The following is an excerpt.
Think Iceland. Think pressure cooker 5 000 metres below the geysers. Think 500 centigrade at 300 bar. Now, that IS hot stuff.
In this case, hot stuff for Equinor, SINTEF, and a number of other partners. Their own description goes like this: “In geothermal energy, a huge potential lies in hydrothermal reservoirs where ultra-high temperature fluid can be utilized to multiply the power production output.”
Growing ambitions and interest
The desire to use the energy resources below Iceland is far from new. With improving technology, ambitions to reach further down have grown. The Icelandic Deep Drilling Project was founded in 2000, with the national energy agency and a number of Icelandic energy companies as partners. Various international research groups have been involved over the years. Interest from industry is growing. SFI CASA partner Equinor is among the companies involved in ongoing research and development projects.
Well in place
Two years ago, Equinor and their Icelandic partners managed to drill down to almost 5 000 metres. This well is now in a “stimulation period”. What follows is a production-testing phase where the objective is to confirm reservoir performance, well integrity and power production potential.
Closely linked to this, Equinor recently initiated the HotCaSe project. Backed by the Research Council of Norway, it has a budget of 30 MNOK. The project seeks to solve the challenges meeting wells under supercritical conditions. A short quote from Wikipedia may serve to illustrate what they are up against:
“A supercritical fluid is any substance at a temperature and pressure above its critical point, where distinct liquid and gas phases do not exist.”
A more practical illustration is the photos from previous failed efforts: casings in the wells have imploded and buckled, pipejoints have suffered tensile failure, hydrogen embrittlement and corrosion have caused fractures.
This points to casing constructions as a central matter of attention in the project.
The link to CASA
Now, this wouldn’t be the SFI CASA Newsletter if there wasn’t a link. There are several. The HotCaSe project is owned and led by Equinor, and administered by SINTEF. Project leader Hieu Hoang defended his PhD at SIMLab in 2011. Gaute Gruben heads the HotCaSe work package on mechanical characterization and constitutive modelling. He also has his PhD from SIMLab, the host research group for SFI CASA.
Their positions in the project is closely linked to their past. SIMLab is a world leader in the behaviour of materials and structures subjected to extreme loadings; know-how much needed in this pioneering work. Even better, this is also linked to their present position as administrators of CASA’s Methods and Tools programme. SINTEF organizes the synthesizing process where research from SIMLab is gathered in the SIMLab Tool Box. Although the structure in HotCaSe is totally different, the research methodology is equally fruitful.
The aim for HotCaSe is to deliver a structure fit to survive and to build a full-scale prototype by 2021. However, there are many steps remaining. The ambition of this project is to reach level four on the Technology Readiness Level scale going from zero to seven.
As far as CASA is concerned, HotCaSe may bring back valuable knowledge from the supercritical environment that could prove useful to the automotive and other partners in the SFI.
Result of brainstorm
HotCaSe is one of the results from a joint brainstorm between Equinor and SINTEF at executive level. When it became clear that both companies had previous experience from geothermal projects and the industrial wish was established, go ahead was given to explore future possibilities. Before long, the project caught international interest, with a three-day workshop identifying innovative well designs as a starting point. International industrial partners have decided to join, including French companies Curistec and IMERYS Aluminates
Still in a checking-out position
Although eagerly involved, Equinor is still in a checking-out position. SINTEF is also looking, possibly including other partners, at potential business cases where Hot stuff is on fire. Still, at this stage, nothing is decided.