Development of Integrated Capacitance Resistive Model for predicting waterflood performance: a study on formation damage

The Integrated Capacitance Resistive Model (ICRM), a linearized form of Capacitance Resistive Models (CRM), has been commonly used to match liquid production history and estimate interwell connectivity (IWC) in waterflooded reservoirs. Although this model fits cumulative production data accurately, it usually fails to estimate correct values of total production, where backward subtraction of cumulative production delivers highly overestimated or underestimated total production rates. To address this issue, a modified optimization approach is presented to minimize the error between both cumulative and total production data through two consecutive constrained objective functions. This paper validates the modified ICRM in homogeneous synthetic examples with vertical wells to show how the new approach can successfully characterize the waterflooded reservoirs. The model was also tested in damaged formations to detect its impact on the communication between wells. Finally, a correlation is proposed to explain the mathematical and physical relationship between formation damage (skin factor) and IWC of the damaged well. Abbreviations BHP: bottom-hole pressure; CMG: computer modeling group Ltd.; COF: Consecutive objective function; CRM: capacitance-resistive model or capacitance-resistance model; CWI: cumulative water injection; ICRM: integrated capacitance-resistance model; IMEX: Implicit-explicit black oil simulator.