Numerical Simulation of Multiphase Flow in Subsurface Reservoirs: Existing Challenges and New Treatments

Two or multiple phases commonly occur as fluid mixture in petroleum industry, where oil, gas and water are often produced transported together. As a result, reservoir engineers spent great efforts the development production of oil reservoirs by conducting interpolating simulation multiphase flows porous geological formation. Meanwhile, environmental scientists use subsurface flow transport models to investigate compare for example various schemes inject store CO2 formations, such depleted deep saline aquifers. In this work, we first present an introduction numerical its challenges including multiscale heterogeneity, strong unbalanced nonlinearity, solution discontinuity, local mass conservation, stability bound preservation. For example, preservation is desired basic property solutions but not easy have. requirement, it have predicted physical quantities sit within physically meaningful range. Specifically, predicated saturation should between 0 1 while molar concentration maximum value allowed equation state. Unfortunately, popular methods used industries do preserve bounds. A fix problem simply apply cut-off operator (say, computed saturation) at each time step, i.e., set be zero whenever becomes negative, one larger than one. However, cutoff practice does only destroy also damages global which seriously ruins accuracy interpretability results. After going through number well-known challenges, three frameworks based on our recent works address some these challenges. The recently-proposed boundpreserving, phase-wise locally conservative IMPES-like semi-implicit method two-phase media [1]. addition, framework unconditionally bound-preserving, fully-implicit [2,3]. Finally, study series learning applied phase behavior calculation, can greatly speed up compositional [4].