The impact of vector processors on petroleum reservoir simulation

For three decades the developers of petroleum reservoir simulators have confronted with a dilemma: cost versus stability. The computational work of the fully implicit method grows like the cube of the number of phases when direct solution methods are used. Thus a single iteration of a fully implicit three-phase black-oil model could cost 27 times more than a single IMPES iteration. The advent of vector computers has almost resolved this conflict. Unconditionally stable models carefully designed to exploit the architecture of vector processing computers have been demonstrated to be no more than twice as costly as IMPES models. This development has extended the domain of unconditionally stable methods to field-scale applications.