The Vermillion Basin of SW Wyoming/NW Colorado: Structural Styles and Seismic Pore Pressure Prediction through Over-Pressure
Rigatti, Vincent G.1, Tony LeFevre1, Richard Newhart2,
Kimberly Kaiser1, Scott Goodwin1, and Robert Parney3
1Questar
Exploration and Production Co, Denver, CO
2Questar
Exploration and Production Co, Salt Lake City, UT
3Tricon
Geophysics Inc, Denver, CO
The Vermillion basin is a sub-basin of the Greater Green River
basin and includes the Canyon Creek, Trail, Kinney, E & W
Hiawatha, & Sugarloaf fields. The basin straddles the Wyoming/
Colorado state lines and includes Sweetwater County, Wyoming and
Moffat County, Colorado.
This sub-basin of the Greater Green River basin lies just to the
northeast of the eastern terminus of the Uinta Mountain front and
exhibits transpressional tectonics with evidence of recent extension.
The area is characterized by SW-NE trending anticlines cored by
compressional faults. The folds exhibit steep fore-limbs and gentle
back-limbs, and some areas exhibit large back thrusts.
The first discovery of gas in the Vermillion basin was made by
Questar predecessor Mountain Fuel Supply Company in 1927 at
Hiawatha Field in NW Colorado. Since that time several prolific
fields have been discovered and the area has produced approximately
1 TCFG and 8 MMBO. To date most of the production has come
from shallow Mesaverde sandstones, however there is an emerging
play targeting the deeper Dakota, Frontier and Baxter formations.
There is a regional over-pressure cell in the lower part of the Baxter
Formation through the Frontier (3,000-4,000 ft thick) that requires
mud weights in the 12-15 ppg range to drill.
Within the Vermillion basin there is approximately 200 square
miles of 3D seismic, composed of 3 separate surveys acquired over
the last 12 years. The data has been merged and processed into one
continuous volume of good-excellent quality (Nominal 30 fold with
110 * 110 bin spacing). Source is a mix of Vibroseis and Dynamite
data and recently reprocessed in 2006. In addition to standard
processing (stack, migration, PSTM) of the merged 3D volumes, the
data has also been processed to generate a 3D pore pressure volume.
AAPG Search and Discovery Article #90071 © 2007 AAPG Rocky Mountain Meeting, Snowbird, Utah