Multiscale Geomodeling of Eolian Reservoir Analogues. A Virtual-Outcrop Study of the Jurassic Page Sandstone Formation

Abstract

Excellent exposures of the eolian Page Sandstone Formation (Bathonian – Bajocian) around Lake Powell have been studied as eolian reservoir analogs. The study is based on an extensive virtual outcrop model gathered using terrestrial LIDAR combined with ground based and UAV (drone) acquired images. A petrophysical dataset was also collected and integrated with 13 traditional outcrop logs. The Virtual Outcrop Model encompasses a c. 1 km² cliff-outcrop volume (with the Page Fm. extending up to 55 m thick locally) on the main mesa and several outlying knobs providing excellent 3D control on the facies architecture at several different scales of heterogeneity. The deposits of the Page Fm. represent the downwind migration of small barchanoid, eolian bedforms superimposed on larger compound dunes. The compound dune sets are further subdivided by a series of regional super-surfaces (Havholm and Kocurek, 1994). This hierarchal complexity which includes 8 lithofacies distributed in a framework with at least 4 orders of bounding surface provides an excellent opportunity to develop multi-scale modelling techniques for eolian reservoirs. A series of geocellular models have been built. These were conditioned from the field data and from a series of process based using three-dimensional quantitative, bedform forward modelling software (after Rubin, 1987). The models were populated with the petrophysical data and used to determine Representative Elemental Volumes for the different scales of heterogeneity within the system.

AAPG Datapages/Search and Discovery Article #90259 ©2016 AAPG Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016