From Discovery to Production in Less than Two Years
In September 2014 Mitsui E&P Australia’s predecessor AWE made a major gas discovery while drilling the Senecio-03 well, near Dongara, Western Australia. That discovery became known as the Waitsia gas field (or Waitsia, named after the locally found Waitzia acuminate wildflower).
By August 2016, less than two years later, AWE sent the first gas from Waitsia down the Parmelia Gas Pipeline to Perth.
Moving from initial discovery to gas production in less than two years was a great result. It made a lot of people excited about the potential for further gas discoveries in the region.
A bit of good luck
Although gas has been extracted from the northern Perth Basin for around 50 years, nobody knew there was so much more gas stored a kilometre deeper than previous discoveries in the ground.
In fact, the discovery of Waitsia was the biggest discovery of conventional gas onshore in Australia for over 40 years.
Of great benefit was its location, right next to infrastructure already in place. AWE didn’t need to build a new production facility because the Xyris gas plant was in place and available. AWE didn’t need a new pipeline because access to the Parmelia Gas Pipeline already existed.
Everything fell into place.
Why does it matter that it’s ‘conventional’?
Natural gas is easier to extract from conventional sandstone reservoirs than other types of reservoirs. This is because it flows freely, so there is no need to use stimulation treatments or any special recovery process to get the gas out of the ground.
Waitsia is a conventional gas field.
There are two reservoirs in the Waitsia field; the Kingia and High Cliff Sandstones. The reservoirs are connected to each other. The wells have excellent flow rates and the gas that comes out is of a very high quality.
Project Life and Longevity in the Mid West
The first thing AWE needed to do was test the productivity potential of the Waitsia field. Were both of the reservoirs equally good?
AWE started producing gas from two wells in 2016, testing each reservoir separately so that productivity could be determined. The results have been excellent.
AWE has been producing around 10 Tj of gas every day since August 2016. That’s enough to supply hot water to over 211,000 homes every day.
During this extended production test AWE formed a detailed understanding of the reservoir and how best to develop it. At the same time further appraisal drilling confirmed a larger volume of gas, the result being Stage 2 of the Waitsia project. This is currently in the planning and design phase and is expected to be a much larger development than Stage 1A resulting in our continued presence and activity in the Mid West well into the future.
The calculated size of the Waitsia field has increased considerably since first production in August 2016. AWE drilled and flow-tested more wells as preparations for Stage 2 continued.
It’s an exciting time for Mitsui E&P Australia and for the Dongara region.