Oil & Gas Glossary 1.0

The operation of hoisting the drill stem from and returning it to the wellbore. v: shortened form of "make a trip."

The action of pull out and subsequently running back into the hole a string of drill pipe or tubing. Making a round trip is also called tripping.

The small amount of additional mud weight carried over that needed to balance formation pressure to overcome the pressure-reduction effects caused by swabbing when a trip out of the hole is made.

A small mud tank with a capacity of 10 to 15 barrels, usually with 1-barrel or H-barrel divisions, used to ascertain the amount of mud necessary to keep the wellbore full with the exact amount of mud that is displaced by drill pipe. When the bit comes out of the hole, a volume of mud equal to that which the drill pipe occupied while in the hole must be pumped into the hole to replace the pipe. When the bit goes back in the hole, the drill pipe displaces a certain amount of mud, and a trip tank can be used again to keep track of this volume.

A tool that goes downhole and is not retrievable.

A complete trip from the bottom of the wellbore to the top

The operation of hoisting the drill stem out of and returning it to the wellbore. See make a trip.

A spherical object used to pump down the drill string or tubing to trip, release, or otherwise operate certain hydraulic-type tools.

Running of a gauge on tubing or slickline to verify casing dimensions.

A sub with a ball seat run on top of a hydraulically set packer to set the packer.

See trip margin

The connected joints of pipe racked in the derrick or mast during a trip. The usual stand is about 90 feet long (about 27 meters), which is three lengths of drill pipe screwed together (a thribble).

To hoist the drill stem out of the wellbore to perform one of a number of operations such as changing bits, taking a core, and so forth, and then to return the drill stem to the wellbore.

To pull the drill stem out of the wellbore to change the bit, to change from a core barrel to the bit, to run electric logs, to prepare for a drill stem test, to run casing, and so on. Also called trip out.

Gas that enters the wellbore when the mud pump is shut down and pipe is being pulled from the wellbore. The gas may enter because of the reduction in bottomhole pressure when the pump is shut down, because of swabbing, or because of both.

The component in a blowout preventer that cuts, or shears, through drill pipe and forms a seal against well pressure. Shear rams are used in floating offshore drilling operations to provide a quick method of moving the rig away from the hole when there is no time to trip the drill stem out of the hole.