Kinematic Analysis Using Profile and Time-Slice Animations of 3-D Siesmic Volumes, with Three Examples from the Rocky Mountain Foreland Province
Kinematic analysis of geologic structures capable of entrapping hydrocarbons has traditionally been` constrained by an incomplete subsurface database. Now that high-quality 3D data volumes have become available for study and interpretation, complete images of the geometry of subsurface structures are available. By creating animations with continuous profiling moving through a 3D data volume in a selected direction, a vivid mental image of the structure is created. For example, in the case of ubiquitous basement-involved thrust-generated folds of the foreland province, a profile movie using profiles oriented orthogonally to the strike of the causal thrust and advancing from the tip of the thrust to the area of maximum displacement and maximum fold amplitude, a self-same image of the kinematic development of the structure is created. Also, time-slice animation of 3D volumes can contribute to better interpretations of the kinematic development of subsurface geologic structures. For example, bottom-up movies can -- with the appearance of fault-plane reflections within basement -- expose the nucleation and upward propagation of fold-generating thrust zones, and top-down movies can bring to light the evolution of circular rim structures and the downward narrowing of rootless impact structures.
Movies of three structural oil fields in the Rocky Mountain foreland province are presented and discussed; 1) the giant Salt Creek anticlinal oil field on the Casper Arch, a Laramide basement-involved thrust-generated fold, 2) the nearby Sussex oil field, a fault-parallel, basculating, pop-up structure at the Paleozoic level produced by left-lateral shearing along a reactivated wrench zone, and 3) the Red Wing Creek field in the Williston Basin, a 9-km-diameter impact structure buried beneath Jurassic strata and supporting a 2800-foot oil column within the Mississippian chaos of the central peak.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009