Drilling

Monday evening, after having a nice relaxed day for my birthday, we started drilling the interesting new stuff in the night.

To do this, we had gamma ray being recorded behind the drilling bit. For most of the drilling, the GR was at about 20m behind the bit, which meant that we had to back-calculate where we wanted to be. It was really fun seeing the data coming in directly, live, and being able to confirm what was going on straight away rather than having to wait for the logging.

Here is an action shot of us discussing the current information and geological model in Petrel:

Once we got to the point we had decided on, we stopped as there was something we were a little bit uncertain about, which could be resolved in the next stage; the drilling bit was pulled up and they removed the directional component, which allowed us to bring the GR down to 4m behind the bit. It also meant that we had to drill straight down, with no deviation, which is why we kept this section to the minimum.


Without any extra drilling, we could therefore get an extra 16m of data, which helped us work out a few answers and decide what total depth we wanted, based still on what data came in as we drilled. We were on the phone/email to Gilles and Alexey during all this, and used software called Petrel, which I had only used back in the office before. It really helped with correlating wells, to understand how similar this well was to the ones nearby, which helps to predict what might be coming in and what decision to make.

The Sperry Sun guys were very good at letting us take over their work unit (see above) during the final GR drilling and getting us the data as we needed it. The drillers listened and did what we needed, drilling slowly and carefully in the tricky bits. All in all good example of interdisciplinary teamwork at the wellsite :-) even though the mudloggers did go to lunch during the most important part of the driling...rig radio can be very entertaining ;-)