Parallel Processing Applied to Local Grid Refinement

Abstract

Abstract Hybrid gridding techniques provide simulation engineers with an efficient technique for refining a simulation grid in regions of the reservoir where fine detail is required. Local grids are usually required near wells to resolve coning effects. This paper describes the implementation of a hybrid gridding system where the individual local grids are processed on separate processors. The implementation is suitable for a range of distributed memory parallel computers including a cluster of workstations linked by an Ethernet type local area network. The basic algorithm solves the global grid with large time steps. This establishes boundary conditions for the local grids which are solved independently with small time steps. The global grid is computed on a master processor with a number of slave processors for the local grids. The algorithm allows the dynamic load balancing of the parallel work and provides a fault tolerant system for the local grids. The system is applied to a full field simulation study, employing a network of workstations. The performance is assessed on both a dedicated cluster of machines and in a typical oil company working environment.