Application of capacitance resistance models to determining interwell connectivity of large-scale mature oil fields

Abstract

In view of the problems existing in the application of Capacitance Resistance Models (CRMs) to large-scale mature oil fields, Capacitance Resistance Model for Producers (CRMP) was selected for analysis, a simplified procedure for applying CRMP to large-scale mature oil fields was proposed, and some examples were analyzed. Several strategies were presented to optimize the solution method, in order to shorten the solution time and speed up convergence rate. These include the implementation of a global optimization algorithm, parameter scaling, and analytical development of gradient vector and Hessian matrix of the CRMP objective function. These improvements enable the application of CRMP to large-scale problems. Stepwise history matching was shown to be an effective technique to improve reliability of the analysis. Our analysis shows that, the connectivity obtained by the presented method agrees with the interpreted connectivities from the observed CO2 injection and production signals, which proves the reliability of the presented method. The connectivity of an injector to the nearby producers can be analyzed based on the CRMP results, and the analysis can be used for related studies, such as determining current water injectors suited for CO2 injection, or current CO2 injectors not suited for CO2 injection. Key words: capacitance resistance model, mature oil field, interwell connectivity, enhanced oil recovery