Page 488 - Practical Well Planning and Drilling Manual

Appendix NEW! revised 11/00/bc 1/30/01 3:30 PM Page 464

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Glossary

Blowout Preventer. A device attached immediately above the casing
to control pressures and prevent escape of fluids from the annular
space between the drill pipe and casing. A BOP can also shut off the
hole if no drill pipe is in the hole.

Blowout Preventer. A set of valves designed to shut off the annulus
around pipe in the hole or to shut off open hole.

Boilerhouse. To make up a report on a condition as fact without
knowledge of its accuracy.

Boll-Weevil (Worm). An inexperienced rig or oil field worker.

Box. The female part of a threaded connection.

Boyles Law. This states that if the temperature of a body of gas is
kept constant, pressure is proportional to volume. Usually expressed
as P1V1 = P2V2.

Break Circulation. To start movement of the drilling fluid after it has
been quiescent in the hole.

Breakout. Refers to the act of unscrewing one section of pipe from
another section, especially in the case of drill pipe while it is being
withdrawn from the well bore. During this operation the breakout
tongs are used to start the unscrewing operation. Also refers to pro-
motion of a crew member to a position of driller or of a driller to a
toolpusher.

Bridge. An obstruction in the drill hole. A bridge is usually formed
by caving of the wall of the well bore.

Bridging. The effect of solids forming an obstruction or ‘bridge’ in the
fluid passages. Bridging in reservoir pores may take place with solids
over about a third of pore size. Bridging may be deliberate (additives
in fluids to reduce fluid loss) or a problem (reservoir permeability
reduction due to a precipitate or mud solids bridging flow paths).

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