Queensland, Australia Coal Seam Methane Gas Wellhead Automation Success Story

Queensland, Australia's second largest state, covers approximately 1,700,000 km2 (656,000 sq. mi.) and is home to more than 3,000,000 inhabitants. It also contains extensive energy supplies in the form of Coal Seam Gas, or CSG.

As an end-use product, CSG is the same as natural gas, and can be utilised in all natural gas appliances and commercial applications. Whereas natural gas is stored in the pore spaces between grains of sand stone or similar rock, CSG collects in the coal seam by bonding to the surface of coal particles. Coal seams in the ground are generally filled with water, where water pressure keeps the gas adsorbed as a thin film on the surface of the coal. In a high quality CSG deposit, fractures within the coal are permeable enough to allow gas and water to flow freely through them. The coal seams that can produce CSG economically are usually between 200m to 1,000m (approx. 650 ft. to 3,330 ft.) below the surface. Multiple shallow wells are used to extract the gas. This project is expected to require more than 300 wellhead sites over the next 2-3 years.

The Queensland CSG project-requirement specification included:

• A projected 40-year design life,
• Use of off-the-shelf equipment,
• Expandability of up to 700 sites,
• Hazardous area certification,
• Operation in a harsh environment, up to 70ºC (160ºF),
• An interface to analog, digital and pulse inputs from various wellhead instruments.