Australian geothermal hopeful Geodynamics delivered some welcome news to the subdued sector on Tuesday with some positive results from a flow test at its Habanero 4 well in the Cooper Basin, the latest in a series of steps that could see the first electricity produced from enhanced geothermal systems in central Australia early next year.
The listed Brisbane-based company said a “staged open flow test” achieved the planned maximum production rate of 35kg per second. The temperature, more than four kilometres underground (4,130m), was 241°C, with a surface temperature of 191°C and increasing after 82 minutes of flow.
That’s technical stuff, but Geodynamics said it was pleased with the result because it delivered bang on target, critical for a company seeking to slowly regain the confidence and enthusiasm of investors. And the well blew some steam, as the company shows in this video, which is what the wells are designed to deliver to turn the turbines and make electrons. And the company says it shows that with each well, it is producing better and better flow rates – the key to increasing productivity and lowering the cost per megawatt hour of delivering electricity.
“We are coming down the learning curve,” CEO Geoff Ward told RenewEconomy. “We are improving how we design wells, we are getting better in the execution, and we are seeing returns in better well outcome and better results.”
The flow test is the first of three that will take place in coming months. The next will take place after a small “stimulation” program – where the company seeks to create fractures in the rock so it can extract more heat – and the third will take place after a major stimulation program. Each is expected to deliver stronger flows.
Ward said the technical achievements of the well should not be underestimated – and the combination of depth, heat, the hardness of the rock, and the high flow made it unique in the industry. He said the results are being watched with intense interest by the geothermal industry – and the drilling industry – around the world.
The Habanero 4 well is costing the company a total of around $51 million – a massive expense that was too much for its larger joint venture partner, Origin Energy, which withdrew earlier this year to save its money for its LNG projects.
However, the linking of Habanero 4 with the older Habanero 1 well nearby will lead to the establishment of a 1MW pilot plant at nearby Innamincka – the first time electrons will be delivered from more than 4km below the surface in an enhanced geothermal system (also known as hot dry rocks) in Australia.
Ward says that the pilot plant will likely run only around three months – as it won’t be getting money for the project. But that should be enough to give it the data and other information to prepare a commercial proposal to take to clients. Then it is a matter of finding a customer. In the Cooper Basin, there are not a million options, but mining, gas or oil operations in the region could be possibilities.
“The significance of these results is that we are achieving what we said we would achieve, and that is important for us to build a track record,” Ward said. “We are much more focused on what our one year goals are rather than where we might be in five or six years.”
Having said that, Ward said the high flows give him confidence that the technology will achieve the numbers talked about in recent technology assessments, which puts geothermal costs at around $150-$250 MWh. The reality is, however, that it will have to deliver at the lower end of that range.
