Understanding reservoir connectivity in waterfloods before breakthrough

Interwell connectivity is a key issue in understanding any field performance, especially when secondary and tertiary recovery methods are initiated. This paper shows that capacitance–resistance modeling (CRM) is a viable alternative to solving the prebreakthrough flow problems in a variety of situations. In each case, CRM is able to mimic the results of streamline simulations for establishing fractional flow directed at each producer. We show that one can discern connectivity between the injector and producers in an inverted-five-spot pattern and in channelized reservoirs, and even with limited injection in prebreakthrough scenarios in heterogeneous media. In closed systems, low-signal amplitude may suffice for characterization, provided reasonable injection perturbation exists. The field case reinforced the notion of nonintuitive reservoir connectivity in an actual situation.