THE INTEGRATED DEVELOPMENT OF GILMORE FIELD AND AN INDEPENDENT POWER PLANT

Abstract

Thirty one years after its discovery in Queensland's remote Adavale Basin, the Gilmore Field has been put into commercial production, supplying fuel gas to Australia's first independent power plant wholly dedicated to feed a state electricity grid.

Gilmore Field is located in PL-65 in Central Queensland. It is a deep, high pressure gasfield which produces dry gas. The gas is primarily methane with up to 21 per cent nitrogen. Three of the five wells in the field currently produce into gas gathering and processing facilities. Gas is piped 240 km to Barcaldine to fuel a Frame-6 gas turbine, generating 37 MW in a peak loading power-station, which operates 14 hours per day, 5 days per week. Further development in Gilmore Field is planned.

Numerous development plans have been proposed for Gilmore Field, since its discovery in 1964, but none were successful due to uncertainties on reserves and remoteness. The recent relaxation of state control on utilities and an increase in local demand for electricity created a niche for development of the field.

Energy Equity Corporation Ltd (EEC) was responsible for the entire development project which consists of gas gathering and field facilities, a 240 km gas pipeline, power plant and the electricity supply contract. This allowed various aspects of the project to be interactively designed to suit the field's capacity and was an important part of the successful development.

As part of the development, the geology was re-evaluated and the field was extensively tested. This resulted in a clearer understanding of the reservoir parameters and a revision of the Devonian stratigraphy of the Adavale Basin. The main producing horizon is the Lissoy Sandstone, a transgressive marine sequence deposited as a strandline over alluvial sandstones of the Log Creek Formation. Reservoir quality is controlled by facies and diagenesis. The productive reservoir consists of near-shore sandstone facies which have developed inter-granular porosity through dissolution of early marine cements. Other facies of the Lissoy Sandstone and the Log Creek Formation are host to low deliverability reserves.