Efficient solution for matrix-fracture flow with multiple interacting continua

An efficient numerical procedure for implementing the multiple interacting continua (MINC) method for fractured porous media in a general-purpose mult iphase simulator is presented. This procedure is substantially faster, requ ires less memory, is amenable to any n-component, multiphase non-isothermal package, and is readily adaptable for parallel processing computers. The p resent procedure results in a reduction of the computing time by a factor o f the order of NMINC3 as compared to the band algorithm, where NMINC is the number of nested continua into which each matrix block is further discreti zed. The memory requirement approaches a reduction factor of the order of N MINC2 for larger problems compared to the band algorithm. The code for the algorithm was structured so as to set up the time consuming, but independen t, computations for each matrix block in a subroutine that was parallelized and tested using a Sequent machine accessed under a UNIX environment. For NMINC = 10, total computing time was reduced by 33 per cent for the use of two versus one processor, with the savings increasing for increasing NMINC. The proposed procedure can be implemented with the same ease and efficienc y in conjunction with any iterative or direct method, and the grid-blocks c an be ordered in any non-standard manner such as in D-4, D-2, and others. C opyright (C) 1999 John Wiley & Sons, Ltd.