Permeability is one of the most important parameters that is generated in static model and utilized in dynamic simulation. It defines directly the dynamic flow characteristics of the reservoir model. The permeability measurement techniques are limited to well locations. Due to high cost and time association of these techniques, permeability data, most of the time, is very limited to well locations and reservoir intervals.
Generally dynamic data is not considered in property modeling. Such workflow results arbitrary modification of permeability field during history match process. In an innovative approach, a very robust workflow is developed to incorporate dynamic data in permeability modeling.
The main steps of this new permeability modeling approach:
Permeability values calculated from production tests are compared and incorporated to core permeability values at well locations. Missing sections of core data is filled with test results. Lawereth J function can also be employed to predict permeability, in addition to test results.
Porosity - permeability relationship is established in bivariate data analysis of porosity versus core permeability in terms of power functions on scaled-up data at well location per each sub-zone. These power functions will be utilized to calculate 3D permeability values by using 3D Porosity model as input values into the power functions.
Variability from main trend was later introduced into the power function derived 3D permeability by simulating permeability residuals. Residual is the difference between power function derived permeability and the original scaled up core permeability.
Multiple residual realizations is created using Sequential Gaussian Simulation. Finally, 3D permeability is calculated by combining 3D residuals generated stochastically and 3D permeability calculated by power function with 3D porosity input.
Statistical results, average permeability maps, vertical permeability distribution and vertical cross-sections of multiple realizations will be utilized to quality check of final model evaluation.
Permeability Modeling Workflow