Landmark Graphics Corporation

Landmark Graphics Corporation, a Halliburton Company

James William Watts

Graham Christopher Fleming

Qinghua Wang

Qin Lu

Dominic Camilleri

Richard Edward Hinkley

Kefei Wang

Wei David Liu

Simulation system and method for a reservoir represented by a model having a plurality of matrix nodes, a plurality of fracture nodes, a fracture zone and a fracture-free zone are described. One embodiment includes computer-implemented steps of, for each of a plurality of matrix nodes in interconnected zones, characterizing the matrix nodes as dual matrix nodes or non-dual matrix nodes. Dual matrix nodes may be treated as a block and eliminated, after which the coefficient matrix and RHS vector for the model are updated. In-fill patterns between and among fracture nodes and non-dual matrix nodes resulting from the elimination are determined. For non-dual matrix nodes, the nodes are merged to a fracture grid, after which the coefficient matrix and RHS vector for the model are updated accordingly. The resultant linear system is linearly solved, and backsolving is performed for any eliminated dual matrix nodes.

System and method for flexible and efficient simulation of varying fracture density in a reservoir simulator

Systems and methods for parallel incomplete LU (ILU) factorization in distributed sparse linear systems, which order nodes underlying the equations in the system(s) by dividing nodes into interior nodes and boundary nodes and assigning no more than three codes to distinguish the boundary nodes. Each code determines an ordering of the nodes, which in turn determines the order in which the equations will be factored and the solution performed.

Systems and methods for improved parallel ILU factorization in distributed sparse linear systems

Systems and methods for determining active constraints in a surface facility network, which include the use of slack variables and multipliers in system equations to eliminate the extraneous (inactive) constraints.

Systems and methods for the determination of active constraints in a network using slack variables

Systems and methods for the determination of active constraints in a network using slack variables and plurality of slack variable multipliers

A method for performing reservoir simulation by solving a mixed implicit-IMPES matrix (MIIM) equation. A variable implicit reservoir model comprises implicit cells and IMPES cells. The MIIM equation includes a first scalar IMPES equation for each IMPES cell and a set of implicit equations for each implicit cell. The simulation method comprises: (a) constructing a global IMPES pressure equation; (b) solving the global IMPES pressure equation for pressure changes; (c) computing first residuals at the implicit cells; (d) determining improved saturations by solving the total velocity sequential equations at the implicit cells; (e) computing second residuals at the implicit cells and at IMPES cells in flow communication with the implicit cells. Steps (b) through (e) are repeated until a convergence condition is satisfied. Alternative to step (d), improved saturations and improved pressures may be computed by performing one or more iterations with a selected preconditioner at the implicit cells.

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Houston, TX, United States of America

James William Watts