Building a Better Framework - The Fused Fault Block Approach

Karen S. Hoffman, John W. Neave, and Erik H. Nilsen
Roxar, Inc, Houston, TX

Reservoir management of mature, complexly faulted fields such as those found in the North Sea requires accurate reservoir models. However, too often shortcuts and compromises are made in the modeling process due to the limitations of the modeling software. Complex fault intersections may be simplified by leaving faults out of the model, and fault dips may be changed in order to avoid intersections or problems in modeling low angle faults. We have developed a new technique for structural framework building that we call the fused fault block method. This method uses a unique approach to creating a fault network and specifying truncations, and eliminates the problems associated with complex truncations and low angle faults. Low angle faults, low angle intersections, crossing faults, and Y-faults are all modeled correctly and without the special handling or workarounds that are often necessary today. The fault framework is carried through to stratigraphic modeling and reservoir grid building without compromising or modifying the framework. Our method provides a mechanism for frequent and rapid updating of the model. Faults and/or horizons may be modified and the reservoir grid re-built without having to re-define all of the fault relationships. Different grids may be built from the structural framework at various resolutions for a range of purposes, such as focusing on a particular platform area or reservoir. The fused fault block method of model building has been used on a number of North Sea fields and has substantially reduced the cycle time for model updates as well as producing a more accurate structural representation.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece