Tuesday, 21 November 2017

Corinth Active Rift Development: Life offshore

IODP Expedition 381 

View 6: Life offshore as a sea-going scientist 


I’ve been at sea on IODP Expedition 381: Corinth Active Rift Development for just over 5 weeks, and I thought it's about time I provided an update on life here. Regular visitors to this blog may have seen my previous “Corinth Active Rift Development: the Expedition begins” blog where I outlined what I have been doing with my time, so I won’t go into it now. But what is it like to keep an MSCL running 24 hours a day? Well to make things simpler to communicate I thought I’d break things down into my 5 repeated stages for an MSCL operator at sea: 

1. Waking up. 

Seems like an obvious place to start. When I’m at home getting out of bed and on my way to work is a simple half-an-hour task. Quick shower, quick bit of brekkie and that’s that. It’s a bit harder after you work 12 hours a day for 5 weeks. And have I mentioned the beds on the Fugro Synergy? It might just be the hours talking (although I don’t think so) but the beds here are super comfortable. The other factor is coffee-management. It’s easy to drink coffee because it helps so much with the long shifts. You've got to be careful you don’t disturb that sleep cycle though. When I first joined the vessel I was drinking one a day but this ramped up to 5 cups of coffee a day by week 4 on board. Since then I have kicked the habit and am now caffeine free. It’s the little things. 


My shared cabin onboard. Mine for 12 hours a day its pretty
well equipped, though the TV doesn't work as a TV
2. Eating. 

Meals are served for an hour and a half every 6 hours on the Synergy. And they are good. At least 4 options of hot mains provided every time and plenty of sides to accompany them. I have managed to limit myself to only 2 three course meals per day thus far but it has been a challenge. The food has changed throughout the cruise. Bananas and most of the other fresh fruit disappeared along with the most popular cereals and condiments. Somehow Nutella has lasted this long despite it being a very popular choice. Through what I can only assume is some sort of black magic fresh salad appeared a couple of weeks into the expedition at the same time as all of the apples were painted in wax; giving them a plastic and cartoonish appearance. However, after a quick wash they’re still fresh and crunchy on the inside. Fresh veg was replenished on board at the port call after the first site but we just repeated the cycle again with its disappearance. Very surreal. After this it’s time to don PPE and start my morning commute. 

3. Exercise. 

The MSCL is built into a 20 foot container, so there’s no chance I’m doing star jumps between cores. It’s okay though the Synergy has a gym. It’s a simple gym with basic equipment (running machine, exercise bike, rowing machine, dumbbell set and a couple of those reclining chair/bench things). It’s more than enough for an end-of-the-day stretch. I have also started a 100-a-day press-up challenge with a few friends from home, and that is something that I can do between loading cores onto the MSCL! I’ve kept it up for three weeks so far and I can see the light at the end of the tunnel. 


The Gym onboard 
4. Sitting at the MSCL.

This is where I spend the majority of my day. It’s a fine enough place to do it. Abah (my opposite shift partner) and I are the only scientists who have a whole container to ourselves (hence the press-ups), which has its positives and negatives. It’s alright though; we have a coffee machine so that is bringing in a lot of visitors nowadays. 

Operating the MSCL as efficiently as possible to keep up with the recovery rate is best achieved by channelling your inner robot. Be an extension of the machine (Neo?). There are many steps that need to be taken in order to make sure that all data is recorded in a meaningful way and at that nothing is missed. This includes (but is not limited to) recording data at the correct time after the core has arrived on deck; QC-ing the curation process with the assistance of the MSCL’s built-in precision ball-screw core pusher and associated laser; and measuring temperature at all stages. The recovery rate thus far on Expedition 381 has been steady and we in the MSCL lab have mostly been able to keep up. That said, there’s a white-board pinned to one of the walls of the MSCL container and it has had become an extension of my brain. Most heavily used during the second half of the shift it’s especially helpful for staving off the post-lunch “I ate too much again” food-coma. 
A waxed apple with the MSCL in the background 

The most interesting thing I have learnt about operating the MSCL all day is how quickly my body adapts. The MSCL motor makes a whirring sound every time it moves and it moves all the time, never pausing for more than 30 seconds. In the first week I developed a 6th sense whereby I subconsciously count in 30 second periods. I don’t know, maybe it came from watching the MSCL for so long, but now if I go for more than 30 seconds without hearing that sound I subconsciously know something requires my attention. It’s really rather cool. 

