A practical approach to history-matching water-recycling in waterflood reservoir simulation - method and case studies in South Belridge diatomite waterflood 2015IFEDC

Premature water breakthrough (water recycling) negatively affects waterfloods in low permeability reservoirs in the South Belridge Diatomite. Water recycling reduces waterflooding effectiveness by partially or entirely bypassing reservoir matrix. Reservoir simulation is handicapped by the inability to accurately characterize the architecture and dynamic nature for the high conductivity flow paths between injectors and producers. As a result, the traditional history match procedures do not generate rational production forecast. The objective in this paper is to investigate practical approaches based on understanding waterflood fundamental with Buckley-Leverett displacement theory. Basic reservoir rock-fluid parameters must be tuned by matching the primary production before water injection related effects dominate. An analytical waterflood method is used to diagnose premature water breakthrough on a well-to-well basis. Effective water injection and production volumes are recalculated and used to achieve a history-match that honors oil production, reservoir pressure and injection/production volume balance. A field-scale case study demonstrates the application of the proposed approach for appropriate history-match and rational production forecast as verified by the analytical solution and the latest field performance data. The new approach has been successfully applied in making development decision for the conversion from waterflood to steamflood in the field.