We awoke today to bad news about the drilling. Just after midnite the drill bit encountered an especially hard object and suffered a catastrophic failure, so that the drilling bit and “shoe” (see photo) were lost from the end of the pipe and dropped into the bottom of the hole. Obviously having several pounds of tough drilling steel in the bottom of your hole is not a good situation and we were forced to abandon drilling in Hole D and bring all our pipe back to the surface to change to the more aggressive RCB (or Rotary Core Barrel).
We will now drill a new hole, skipping coring at the top to save time and try again to reach the basement that we need to have to meet our primary objectives. We were going to change to RCB soon anyway, so the loss of time is not too bad. Such set-backs are quite common when drilling tough, unconventional formations of the type we have here so we are being stoic, getting on with describing the remaining cores and waiting for the resumption of core flow tomorrow afternoon. The break also gives us the chance to digest what we have already collected and think about their meanings for the origin of the South China Sea.