The drilling process is controlled from the rig floor. The pipes are stored in a large rack, located aft of the drill floor. The crew begin by assembling the BHA (Bottom Hole Assembly). The BHA includes the core bit, outer core barrel and drill collars. The pipes of the BHA ar very stiff and heavy. They will hang below the drill pipe and provide weight to the drill bit to induce the teeth to penetrate the sea floor sediments. At the Site U1480, the BHA is 137 m of length.
This is how the BHA is assembled:
When the BHA is put together, some other, less rigid pipes are screwed to it. 142 sections of pipe, each 28.8 m long, have been screwed to the BHA.
So, if we do the calculation, we have 137 m of BHA plus 142 x 28.8 m of pipes = 4215.5 m below sea level. It makes it! We reached the sea floor.
Putting all the pipes together has taken the crew more or less 11 to 12 hours.
You have to be very patient on board! 🙂