Sentences with phrase «drill returning to the surface»
Longer cores have to be drilled piece by piece, with the drill returning to the surface with each one.
https://www.newscientist.com/ Not exact matches
One incident that is emblematic of the problems occurred on 8 March, a month before the accident, when BP discovered that drilling fluid had leaked into rocks 5000 metres below the sea floor instead of returning to the surface via a pipe.