Production of Geothermal Electric Power from a Producing Gas Well, St Mary Parish, Louisiana

In February 2012, Access Energy through its parent company Calnetix, initiated a 125 kW Organic Rankin Cycle (ORC) unit on a well in St Mary Parish, Louisiana for the purpose of extracting geothermal heat energy for power production. The unit was on location in January but due to cold weather concerns, unit start-up was postponed till February. The well is operated by Hilcorp Energy Company however the power was produced for Cleco Power LLC. The well is listed as a gas and condensate well by SONRIS and was spudded in June 1979. The well was completed in December 1979 at a TD of 17,300 feet with production in Lower Miocene sands just above the TD. As of the end of May 2011, production from this well was listed by IHS Enerdeq with 769,646 bbls oil, 26,691,789 mcf of gas, and 24,877,655 bbls water.

The power production system is comprised of a high-speed turbine expander and high-efficiency generator as a sealed unit (Integrated Power Module - IPM) connected to a heat exchanger and a condenser. The technology has the capability of operating with a heat source between 180 and 350oF using a refrigerant as the working fluid to drive the turbine-generator. Heat is captured by a heat exchanger from the produced hot water and transferred to the working fluid that is vaporized prior to entering the IPM for power generation. The maximum engineered power output is 125 kW when sufficient BTUs are present for heat-to-electric conversion.

Daily water production through the ORC system is around 5,000 bbls/day at a produced water temperature of around 260oF. Gross power output has been in the 60 to 65 kW, with a parasitic load of around 17 kW, leaving 43 to 48 kW of net power for utility use. This is the first such unit on a producing O&G wells as coproduced geothermal energy. A similar project is underway in conjunction with the DOE, the University of North Dakota, and Continental Resources, Inc. in the Cedar Creek Field water flood in the Williston Basin.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California