LAN - Local Area Network

A data communications network which is geographically limited (typically to a 1 km radius) allowing easy interconnection of devices.
Ethernet is an example of a standard LAN.
Further Reading

LCIE

French based Notified Body

Further Reading

LED

Light Emitting Diode

Further Reading

LEL - Lower Explosive Limit

Below the LEL a mixture of substance and air lacks sufficient fuel (substance) to burn.

Further Reading

LER

Local Equipment Room

Further Reading

LHV

Heating Value is defined as the amount of energy released when a fuel is burned completely in a steady-flow process and the products are returned to the state of the reactants.
The heating value is dependent on the phase of water/steam in the combustion products. When H2O is in vapor form the heating value is called LHV (Lower Heating Value).
Further Reading

Linearity

The closeness to which a curve approximates a straight line or the deviation of an instrument's response from a straight line.

Further Reading

LNG - Liquefied Natural Gas

Natural gas (mainly methane) refrigerated to reach liquid phase suitable for transportation in specialised vessels or by pipeline.

Further Reading

LOA

Letter of Authorisation

Further Reading

LOGIC

Leading Oil & Gas Industry Competitiveness
An industry funded organisation that works with companies throughout the O&G industry to stimulate collaboration and improve competitiveness.
Further Reading

LOI

Letter of Intent

Further Reading

LOLER

Lifting Operations and Lifting Equipment Regulations
UK regulations that aim to reduce risks to people’s health and safety from lifting equipment provided for use at work.
Further Reading

LOM

Spanish based Notified Body

Further Reading

LOPA - Layers of Protection Analysis

A semi-quantitative risk analysis technique.
LOPA results are intended to be conservative (overestimating the risk) and usually adequate to understand the required safety integrity level.
Further Reading
SIL Ratings Toolbox Page

LOS

Line of Sight
Typically used with reference to telecommunication devices.
Further Reading

LP - Low Pressure

Often used with reference to a utility or vent line e.g. LP air supply.

Further Reading

LPG - Liquefied Petroleum Gas

Butane and propane mixture separated from well fluid stream. LPG can be transported under pressure in refrigerated vessels

Further Reading

LSA Scale

Low Specific Activity scale found adhering to pipe and equipment internals is mainly due to radium-226 produced from the decay of naturally occurring uranium-238.
Can present decommissioning problems.
Further Reading

LTI - Lost Time Incident

Accident resulting in personnel not being able to work as a result of their injury is called an LTI

Further Reading

LtO

Licence to Operate

Further Reading

Lump Sum

Contract term generally denoting fixed price covering all services provided.

Further Reading

LWD

Logging While Drilling

Further Reading

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