1.
vb. [Drilling]
To plug the wellbore around a
drillstring. This can happen for a variety of reasons, the most common being that either the
drilling fluid is not properly transporting
cuttings and
cavings out of the
annulus or portions of the wellbore wall collapse around the drillstring. When the well packs off, there is a sudden reduction or loss of the ability to
circulate, and high pump pressures follow. If prompt remedial action is not successful, an expensive episode of
stuck pipe can result. The term is also used in gravel packing to describe the act of placing all the
sand or gravel in the annulus.