land-based rigs, a rotary table on the rig floor rotates the kelly, which turns
the drill pipe and drill bit. As the drill bit penetrates deeper, the crew
threads additional pipe onto the top of the drill string.
Sections of pipe
are typically 9.5 metres long, but may be longer; diameters and wall thickness
also vary, depending on well depth. The elevator is a device used when lifting
the drill string out of the wellbore.
Petroleum Communication Foundation. Our Petroleum Challenge: Exploring Canada's Oil and Gas Industry, Sixth Edition. Calgary: Petroleum Communication Foundation, 1999. With permission from the Centre for Energy.