Reservoir Simulation of a Heterogeneous Carbonate Field, Key Sensitivities and Dependencies, Kangan/Dalan Formation, Iran

Jens H. Rolfsnes¹*, Daniel Berge Sollien¹, Arild Eliassen¹, Arnstein Waldum¹, Joanna Garland², and Ali A. Taghavi^3
1StatoilHydro, Norway
²Cambridge Carbonates Ltd., UK
³Reslab Integration, Norway
*[email protected]

Gas-condensate production from a strongly heterogeneous carbonate field of the Kangan-Dalan (Khuff) Formation was studied through reservoir flow simulations. The dynamic behaviour and production performance were investigated for reservoir simulation models resulting from different geologic modelling strategies. Simulation models were scaled-up from 3-D geologic reservoir models populated with properties based on different stochastically generated facies distributions. Results for two qualitatively different stochastic modelling procedures were compared; one using a depositional facies model and another that includes diagenetic facies to account for diagenetic overprint of reservoir rocks and the corresponding alteration of properties. The differences in predicted production, resulting from the different modelling strategies, demonstrate the control on fluid-flow properties by diagenesis. Simulation results from the heterogeneous models were compared with those from a simple layer-cake -type model obtained from averaging well-log data in each reservoir zone. The results showed the impact of heterogeneity on production rates and ultimate production. Key model sensitivities in the prediction of fluid flow, initial fluid volumes and recoverable volumes will be discussed. In particular, the dependencies on choice of up-scaling techniques, the modelling of initial water saturation and the determination of residual gas saturation to water flooding are demonstrated.

AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain