A generalized framework for Capacitance Resistance Models and a comparison with streamline allocation factors
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2017 Elsevier B.V. The Capacitance Resistance Model (CRM) is a fast way for modeling and simulating gas and waterflood recovery processes, making it a useful tool for improving real-time flood management and reservoir analysis. The CRM is a material balance-based model that requires only injection and production history, which are the most readily available data gathered throughout the production life of a reservoir. In this work, state-space (SS) equations are derived to describe the dynamic behavior of several CRM representations as a multi-input/multi-output system (matrix representation), computing reservoir dynamics simultaneously as a single system with interactions between injectors and producers. Interwell connectivities, time constants and productivity indices are estimated using a grey-box system identification algorithm. The matrix form of the CRM history matching and a sensitivity analysis to the CRM parameters estimates are presented. This process is computationally fast and easy to apply in fields with a large number of wells. Two case studies validate the proposed methodology: (1) homogeneous reservoir with flow barriers; and (2) channelized reservoir. A comparison between streamline allocation factors and CRM interwell connectivities for every injector-producer pair in the case studies is included to clarify their physical meaning, similarities and differences. The results lead to the following findings: 1) there is a fair correlation between CRM interwell connectivities and streamline allocation factors but the CRM values correspond to the pressure support and can connect more distant injector-producer pairs. The streamline allocation factors reflect water front advance and are largely limited to adjacent wells; 2) the CRM is significantly less sensitive to noise in flowrates than in BHP measurements; and 3) Different CRM representations show important performance differences based on reservoir heterogeneity, input variations and noise levels.
Journal of Petroleum Science and Engineering
author list (cited authors)
Wanderley de Holanda, R., Gildin, E., & Jensen, J. L.
complete list of authors
Wanderley de Holanda, Rafael||Gildin, Eduardo||Jensen, Jerry L