Creating Reservoir Analogs from Outcrop: Immersive 3-D Digital Models from 2-D Mapping

Jana M. Van Alstine¹ and Marek K. Czernuszenko^2
1Geology & Geophysics, University of Wisconsin, Madison, WI
²ExxonMobil Upstream Research, Houston, TX

Outcrop analogs of reservoirs are valuable for characterizing reservoir distribution and connectivity. Field mapping provides detailed description of sedimentary architecture, and observations of faults, fractures, and depositional systems that can be incorporated into reservoir models to increase reliability. The advent of LIDAR (Light Detection And Ranging) has allowed geoscientists to create 3D outcrop models that include field observations. However, candidates for field-based reservoir analogs may be limited by access, location, or an outcrop profile that does not suit LIDAR imaging. We have established an efficient method to create immersive three-dimensional models from detailed field mapping and digital photographs. Our example utilizes high-resolution photographs taken from a minimum of two different angles in order to capture all faces of an outcrop. A surface that mimics the outcrop profile is created out of a user-defined digitized point set, and the photographs are uniquely texture-mapped to that surface. This creates photo-realistic framework that can be populated with quantitative field measurements. Outcrop data are incorporated using the surface as a base for digitizing. Three-dimensional surfaces are built from bedding and fault orientations, and sedimentary bodies are developed as volumes characterized by lithology, grain size, and porosity. The resulting model is an accurate representation of an outcrop, built from quantitative field data, which can be used in an immersive 3D environment. A model can be built out of any outcrop efficiently using digital photographs without the challenges LIDAR data collection may present. This method increases the efficiency and ease of incorporating outcrop geology into reservoir models, and creates virtual examples for education and subsurface comparison.

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas