Presented: Indonesia International Geothermal Convention 2024 – John Clegg, Peter Harvey, Steve Krase, Gorka Plata, Shraddha Singh and Matthew White, Hephae Energy Technology.
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ABSTRACT
Enhanced and advanced geothermal systems (EGS and AGS) are new methods of creating geothermal installations that will potentially increase electric power production by a factor of greater than 10 when compared with more conventional methods. Many such systems are emerging, and they are attracting a lot of funding and excitement. But compared with conventional hydrothermal wells, they are technically challenging to drill. Accurate well positioning, generally including horizontal wells, will be required for the most advanced well designs to succeed. The oil and gas industry can already drill accurate directional wells and this capability is directly transferable to some of the first EGS and AGS wells because they are likely to be drilled at temperatures familiar to oil and gas drillers. But to make EGS and AGS wells more economically interesting, they will need to be drilled at higher temperatures which are currently beyond the capabilities of oil and gas drilling, completions, and production equipment.
Even the claimed 175°C operating capability of oil and gas technologies is challenging for the economics of geothermal drilling because equipment operated at this maximum temperature limit exhibits low main time between failure and/or service. Therefore, the industry needs a step change in its approach to the temperature capabilities of downhole equipment. This presentation will outline just such an approach to the temperature resistance of the electronics and sensors needed.
Showing in detail a new approach to tool design, it will describe how a combination of component selection, a completely reimagined approach to downhole electronics, and multiple cooling strategies will allow measurement and control to be reliably implemented at higher temperatures, initially above 200°C and ultimately as high as 300°C. This will finally make reliable drilling at high temperature a reality and the presentation will conclude by showing results achieved to date during high temperature testing.