Page 334 - Geology and Geochemistry of Oil and Gas

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Appendix C

GLOSSARY

A

Abandon To cease efforts to test dry hole or to produce oil or
gas from a well when it becomes unprofitable and to
place the cement plug(s) in the borehole to prevent
migration of fluids between the different formations
penetrated by the borehole. See: Plug and abandon
(P&A)
Abiogenic Products (minerals, sediments, or rocks) resulting
from inorganic processes of formation. Cf: Biogenic.
Abnormal pressure Pressure exceeding or falling below the normal
pressure to be expected at a given depth.
Absolute permeability A measure of the ability of a single-phase fluid (such
as water, gas, or oil) to flow through a rock formation
when the formation is totally filled (saturated) with
this fluid.
Accretion Vertical buildup or lateral extension of deposits as a
consequence of sedimentation or biotic activities.
Accuracy Closeness to the true value or to value accepted as
being true; the degree of perfection attained in a
measurement, computation, or estimate, or degree of
conformity to some recognized standard value (such
as conventional unit of measure, an exact
mathematical value, or a survey observation
determined by refined methods). Accuracy related to
the quality of a result, as distinguished from
precision.
Acidizing The introduction of acid (hydrochloric, formic, and
acetic, for carbonates; and hydrofluoric for
sandstones) into a formation to dissolve rocks, thus
opening new and widening old passageways for fluids
to flow through. See also: Fracture acidizing, Matrix
acidizing.
Acoustic (sonic) log Measurement of porosity, lithology, and cement
bonding by the use of sonic waves.

Also see Chilingarian et al., 1986, 1996.