A glossary of common terms and abbreviations used in the industry, with links to more in-depth articles on key words
Laboratory - part of the refinery that is responsible for physical testing of crude oil, refined products and intermediate streams
Labuan (crude) - a heavy, sweet crude grade from Malaysia
LAGO - (Light atmospheric gasoil) a distillation cut derived from an atmospheric distillation unit primarily comprised of molecules with 14 to 20 carbon atoms
Lamp oil - a distillation cut derived from an atmospheric distillation unit primarily comprised of molecules with 14 to 20 carbon atoms
Laycan - the period in which a ship must be ready to load or discharge a cargo
LC-fining - a type of resid hydrocracker, a refinery unit that upgrades vacuum resid through cracking while injecting hydrogen
LCFS - (Low carbon fuel standard) a regulatory program that encourages the adoption of low-carbon fuels
Lead - a gasoline additive that was widely used to improve gasoline octane
Lease condensate - a mixture of light liquid hydrocarbons, similar to a very light (high API) crude oil
LHS (crude) - a light, sweet crude grade from Louisiana, in the US
LHV - (Lower heating value) a measure of the amount of heat generated from full combustion of a hydrocarbon not accounting for the heat contained in combustion products if not returned to per-combustion temperature
Light atmospheric gasoil - (LAGO) a distillation cut derived from an atmospheric distillation unit primarily comprised of molecules with 14 to 20 carbon atoms. The AGO distillation cut boils between 420 and 650F (215 - 343C)
Light ends - the light hydrocarbon gases and liquids that come off the top of distillation towers and fractionators
Light gasoil - a distillation cut derived from an atmospheric distillation unit primarily comprised of molecules with 14 to 20 carbon atoms. The AGO distillation cut boils between 420 and 650F (215 - 343C)
Light heavy differential - a measure of the difference in price between light products (e.g., gasoline and diesel) and heavy fuel oil
Light hydrocrackate - a light naphtha range product from the hydrocracker
Light naphtha - a finished product used as a petrochemical feed stock, or a distillation cut commonly called light straight run naphtha
Light straight run naphtha - (LSR) a type of light naphtha that comes from distillation cut comprised of pentane and slightly heavier naphtha-range material
Light tight oil - (LTO) a crude oil produced from thin, tight formations using unconventional production techniques including horizontal drilling and hydraulic fracturing
Lightering - the use of a small tanker or barge to move cargo between a larger ship and shore
Line 63 (crude) - a heavy, sour crude grade from the US
Linear program - (LP) an analytical tool used at most refineries to make economically optimal short-term decisions around operations and commercial activities
Liquified petroleum gas - (LPG) the lightest (lowest density) liquid fuels produced by a refinery, primarily C3s (propane) and C4s (butane)
Liza (crude) - a medium, sweet crude grade produced in Guyana
LLB (crude) - (Lloyd blend) a heavy, sour crude grade from Canada
LLS (crude) - (Louisiana light sweet) a light, sweet crude grade produced in Louisiana, in the US
LNG - (Liquified natural gas) natural gas that has been liquified through a cryogenic process to make it easier to store and transport
Long residue - the heaviest of the distillation cuts out of the atmospheric distillation tower
LOOP (terminal) - (Louisiana offshore oil port) a crude oil unloading terminal located off of the coast of Louisiana in the Gulf of Mexico
Loreto (crude) - a heavy, sour crude grade from Peru
Louisiana offshore oil port - (LOOP) a crude oil unloading terminal located off of the coast of Louisiana in the Gulf of Mexico
Low carbon fuel standard - (LCFS) a regulatory program that encourages the adoption of low-carbon fuel
Lower heating value - (LHV) a measure of the amount of heat generated from full combustion of a hydrocarbon not accounting for the heat contained in combustion products if not returned to per-combustion temperature
Low sulfur waxy resid - (LSWR) a low-sulfur resid produced primarily in Indonesia and used as a conversion feedstock and fuel oil blendstock across Asia
LP (model) - (Linear program) an analytical tool used at most refineries to make economically optimal short-term decisions around operations and commercial activities
LPG - (Liquified petroleum gas) the lightest (lowest density) liquid fuels produced by a refinery, primarily C3s (propane) and C4s (butane)
LPG merox - a proprietary UOP technology that selectively sweetens petroleum products by oxidizing the foul smelling mercaptans into the sweeter disulfides which remain in the product, leaving the total sulfur content the same
LR1 - a class of oil product tanker of small size or Panamax class (60-80 DWT)
LR2 - a class of oil product tanker of small size or Panamax class (60-80 DWT)
LSB (crude) - (light sour blend) a medium, sour crude grade from Western Canada
LSWR - (Low-sulfur waxy resid) a low-sulfur resid produced primarily in Indonesia and used as a conversion feedstock and fuel oil blendstock across Asia
LTO - (Light tight oil) a crude oil produced from thin, tight formations using unconventional production techniques including horizontal drilling and hydraulic fracturing
Lubes - non-fuel product used for lubricating machinery, including automobile engines
Lubes plant - part of a refinery that produces base oils and/or finished lubricants
Lubricants - non-fuel product used for lubricating machinery, including automobile engines