Lake E News of the Day April 3
Its been a long day at Lake E. The Night Shift continued drilling from 135 m to 149 m depth but again found themselves stuck in coarse sand and gravel. We had an emergency meeting of Doug, Pavel, Jochem, and Julie BG at 3:30 AM when it was decided that we pull out the drill string, and clean out the hole. By 6 AM the night shift started tripping pipe back down the hole.
The Day Shift on at 8 AM then used the center bit to ream down to about 148 meters. After this they tried to resume coring using the Alien but again, became stuck in this problematic sand unit. Mid- afternoon, the group started to mix mud in an attempt to stabilize the hole. They pulled out pipe to 96 m and again, cleaned out the hole this time using mud to get through the gravels. It seems clear that the hole keeps collapsing in the range of 130 to 150m sediment depth. Total recovery today was only 10 cm. By the end of the Day Shift, the drilling was down to 103 m with mud.
On a positive note, Jochem and Martin from the ICDP OSG successfully tested the infamous winch delivered to the platform on the crane and it was placed inside the rig near the mud tanks. They also positioned all of their down hole logging tools in a container at the drill site after some preliminary testing.
Late today, given the difficulties, we decided to have the night shift tonight use mud to clean out the hole, seal off the gravel and stabilize the hole, as deep as possible but esp. to 130 to 150m. Then tomorrow, we will have the OSG team do the down hole logging so that we have a completed science section to at least 130 m, and maybe to 150 m. If the hole is successfully stabilized there is a minor chance we could resume coring instead. We decided tonight to make that decision in the morning after reports from the night shift.
The weather was clear and calm again today with lows to -30 C last night and day temps in the range of -20C or so.
Cheers from the Lake. Julie BG
