A novel flow-based geometrical upscaling method to represent three-dimensional complex sub-seismic fault zone structures into a dynamic reservoir model



Islam, M.S. & Manozocchi, T.
Fault Analysis Group, School of Earth Sciences, University College Dublin.

Abstract - Most hydrocarbon reservoirs contain faults, which are highly complex heterogeneous and anisotropic three-dimensional (3D) volumes of deformed rock. A major technical challenge in full-field flow simulation is to represent the effects of 3D fault zone structure within the two-dimensional (2D) fault planar surfaces using the industry standard commercial reservoir flow simulator due to its limited functionality. Therefore, a new flow-based geometrical upscaling (FBGU) method has been developed for capturing the effects of 3D fault zone structures in conventional low-resolution upscaled flow simulation models. Geometrical upscaling (GU) is the process of calculating across-fault and up-fault transmissibility arising from 3D flow paths through fault zones, and expressing these transmissibilities as implicit connections in a low-resolution upscaled flow simulation model. The high accuracy of the method is demonstrated by comparing the flow responses of high-resolution (referred as truth model in this paper) simulation models in which the 3D fault zone structure is represented explicitly in the grid geometry, with that of conventional resolution models in which it is upscaled using FBGU method. The flow results show that the newly developed FBGU method is extremely accurate and geometrically flexible.

Scientific Reports, 9, 5294.