Application of Hydraulic Flow Unit Technique for Permeability Prediction in one Iranian Gas Reservoirs, Case Study

Estimating reservoir permeability in un-cored intervals-wells are a generic problem common for all reservoir engineers. In this paper, routine core analysis and well log data of an actual existing gas reservoir, from southwest west of IRAN, were used to develop a model of matrix permeability in un-cored well by using Hydraulic Flow Unit Approach (HFU). The Graphical Clustering Methods such as histogram analysis and probability plot are used to identify the number of hydraulic flow units. Also, the sum of square errors (SSE) method was used as criterion for confirming the optimal number of HFU’s. Permeability data can be obtained from well tests, cores or logs. Normally, using well log data to derive estimates of permeability is the lowest cost method. Formation permeability controls the strategies involving well completion, stimulation, and reservoir management. Results showed that six HFUs were identified from core data and each unit has its own mean Flow Zone Indicator (FZI). In addition, a correlation between FZI calculated from core data and that obtained from well log data was developed for estimating permeability in un-cored intervals-wells with R-Squared Value of 0.60. Also, Lorenz plot shows that the flow units 3 and 6 have a good porosity and high permeability.