Glossary

KB	Kelly bushing.

kelly	The heavy steel, pipe-like, four- or six-sided member suspended from the swivel through the rotary table and connected to the top-most joint of drill pipe which turns the drill stem as the rotary table turns. It has a bored passageway that permits fluid to be circulated into the drill stem and up the annulus, or vice versa. Sometimes called kelly joint.

kelly bushing	KB. The heavy bushing at the rotary table, through which the kelly passes, which transmits the rotary motion of the rotary table to the drill pipe. The top of the bushing is often taken as a depth datum.

kelly joint	See kelly.

kelly hose	Flexible steel-reinforced hose which carries mud between the standpipe and the kelly. Permits the drill string to be moved vertically while mud-pumping and drilling operations continue.

Kelvin temperature scale	A temperature scale with the degree interval of the centigrade scale and the zero point at absolute zero. On the Kelvin scale, water freezes at 273° and boils at 373°. See absolute temperature scale.

kerogen	Organic matter found in rock in the form of a mineraloid which is of indefinite composition, insoluble in petroleum solvents. Kerogen is a pyrobitumen, and oil is formed from kerogen by heating. It consists chiefly of low forms of plant life such as algae, of pollen, spores, spore coats, enzyme shells, coal, and protein material. Chemically it is a complex mixture of hydrocarbon compounds of large molecules, containing hydrogen, carbon, oxygen, nitrogen, and sulfur. Kerogen is the chief source of oil in oil shales.

key-seat	A crevice or groove in the formation wall of the well bore or a split in casing in which a survey cable can become wedged. Most likely to occur at "dog legs" in deviated boreholes.

kick	An eruption or flow of drilling mud from a wellbore resulting from the entry of formation fluids, oil, gas, or water into the borehole. Such entry occurs when the pressure in the borehole does not counterbalance the pressure in permeable formation.

kill a well	(1) To bring under control a well that is threatening to blow out. (2) To circulate water and mud into a completed well before starting well-servicing operations.