Fast high-resolution prediction of multi-phase flow in fractured formations

• We describe and apply a new reduced order modeling technique that allows flow in fractured reservoirs to be accurately determined with significant reduction in computational cost.
• The method does not require intrusive changes to codes, and readers can easily replicate the method; only low- and high-resolution models are needed.
• The accuracy of the reduced order model is approximately determined using an error estimator.

The success of a thermal water flood for enhanced oil recovery (EOR) depends on a detailed representation of the geometrical and hydraulic properties of the fracture network, which induces discrete, channelized flow behavior. The resulting high-resolution model is typically computationally very demanding. Here, we use the Proper Orthogonal Decomposition Mapping Method to reconstruct high-resolution solutions based on efficient low-resolution solutions. The method requires training a reduced order model (ROM) using high- and low-resolution solutions determined for a relatively short simulation time. For a cyclic EOR operation, the oil production rate and the heterogeneous structure of the oil saturation are accurately reproduced even after 105 cycles, reducing the computational cost by at least 85%. The method described is general and can be potentially utilized with any multiphase flow model.