kelly n: the heavy square or hexagonal steel member suspended from the swivel
through the rotary table and connected to the topmost joint of drill pipe to
turn the drill stem as the rotary table turns.
bushing n: a device fitted to the rotary table through which the
kelly passes and the means by which the torque of the rotary table is
transmitted to the kelly and to the drill stem. Also called the drive bushing.
kelly bypass n: a system of valves and piping that
allows drilling fluid to be circulated without the use of the kelly.
kelly cock n: a valve installed at one or both ends
of the kelly. When a high-pressure backflow occurs inside the drill stem, the
valve is closed to keep pressure off the swivel and rotary hose.
kelly drive bushing n: see kelly bushing.
kelly driver n: a device that fits inside the head and inside of which
the kelly fits. The kelly driver rotates with the kelly.
kelly saver sub n: a heavy and relatively short length of pipe that
fits in the drill stem between the kelly and the drill pipe. The threads of
the drill pipe mate with those of the sub, minimizing wear on the kelly.
spinner n: a pneumatically operated device mounted on top of the
kelly that, when actuated, causes the kelly to turn or spin.
keyseat n: 1. an undergauge channel or groove cut in
the side of the borehole and parallel to the axis of the hole. A keyseat
results from the rotation of pipe on a sharp bend in the hole. 2. a groove cut
parallel to the axis in a shaft or a pulley bore.
kick n: an entry of water, gas, oil, or other
formation fluid into the wellbore during drilling. It occurs because the
pressure exerted by the column of drilling fluid is not great enough to
overcome the pressure exerted by the fluids in the formation drilled. If
prompt action is not taken to control the kick, or kill the well, a blowout
kick fluids n pl: oil, gas, water, or any combination that enters the
borehole from a permeable formation.
kick off v: 1. to bring a well into production; used most often when
gas is injected into a gas lift well to start production. 2. in workover
operations, to swab a well to restore it to production. 3. to deviate a
wellbore from the vertical, as in directional drilling.
kickoff point (KOP) n: the depth in a vertical hole at which a deviated
or slant hole is started; used in directional drilling.
kill v: 1. in drilling, to control a kick by taking suitable preventive
measures (for example, to shut in the well with the blowout preventers,
circulate the kick out, and increase the weight of the drilling mud). 2. in
production, to stop a well from producing oil and gas so that reconditioning
of the well can proceed.