Today was our final day working in the caldera. It was a very relaxed day as we just had a few last things we wanted to return to.
Helen, Florence and I as we had to say our goodbyes. I really can't believe our time here has come to an end.
We had the first of our goodbyes as we were leaving. It was our last time with Florence, one of the girls working here at Maili Saba. It was so sad to give her hugs goodbye, I’ve loved getting to know Florence. As we said goodbye both Florence and Helen got very teary… I’ve a feeling this may continue a bit through the next two days as we must say goodbye to everyone we’ve become friends with out here.
We headed off into the caldera, with a bit of a heavy heart. It is crazy to think that the three weeks of fieldwork has come to an end already. We first headed over to one of the well sites in the hopes of finding one of the people Helen has been trying to meet with the whole time we’ve been here, but our paths never quite crossed. We had come to this well site in the first week here, and there was nothing but a capped well. Today there was a drill rig up and ready to be operational.
The hydraulic drill rig
This was not one of the traditional drill rigs (like the one we were shown around on day 2), this a hydraulic drill rig; much smaller and much more high-tech. It was very impressive. We were given a tour of this rig and Jeff (the drill site manager) explained to us how it works and where it differs from the traditional rigs. The key differences are: the level of control they have while drilling, the amount of water used when drilling, and the depth this rig can drill to. The hydraulic rig has a much greater level of control with all aspects of the drilling. This is mostly because it’s almost fully computer controlled – it’s the best remote control truck I’ve ever seen! Air is used instead of water for lubrication and bringing the cuttings up (cuttings are essentially the material removed in the process of drilling). This significantly reduces the volume of water used in drilling. They will use mud when drilling through weaker lithologies that are prone to collapse into the drill hole, but the mud mix requires much less water than the conventional drill rigs, and the mud is recycled.
The traditional drill rigs require an entire tank ( as you can see the tanks are huge) of water each day they're operating, the hydraulic rig uses less than half of that.
The hydraulic rig being much smaller has half the maximum operational weight than the traditional drill rigs meaning it can’t drill as deep. This rig can drill down to 3000m, but can only put casing down to 2000m.
There are only four of these hydraulic rigs in the world at the moment. It is new technology and engineering being put to the test. As Jeff put it; “we are having to prove the capabilities and benefits of this set-up.” I was very impressed by the hydraulic drill rig and have every confidence it will prove itself here at Menengai, and to the rest of the world, especially if -with the success of this model- the technology is applied to produce bigger versions capable of the drilling power of the traditional rigs. To me, the most surprising revelation was the cost of this drill rig. I had expected it to be much more costly. The initial costs – the high-tech equipment- are only marginally greater than a traditional drill rig, and this more than pays for itself in the savings made during operation. It is also much more flexible than the traditional rigs, taking just 4 days to move from one site to the next (on traditional rigs this takes 21 days), and doing so at a tenth of the cost.
The hydraulic drill rig is certainly the coolest remote-control truck
We left the rig and headed to the fault we found in the north-east of the caldera on day 10We had come back to measure the fractures on the fault. We hadn’t done so when we first found the fault because the fractures appeared to be constructional rather than structural. However it is still better to get the measurements as it is the only way to confirms if the fractures are structural or constructional. Our last task was to collect samples of the altered lava by the fumaroles.
Sampling the altered lava at the fumaroles. The lava's are so altered by hot fluids seeping through them, that they are very soft....to the point that we used a spoon to collect the samples not the hammer
This was a very quick and easy task, but it did get our hands very dirty, especially under our nails. It has become a bit of a tradition of ours to clean our nails in a water pipe leak on the way home. With nails clean it was time to leave the caldera for the last time.
The security guards at the gate are another bunch of people we have made friends with and once again it was sad to say bye to them for the last time. Knowing how much they loved the Haribo Goldbears we shared with them. We left them with a parting gift of some Haribo Minions.
Leaving the caldera for the last time. Vincent and I with the security guards
So that is it we won’t be back in the caldera for some time. Helen will be back next year, I hope to be able to join her though that will depend on funding, and also where I end up after graduating!
We were thrilled to be back before Florence finished her shift, this enabled us to relax with her for a while, and make plans for her to come to Scotland in the near future :)
La la Salama