A glossary of common terms and abbreviations used in the industry, with links to more in-depth articles on key words
M-85 - a mix of methanol (85%) and gasoline (15%) used as an alternative fuel in tramsportation
Magdalena (crude) - a heavy, sour crude grade produced in Colombia
Magellan East Houston - (MEH) a crude oil terminal in Houston, Texas that is an aggregation point from crude brought down to the Gulf Coast from inland producing regions
Magnaforming - a type of reformer, the refining process unit that upgrades low-octane heavy naphtha to make gasoline that meets minimum octane requirements
Majors - oil companies that play across the entire petroleum value chain from oil exploration and production to transport, refining, and marketing
Margins - a measure of the value contribution of the refinery per unit of input
Marginal configuration - the refinery configuration that is operating at the margin in a market, balancing refined product supply and setting market conditions by its break-even economics
Marine diesel - (MDO) a diesel range light product used for non-transportation purposes
Marine gasoil - (MGO) a diesel range light product used for non-transportation purposes
Marker crude - a crude grade that is used as a price index off which other crudes are priced
Marlim (crude) - a heavy, sweet crude grade produced in Colombia
Marpol - (Marine pollution treaty) the international convention or treaty that regulates pollution from ships at sea
Mars (crude) - a medium sour grade of crude grade produced off-shore in the Gulf of Mexico
Masila (crude) - a medium, sweet crude grade produced in Yemen
Max distillate - a mode of operation for refiners where they are trying to maximize the production of middle distillates (diesel, heating oil and jet fuel) at the expense of gasoline
Max gasoline - a mode of operation for refiners where they are trying to maximize the production of gasoline at the expense of middle distillates (diesel, heating oil and jet fuel)
Maximum demonstrated rate (capacity) - (MDR) the maximum rate at which a unit has been seen to sustainably run in the past
Maya (crude) - a heavy, sour crude grade produced in Mexico
Mcf - (Thousand cubic feet) a common measurement of volume in the US for gases such as natural gas or hydrogen
MDR (capacity) - (Maximum demonstrated rate) the maximum rate at which a unit has been seen to sustainably run in the past
MEA - (Monoethanolamine) a common process chemical used to extract H2S gas from refinery gas streams in the amine or girbotol unit
Mean of Platts Singapore - (MOPS) a pricing basis for many refined products in southeast Asia
Mechanical availability - a measure of a refinery or process unit's capacity to operate based on the condition of the equipment, without adjusting for any other operational or commercial limits
Medanito (crude) - a light, sweet crude grade produced in Argentina
MEH - (Magellan east Houston) a crude oil terminal in Houston, Texas that is an aggregation point from crude brought down to the Gulf Coast from inland producing regions
MEK - (Methylethylketone) one of the solvents used in the dewaxing units. The alternative to using a ketone such as MEK is propane
Mercaptan - highly odorous sulfur containing hydrocarbons that are often removed from light products such as LPG or jet fuel in a merox unit
Merey (crude) - a heavy, sour crude grade produced in Venezuela
Merox - (Mercaptan oxydation) proprietary UOP technology that selectively sweetens petroleum products by oxidizing the foul smelling mercaptans into the sweeter disulphides which remain in the product, leaving the total sulfur content the same
Mesa 30 (crude) - a medium, sour crude grade from Venezuela
Metals - naturally occurring contaminants in crude oil that pose a risk to conversion unit catalysts in high concentration
Methane - (C1) a simple hydrocarbon with carbon atom and four hydrogen atoms
Methanol - (MeOH) an important petrochemical produced from natural gas, a feedstock to make the gasoline oxygenate blendstock MTBE, and a potential alternative fuel for the shipping industry
Methylethylketone - (MEK) one of the solvents used in the dewaxing units. The alternative to using a ketone such as MEK is propane
MGO - (Marine gasoil) a diesel range light product used for non-transportation purposes
Midale (crude) - a medium, sour crude grade from Canada
Middle distillates - a term used to refer both to the atmospheric gasoil cut from atmospheric distillation, and to a range of light products ranging from kerosene to diesel.
Midstream - the part of the petroleum value chain focused on transportation of crude oil and refined products
Midway sunset (crude) - a very-heavy, sour crude grade produced in the US
Minas sunset (crude) - a medium, sweet crude grade produced in the Indonesia
Mineral oil - a specialty refined product used for non-fuel purposes such as food and cosmetics
Miri light (crude) - a medium, sweet crude grade produced in the Malaysia
MMBtu - (Million British thermal units) a common measure of energy content for crude oil and refined products, and a volume measurement for natural gas
Mogas - (Motor gasoline) one of the major petroleum products produced from processing crude oil in a petroleum refinery
MON - (Motor octane) one of the two primary measures of the octane value of gasoline or a gasoline blendstock
Mont Belvieu - a major hub for NGL fractionation and trading, located on the US Gulf Coast outside of Houston, Texas
MOPS - (Mean of Platts Singapore) a pricing basis for many refined products in southeast Asia
Mostarda (crude) - a heavy, sour crude grade produced in Angola
Motor octane - (MON) one of the two primary measures of the octane value of gasoline or a gasoline blendstock
MSW (crude) - a light, sweet crude grade produced in western Canada
MTBE (product) - (Methyl-tertiarybutyl- ether) a common oxygenate blendstock into gasoline
MTBE (unit) - a process unit that converts methanol and isobutylene to MTBE
Methyl-tertiarybutyl-ether (product) - (MTBE) a common blendstock into gasoline
Murban (crude) - a light, sweet crude grade produced in the UAE