Distance between wells producing from the same pool (usually expressed in terms of acres, e.g., 10-acre spacing).

The joint of drill pipe that is used in hang-off operations so that no tool joint is opposite a set of preventer rams.

A clamp used to hold the rod string in pumping position when the well is in the final stages of being put back on the pump.

Position the correct number of feet or joints of pipe from the packer to the surface tree, or from the rig floor to the stack.

A special-purpose valve used to facilitate spacing out and ranging up the well, run in on the tubing string.