Performing fault seal analysis

Fault transmissibility is an important aspect of modeling the fluid distribution in the reservoir. In compartmentalized settings, low permeability fault zones can significantly impact initial fluid presence, pressure decline, fluid flow and sweep efficiency. In flow simulation, these fault seal characteristics are commonly represented by transmissibility multipliers defined for the grid cell connections across the fault.

The Fault Seal strip (MODEL > Fault Stability) contains two workflows. The preferred workflow is the Fault Seal Modeling workflow, where you can calculate fault transmissibility directly from the reservoir properties of your grid. The workflow steps lead you through these calculations, from fault displacement to fault smear (seal) zones, fault permeability and fault thickness. The calculated properties are used as input to fault transmissibility (Tf) calculations in the last step of the workflow. Each calculation uses grid cell properties as input.

At the end of this workflow you have a geologically constrained 3D Fault Seal Model that can be selected as input to a reservoir simulation case via the simulation workflows (IMEX™, GEM™, STARS™, ECLIPSE™ and tNavigator™). Reservoir simulation workflow will incorporate the fault transmissibilities to the (conventional) cell to cell transmissibilities. A requirement to start the Fault Seal Modeling workflow is that you have a faulted reservoir grid populated with a V_shale property. You can also map the transmissibilities to your fault model and link the fault model to the fracture model which is used for creating a DFN model using ConnectFlow™.

The second workflow is the Zone to Zone Transmissibility Multipliers workflow. This allows you to manually specify fault transmissibility multipliers per zone-to-zone connection (Z2ZTM) and per fault (FTM) independent of the geological grid properties. With the zone-to-zone transmissibility multiplier option you can capture general lithological characteristics of the (stratigraphic) zonation by reducing the transmissibility between cross-fault connections.

At the end of this workflow you have a Zone to Zone Multiplier Model that can be selected as input to a reservoir simulation case via the simulation workflows (IMEX™, GEM™, STARS™, ECLIPSE™ and tNavigator™). Reservoir simulation workflow will incorporate the fault transmissibility multipliers to the (conventional) cell to cell transmissibilities.