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Curvature gradient attributes for improved fault characterization. Jamie Rich Kurt Marfurt. University of Oklahoma ConocoPhillips School of Geology and Geophysics. Review of Curvature for Faults. Curvature is commonly used along side coherency to characterize faulting
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Curvature gradient attributes for improved fault characterization Jamie Rich Kurt Marfurt University of Oklahoma ConocoPhillips School of Geology and Geophysics
Review of Curvature for Faults • Curvature is commonly used along side coherency to characterize faulting • Curvature quantifies the degree of bending on a surface and is generalized as a volumetric attribute • We must consider direction and magnitude of curvature
Direction of curvature measurement Circle with a radius equal to the inverse of curvature Largest curvature Smallest curvature Curvature
Circle with a radius equal to the inverse of curvature Largest curvature Smallest curvature Curvature Direction of curvature measurement
Circle with a radius equal to the inverse of curvature Largest curvature Smallest curvature Curvature Direction of curvature measurement
Curvature as a Fault Attribute Largest Magnitude Positive Curvature Largest Magnitude Negative Curvature White, 2013
Moving in the right direction Mai, 2010
Curvature vs Coherence Mai, 2010
Curvature Example Mai, 2010
Curvature and Coherence Mai, 2010
Curvature and Coherence Mai, 2010
Flexure • In order to better locate the fault we are interested in the inflection point • Where does the curvature change sign? • Is that change positive or negative? • Coherency can’t tell us this!
Derivative of Curvature Gao, 2013
Maximum Curvature N Xline Inline
Differential of Maximum Curvature in Maximum direction N Xline Inline
A comment about signs Gao, 2013
Maximum Curvature N Xline Inline
Differential of Maximum Curvature in Minimum Direction N Xline Inline
Maximum Curvature N Xline Inline
Differential of Minimum Curvature in Maximum direction N Xline Inline
Conclusions • Differentials of curvature (Flexure) can be useful for defining fault planes • Care must be used when defining directions and signs • Further consideration and 3D application may expand usefulness