Multiphase flow in fractured reservoirs
Simulating oil/gas production from fractured unconventional reservoirs is challenging because information regarding fracture characteristics is often unknown or insufficient. The Lawrence Livermore National Lab developed GEOS model, which is used to simulate propagation of hydraulic fractures during stimulation process. With fracture characteristics obtained from GEOS, field data provided at the Hydraulic Fracturing Test Site (HFTS) in Texas, we are able to test our multiphase flow model (TOUGH) in predicting water/oil/gas production at the HFTS. The key challenge in this project is to develop means of coupling between GEOS and TOUGH, which should ideally capture details of multiphase flow inside hydraulic fractures, between multi-scale fractures, and between fracture and matrix.
The figures below shows a 3D, 3-phase simulation of a fractured reservoir. The fracture aperture is obtained from GEOS, which displays certain level of heterogeneity. It can be seen that saturations of the 3 phases in the fracture are affected by fracture shape, heterogeneity as well as the gravitational effects.
The video below shows a 3D, 2-phase (water and gas) example of gas flow in fractured reservoirs.