5. Scratching my head. 

The 5th and final task where time is allocated in any day is time allocated to scratching my head. There are a lot of questions raised when you are on the front-lines of scientific discovery, so I spend a more significant portion of my day than usual in quiet contemplation as I troubleshoot unexpected values and strange data points. Despite the MSCL producing a tremendous amount of high-resolution data very quickly we still have a task on our hands processing it to output a high quality (and usable!) dataset. That’s not to say that we have discovered everything there is to see so far already, far from it. After all, we are only one cog in the engine and this is only the first half of the expedition. We will need to wait to see the rest of the puzzle pieces when we split the cores at the Onshore Science Party in a couple of months. 

And that’s pretty much what I do daily while I am here. Rinse and repeat. 

Laurence 

Tuesday, 14 November 2017

Corinth Active Rift Development: first hole complete!


IODP Expedition 381 
View 5: what does everyone else do during logging?

So the first logging operations were completed over the weekend………….but I am only blogging about this now because unlike those offshore I don’t have to work all weekend! However, all of the team onshore are always on call to answer any queries that the offshore team have and are very good at sending virtual chocolate supplies.

Downhole logging takes place once coring has finished in a borehole (ok this can be a simplification but applies to the first hole in Corinth Active Rift Development: Expedition 381). And logging can take several days, with different toolstrings and different stages, especially when borehole conditions throw up challenges, such as was the case for this borehole. For anyone impatient, here is a photo from early on in the logging operations.

Laurent Brun and Erwan Le Ber early on in logging the first hole. credit: L. Phillpot

What does everyone else do while this is happening? Well, of course supply the loggers with chocolate………
As this is a petrophysics blog, you will have to check out the Expedition blog to find out what other participants do, but here I can discuss how EPC’s Laurence and Abah from the Science Party spent their time. Did they put their feet up and relax? No, certainly not, the gap in core arriving on the ship is often time for the hard-working MSCL operators to catch up on any backlog that has accumulated. Here, as Laurence and Abah had that under control they had plenty of time to run quality assurance and quality control (QAQC) cores through the MSCL to provide checks on the data being acquired and ensure that all sensors are operating to their optimum efficiency. This process is achieved both by using specially selected cores to act as QAQC cores, but also by using the calibration pieces that are prepared in the liners used for each specific expedition.
Laurence Phillpot preparing calibration pieces for the MSCL. credit: E. Le Ber


In summary the Petrophysics team have had a busy few days! What is really enjoyable once the team have both core petrophysical and logging data is tying this together, analysing correlations and identifying where gaps or questions in one dataset can be answered by studying another, and of course starting talks with other scientists about the data that continue into the onshore phase (in Bremen in February 2018) and beyond.
 
 
Jenny

 
 

Tuesday, 7 November 2017

Corinth Active Rift Development: petrophysical measurements in the first borehole

IODP Expedition 381
View 4: looking forwards to the first downhole logging

The petrophysical measurements that are taken offshore include both petrophysical measurements on the recovered core and measurements taken in situ in the borehole by downhole tools. The core measurements on the first hole of the expedition are well underway and we are excited that the first logging is due to take place fairly soon. The next blog post will contain news from offshore on this!

The last blog post introduced the Geotek™ Multi-Sensor Core Logger (MSCL), which is a piece of equipment that EPC staff and those scientist who operate it offshore become very familiar with, and on Corinth Active Rift Development: IODP Expedition 381, EPC’s Laurence and Abah from the science party are working in opposite 12 hour shifts. The MSCL has sensors measuring magnetic susceptibility, electrical resistivity, P-wave velocity, gamma density, and natural gamma radiation, each of which have their own special ways in which they contribute to the expedition aims. Offshore these measurements are also helpful in providing the petrophysics team with some prior understanding of the borehole before downhole logging commences.

Laurence Phillpot introducing Abah Omale to the expedition MSCL logsheets. (credit: E. Le Ber)

The downhole logging measurements plan and operation is coordinated by the Expedition Petrophysics Staff Scientist, Erwan, requiring detailed discussions offshore with the operational team, the Expedition Co-chief Scientists and the logging engineers. In a perfect formation, in a perfect hole, logging is straightforward and each tool can be run in open hole down to the bottom and measure all parts of the borehole. That can and does happen! By this phase of the operation, analysis of the MSCL measurements and observation of the lithologies recovered can help to inform the logging program in this first hole. Where parts of the hole are anticipated to be less than perfect (which also can and does happen!), the logging team consider options such as logging the hole in more than one phase. Again, watch for the next blog post to find out more about the first downhole logging from Corinth Active Rift Development: IODP Expedition 381 …………. or if you can’t wait for that, check out the recent articles on the Expedition 381 blog!

Laurent Brun and Erwan Le Ber testing logging tools. (credit: L. Phillpot)

Jenny