Riley Ridge Gas Plant
Capture, Transport and Storage: Denbury Resources
LOCATION: Wyoming, United States
CO2 capture source: Riley Ridge gas treating facility, Big Piney, Wyoming
CO2 storage site: CO2 would be distributed to a number of depleted oil fields in Wyoming
INDUSTRY (FEEDSTOCK): Natural gas processing (natural gas)
OVERALL PROJECT LIFECYCLE STAGE: Evaluate
CO2 CAPTURE CAPACITY VOLUME: 2.5 million tonnes per annum (Mtpa)
CAPTURE TYPE: Pre-combustion capture (natural gas processing)
CAPTURE METHOD: Absorption chemical solvent-based process (Amine)
NEW BUILD OR RETROFIT: Retrofit (to an existing plant)
CO2 CAPTURE START DATE: 2020
PRIMARY STORAGE OPTION: Enhanced oil recovery
STORAGE FORMATION AND DEPTH: Not specified
TRANSPORTATION TYPE: Pipeline (onshore to onshore)
TRANSPORTATION DISTANCE TO STORAGE SITE (LENGTH OF PIPELINE): Not specified
Denbury Resources holds a 100 per cent working interest in the Riley Ridge Federal Unit (in southwestern Wyoming) and a 33 per cent working interest in the Horseshoe Unit acreage adjoining the Riley Ridge Unit. The Riley Ridge Unit and the adjoining acreage is located in the LaBarge Field, from which natural gas, helium and CO2 are currently being produced (see Shute Creek Gas Processing Facility description) which is also the same reservoir from which the Riley Ridge Unit will produce. The gas composition from the Riley Ridge Unit is approximately 65 per cent CO2, 20 per cent methane, five per cent hydrogen sulphide (H2S), less than one per cent helium, and the remainder other gases.
In a series of two acquisitions in 2010 and 2011, Denbury acquired 100% of the operating interests in Riley Ridge. These purchases included a gas processing facility that was under construction at the purchase dates. Denbury placed this gas processing facility at Riley Ridge into service in the fourth quarter of 2013. The plant separates for sale the natural gas and helium from the full well stream and the remaining gases, including the CO2, will initially be re-injected into the producing formation until a planned CO2 capture facility and pipeline are built. Early engineering studies have indicated initial CO2 capture capacity of up to 2.5 Mtpa. The CO2 supply would be slated for Denbury assets in the Rocky Mountain area in Wyoming with high CO2-EOR potential.
Initial development plans for CO2 capture from the Riley Ridge Gas plant envisaged a 2015-17 start-up date. Denbury has indicated that the new plan is for a 2020 development time-line (as conventional developments in the Cedar Creek Anticline area and the Hartzog Draw field are prioritised and CO2-EOR production is pushed back).