Project Profile
Value: Undisclosed
Location: Wind River Basin, 35 miles west of Casper, Wyoming, USA
Reserves: 18.6 MMBoe
Production: 20 MMBbl of oil
The Grieve Oil Field was discovered in 1954 by Forest Oil and has produced 30.2 million barrels of oil with the peak rate of 12,000 barrels of oil per day (BOPD) achieved in 1960. In January 2011, Elk signed an agreement with ExxonMobil for the supply of CO and a transport agreement with Anadarko in April 2011to convey the CO2 in a pipeline to the vicinity of the field. In May 2011, Elk signed an agreement with leading US EOR player Denbury Resources to joint venture the project. Under the agreement, finalised in June 2011, Elk holds a 35% working interest in the Grieve EOR Project with Denbury holding a 65% working interest and is Operator.
Since 1955, the Grieve Field has produced more than 30.2 MMBbls from the Muddy Sandstone reservoir via gas expansion and partial water drive. Pressure maintenance was achieved by early gas injection then blow down. Original Oil In Place estimated volumetrically to be 85 MMBbls; recovery to date is therefore 38%. Enhanced oil recovery (EOR)** has not been previously applied; field is considered ideal for CO2 EOR; additional recovery 25-18% of OOIP ie additional 20-15 MMbbls. In January 2011, Elk signed an agreement with ExxonMobil for the supply of CO2 and is currently working on advancing the project. Elk has assessed various EOR development methods, including alkaline surfactant polymer chemical (ASP) EOR flood. However, the availability of a secure supply of CO2 has provided the opportunity to achieve a significantly higher recovery and greatly improved economics from a CO2 EOR. In 2008, Ryder Scott petroleum consultant’s 3P reserve estimate of the Grieve field from a CO2 flood was 18.6 MMBoe.
The gross oil production rates is expected to exceed 10,000 barrels per day within two years after “first oil”. As a result of an improved reservoir model and history match, the upgraded simulation undertaken by Nitec has forecast an incremental volume exceeding 20 MMBbl of oil may be produced by the CO2 flood. Ryder Scott is currently undertaking an upgraded reserve estimate and classification for Grieve using this additional information. Elk is considering a number financial structures to implement this development. The field also includes an Enhanced Oil Recovery project (EOR). The Grieve EOR Project is in the development phase with injection of CO2, marking the start of the CO2 flood.
Operators:
Elk Petroleum Ltd: With 49% interest
Denbury Onshore LLC: Operator with 51% interest
Contractor:
Ryder Scott: Upgraded reserve estimate and classification