Identification of activated (therefore potentially conductive) faults and fractures through statistical correlations in production and injection rates and coupled flow-geomechanical model

Long-range, stress-related and fault-related characteristics of correlations in fluctuations in flow-rates are explained conceptually in the context of the lithosphere's near-critical mechanical state and a strong feedback between deformation and local permeability. A more sophisticated statistical model, devised to extract a parsimonious set of flow-rate correlations, has shown similar characteristics. Coupled geomechanical-flow modeling was able to reproduce those characteristics for a generic pattern watcrflood perturbed with random noise, but only when loaded to a near-critical state, hence providing strong support for the conceptual model. Coupled modeling of a cross-section representative of the Gullfaks field also demonstrated long-range influences. The matrix of empirical correlations between all well-pairs for a field can be decomposed in various ways. The principal components of the matrix, when interpolated with appropriate spatial correlation functions, have indicated the importance of particular faults in the rate fluctuation history; it is inferred that those faults are mechanically active during the development, and thus are potentially conductive features.