Abstract
Streamline methods are gaining popularity in the industry by providing fast desktop simulation of large reservoir models or multiple realizations. Traditionally, streamline simulation has been associated with simplified physics, but recent advances have demonstrated its potential also for compressible three-phase or component flows. However, streamline simulation is still most efficient for two-phase incompressible flow, for which one can utilize a particularly efficient front-tracking method to solve 1-D transport equations along streamlines that is unconditionally stable and independent of the strongly irregular time-of-flight grid. In a recent paper, we presented, for the first time, front-tracking methods for simulating 1-D compressible two-phase flow. We also developed two methods that were particularly efficient for solving compressible flow in which one phase is incompressible, motivated by the simulation of CO2 injection. Here we apply these methods to streamline simulation of 3-D models, including a real-life model of a North Sea formation, which is under consideration as a potential target for CO2 deposition. Our numerical results demonstrate that streamlines and front tracking together give very efficient simulation of compressible flow. Similar ideas can also be applied for dual-porosity models, but this is not investigated in great detail herein.