Abstract

As part of the US DOE's Regional Carbon Sequestration Partnership program, the Midwest Geologic Sequestration Consortium has four active field demonstrations: two EOR pilots, one S/ECBM pilot, and one brine-saturated formation CO2 injection pilot.

The S/ECBM pilot injection period was seven months which ended in mid-January 2009. The pilot included four wells completed in a coal seam at 900 ft. The injection well and three monitoring wells are oriented in the face and butt cleat directions. About 100 tons of CO2 were injected at 0.50-0.75 tons/day. Results indicate the enhancement of methane gas production and sequestration of CO2 through competitive desorption. Presently, post-CO2 water injection pressure transient tests are being completed to identify changes in cleat permeability resulting from CO2 adsorption.

An immiscible (gas) CO2 EOR flood was started in May 2009 in a sandstone at 1900 ft. The injection rate was 20-25 tons/day. A water injection well was converted to a CO2 injection well. The well is centrally located between eight oil producing wells. CO2 injection ended in May 2010 with cumulative injection of about 7,200 tons. Twelve months of water injection are planned after CO2 injection. Several 100 barrels of incremental oil recovery have been measured; less than 5% of the injected CO2 has been produced.

A liquid CO2 EOR, inverted 5-spot pilot was started in September 2009 and injection continued through January 2010 until winter road restrictions were enforced. During this time 2,860 tons were injected at 25-30 tons/day. While road travel was restricted, 13,000 barrels of water were injected. CO2 injection resumed in May 2010 and is planned to continue through the summer. At the end of the first CO2 injection period, the pattern’s oil production rate increased 200% from its baseline.

The injection well of the deep saline formation test was drilled and completed in 2009. A verification well is scheduled to be drilled later in 2010. Injection is planned for 2011. The UIC permit process is near completion. This one million ton injection project will be in the Mt. Simon sandstone, the deepest sedimentary formation in the Illinois Basin. Injection rates of 1,100 tons/day are anticipated.

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