Integrated Workflow for Reservoir Characterization and Simulation of a Devonian Carbonate Pool in Southern Alberta, Canada

Collazos, Juan Pablo, Anadarko Canada Corporation, Calgary, AB

The purpose of this paper is to set a clear and effective workflow to be applicable to any project that might be used in a shared earth modeling application for detailed reservoir char­acterization and simulation. Traditionally, all different steps were performed on individual platforms that were not interacting with each other, leading to restricted interaction between the Disciplines. In this project, we made sure that all technical Disciplines were fully involved in the modeling process. The Geologist, the Carbonate Sedimentologist and the Petrophysicist, teamed up to describe the lithological facies that will be used in the model. Once the rock facies are interpreted, the next step is to define the ‘petrofacies’ and flowing units from logs which will be the building blocks of the model. Using primarily Rhob, Neutron,Gr, and Resistivity, we have defined a series of cutoffs or ‘rules’ that were entered into Petrel as an equation to calculate the different ‘petrofacies’ for all the wells. Both facies and petrophysical properties were stochastically distributed in three dimensions using Sequential Indicator Simulation and Sequential Gaussian Simulation methods, respectively. For each input parameter of the hydrocarbon-in-place equation, sensitivities have been per­formed and tied back to production history matching. This has allowed the correct level of heterogeneity to be applied to the geological model, together with the optimal approach to water saturation calculation within the model. This approach to validation has lead to better, more accurate quantification of hydrocarbon reserves, especially when compared to the ‘tra­ditional’ ‘layered’ approach to reservoir characterization.