We have 20 entries in our Glossary for this letter.
Mixture of water and special additives circulating within the well for the purpose of cooling the drill-bit; removing rock cuttings and transporting them back up to the surface.
Also prevents the well wall from caving in and maintains sufficient pressure at the well bottom to avoid hydrocarbon blowout.
A pipe spool in which a number of incoming pipes are combined to feed to a common output line.
Maximum Allowable Working Pressure
The maximum pressure allowed in a piece of equipment e.g. vessel or pipe at its designated temperature.
Motor Control Centre / Switchboard
Molecules containing sulphur with a low molecular weight and therefore very light.
An electronic load indicator and monitoring system fitted to cranes - can store data for future analysis and maintenance planning based on the actual crane usage.
Manufactured by Norwegian firm Datainstrument AS
MMI - Man Machine Interface
A dated term superseded by SCADA
MOB - Man Over Board
Some offshore platforms issue personnel with MOB detectors when performing over the side work.
These detectors automatically emit a signal when imersed in the sea thereby allowing possible faster rescue.
Management of Change
This Protocol is a messaging structure developed by Modicon in 1979.
It is used to establish master-slave/client-server communication between intelligent devices.
MOL - Main Oil Line
Name often given to the oil export line from a platform.
Often used as a prefix to the main export pumps e.g. MOL Pumps
A nickel-copper alloy which combines high strength with high ductility - these usually being a trade off in metals selection.
Also offers excellent general corrosion resistance. Commonly used in seawater applications.
Memorandum of Understanding
Motor Operated Valve
Magnetic Particle Examination. A form of NDE used to detect surface cracks on castings.
MTBF - Mean Time Between Failures
The time interval between 2 failures of a component. The reciprocal of the failure rate.
MTO - Material Take Off
A count of all materials needed to complete a task
MTTR - Mean Time To Repair
The average time taken from the failure of a system until it is successfully restarted.
Mux - Multiplexer
A switching device that sequentially connects multiple inputs or outputs in order to process several signal channels with a single A/D or D/A converter
MWD - Measurements While Drilling
The evaluation of physical properties (usually including pressure; temperature and wellbore trajectory in three-dimensional space) while extending a wellbore
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