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 acuminata 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.
Since then, MEPAU has expanded the Waitsia gas production capacity and increased the reach to market by connecting to the Dampier to Bunbury Natural Gas Pipeline. Waitsia Stage 2 is scheduled to start construction in mid-2021 with first gas planned in mid-2023.
Waitzia acuminata – image by Gail Reed
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 Production Facility 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 the company needed to do was test the productivity potential of the Waitsia field. Were both of the reservoirs equally good?
Gas production started from two wells in 2016, testing each reservoir separately so that productivity could be determined. The results have been excellent.
Around 10 TJ of gas has been produced every day since August 2016. That’s enough to supply hot water to over 211,000 homes every day.
During this extended production test MEPAU 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 1 Expansion, which began construction in January 2020, and the proposed Stage 2 of the Waitsia project. Stage 2 is nearing the end of the planning and design phase and will be a much larger development than Stage 1 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. MEPAU 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-Port Denison region.