Reservoir characterization based on Conventional logs, CMR tool and comparison with Core data in Sarvak (Kuh-e-Mond)

This paper explains a case study of heavy oil carbonate reservoir Sarvak formation in one of the fields South of Iran (Kuh-e Mond). One accomplishment in this processing is good agreement of porosity and permeability profile between CMR logs and core data. CMR log has been able to determine lithology independent porosity, heavy oil identification, permeability, pore size and geometry variations. This reservoir was divided into 2 parts (lower and upper Sarvak). The three 3 and four rock types and flow units were defined for upper and lower Sarvak respectively .These rocks types were distinguished by relationship between logs data, routine and special core analysis and good reservoir has comprised limestones facies with interparticles and vuggy porosity. Reservoir under investigation has calculated CMR Porosity (CMPR), Permeability SDR and Timur/Coates permeability demonstrating a linear relation. Pore throats analysis illustrated a bimodal distribution. Short T2 times has shown small pores with large surface to volume ratio and low permeability whiles large pores has indicated long T2 times. These pore throats classified based on laboratory mercury injection results and T2 relaxation decay time which comprised ranges micro pore, meso pores and mega pores. In pay zone CMR irreducible water saturation have high accordance to irreducible water saturation computed from resistivity measurement .The difference in various relaxations made it possible to distinguished bound water, moved water and high viscosity oil. Heavy oil and water indicate low and high relaxation time (T2) respectively.