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7th Middle East Geosciences Conference and Exhibition
Manama, Bahrain
March 27-29, 2006
1 Chevron Kuwait
2 Kuwait Oil Company
Geomechanical modeling is a powerful tool in prediction of fracture distribution in fractured reservoirs. Better understanding of its uncertainty and limits would help us to improve our prediction and reduce inaccuracy of the result.
Several uncertainty sources in the modeling have been identified and discussed. These
uncertainties include 1) seismic
interpretation
, 2) paleo stress orientation, 3) stress status,
and 4) lack of hard
data
for validation. Since 2 and 3 are related to the knowledge of
regional geology and tectonic history our focus in this paper is the impact of
seismic
interpretation
on the results of geomechanical modeling.
We chose Jurassic section in west Kuwait where 3D seismic
image is relatively blur and
built fracture models based on two extreme interpretations, one addressing regional setup
and one focusing local details. The major differences in these interpretations which are
common in interpretations in other areas are 1) fault size in horizontal plane, 2) fault
dimension in vertical direction, 3) fault location, and 4) fault geometry. They also show
some similarities: 1) fault orientation, 2) fault density, and 3) cutting relationship.
Comparison and analysis of the results show that the uncertainty in fracture orientation is
much higher than that in fracture density distribution. Finally, we quantitatively evaluate
and list the uncertainty of predicted fracture versus interpretation
differences.