Glossary
Lay Barge |
a specially designed barge used to lay an underwater pipeline; also called a pipe laying barge. |
Leak-off test |
the process of applying pressure to the formation below the casing seat to test the quality of cementing and to determine the fracture pressure in the permeable zone immediately below the casing seat. |
Lean gas or dry gas |
gas with relatively few hydrocarbons other than methane. The calorific value is typically around 1,000Btu per scf, unless there is a significant proportion of non-hydrocarbon gases present. |
Licence |
an authority to explore for or produce oil or gas in a particular area issued to a company by the governing state; see exploration/production licence. |
Licence round |
a stage in the allocation of licences (both onshore and offshore) in which a country places a number of specified areas in its sector on offer to oil companies at one |
Light crude |
crude oil with a low specific gravity and high API gravity due to the presence of a high proportion of light hydrocarbon fractions. |
Light fractions |
the low molecular weight, low boiling point fractions that emerge from the upper part of a fractionating column during the oil refining process. |
Liner |
small-diameter casing that extends into the production layer from just above the casing seat and is perforated when production or well testing starts. |
Liquefied natural gas (LNG) |
natural gas that has been liquefied by refrigeration or pressure in order to facilitate storage or transport; generally consists mainly of methane. See also gas liquefaction. |
Liquefied petroleum gas (LPG) |
a mixture of light hydrocarbons derived from oil-bearing strata which is gaseous at normal temperatures but which has been liquefied by refrigeration or pressure in order to facilitate storage or transport; generally consists mainly of propane and butane. |
LNG carrier |
a tanker specially designed to carry LNG, fitted with insulated pressure tanks made of stainless steel or aluminium. The load is refrigerated to 162C. |
Lost circulation |
the loss of substantial volumes of drilling mud into a formation; also called loss of returns. |
Lost time |
time in which no work is possible on an operation due to bad weather, industrial dispute, etc. |
