T2SOLV: an enhanced package of solvers for the TOUGH2 family of reservoir simulation codes

T1SOLV is an enhanced package of matrix solvers for the TOUGH1 family of codes[ T1SOLV includes all the Preconditioned Conjugate Gradient "PCG# solvers used in T1CG0\ the current solver package\ as well as LUBANDa new direct solver and DLUSTB\ a PCG solver based which implements the BiCGSTAB"m# method[ LUBAND\ the new direct solver\ is faster\ more reliable and capable of solving problems orders of magnitude larger than the MA17 routine which it replaces[ A signi_cant capability of T1VOC is two types of matrix preprocessing\ which make possible the solution of a class of challenging numerical problems "previously tractable only with direct solvers# using the PCG routines[ For regular grids\ the size of problems tractable with direct solvers is doubled by implementing aD3 alternative diagonal gridblock ordering option[ 0887 CNR[ Published by Elsevier Science Ltd[ All ri`hts reserved