A rotary drilling rig works by rotating a drill string, which applies downward pressure to a drill bit that grinds the earth. Drilling fluid or air is pumped down the drill string to cool the bit, carry cuttings to the surface, and stabilize the borehole.
[pdf] A rotary table is a mechanical device on a drilling rig that provides clockwise (as viewed from above) rotational force to the to facilitate the process of drilling a . Rotary speed is the number of times the rotary table makes one full revolution in one minute (rpm).
[pdf] In oil drilling, a casing head is a simple metal welded or screwed onto the top of the (also known as drive-pipe) or the and forms part of the system for the well. The casing head in a conventional wellhead system is the lowest part of the wellhead assembly and is almost always connected to the surface casing string. It supports the remaining parts of the wellhead and completion equipment. The casing head performs the following functions:
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