A massively parallel reservoir simulator

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:153089

Kaarstad, T ^[1]; Froeyen, J; Bjoerstad, P; Espedal, M ^[2]

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1. Statoil, Stavanger (Norway)
2. Univ. of Bergen (Norway)

A two-phase sequential IMPLICIT three dimensional reservoir simulator has been developed for massively parallel computer systems. The parallel algorithm is based on recently developed domain decomposition methods. The simulator has been tested using a 16384 processor MasPar MP-2. The simulator building blocks are robust Krylov space iterations using Additive Schwarz as the preconditioner. This approach naturally supports a distributed data structure with overlapping subdomains. In the simulator each subdomain is treated as a small reservoir in its own right, and each subdomain communicates with the neighboring subdomains through boundary conditions. Previous work has shown that the use of minimal overlap is sufficient and computationally nearly optimal for these problems. To solve the pressure equation the authors use a two level Additive Schwarz preconditioner. The coarse grid problem is solved by a multigrid solver and each subdomain problem can be solved with a range of simple iterative or direct methods depending on time, space or robustness considerations. The saturation equation is solved by splitting the equation into one hyperbolic saturation equation and one elliptic saturation equation. The hyperbolic saturation equation is solved by the Modified Method of Characteristics. The solution of the (nonsymmetric) elliptic saturation equation is again obtained using an Additive Schwarz preconditioner.

• OSTI ID: 153089
• Report Number(s): CONF-950206--
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
ALGORITHMS
COMPUTER CALCULATIONS
COMPUTERIZED SIMULATION
FLOW MODELS
FLUID FLOW
OIL SATURATION
PETROLEUM DEPOSITS
RESERVOIR ENGINEERING