Top Drive Drilling
Top drive drilling replaces the kelly method of rotation
used in conventional rotary drilling. Using hydraulic or electric motors
suspended above the drill pipe enables top drives to rotate and pump
continuously while drilling or during the removal of the drill pipe from the hole.
An increasing number of land rigs use top
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.