Since the mid 1990's the technology and methodology for effective gas extraction have been developed to a level where commercialisation of reserves is both technically and financially viable, supporting reliable long term market supply.
The development of effective gas extraction technologies appropriate for the nature and characteristics of Australian coal deposits, at a time of decline in conventional gas reserves, has enabled the industry to take advantage of the growth in demand from major industrial and utilities consumers - both public and private.
In line with conventional practice in the North American CSG industry, development of most CSG in Queensland has been based on vertical drilling technologies. Subject to the characteristics of the target coal seam, this approach has been used to develop a network of vertical wells which are linked to separate gas and water removal systems.
On completion of a well the pump is installed and dewatering begins. If the coal is fully ‘saturated’ with gas, then gas can begin to be released soon after starting the pump. However, gas production would normally be expected to take a number of weeks.
Once gas production starts increasing, water production declines. Over a period of time, which can be many months, gas production progressively increases to a peak rate. WestSide is targeting gas output of at least 500,000 cubic feet a day for every $1 million spent on production well development.
Over a longer period of time the gas production begins a long predictable rate of decline. Individual wells can have an economic life of at least 10-15 years.