June 13, 2023

Drill stuck again, glycol added to borehole, a screw came to surface

The glycol attacked core. The left-hand side break is a run break with deep core catcher marks. The right-hand side break is that caused by glycol in bottom of the borehole. Both breaks are fitted, but there is some core loss.


It is hard to believe that just a week ago, 3+ m long ice cores were routinely drilled in camp. Since then, drilling has become a lot more difficult with shorter cores and the drill stuck for shorter or longer periods unable to break the core. The first run of the day reached 0.6 m drilling depth, but the drill came to surface without core. For the second run, the drill got stuck at around noon. At 14:30 two kilos of glycol pellets were dropped into the borehole with the purpose of freeing the drill. At 14:40 the drill came free by itself. After waiting for the glycol to sink to the bottom the drill was pulled to surface. This time it contained a 60 cm ice core with 3 core catcher scratches on the sides from the first run. Furthermore, a lost screw came to surface. The screw in the borehole can probably explain why it has been difficult to engage the cutters over the last days, but it can hardly explain the hard core breaks or the stuck drill. The third run of the day (now with glycol in the hole) retrieved a 3.3 m core with an easy core break of 1200 kg. At surface, the core was in two pieces, but continuous and it could be logged and fitted to the previous run. At the top of the core, where the glycol had been active for some hours, 1-2 cm of the outer side of the core was eaten away in a 4-5 cm wide band. The run brought large amounts of blue chips to surface hopefully containing most of the dumped glycol. At 10 pm the drill was again on its way down the borehole to recover another core together with any leftover glycol in the hole. An eventful day for the drilling.

What we did today:

  1. Drilled one short and one long core. Added 2 kg glycol to the hole and recovered a screw.
  2. Logging depth: 2616.22 m. Processing depth: 2610.85 m.
  3. No change: Physical properties measurement 2608.65 m.
  4. Cleared drift snow away from dome and trench entrances.
  5. Groomed apron, taxi-ways and part of skiway.
  6. Re-mounted escaped track belt on snow blower.
  7. Refurnished outdoor living room.

Weather today: After some days with overcast and high winds, we got the blue sky and calm conditions back after noon. In the evening the wind dropped to zero and the volleyball was aired again. Temperatures -18°C to -12°C. Wind dropping from 20 to 0-4 kt from SW-W and E in the evening.

FL, Anders Svensson

Drill trench celebrating the first 3+ m core drilled in a week.

And here was the troublemaker back on surface.

Søren is preparing the glycol pellets to be dropped in the borehole.

We have seen it before, but the snow blower in action on a sunny day is always an impressive sight. Here Yannick is on duty removing the drift snow piled up in the trench entrances over the last days.