Lake E Daily News, Friday, 17 April, 2009
The night shift finished the downhole logging last night at 12 midnight and then the drillers started again into the impact material. It was really tough going but we reached a depth of -395m with low recovery because of the nature of the deposits. So we are now 80m into the impact complex. And complex it is, unfortunately! The material has varied from solid rock to soft highly weathered looking clay and grus, but a lot of the breccia is very angular small cobbles, gravels and gritty coarse sand. The materials are so abrasive that bit rotation with that grit inside has worn out the hard rock lifter cases and the steel inside the diamond bit, creating a large incised groove in the bit. The hard rock lifter cases we have are now completely shot and by going further, we face a very high risk of twist off or getting the bit stuck and losing the BHA. Jerry says in his experience, he has never seen lifter case shoes worn out like this (and he drills a lot of rock). But this loose breccia is extremely abrasive and we are now without necessary lifter cases. Our 8 tons of new mud has not arrive either, but it is on the way by truck to arrive any time.
So the collective science crew and drilling crew had a meeting before the arrival of the helicopter about how to proceed and we have sent 2 plans out to the funding agencies for their input. Replacement parts are on the way in the mean time and will soon come with Christian Koeberl. Because decisions are still being made, I will not say more here.
The helicopter arrived around 12:30 to pick up 8 people, some of whom have been here since early February. The outgoing party included Doug Schnurrenburger, John Joice, Jim Cranmer, Catalina Gebhardt, Julia Gottchalk, Tim Martin, and ICDP downhole loggers Jochem Kuck and Martin Topfer. Thanks to all of them for their fabulous efforts out here to pull the project along this far. Thanks to Tim Martin for all of his wonderful blogging and instructional videos -- he promises to post a few more before heading back to his 8th grade classroom.
Well, It sure seems quiet around here now! Julie BG
