Publica
Hier finden Sie wissenschaftliche Publikationen aus den FraunhoferInstituten. On the convergence of systemAMG in reservoir simulation
 Society of Petroleum Engineers SPE, Richardson/Tex.: SPE Reservoir Simulation Conference 2017 : Montgomery, Texas, USA, 2022 February 2017 Red Hook/NY: Curran Associates, 2017 ISBN: 9781510838864 S.709720 (Vol.1) 
 Reservoir Simulation Conference <2017, Montgomery/Tex.> 

 Englisch 
 Konferenzbeitrag 
 Fraunhofer SCAI () 
Abstract
SystemAMG provides a flexible framework for linear systems in simulation applications that involve various different types of physical unknowns. Reservoir simulation applications, with their driving elliptic pressure unknown, are principally wellsuited to exploit SystemAMG as a robust and efficient solver method. However, in order to be efficient and robust, the coarse grid correction process of AMG on the one hand needs to be possible, i.e., the matrix needs to fulfill certain requirements. It has been demonstrated earlier how to ensure this by the dynamic rowsumming (DRS) method. On the other hand, the coarse grid correction must be physically meaningful in order to speed up the overall convergence. It has been common practice in CPRtype applications to use an approximate pressuresaturation decoupling to fulfill this requirement. This, however, can have drastic impacts on AMG's applicability and, thus, is not performed by the DRSmethod. In this work, we are going to see that the pressuresaturation decoupling indeed is not necessary for ensuring an efficient interplay between the coarse grid correction process and the finelevel problem. We will find that a comparable influence of the pressure on the different involved PDEs is much more crucial. As an extreme case w.r.t. the outlined requirement, we will discuss linear systems from compositional simulations under the volume balance formulation. In these systems, the pressure typically is associated with a volumebalance, rather than a diffusion process. The corresponding coarse grid correction does, hence, not provide any benefit regarding the overall convergence: the other PDEs involve pressurebased diffusive parts that have a drastically different structure than the volumebalance has. We will see how SystemAMG can still be used in such cases.