An Evaluation of Criteria for Dynamic Gridding during Reservoir Simulation of Water Flooding and Solvent Injection

Abstract

Some hydrocarbon recovery processes are characterized by the existence of sharp saturation and/or concentration fronts. Examples of such processes are VAPEX, in situ combustion, or water flooding of heavy oil reservoirs in presence of viscous fingering. In order to simulate correctly what happens around the fronts, small grid sizes need to be used. If however the whole reservoir is gridded very finely, computational time becomes prohibitive. In order to circumvent this problem, dynamic gridding, also callled, automatic mesh refinement may be used. During the computation, the computational grid is adapted to the dynamics of the flow. This requires the use of an estimator in order to decide where to refine or to coarsen the grid. In this work we studied dynamic gridding for a water flooding problem. We implemented this problem using the mixed hybrid finite element method in 2-D on a triangular grid. The resulting code was validated by comparison to a commercial reservoir simulator. From literature, we adapted an a posteriori estimator that had been derived for incompressible flow, and we used this to refine our grid on each time step. We show that the grid refinement criterion captures relatively well the sharp saturation front. Heterogeneities are also well captured. The code is able to reproduce some tendencies of viscous fingering, although more time is required to avoid definitely the numerical disperion and dynamic gridding influence. This work is a preamble for a second work considering simulation of the VAPEX process using dynamic gridding. For this we decided to switch to the finite volume method, for which a second code was developed which is shortly mentionned in the perspectives. We think that dynamic gridding may be a solution that will allow the simulation of processes such as VAPEX and in situ combustion at reservoir scale, using effective grid refinement in the region of the front.

Dynamic Coarsening and Local Reordered Nonlinear Solvers for Simulating Transport in Porous Media

“…7) are the coarse-scale transmissibilities in the buoyant and capillary terms. Any upscaling technique that yields coarse-block permeabilities or coarse-interface transmissibilities (Christie 1996;Farmer 2002;Barker and Thibeau 2007;Lie 2019) should be suitable. Herein, we use a simple and robust strategy that first upscales block permeabilities by harmonic averaging:…”

“…More complex cases involving compositional simulations have been demonstrated for an early version of the dynamic coarsening method in Klemetsdal et al (2019b), and the efficiency of LRNTS has been demonstrated for black oil and compositional simulations in Klemetsdal et al (2019bKlemetsdal et al ( , 2019d. All results reported in the following are based on a proofof-concept implementation in the MRST (Lie 2019). This implementation will be included in a future release of the MRST.…”

Cognitive Data-Driven Proxy Modeling for Performance Forecasting of Waterflooding Process

“…Injected water into a reservoir aims to provide pressure support to the reservoir which is called voidage replacement, and to displace or drive oil from the reservoir to production wells. Water flooding performance assessment has been widely investigated in both experimental [1][2][3][4][5] and detailed numerical simulation [6][7][8][9][10] frameworks. Numerical modeling of water flooding recovery performance can be carried out with traditional simulators.…”