Top Drive Drilling
Definition - What does Top Drive Drilling mean?
Top Drive Drilling is a drilling technique whereby a mechanical component (a top drive) is fitted on a drilling rig to provide rotation to the drill string during drilling process. The top drive is connected to drill string via a quill and then suspended to the derrick of the rig by a hook. The device can move the derrick up and down.
Petropedia explains Top Drive Drilling
A top drive is a critical device which is used in Top Drive Drilling. It is a component of the rig’s hoisting, rotating and circulating system as it functions to satisfy all the three systems. The system can be considered as an engineering marvel as it can simultaneously withstand loads of up to 1 million pounds (the capacity can be even more) with pressure of up to 5000 psi and rotate the drill string up to 200 or beyond rpm. In addition, it can spin and torque a drill pipe connection. A modern top drive has replaced the swivel, Kelly, Kelly bushing, rotary table with its own tongs to torque up.