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Drilling Swivel Arrangement

Various aspects of a drilling rig circulation system showing a swivel.

The swivel is a rotary tool that is hung from the hook and the travelling block to suspend and permit free rotation of the drill stem.  The swivel also provides a connection for the rotary hose and a passage way for the flow of drilling fluid into the drill string (drill stem).


The swivel uses seals called swivel packing, which are special rubberized compounds placed in a swivel to prevent drilling fluid under high pressure from leaking out.


The swivel stem is a length of pipe inside the swivel that is installed to the swivel's washpipe and to which the kelly (or a kelly accessory, such as the upper kelly cock) is attached.  A swivel sub may also be present to protect the threads of the swivel from excessive wear during make-up and breakout.


The arrangement allows the drill stem to rotate the swivel's stem while the swivel itself is moved vertically up and down without rotational movement.  Regardless of whether a kelly or top drive are used, a swivel will be present between the rotary hose carring fluid from the mud pumps.


The swivel is parrt of the circulating system which circulates drilling fluid, or mud, down the rotated drill string, or drill stem, and pushes the mud with drill cuttings up the bore hole until the shakers can remove the cutting and place the mud in the mud pits.  Mud is then pumped from the mud pits to the standpipe and rotary hose into the swivel an drill string to complete the circulated flow of drilling mud.