Oil industry's basic tool for in-situ determination of hydrocarbon saturation is resistivity log. Since 1942, Archie's empirical relations have been used to calculate oil (and water) saturations, which are vital for field development. Sw (Water Saturation) and So (Oil Saturation) values are needed in several phases of reservoir life; exploration, development, monitoring, management and long term plans.
In one of major Abu Dhabi offshore fields, a study to develop optimum methodology for determining Archie parameters that represent the corresponding rock properties is initiated. This is to replace the use of one constant value of by variable curve that respond to different rock properties.
In this paper, Archie's equation parameters determination techniques have been reviewed and analyzed. Cost effective, high confidence rock & Log type integration methodology were innovated to determine variable values of two parameters; Cementation and Saturation Exponent. Before this study, Special Core Analysis measurements were the main techniques to get the two parameters.
In this study, thorough investigation on utilizing Neutron, Density, Resistivity & Dielectric logging measurements as replacement of core analysis have showed for valuable opportunity to establish new water saturation log interpretation standards in carbonate rock.