Daily News Apr 12 - Apr 14, 2009
April 12, 2009
Daily News:
No Arctic Easter Bunnies around here. The night shift made it down to 272.47m with only about 20% recovery in sections of interbedded muds and sand. The day shift tried to take the next core but found the rig was really straining to lift the PQ core barrel so we risked damaging the derrick. Both the on-line winch and the rotating head were needed to pull it up. So Doug asked me about switching to HQ and I said yes -- a damaged derrick is no good to anyone. So by noon we stopped drilling operations and started down hole logging of the section from 200 to 272 m and tonight as I write we expect them to finish by midnight. (See April 4th for list of what is measured).
Then during the night shift, we will which over to HQ pipe (smaller diameter) and see if we can get sediment cores that way -- knowing that we could hit the breccia any moment. We are starting to take bets about the depth at which we will be into it. But its likely we will hit it by mid-week.
We have made a request to purchase more mud, maybe 8 tons, from one of the local gold mining companies to keep us in business. Our consumption rate in core 1c has been much more than we expected.
Weather is turning a bit....back to strong winds tonight.
....Julie BG
April 13, 2009
Daily News:
Today was a big day for us -- will the HQ collect good sediment core?
The OSG group finished down hole logging last night around midnight and the nightshift worked to trip down with the PQ (removed for logging) and then started tripping down most the HQ (smaller diameter) pipe. The dayshift finished that job in the morning and then tried coring by noon. But it became clear that the tools were getting stuck in the pipe part of the way down -- meaning that a few of the HQ had been damaged slightly.
A dent of even a few mms (not much clearance for the tools after all) can be caused by a bulldozer driving over the pipe or something like that. It takes a heck of a lot to dent this stuff. Doug estimates that you need 8,777 lbs/square inch! Luckily we have 900 m of HQ and it appears that only 5 of 190 pieces are damaged. So we have plenty of good pipe.
So they tripped part way out and replaced 2 of the apparently dented pipes. After that the drillers recovered 2 successful drives into the sediment with 105% recovery (3m+ each) due to the expansion of some of the muds. A third drive was zero recovery but we think we know why. So the night crew is now out there seeing what they can do. Sediments in the recovered sections consisted of beautifully laminated muds and fine sand.
We are thrilled that the HQ is working and we are getting mud -- thanks to the core catchers, as well as the drillers. We are using a hard rock bit on the BHA and a modified hard rock core catcher sized to accept fingers to hold sediment back. So we continue into the night. We have started the "Breccia Lotto" with everyone here placing bets as to the depth, day and time we will encounter the breccia. Sorry.... new entries are no longer accepted.
We are also pleased to report that Kinross Mining is willing to sell us 8 tons of drilling mud. Chico in Pevek is doing a great job finding a means of transport.
Dobroy Nochee! Julie BG
April 14, 2009
Daily News: Eureka!!! Eureka!!! Its time to dance!!! At 6:55 this evening after 12 fabulous fine grained sediment cores taken at 3 m runs with 97% recovery (should be the best record of the lake history right after the impact), we are sure we have entered the transition zone into the impact breccia. Depth of contact at -315 m below lake floor. This event is beyond words for us here, that we have both good recovery and with luck, the down hole loggers to drop their tools down through this zone. We plan to continue drilling through the transition and into the impact breccia until sometime around Wednesday noon (April 15, locally) and then stop to do the down hole logging. The next helicopter will take Doug, Jim, John, Catalina, Julia, and OSG downhole loggers Jochem and Martin.
Impressum