Propagating Fault-Throw Uncertainty for Probabilistic Forecasting Using a Structurally Consistent Perturbation Method
G. Godefroy, A. Irving and Y. Chen
Event name: 81st EAGE Conference and Exhibition 2019
Session: Petroleum Systems - Fault Seal Analysis and Compartamentalization
Publication date: 03 June 2019
Info: Extended abstract, PDF ( 2.43Mb )
Price: € 20
Numerical reservoir simulation models represent subsurface geometries and heterogeneities affecting fluid flow, supporting hydrocarbon production forecasts and reserve evaluations. Uncertainty on horizon and fault geometries affects assessments of hydrocarbon volumes and across fault connectivity. We present a stochastic method that perturbs horizon geometries around faults to represent seismically unresolved fault drag. This method preserves the structural style of dip-slip faults, even close to branch lines. The method is implemented in the frame of the Geochron model, facilitating the generation of a flow simulation grid for each realization. We perform multiple flow simulations to assess the impact of fault throw uncertainty on reservoir dynamic behaviour. As a first example, we applied the method to a synthetic layered reservoir model having single production and injection wells separated by a fault with uncertain throw. Simulated oil and water production rates vary considerably over the realizations, demonstrating the impact of the uncertainty in fault throw. Future work includes evaluating the method for more complex fault networks, assessing the relative impact of uncertainties in fault throw and other parameters, and including both in assisted history matching procedures.