Towards the end of January, Jess was invited to the official opening of the Moomba Carbon Capture & Storage Project (CCS) at Santos’ Moomba Gas Plant in northeastern South Australia. The project is designed to store up to 1.7 million tonnes of CO2 per year, which is equivalent to 10% of South Australia’s annual CO2 emissions, and is one of the largest operational CCS projects in the world. Santos has also stated that this is one of the lowest cost CCS projects globally, with a lifecycle cost of less than US$30 per tonne of CO2.
The Cooper Basin, where Moomba is located, covers 130 square kilometres and stretches 500 kilometres from east to west. The gas field is twice the size of Tasmania and the actual size of England. Out there, the operational team need to bring in or generate everything needed. They generate all the water and bring in the food needed to support 1000 people working on the fields at any one day. There are 150 separate gas fields and 1,000 producing gas wells.
A group of about 80 people, including staff, project partners and other key stakeholders, flew in for the day to see the new facility and hear about the achievements of the project team. The site tour was brief, and they were only able to view it from outside the fence. Still, she gained a strong understanding of what a CCS project actually looks like.
Essentially, it is a bunch of pipes and pumps in a shed, and Jess was struck by just how simple it all was. In fact, there is nothing that special at the site at all. This is not to downplay the achievement of the company in getting this project up and running, or the capital that has been spent building the pipeline infrastructure across a gas field the size of England. However, in the end, the technology and infrastructure involved are relatively simple. CO2 is captured at the Moomba gas plant and fed through dehydration units, it then goes through a four-stage modified natural gas compressor, and finally the CO2 itself is piped out to five injection wells using a mild steel pipe.
First injection at Moomba started mid-2024 and, so far, the team has achieved 98% effectiveness. The main limitation is during days of extreme heat, as the processing power of the compressors needs to be reduced; other than that everything has been working as expected. From here, the focus moves to monitoring and making sure that there are no adverse impacts from injecting CO2 back into the empty gas reservoirs.
At this point, there is only one other working CCS project in Australia, which is at Gorgon off the coast of Western Australia. Chevron’s Gorgon CCS plant is the largest in the world with the ability to store 4 million tonnes of CO2 per year. Its plant injects the CO2 into a giant sandstone formation two kilometres under Barrow Island. Both projects have been heavily criticised by environmental groups, some investors, and some community members. CCS is still controversial. However, from what we saw during the site visit , this may well be a turning point for CCS in Australia.
CCS can be quite expansive to achieve but for Moomba, a few unique attributes has kept the lifecycle cost relatively low. Firstly, CO2 separation was already taking place at the site and secondly, transportation over long distances was not needed. Unlike other developments where hundreds of kilometres of pipelines might be needed, in this case only one 50km pipeline was built. This is the first of a number of CCS projects that Santos is proposing. Although the jury is still out as to whether the economics will work as well as they do at Moomba, the outlook is positive.
