FSAI Preconditioner for Reservoir Simulations

In most of the fully implicit reservoir simulations, the CPR-like preconditioner, which relies heavily on ILU-type preconditioning, is the most widely used. However, ILU is inherently a sequential algorithm. Given the increasing computational demands of modern reservoir simulations, which often run on massively parallel architectures, it is essential to employ a preconditioner that is equally parallel. In this work, we propose an alternative: a CPR preconditioner based on the FSAI preconditioner which is known for its high parallelism. Additionally, we introduce several modifications to enhance overall preconditioning performance.