Facies and Reservoir Characterization of the Permian White Rim Sandstone, Black Box Dolomite, and Black Dragon Member of the Triassic Moenkopi Formation for CO2 Sequestration at Woodside Field, East-central Utah

Walter Harston and Thomas H. Morris
Brigham Young University

Geologic sequestration of anthropogenic CO2 gasses is an engineering solution that potentially reduces CO2 emissions released into the atmosphere limiting their effect on climate change. This study focuses on Woodside Field as a potential storage site for captured CO2. The Woodside Anticline is a doubly-plunging anticline on the northeast flank of the San Rafael Swell. Particular focus will be on the Permian White Rim Sandstone, Black Box Dolomite and Black Dragon Member of the Triassic Moenkopi Formation as the reservoir-seal system for CO2 storage and sequestration at Woodside Field. The White Rim Sandstone, the primary storage target, is divided into three broad facies: a lower sand sheet facies, a middle eolian sandstone facies, and an upper reworked facies. Porosity in the White Rim Sandstone can be as high as 23% and permeability can reach 2.1 D. The White Rim Sandstone is up to 525 ft (160.0 m) thick at Woodside Field providing a significant volume of porous and permeable rock in which to store CO2. The Black Box Dolomite is the secondary potential reservoir for CO2 storage at Woodside Field. The Black Box Dolomite may be divided into four lithofacies: a caliche, a dolowackestone, a dolomitic sandstone, and a sandy dolowackestone. The combined thickness of these facies is up to 75 ft (22.9 m) at Woodside Field. Porosity can be as high as 29.2% and permeability up to 358 mD. The Black Dragon Member of the Triassic Moenkopi Formation will serve as the seal rock for the relatively buoyant CO2 stored in the underlying formations. Silty mudstones comprise 75% of this member at Black Dragon Canyon. Mudstone beds have from 0.16 to 0.47% porosity. Minerals within these beds that may react with a CO2-rich brine include calcite, dolomite, alkali feldspar, glauconite, and plagioclase. The Black Dragon Member is up to 280 ft (85.3 m) thick at Woodside Field. Volumetric estimates for Woodside Field were calculated based on the 10th, 50th, and 90th percent probabilities (P10, P50, and P90). The White Rim Sandstone is the primary target reservoir and has capacity to store 2.2, 8.8, or 23.7 million metric tonnes (P10, P50, and P90, respectively) of CO2 within the structural closure of Woodside Field. The Black Box Dolomite may additionally store 0.5, 1.8, or 4.5 million metric tonnes, respectively. Combined they have the capacity to capture up to 28.3 million metric tonnes (P90) of CO2.

AAPG Search and Discovery Article #90169©2013 AAPG Rocky Mountain Section 62^nd Annual Meeting, Salt Lake City, Utah, September 22-24, 2013