Page 360 - Geology and Geochemistry of Oil and Gas

GLOSSARY 321
Logging Recording of data (various physical, chemical, and
mechanical properties of reservoir) obtained by
lowering of various types of measuring tools into a
wellbore. Well-logging includes: acoustic (sonic) log,
caliper log, conduction log, density log, driller’s log,
electric log, gamma-ray log, induction log, nuclear
log, neutron log, pressure log, production log,
resistivity log, spontaneous potential log, temperature
log, and some others.
Lost circulation additives Materials (fiber, flake, or granular) added to the
drilling mud in varying amounts to control or prevent
lost circulation.
M

Mathematical expectation The average value resulting from an infinite series of
repetition of an experiment or observations of a
random variable. Syn: Expectation. Symbol: E.
Mathematical geology Mathematics as applied to geology; ‘‘the name given
to the discipline devoted to the investigation of
probability distributions of values of random
variables with the object of obtaining information
concerning geological processes’’ (Vistelius, 1980).
These investigations are based on the methods of
mathematical probability, statistical theory, and
special computational mathematics developed in
work on the solutions of various particular problems.
Syn: Geomathematics.
Mathematical modeling The representation by mathematical expressions of a
physical system to understand its structure (static
mathematical models) and/or behavior (dynamic
mathematical models).
Matrix The continuous material (sediment, cement)
composing rocks; the continuous material enclosing
interstices in rocks.
Matrix acidizing Enlargement of preexisting pores without
fracturing. Acid can also enlarge (etch) the preexisting
fractures.
Maturation [petrol] Term pertaining to the thermocatalytic state of
hydrocarbons, i.e., the evolution of hydrocarbons
through the increasing pressure and temperature
associated with burial, or to the hydrocarbon source
material.
Maturation [sed] Term pertaining to the mineralogic composition of
siliciclastic or carbonate rocks as they approach a