| mica |
a
silicate mineral characterized by sheet cleavage; i.e., it separates in thin sheets.
Biotite is ferromagnesian black mica, and muscovite is potassic white mica.
Sometimes mica is used as a lost circulation material in drilling. |
| micellar-polymer flooding |
a
method of improved oil recovery in which chemicals dissolved in water are pumped into a
reservoir through injection wells to mobilize off left behind after primary or secondary
recovery and to move it toward production wells. The chemical solution includes
surfactants or surfactant-forming chemicals that reduce the interfacial and capillary
forces between oil and water, releasing the oil and carrying it out of the pores where it
has been trapped. The solution may also contain cosurfactants to match the viscosity
of the solution to that of the oil to stabilize the solution and to prevent its absorption
by reservoir rock. An electrolyte is often added to aid in adjusting viscosity.
Injection of the chemical solution is followed by a slug of water thickened with a
polymer, which pushes the released oil through the reservoir, decreases the effective
permeability of established channels so that new channels are opened, and serves as a
mobility buffer between the chemical solution and the final injection of water. |
| micelle |
a
round cluster of hydrocarbon chains formed when the amount of surfactant in an aqueous
solution reaches a critical point. The micelles are able to surround and dissolve
droplets of water or oil, forming an emulsion. |
| micron |
one-millionth
of a meter, a metric unit of measure of length equal to 0.000001 meter
or 0.001 millimeter. |
| migration |
the
movement of oil from the area in which it was formed to a reservoir rock where it can
accumulate. |
| milk emulsion |
see oil-emulsion water. |
| mill |
a
downhole tool with rough, sharp, extremely hard cutting surfaces for removing metal by
grinding or cutting. Mills are run on drill pipe or tubing to grind up debris in the
hole, remove stuck portions of drill stem or sections of casing for sidetracking, and ream
out tight spots in the casing. They are also called junk mills, reaming mills, and
so forth, depending on what use they have. |
| millidarcy (md) |
one-thousandth
of a darcy. |
| milling shoe |
see rotary shoe, burn shoe. |
| milling tool |
the
tool used in the operation of milling. See mill. |
| mill out |
to
use a mill on the end of a workstring to remove a permanent tool or fish. |
| mill-out extension |
a
pinned-end pup joint used to provide additional length and inside diameter necessary to
accommodate a standard milling tool. |
| mined (humic) acids lignins |
naturally
occurring special lignite, e.g., leonardite, that is produced by strip mining from special
lignite deposits. The active ingredient is the humic acids. Mined lignins are
used primarily as thinners, which may or may not be chemically modified; however, they are
also widely used as emulsifiers. |
| mineral rights |
the
rights of ownership, conveyed by deed, of gas, oil, and other minerals beneath the surface
of the earth. In the United States, mineral rights are the property of the surface
owner unless disposed of separately. |
| Minerals Management
Service (MMS) |
an
agency of the U.S. Department of the Interior that establishes requirements through the
code of Federal Regulations (CFR) for drilling while operating on the Outer Continental
Shelf of the United States. The agency regulates rig design and construction,
drilling procedures, equipment, qualification of personnel, and pollution prevention. |
| miniaturized completion |
a
well completion in which the production casing is less than 4.5 inches in diameter.
Compare conventional completion. |
| minimum internal yield
pressure |
the
lowest internal pressure at which a failure (of pipe) will take place. |
| miscible flood |
an
oil-recovery process which involves the injection of a solvent followed by a displacing
fluid. - A method of secondary recovery of fluids from a reservoir by injection of
fluids that are miscible with the reservoir fluids. |
| mist drilling |
a
drilling technique that uses air or gas to which a foaming agent has been added. |
| ml |
abbreviation:
milliliter. |
| MMS |
abbreviation:
Minerals Management Service |
| mobile offshore drilling
unit |
a
drilling rig that is used exclusively to drill offshore exploration and development wells
and that floats upon the surface of the water when being moved from one drill site to
another. It may or may not float once drilling begins. Two basic types of
mobile offshore drilling units are used to drill most offshore wildcat wells:
bottom-supported drilling rigs and floating drilling rigs. |
|
MODU |
abbreviation:
mobile offshore drilling unit. |
| modular-spaced workover rig |
workover
equipment designed in equipment packages or modules that are light enough to be lifted
onto an offshore platform by a platform crane. In most cases, the maximum weight of
a module of 12,000 pounds. Once lifted from the work boat, the rig can be erected
and working within twenty-four to thirty-six hours. |
| mole |
the
fundamental unit of mass of a substance. A mole of any substance is the number of
grams or pounds indicated by its molecular weight. For example, water has a
molecular weight of approximately 18. Therefore, a gram-mole of water is 18 grams of
water; a poundmole or water is 18 pounds of water. See molecular weight. |
| molecular weight |
the
sum of the atomic weights in a molecule. For example, the molecular weight of water
is 18, because the atomic weight of each of the hydrogen molecules is 1 and the atomic
weight of oxygen is 16. See mole |
| molecule |
the
smallest particle of a substance that retains the properties of the substance. it is
composed of one or more atoms. |
| monkeyboard |
the
derrickman's working platform. As pipe of tubing is run into or out of the hole, the
derrickman must handle the top end of the pipe, which may be as high as 90 feet (27 m) in
the derrick or mast. The monkeyboard provide a small platform to raise him to the
proper height for handling the top of the pipe. |
| montmorillonite |
a
clay mineral often used as an additive to drilling mud. It is a hydrous aluminum
silicate capable of reacting with such substances of magnesium and calcium. See bentonite. |
| moon pool |
a
walled round hole or well in the hull of a drill ship (usually in the center) through
which the drilling assembly and other assemblies pass while a well is being drilled,
completed, or abandoned from the drill ship. |
| mosquito bill |
a
tube mounted at the bottom of a sucker rod pump and inside a gas anchor to provide a
conduit into the pump for well fluids that contain little or no gas. |
| mousetrap |
a
fishing tool used to recover a parted string of sucker rods from a well. |
| mud |
the
liquid circulated through the wellbore during rotary drilling and workover operations.
