Linc Energy Ltd., Brisbane, will soon start cyclic carbon dioxide injection into one of several fields in which it plans to implement enhanced oil recovery projects in the Powder River basin in Wyoming.
Linc Energy let a contract to Praxair to inject 500 tonnes of liquid CO2 into the South Glenrock B Unit-34 well, in which it cemented a new liner to ensure injection integrity.
Injection is to start by the end of 2011 into the Cretaceous Dakota formation, the first of nine potential stratigraphic zones identified for EOR using CO2 injection. Initial injection rates of up to 7 MMcfd will increase to more than 30 MMcfd as the CO2 injection infrastructure is developed.
In February 2011, Linc Energy acquired Big Muddy, South Glenrock, and South Cole Creek oil fields in Converse County from Rancher Energy Corp. Four operating units produce a combined 215 b/d of oil.
Nitec LLC, Denver, has estimated that CO2 flooding could potentially recover in excess of 10,000 b/d each from South Glenrock and Big Muddy fields. Linc Energy has reengaged Nitec to work with company engineers to evaluate the South Glenrock B Unit for varying volumes of CO2 to allow the company to begin a CO2 flood with lower initial volumes, ramping up to a larger scale in the future.
Praxair, meanwhile, has staged seven 60-tonne CO2 bullet storage tanks at the South Glenrock B-34 wellsite and is trucking CO2 about 250 miles from its Walden, Colo., facility until a pipeline can be built. CO2 will be piped from the bullet tanks through a manifold system, heated to 60° F., and pumped downhole at high pressure at 1-3 bbl/min.
The well will be allowed to “soak”" for 19-21 days before oil, water, and CO2 are flowed back and separated. A similar program was conducted in the South Glenrock B Unit in 1991 in which 250 tons of CO2 were injected, boosting oil output to 50 b/d from a preinjection 13 b/d. Production above the baseline rate was sustained for nearly 6 years and an incremental 12,000 bbl of oil produced.
The Glenrock assets have produced more than 140 million bbl of oil under traditional drilling.
Linc Energy also contracted Nicolas Consulting Group, Midland, Tex., to finalize the front-end engineering and design study for production and recycle compression facilities for the Glenrock CO2 EOR project.
Linc Energy contracted Wood Group PSN to prepare Glenrock field for construction. Wood Group is performing an “as-built” survey from which it will use existing rights of way to minimize surface disturbance. Wood Group is also developing a project execution plan, due in January 2012.
Linc Energy has executed an engineering services agreement with Rocky Mountain Power to evaluate and provide preliminary engineering and construction cost estimates for the power infrastructure improvements necessary for wellsite, production, and recycle facilities. Scope deliverables are due January 2012.
South Cole Creek, smallest of the three fields, has produced more than 17 million bbl and is yet to be evaluated for EOR.