3-D Reconstruction of Clinoform Geometries Using Drone-Based Photogrammetry, Upper San Andres Formation, Last Chance Canyon, New Mexico

Abstract

We present the integration of field-based geological data and drone-based photogrammetry to produce a 3D digital model of the carbonate ramp system in Last Chance Canyon (LCC). The study area represents an outcrop analogue for the Upper San Andres reservoirs on the Northwest Shelf and Central Basin Platform of the Permian Basin. Goal of this study is to quantify the 3D facies distribution in order to improve our understanding of how external and internal controls affect along-strike variability and sediment volume distribution in the system.

Our 3D model contains quantitatively constrained ranges of geometries and stratal stacking patterns, which can be used as guidelines for facies correlation and the reconstruction of reservoir architecture. This enables a better reservoir characterization for continued development and production in the Upper San Andres Fm by reducing uncertainty in existing reservoir subsurface models away from well control. Ultimately, the resulting model can be used to link between the scales of well information and seismic data.

Previous work in LCC does not capture the along-strike variability and sediment volume distribution of the clinoforms that form the 5^th-order parasequences. Our study integrates 2D field data into a digital 3D model that honors outcrop descriptions and extrapolates realistic 3D geometries and volumes of depositional facies. The clinoforms have slope angles of up to 15 degrees and a progradational extent of about 400 m in dip direction. We identified siliciclastic slope channels in strike directional outcrops that have a maximum width of 250 m and depths of up to 30 m. Based on these outcrop observations, we estimate that a well spacing of 40 acres or less is required to encounter connected internal clinoform facies in dip direction. Along strike, we estimate overlap and/or connectivity of clinoform facies to be encountered at a well spacing of 15 acres or less.

Our photogrammetry work pushes the physical limits of current drone technology and advances previous outcrop-based investigations of carbonate systems by enhancing and transforming traditional 2D outcrop information into a comprehensive 3D geological model. A key technical contribution of this study is the capturing and quantification of three-dimensionality in the Upper San Andres clinoforms, as well as their internal 3D sediment volume and facies distributions.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018