It is located at the swivel's place below the traveling block and moves vertically up and down the derrick.
With a top drive, the draw works only has to pick up a new stand from the rack and make up two joints.
Making fewer and quicker connections reduces the risk of a stuck string[3] from annulus clogging while drilling fluid is not being pumped.
[4] Several different kinds of top drives exist, and are usually classified based on the "Safe Working Load" (SWL) of the equipment and the size and type of motor used to rotate the drillpipe.
[citation needed] The American Petroleum Institute has set standards for top drives in a number of its publications including: The International Organization for Standardization publishes a standard relating to top drives in: Notable manufacturers of top drives: This article related to natural gas, petroleum or the petroleum industry is a stub.