Page 352 - Geology and Geochemistry of Oil and Gas

GLOSSARY 313
and ship-shaped barges, and semisubmersibles. See
also: Mobile offshore drilling rig.
Floatstone Reef rock composed of matrix-supported organic
particles, the particles being of allochthonous
(transported) rather than in-place origin.
Flocculation The coagulation of solids in the drilling mud,
produced by special additives or by contaminants.
Flow Movement of fluids through the reservoir.
Flowchart Diagrammatic representation of the operations
involved in an algorithm or a technological
process. Flow lines indicate the sequence of
operations or the flow of data/information. Syn:
Block diargam.
Flow test Preliminary test to confirm flow rate through a testing
tool prior to going downhole. Syn: Formation testing.
Fluidity The measure of rate with which a fluid is continuously
deformed by a shearing stress; ease of flowing. Cf:
Viscosity.
Fluid level Distance between well head and point to which fluid
rises in the well.
Fluid loss The unwanted migration of the liquid part of the
drilling mud or cement slurry into a formation, often
minimized or prevented by the blending of additives
with the mud or cement.
Fluid loss agent Materials added to the drilling mud to reduce water
loss into the formation.
Fluorescent Instantaneous re-emission of light of a greater
wavelength than the light originally absorbed.
Flushed zone The area near the wellbore, which has had all the
original formation water and/or movable
hydrocarbons replaced by the invading mud filtrate.
Cf: Uninvaded zone.
Fluvial Of or pertaining to rivers; growing or living in a
stream or river; produced by the action of a stream or
river.
Formation [strat] A bed or deposit composed throughout of
substantially the same kind of rock. The fundamental
unit in lithostratigraphy. Specific features distinguish
one rock formation from another.
Formation [drill] A general term applied by drillers without
stratigraphic connotation to a sedimentary rock that
can be described by certain drilling or reservoir
characteristics: e.g., hard formation, porous
formation, productive formation, etc.