DRILLING Drilling Equipment

Hoisting Equipment


The machine on the rig consisting of a large-diameter steel spool, brakes, a power source and assorted auxiliary devices.

The primary function of the drawworks is to reel out and reel in the drilling line, a large diameter wire rope, in a controlled fashion.

The reeling out of the drilling line is powered by gravity and reeling in by an electric motor or diesel engine.



Travelling block

The set of sheaves that move up and down in the derrick.

The wire rope threaded through them is threaded (or “reeved”) back to the stationary crown blocks located on the top of the derrick.

This pulley system gives great mechanical advantage to the action of the wire rope drilling line, enabling heavy loads (drillstring, casing and liners) to be lifted out of or lowered into the wellbore.

Kelly Rig Schematic travelling block


   Crown block

The fixed set of pulleys (called sheaves) located at the top of the derrick or mast, over which the drilling line is threaded.

The companion blocks to these pulleys are the traveling blocks. By using two sets of blocks in this fashion, great mechanical advantage is gained, enabling the use of relatively small drilling line (3/4 to 1 1/2 in. diameter steel cable) to hoist loads many times heavier than the cable could support as a single strand.



crown block 1 crown block 2



The high-capacity J-shaped equipment used to hang various other equipment, particularly the swivel and kelly, the elevator bails or topdrive units.

The hook is attached to the bottom of the traveling block and provides a way to pick up heavy loads with the traveling block.

The hook is either locked (the normal condition) or free to rotate, so that it may be mated or decoupled with items positioned around the rig floor, not limited to a single direction.


hook 1 hook 2



Drilling line

A wire rope hoisting line, reeved on sheaves of the crown block and traveling block (in effect a block and tackle).

Its primary purpose is to hoist or lower drill pipe or casing from or into a well. Also, a wire rope used to support the drilling tools.

drilling line



A set of clamps that grips a stand, or column, of casing, tubing, drill pipe, or sucker rods, so the stand can be raised or lowered into the hole.



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