Page 501 - Practical Well Planning and Drilling Manual

Appendix NEW! revised 11/00/bc 1/30/01 3:30 PM Page 477

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Glossary

Flag. To tie a piece of cloth or other marker on a bailing or swabbing
line to enable the operator to know the depth at which the swab or
bailer is operating in the hole.

Flipped. In an invert water-in-oil emulsion, the emulsion is said to
be flipped when the continuous and dispersed phases reverse.

Flocculation. Loose association of particles in lightly bonded groups,
non-parallel association of clay platelets. In concentrated suspensions
such as drilling fluids, flocculation may be followed by irreversible
precipitation of colloids and certain other substances from the fluid.

Fluid Flow. The state of fluid dynamics of a fluid in motion is deter-
mined by the type of fluid (e.g., Newtonian, plastic, pseudoplastic,
dilatant), the properties of the fluid such as viscosity and density, the
geometry of the system, and the velocity. Thus, under a given set of
conditions and fluid properties, the fluid flow can usually be
described as plug flow, laminar flow, turbulent flow, or transitional.

Fluid Loss. Measure of the relative amount of fluid lost (filtrate)
through permeable formations or membranes when the drilling fluid
is subjected to a pressure differential.

Fluid. A fluid is a substance readily assuming the shape of the con-
tainer in which it is placed. The term includes both liquids and gases.
It is a substance in which the application of every system of stresses
(other than hydrostatic pressure) will produce a continuously
increasing deformation without any relation between time rate of
deformation at any instant and the magnitude of stresses at that
instant. Drilling fluids are usually Newtonian and plastic, seldom
pseudoplastic, and rarely dilatant fluids.

Formation Damage. Damage to the productivity of a well resulting
from invasion into the formation by mud particles or mud filtrates.
Asphalt from crude oil will also damage some formations.

Formation Micro Imager tool. Wireline logging tool that takes sever-
al sets of microresistivity readings and produces an image of the bore-

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