In addition to its function of bringing cuttings to the surface, drilling mud cools
and lubricates the bit and drill stem, protects against blowouts by holding back
subsurface pressures, and deposits a mud cake on the wall of the borehole to prevent loss
of fluids to the formation. See drilling
fluid. |
| mud acid |
a
mixture of hydrochloric and hydrofluoric acids and surfactants used to remove wall cake
from the wellbore. |
| mud additive |
any
material added to drilling fluid to change some of its characteristics or properties. |
| mud balance |
a
beam balance consisting of a cup and a graduated arm carrying a sliding weight and resting
on a fulcrum. It is used to determine the density or weight of drilling mud. |
| mud circulation |
the
process of pumping mud downward to the bit and back up tot he surface in a drilling or
workover operation. See normal
circulation, reverse
circulation. |
| mud density |
weight
per unit volume of drilling fluid usually expressed in pounds per gallon or pounds per
cubic foot. See hydrostatic
pressure. |
| mud engineer |
an
employee of a drilling fluid supply company whose duty it is to test and maintain the
drilling mud properties that are specified by the operator. |
| mud-flow indicator |
a
device that continually measures and may record the flow rate of mud returning from the
annulus and flowing out of the mud return line. If the mud does not flow at a fairly
constant rate, a kick or lost circulation may have occurred. |
| mud-flow sensor |
see mud-flow indicator |
| mud gas separator |
a
device that removes gas from the mud coming out of a well when a kick is being circulated
out. |
| mud hose |
also
called kelly hose or rotary hose. See rotary
hose. |
| mud house |
structure
at the rig to store and shelter sacked materials used in drilling fluids. |
| mud inhibitor |
substances
generally regarded as drilling mud contaminants, such as salt and calcium sulfate, are
called inhibitors when purposely added to mud so that the filtrate from the drilling fluid
will prevent or retard the hydration of formation clays shells. |
| mud log |
a
record of information derived from examination of drilling fluid and drill bit cuttings.
See mud logging. |
| mud logging |
the
recording of information derived from examination and analysis of formation cuttings made
by the bit and of mud circulated out of the hole. A portion of the mud is diverted
through a gas-detecting device. Cuttings brought up by the mud are examined under
ultraviolet light to detect the presence of oil or gas. Mud logging is often carried
out in a portable laboratory set up at the well. |
| mud-mixing devices |
any
of several devices used to agitate, or mix, the liquids and solids that make up drilling
fluid. These devices include jet hoppers, paddles, stirrers, mud guns, and chemical
barrels. |
| mud-off |
1. to
seal the hole against formation fluids by allowing the buildup of wall cake. 2. block off the flow of oil into the wellbore. |
| mud pit |
an
open pit dug in the ground to hold drilling fluid or waste materials discarded after the
treatment of drilling mud. For some drilling operations, mud pits are used for
suction to the mud pumps, settling of mud sediments, and storage of reserve mud.
Steel tanks are much more commonly used for these purposes now, but they are still
sometimes referred to as pits. |
| mud program |
a
plan or procedure, with respect to depth, for the type and properties of drilling fluid to
be used in drilling a well. Some factors that influence the mud program are the
casing program and such formation characteristics as type, competence, solubility,
temperature, and pressure. |
| mud pump |
a
large, high-pressure reciprocating pump used to circulate the mud on a drilling rig.
A typical mud pump is a two-cylinder, double-acting or a three-cylinder,
single-acting piston pump whose pistons travel in replaceable liners and are driven by a
crankshaft actuated by an engine or a motor. Also called a slush pump. |
| mud return line |
a
trough or pipe that is placed between the surface connections at the wellbore and the
shale shaker and through which drilling mud flows upon its return to the surface from the
hole. Also called flow line. |
| mud scales |
see mud balance. |
| mud screen |
see shale shaker |
| mud still |
instrument
used to distill oil, water, and other volatile materials in a mud to determine oil, water,
and total solids contents in volume-percent. |
| mud-up |
to
add solid materials (such as bentonite or other clay) to a drilling fluid composed mainly
of clear water to obtain certain desirable properties. |
| mud weight |
a
measure of the density of a drilling fluid expressed as pounds per gallon, pounds per
cubic foot, or kilograms per cubic meter. Mud weight is directly related to the
amount of pressure the column of drilling mud exerts at the bottom of the hole. |
| mud weight recorder |
an
instrument installed in the mud pits that has a recorder mounted on the rig floor to
provide a continuous reading of the mud weight. |
| mule shoe |
a sub
part of which is formed in the shape of a horseshoe and used to orient the drill stem
downhole. |
| multiple completion |
an
arrangement for producing a well in which one wellbore penetrates two or more
petroleum-bearing formations. In one type, multiple tubing strings are suspended side by
side in the production casing string, each a different length and each packed to prevent
the commingling of different reservoir fluids. Each reservoir is then produced through its
own tubing string. Alternatively, a small-diameter production casing string may be
provided for each reservoir, as in multiple miniaturized or multiple tubingless
completions. |
| multiple completion well |
a
well equipped to produce oil and/or gas separately from more than one reservoir. |
