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Two or three joints together constitute what is termed a "stand". Crew members
pull pipe out of the hole in stands to save time. If three joints comprise a stand, and that is
the usual case, then the stand is sometimes called a "triple" or a "thribble" (although
you don't hear this term much anymore). If two joints make up stand, it is called a
"double." In a few cases, crew members may pull four-joint stands; in such a case, they
pull "quadruples," or "fourbles." The height of the mast or derrick determines whether the
crew pulls doubles, thribbles, or fourbles. Because the surface hole is usually relatively
shallow, it does not take crew members very long to get all the drill stem and bit out of the
hole.

Tripping out with a top-drive unit

Tripping the drill string out of the hole with a top drive is much like tripping
out with a kelly-and-rotary-table system. The main difference, of course, is that the top
drive does not use a kelly and swivel. Thus, the rig has no need of a rathole. Instead, the
driller simply unscrews the top drive's drive shaft from the drill string after the
floorhands suspend the drill string in the hole with the slips. They use the top drive's
built- in elevators to raise the pipe out of the hole and they usually use regular tongs to
loosen the joints. The driller spins out the joints with the top drive. The floorhands then
set the stands back in the mast or derrick while the derrickman handles the upper end of
the stands on the monkeyboard.

Tripping out with a pipe racker
The latest equipment to pull pipe out of the hole, as well as to run it in, is an
automatic pipe-handling device. Called an "automatic pipe racker," it moves on a track

on the rig floor beneath the fingerboard. The driller usually operates it from the rig
floor. To pull pipe out, the driller uses the drawworks to raise the pipe, stops it at the
desired height, and applies automatic slips to suspend the string.
The driller then actuates a control that moves the pipe racker into position
near the tool joint to be broken out. Automatic breakout tongs built into the racker
loosen the joint and a built-in automatic spinner spins the joint apart. The operator
retracts the racker's tongs and extends two arms from the racker. One of the arms grips
the pipe near the rig floor and the other grips it higher up, just beneath the
fingerboard. Gripping the pipe and moving the racker in its track sets the bottom of the
stand or joint on the rig floor and places the top of the stand or joint into the
fingerboard.
With the stand or joint set back in the mast or derrick, the driller retracts the
racker's arms and moves the racker into position for the next stand or joint to be pulled
from the hole. The driller extends the racker's automatic tongs and breaks out the next
stand or joint of pipe. The racker then sets back the stand or joint in the fingerboard.
The driller repeats this process until all the pipe is out of the hole.

Running surface casing
Once the drill stem and bit are out of the hole, the casing crew moves in to do its
work. Because the drilling crew just drilled the surface hole, the first string of casing run
into the hole is called "surface casing," or "surface pipe. Surface casing is usually

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