Reservoir Surveillance Program Optimization Using Rapid Nuclear Modeling Integrated with Formation Testing and Sampling

Abstract

Abstract Reservoir surveillance is of critical importance for the intergrated management of mature reservoirs. Accurate oil saturation monitoring is needed for operational decision making and planning. Reducing saturation uncertainties relies on accurate petrophysical parameters that reflect static and dynamic reservoir properties. The accuracy requirement for remaining and residual oil saturation is trending to be tighter for applications like improving flood sweep efficiency. The conventional technique using a pulsed-neutron (PN) measurement has been proven effective for most applications of time lapse saturation analysis. Traditional PN interpretation workflow underlies standardized tool responses for specific corrections based on borehole conditions, as well as reservoir rock and fluid properties. The measurements are converted into standardized tool responses using environmental correction algorithms before further processing with saturation models, which lead to answers of petrophysical significance. This paper documents a new model that integrates rapid nuclear modeling of PN tool responses, along with formation testing and sampling data so that variations in reservoir fluid properties are considered, for more accurate in-situ oil characterization.