I’ve always been fascinated by volcanoes and interested in renewable energy. Geothermal came as an exciting topic joining them both! As a graduate student, I worked for a year at Iceland Geosurvey and was very lucky to be there for the IcelandDeep Drilling Project at Krafla which aimed to reach supercritical fluids. The potential of producing 10 times the energy from a single well by drilling deep in the un-chartered depths of a volcano was simply mind-blowing. I still carry this excitement, and while supercritical geothermal is not an easy feat (hitting magma at Krafla was a surprise!), this fantastic sustainable energy source is just too promising to not study it.
As a geologist, I’ve been attracted to studying fractures and find out how they control how fluids move through rocks. This research is directly applicable to geothermal, but it also helps understanding how earthquakes and volcanic eruptions happen. My favourite method to study fractures is to look directly underground using pictures from the inside of boreholes. I then compare these subsurface measurements to wider views in the field and aim to link one to another. A favourite part of my work is to collaborate with a wide range of scientists and engineers, whether it’s on a drilling rig, on the field or trying to make computer models more “real” and useful.
Massiot,C., Nicol, A., Townend, J., McNamara, D.D., Garcia-Sellés, D., Conway, C.E. andArchibald, G., 2017. Quantitative geometric description of fracture systems in an andesite lava flow using terrestrial laser scanner data. Journal of Volcanology and Geothermal Research, 341, pp.315-331. https://doi.org/10.1016/j.jvolgeores.2017.05.036
What was the research finding?
This paper quantified the geometries of thousands of fractures in a lava flow, and represented them in a computer model, at a scale which is relevant to a geothermal reservoir. This project used novel measurement techniques (terrestrial laser scanner) and analysis methods to make the process faster and cover more ground.
Why is it important?
In many geothermal reservoir rocks, fluids travel through the fractures. There are many, many fractures in these rocks – and we don’t have access to the underground to measure them all. Quantifying the fracture geometries on surface in rocks which are similar to those hosting underground geothermal resources isa practical way to estimate where the fractures are in a real underground reservoir, and how the fluids travel. This project was also my first real exposure to Māori world views. I am grateful for the learnings provided by Ngāti Rangi and the blessing of our field work.
Where are you?
Ruapehu, Whakapapa Village
What are you doing?
I’m counting cracks! As part of my PhD, I measured length, orientation and location of a couple hundreds cracks crossing a tape meter. These manual measurements over a “small”200m-long line were very useful to extract the same parameters of thousands of fractures using a more high-tech method covering the entire lava flow. And it was a sunny week on the Maunga with magnificent views.
Read more about Cecile's experience here.