Page 510 - Practical Well Planning and Drilling Manual

Appendix NEW! revised 11/00/bc 1/30/01 3:30 PM Page 486

[ ]
Glossary

the circulation of drilling fluid due to the fact that the fluid is enter-
ing into a porous or fractured formation underground rather than
returning to the surface.

Low-Solids Muds. A designation given to any type of mud where
high performing additives, e.g., CMC, have been partially or wholly
substituted for commercial or natural clays. For comparable viscosity
and densities (weighted with barite), a low-solids mud will have a
lower volume percent solids content. Higher ROP’s are often seen
with low-solids muds.

Making a Trip. Consists of hoisting the drill pipe to the surface and
returning it to the bottom of the well bore. This is done for the pur-
pose of changing bits, preparing to take a core, etc.

Marsh Funnel. An instrument used in determining the Marsh funnel
viscosity. The Marsh funnel is a container with a fixed orifice at the
bottom so that when filled with 1,500 cc fresh water, 1 qt (946 ml)
will flow out in 26 ± 0.5 sec. For 1,000 cc out, the efflux time for
water is 27.5± 0.5 sec. See API RP 13B for specifications.

Master Bushing. Adapter used to reduce the size of the rotary table
opening to accommodate bushings, slips, etc.

Mechanical Powered Rig
1. Mechanical Clutch Type Rig - one which connects the internal
combustion engines to the load by means of friction clutches
which can be “slipped” a moderate amount to get the load started
while the engines are operating at a moderate speed.
2. Fluid drive, fluid coupling, and torque converter - consists of a
pump and turbine and fluid combination for transmitting power
from engine to load permitting considerably more “slipping” and
flexibility than a friction clutch and minimize shock loads getting
back to engine. The older fluid coupling involves little slip and the
same torque in the load as in the engine. The torque converter
involves a multistage turbine (sometimes adjustable) which, at low
speeds of the load, can develop several times as much torque in
the load as in the engine, obviously useful for accelerating heavy
loads. (Slightly less efficient.)

486