An ED-Like
Method for 3D Structural Restoration and QC of Planar Faulted Reservoirs
Freeman, Brett1, Alan Gibbs2,
Graham Yielding1, Stephen J. Dee3, Alan Roberts4,
Peter Bretan1 (1) Badley Geoscience Ltd, Lincolnshire, United
Kingdom (2) Midland Valley Exploration Ltd, Glasgow, United Kingdom (3) Badley
Geoscience Limited, Hundleby, Lincolnshire, United Kingdom (4) Badley
Geoscience Ltd, Hundleby, Spilsby, Lincs, United Kingdom
Structural restoration and fault
displacement mapping are both useful and (to some degree) independent
techniques for assessing the validity of structural interpretation. Restoration
is usually performed using a kinematic model of the volume deformation whereas
displacement mapping is, as far as possible, direct observation. Restorations
using mechanical or physics based methods, including boundary element elastic
dislocation (ED) approaches, are computationally expensive and are often
difficult to pose.
In this paper we propose a hybrid method
that models volume displacement defined by an ED-like displacement function but
with a kinematic implementation. The shape of the displacement function is
exponential and ellipsoidal; its magnitude is scaled such that the volume of
the 1% strain isosurface has approximately the same volume as that for an
elastic dislocation of equal moment and dimensions. The displacement vector can
be chosen arbitrarily and is, most simply, everywhere parallel to the
interpreted fault slip vector.
The benefits of this method are (a) it is
computationally cheap (b) the effects of all faults are dealt with at the same
time (c) the procedure runs directly on the geological model and (d) the
combined use of restored horizon metrics and fault displacement maps provide a
compelling route to 3D validation/QC.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California