We propose a novel approach that uses streamline-based drainage-volume computations using a "diffusive time of flight" to infer reservoir compartmentalization during primary production. Our approach consists of three steps. First, we perform a traditional decline-type-curve analysis of the primary production data to identify well communications and estimate the drainage volume of individual wells. Second, starting with a geological model, the drainage volumes of each well are recomputed with a streamline-based flow simulation. Finally, flow barriers and reservoir compartmentalization are inferred through a matching of the streamline-based drainage volumes with those from the decline-curve analysis.
Our approach is completely general and can be applied to reservoirs in the early stages of field development and with very few wells. We demonstrate the power and utility of our proposed method using synthetic and field examples. The field example is from a field in the Gulf of Mexico. Starting with a reservoir model based on well-log and seismic data, reservoir compartmentalization and flow barriers are identified from 3 years of primary production response.