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Laser Welding	A method which uses a laser beam to apply a hardfacing layer. The layer used to be applied by welding resulting in undesired deviations in high-precision parts. More precise results can be achieved by using a laser beam.

Laser welding	A method which uses a laser beam to apply a hardfacing layer. The layer used to be applied by welding resulting in undesired deviations in high-precision parts. More precise results can be achieved by using a laser beam.

Light crude oil	Crude oil that has a high API gravity, usually more than 31.1o.

Limestone	Sedimentary rock (see sedimentary basin) consisting mainly of calcium carbonate.

Liner	A string of pipe used to case open hole below existing casing, overlapping inside the upper string and held in place by a liner hanger packer. A casing string that does not extend to the top of the wellbore, but instead is anchored or suspended from inside the bottom of the previous casing string.

Liquefied petroleum gas (LPG)	Gas mainly composed of propane and butane, which has been liquefied at low temperatures and moderate pressures. The gas is obtainable from refinery gases or after the cracking process of crude oil. Liquefied petroleum gas is also called bottle gas. At atmospheric pressure, it is easily converted into gas and can be used industrially or domestically. The term is commonly abbreviated as LPG.

Liquified natural gas (LNG)	Natural gas, mainly methane and ethane, which has been liquefied at cryogenic temperatures. This process occurs at an extremely low temperature and a pressure near the atmospheric pressure. When a gas pipeline is not available to transport gas to a marketplace, such as in a jungle or certain remote regions offshore, the gas may be chilled and converted to liquefied natural gas (a liquid) to transport and sell it. The term is commonly abbreviated as LNG.

Log	A detailed record, usually correlated with depth, of certain parameters of the formations penetrated during drilling. Data recorded may include electrical and radioactive surveys, description of cuttings, core analyses, etc.

Logging Tool	A tool for performing downhole well log data gathering services for determining properties of the formation, or characteristics of the wellbore and its environment.

Logging-While-Drilling-Collars (LWD)	Logging While Drilling collars help to analyse geological formations and, therefore, to locate reservoirs.

Lost Circulation Material (LCM)	In case drilling fluid is being lost to the formation downhole, Lost Circulation Material (LCM) such as flaky or granular material is added to the drilling mud in order to seal the formations in which lost circulation has occurred.

Lost Circulation Material (LCM)

LWD-Collars: Logging While Drilling	LWD collars help to analyse geological formations and, therefore, to locate reservoirs.