New Approach Using Dual Porosity Dual Permeability and Dissolved Pore Network to Simulation Modeling for Fractured Carbonate Reservoir in Abu Dhabi

Abstract

Abstract In this paper, we present a case study of using dual porosity dual permeability (DPDP) simulation for an offshore Abu Dhabi carbonate oil reservoir exhibiting complex flow behavior through matrix, fracture system and conductive faults. The main objective of the study is to present and explain the reservoir flow behaviors by constructing and using advanced reservoir geologic and simulation models. The results of the study will be utilized as part of the inputs for full field development plan. Initially, an extensive work on the faults and fractures characterization was conducted to properly integrate this information into a dynamic model using DPDP modeling approach. However, the poor response of some wells or field sectors indicated the insufficiency of this concept to capture the full complexity of the reservoir system. Consequently, a new geological concept was proposed to represent the effect of enhanced matrix permeability related to facies dissolution process in the reservoir model properties distribution. To perform such model modification, an innovative new approach was developed called "Dissolved pore network" concept, linking matrix permeability to the fraction of matrix rock macro pores system inferred from the pore size distribution of MICP plug analysis. This "Dissolved pore network" concept was originally developed by Schlumberger in previous projects based on their worldwide experiences. The concept was successfully implemented in this study using an empirical equation to enhance the permeability of a certain category of facies affected by the dissolution process. The study successfully demonstrated that the proposed geological concept integrating the dissolved pore network concept with the faults and fractures system in the reservoir modelling workflow allowed better understanding and representation of the reservoir complexity and the well flow behavior. This smart combination of the two distinct systems was never implemented in a similar manner in the oil industry. Therefore, we strongly believe that this successful implementation will pave the way for constructing more realistic reservoir models for a complex reservoir with multiple pore systems.