Abstract - Most petroleum reservoirs contain faults which are highly complex heterogeneous
and anisotropic volumes of 3D deformed rock but are generally
represented in production flow simulation models as 2D planar surfaces. A
major technical challenge is modeling the influence of fault zones and their
associated fault rock properties on fluid flow in hydrocarbon reservoirs.
Vendor commercial reservoir simulators have limited functionality for modeling
faults. Faults are usually expressed as ad hoc transmissibility variations
during the history matching phase of the model instead of retaining
geologically realistic fault zone description. As a result, simulators are inept
to describe the nature of across-fault and along-fault fluid flow. To address
these shortcomings, we aimed to find a flexible and improved solution for
representing faults in hydrocarbon reservoir models considering the geometrical
complexity of fault zones and their associated fault rock properties.
To accomplish these objectives, we devised an emerging algorithm
called flow-based geometrical upscaling (FBGU), defined as the process of
calculating the connection transmissibilities arising from a high-resolution
truth model (which contains 3D fault zone geometry explicitly) and representing
those transmissibilities at the equivalent location of a production
flow simulation model (which is referred as a low-resolution upscaled model
in this paper). The accuracy of the method is assessed by comparing the
flow responses of high-resolution truth model with that of model upscaled
using FBGU method. The results revealed that the FBGU method is extremely
accurate and geometrically flexible.
GCAGS Transactions, 69, 111-123, 2019.