Back to (Petrophysics) School

Two weeks ago, on Sunday the 26th of June, the first ever summer school in Petrophysics hosted by the University of Leicester kicked off with drinks and a free out-of-hours tour of the King Richard III Visitor Centre in Leicester City’s old town. A moderately-well documented event, you can find out more about the formalities on the web page, or you could read a more formal blog post on the Leicester University website. Here though, I am going to list some of my personal reflections: Looking back on the event from my perspective as an assistant. But as a summary; there are two non-work-related aspects that stand-out as highlights. 1) Meeting the colleagues of my colleagues and; 2) the opportunity to get a sense of the wider petrophysics community and the work that is going on. But let’s start at the beginning for context.

Paleontologist and guest lecturer Dr Tom Harvey
at the New Walk Museum

Striking the perfect balance of formal to informal; the ice was thoroughly broken at the aforementioned visitor centre meet-up, where awkward-silence-littered conversations slowly dissipated at roughly the same pace as the wine was consumed. Many participants had travelled thousands of miles to be at the summer school, and this diversity was reflected in a wide range of approaches, dress, and above all accents. Between the 30 participants, 19 different nationalities were represented; coming from 11 separate countries institutionally. It was a similar story with the summer school’s tutors as well, whereby of the 20 tutors/helpers, 12 separate institutions/organisations from 6 different countries were present.

Setting up a Geotek Core Logger for demonstrations

This atmosphere of like-mindedness though a passion for petrophysics lingered throughout the week as experts and professionals alike shared their experiences with participants through a series of lectures that built from the ground up. With various practicals spread throughout the week including operational demonstrations of equipment, fieldtrips and courses on the fundamentals of industry-standard software packages. But this is going off topic.

This week was the first time that I had met some of our professional partners in person, but I don’t think this was entirely a unique experience. The atmosphere suggested that this meet was the first time that so many had been in the same room for a while. Not really surprising though, given the large offshore expedition-focussed aspect of the job. There were many people that I had ‘met’ over skype or had ‘conversations’ with through email; and many more that I had heard of through reading their name on an expedition proceeding or scientific paper. However this week provided some time to get to know them as people rather than solely in the limelight of their professional career. A real privilege, especially given the calibre of character. But that’s all you’re getting on that subject, if you want to know more you’ll have to start studying to become a petrophysicist and get involved!

Clever scientists being clever

So, onto my second point. The petrophysics community. I think there is one thing that we can agree on about scientists – they’re clever people. So when you gather a bunch of them in a room and give them an opportunity to tell you what they are researching right now, the results can be pretty interesting. This is why throughout the first half of the week coffee breaks were combined with a series of poster sessions. To give people ample opportunity to bring and share.

Research areas were wide ranging. All the way from the realms of ‘classic’ petrophysics such as: the effect of particle size on fluid migration or the architecture of carbonate reefs; all the way to where interests were more than a little outside the box, such as using borehole imaging to re-orient core samples in order to investigate high-temperature deformation; or assessing the mechanical and chemical processes that occur when seawater interacts with rocks that have come from hundreds of kilometres underground (spoiler alert – this may give rise to primitive life forms that are not dependent on sunlight!). Full disclosure, some of these terms go straight over my head too – that’s why these guys usually stand next to their posters to explain… but I do recommend googling some of these terms, or getting involved yourself so you too can learn some science. It is a wonder to hear about the amazing things scientists in the petrophysics community can achieve, especially when using old data from the IODP legacy dataset.

So there’s my two cents on the petrophysics summer school. I wish I could tell you more about the content of the course but unfortunately I wasn’t able to attend all the lectures thanks to “work” and all that. Maybe I will next time though.

Laurence

40,000 Points

It has been more than one month since the end of the offshore phase of IODP expedition 364. I wanted to wait a bit to review this experience, because writing something just after would have been a mix of “it was so hot”, “I think I had too many cookies/brownies” and “that was intense”. Now I am rested and relaxed, I can look back at these 58 days spent offshore Mexico on the 42-meter-long Liftboat Myrtle. A tiny, yet impressive place where I was part of such a fantastic scientific expedition: to drill the peak ring of the Chicxulub Impact Crater . That was my first offshore experience.

So, yes it was hot, and yes it was intense. But there are more important things to report from this experience. First of all, even if I heard of what a mission specific platform was and what the missions of the IODP  (International Ocean Discovery Program) were, it was impressive. It was impressive to see such a geoscientific operation taking place, just to bring rock samples to the surface, describe and analyse them. Just science.

My main role offshore was to measure physical properties of the cores, using a multi-sensor core logger (MSCL). It was not only me on the MSCL; we worked on 12-hour shifts to ensure a continuous workflow. Analysing cores for 12 hours in a row, 90 minutes for every 3 meters of core material, can be long. But it can also be rewarding: other scientists were really interested in this petrophysical data. We provided instant valuable information like rock density and magnetic susceptibility. Density was probably the most useful while offshore, for scientists to better understand what they described and how it fitted with their model. On the other hand, the magnetic susceptibility data (usually useful for correlations between boreholes and cores) was more of an amazement, to see the range of responses measured from the different materials recovered from the peak ring. I am sure that even if we do not use magnetic susceptibility as a correlation tool here, it will give scientists crucial information about the variation in composition of the rocks formed or affected during the impact.

The MSCL lab

Some feelings now about the measurements:

• Satisfying: we were lucky enough to have a measurement time that fitted perfectly with the core recovery rate, never too far behind the drilling team;
• Mildly frustrating: it was a single well and we did not know what lithology will be recovered in the next core, making it difficult to visualise the big picture;
• Highly satisfying: to look at the MSCL dataset now; measurements every 2 cm across a total length of 830 m of core: more than 40000 measurement points in total;
• Even more satisfying: to see that downhole logging data I helped to collect (with EPC staff from the University of Montpellier ) match very well with the physical properties measured on the cores. The hole was very nice and we collected good data; the cores were continuous, fairly well preserved and we collected good data. Of course it is not possible to show them now because they are under moratorium.

I think it was good to wait a bit before reviewing this experience; to dim the excitement of the expedition and of coming back home; to forget about some unimportant but inevitable technical problems; to relax. What I will remember from this first expedition is satisfying: good data, good team effort and epic geological setting.

Erwan