allowing for extension of flow units to these wells. Statistical methods were utilized using core permeability and predicted permeability data to identify and describe the Flow Unit in this reservoir. Then the Flow Units from well to well were correlated by statistical calculation to characterize the reservoir.