--> --> Predicting the Hydraulic Behaviour of Carbonate-Hosted Extensional Fault Zones
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Predicting the Hydraulic Behaviour of Carbonate-Hosted Extensional Previous HitFaultNext Hit Zones


Predicting the sealing capacity of carbonate Previous HitfaultNext Hit zones is complicated by the heterogeneity of intact carbonates and their respective Previous HitfaultNext Hit rock textures, and the propensity for carbonates to respond to fluids and diagenetic processes. Carbonate-hosted extensional Previous HitfaultNext Hit zones have been examined for locations of Previous HitfaultNext Hit rock, types of Previous HitfaultNext Hit rock produced and their influence on a Previous Hitfault'sNext Hit hydraulic behaviour. The location of Previous HitfaultNext Hit rock affects fluid flow pathways across/along faults and is dependent on the Previous Hitfault'sNext Hit architecture. Previous HitFaultNext Hit zones with multiple slip surfaces often occur in weaker carbonates, distributing Previous HitfaultNext Hit rock and preventing production of a continuous Previous HitfaultNext Hit core at lower displacements, allowing fluids to flow across the Previous HitfaultNext Hit. The sealing potential is also a function of the deformation mechanisms active during Previous HitfaultNext Hit rock production. Lithological heterogeneity in a faulted carbonate succession leads to a variety of deformation mechanisms, generating several Previous HitfaultNext Hit rock types with a range of microstructures along a single slip surface. The types of Previous HitfaultNext Hit rock produced is a function of the host rock texture, specifically grain size, sorting, porosity and strength. Dispersed deformation creates large fracture networks within homogeneously fine-grained, weaker carbonates. In contrast, localised deformation occurs in heterogeneous, coarse-grained, stronger carbonates, creating cataclasite and cemented Previous HitfaultNext Hit rocks. Each microstructure has different poroperm values, varying along-strike and down-dip. Permeability of all analysed Previous HitfaultNext Hit rocks range from 0.0001 to >1000 mD and porosities vary from 1.6% to 34.7%. However, trends to the variable poroperm are observed, dependent on host lithofacies, juxtaposition and displacement. Mixing of different lithofacies at higher displacements increases the types of deformation mechanisms active, creating a variety of Previous HitfaultNext Hit rocks, each with different poroperm values. This causes faults to have a negligible response when simulating reservoir models, with transmissibility multipliers of c. 0.86. Conversely, juxtaposition of similar lithofacies increases the Previous HitfaultNext Hit rock homogeneity including their poroperm, and reduces the transmissibility multipliers to 0.001, causing the faults to significantly reduce flow. Understanding the deformation mechanisms active during faulting of a carbonate sequence aids prediction of the types of Previous HitfaultTop rocks formed, their hydraulic properties and influence during reservoir simulation.