Onshore, when used in relation to

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...

s, refers to an

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

natural gas Natural gas (also called fossil gas or simply gas) is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon d ...

or condensate field that is under the land or to activities or operations carried out in relation to such a field. Onshore may also refer to processes that take place on land that are associated with oil, gas or condensate production that has taken place offshore. The offshore production facility delivers oil, gas and condensate by pipelines to the onshore terminal and processing facility. Alternatively oil may be delivered by ocean-going tanker to the onshore terminal.

Onshore oil terminals

Onshore oil terminals may include large crude oil tanks for the initial storage of oil prior to processing. Such tanks provide a buffer volume where oil is delivered by tanker. The oil tanker delivery rate is considerably greater than the processing capacity of the plant. Crude oil tanks also allow offshore production to continue if the export route becomes unavailable. Onshore oil terminals generally have fired heaters to heat the oil to improve subsequent separation. Separator vessels and coalescers stabilise the crude and remove any sediments, produced water and allow light hydrocarbons to flash-off. Large separation vessels give the oil an appropriate residence time in the vessel to allow effective separation to occur. Onshore separators operate at near atmospheric pressure to release as much vapor as possible. The oil processing plant aims to achieve an appropriate vapor pressure specification for the oil. The associated gas is processed for export or used in the plant as fuel gas. Stabilised oil is routed to storage tanks prior to dispatch for international sales delivery by tanker, or to a local

oil refinery An oil refinery or petroleum refinery is an industrial process plant where petroleum (crude oil) is transformed and refined into useful products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, liq ...

for processing.

Onshore gas terminals

See main article

Natural-gas Processing Natural-gas processing is a range of industrial processes designed to purify raw natural gas by removing impurities, contaminants and higher molecular mass hydrocarbons to produce what is known as ''pipeline quality'' dry natural gas. Natural gas ...

Onshore gas terminals may have facilities for removal of liquids from the incoming gas stream. Liquids may include natural gas liquids (NGL), produced water, and glycol (MEG or TEG). Separation of liquid from gas is done in slug catchers, which either comprise an array of pipes or a large cylindrical vessel. A variety of treatment processes are used to condition the gas to a required specification. Such processes may include glycol dehydration, gas sweetening, hydrocarbon dew-point control, fractionation,

natural gas liquids Natural-gas condensate, also called natural gas liquids, is a low-density mixture of hydrocarbon liquids that are present as gaseous components in the raw natural gas produced from many natural gas fields. Some gas species within the raw natu ...

(NGL) recovery, gas compression before gas distribution to users. The hydrocarbon dewpoint changes with the prevailing ambient temperature, the seasonal variation is:

References

Petroleum industry glossary from Saipem Spa

Petroleum geology Oilfield terminology Petroleum industry {{petroleum-stub

Onshore oil terminals

Onshore gas terminals

See also

References