Editing Natural gas (section)

==Storage and transport==
{{see also|List of natural gas pipelines}}
[[File:Polyethylene gas main.jpg|thumb|upright|[[Polyethylene]] plastic [[Gas main|main]] being placed in a [[trench]]]]
[[File:Gas underpipe warning notice.jpg|thumb| Construction close to high pressure gas transmission pipelines is discouraged, often with standing warning signs.<ref>{{Cite web |last=[[Ervia#Gas Networks Ireland|Gas Networks Ireland]] |date=2016-06-01 |title=Advice for Working in the Vicinity of Gas Pipelines |url=https://www.gasnetworks.ie/home/gas-meter/meter-services/Safety-Advice-for-Working-in-the-Vicinity-of-Natural-Gas-Pipeline.pdf |access-date=2020-06-20}}</ref>]]{{Update section|date=May 2022|reason=change in transport from Russia}}
Because of its low density, it is not easy to store natural gas or to transport it by vehicle. Natural gas [[pipeline transport|pipelines]] are impractical across oceans, since the gas needs to be cooled down and compressed, as the friction in the pipeline causes the gas to heat up. Many [[List of natural gas pipelines#North America|existing pipelines in the US]] are close to reaching their capacity, prompting some politicians representing northern states to speak of potential shortages. The large trade cost implies that natural gas markets are globally much less integrated, causing significant price differences across countries. In [[Western Europe]], the gas pipeline network is already dense.<ref>{{Cite web |title=Gas Infrastructure Europe |url=http://www.gie.eu.com/ |url-status=dead |archive-url=https://web.archive.org/web/20090830051945/http://www.gie.eu.com/ |archive-date=2009-08-30 |access-date=2009-06-18 |website=Energia Mexicana |language=es}}</ref>{{better source needed|date=November 2017}}{{full citation needed|date=November 2017}} New pipelines are planned or under construction between Western Europe and the [[Near East]] or [[Northern Africa]].<ref>{{Cite web |date=2022-06-23 |title=African gas pipeline projects revived due to European gas crisis |url=https://intellinews.com/african-gas-pipeline-projects-revived-due-to-european-gas-crisis-248456/ |access-date=2023-04-22 |website=intellinews.com |language=en}}</ref>

Whenever gas is bought or sold at custody transfer points, rules and agreements are made regarding the gas quality. These may include the maximum allowable concentration of [[Carbon dioxide|{{chem|C|O|2}}]], [[Hydrogen sulfide|{{chem|H|2|S}}]] and [[Water vapor|{{chem|H|2|O}}]]. Usually sales quality gas that has been [[Natural-gas processing|treated to remove contamination]] is traded on a "dry gas" basis and is required to be commercially free from objectionable odours, materials, and dust or other solid or liquid matter, waxes, gums and gum forming constituents, which might damage or adversely affect operation of equipment downstream of the custody transfer point.

Based on their geographic origin, H-gas (high-calorific gas) and L-gas (low-calorific gas) are to be distinguished.<ref>{{Cite web |last=PowerUP |first=Team |date=2023-10-24 |title=Natural gas – everything you need to know - PowerUp – Parts for Gas-engines |url=https://www.powerup.at/knowledge/natural-gas/natural-gas/ |access-date=2024-12-05 |language=en-US}}</ref> Both types require separate transport, leading to two separate pipeline networks, e.g. in parts of Germany (with a strengthened focus and transition towards H-gas, as the L-gas reservoirs in Germany and the Netherlands are declining).<ref>{{Cite web |date=2024-11-28 |title=Von L-Gas auf H-Gas: Darum wird das Erdgas umgestellt {{!}} Verbraucherzentrale.de |url=https://www.verbraucherzentrale.de/wissen/energie/heizen-und-warmwasser/von-lgas-auf-hgas-darum-wird-das-erdgas-umgestellt-13264 |access-date=2024-12-05 |website=www.verbraucherzentrale.de |language=de}}</ref>

[[LNG carrier]] ships transport [[liquefied natural gas]] (LNG) across oceans, while [[tank truck]]s can carry LNG or compressed natural gas (CNG) over shorter distances.<ref>{{Cite journal |last1=Ulvestad |first1=Marte |last2=Overland |first2=Indra |date=2012 |title=Natural gas and CO2 price variation: Impact on the relative cost-efficiency of LNG and pipelines |journal=International Journal of Environmental Studies |volume=69 |issue=3 |pages=407–426 |doi=10.1080/00207233.2012.677581 |pmc=3962073 |pmid=24683269|bibcode=2012IJEnS..69..407U }}</ref> Sea transport using [[CNG carrier]] ships that are now under development may be competitive with LNG transport in specific conditions.<ref>{{Cite journal |last=Bortnowska |first=Monika |title=Development of new technologies for shipping natural gas by sea |date=2009 |journal=Polish Maritime Research |volume=16 |issue=3/2009 |pages=70–78|doi=10.2478/v10012-008-0036-2 |bibcode=2009PMRes..16c..70B |doi-access=free }}</ref>

Gas is turned into liquid at a [[liquefaction of gases|liquefaction]] plant, and is returned to gas form at [[gasification|regasification]] plant at the [[Liquefied natural gas terminal|terminal]]. Shipborne regasification equipment is also used. LNG is the preferred form for long distance, high volume transportation of natural gas, whereas pipeline is preferred for transport for distances up to {{convert|4000|km|abbr=on}} over land and approximately half that distance offshore.

[[CNG]] is transported at high pressure, typically above {{convert|200|bar|kPa psi|lk=in}}. Compressors and decompression equipment are less capital intensive and may be economical in smaller unit sizes than liquefaction/regasification plants. Natural gas trucks and carriers may transport natural gas directly to end-users, or to distribution points such as pipelines.

[[File:Manlove gas storage facility crop.jpg|thumb|[[Peoples Gas]] Manlove Field [[natural gas storage]] area in [[Newcomb Township, Champaign County, Illinois]]. In the foreground (left) is one of the numerous wells for the underground storage area, with an LNG plant, and above-ground storage tanks are in the background (right).]]

In the past, the natural gas which was recovered in the course of recovering [[petroleum]] could not be profitably sold, and was simply burned at the oil field in a process known as [[gas flare|flaring]]. Flaring is now illegal in many countries.<ref>{{Cite book |last=Hyne |first=Norman J. |url=https://books.google.com/books?id=6CQKozxTKG4C |title=Dictionary of Petroleum Exploration, Drilling & Production |publisher=PennWell Books |year=1991 |isbn=978-0-87814-352-8 |page=190}}</ref> Additionally, higher demand in the last 20–30 years has made production of gas associated with oil economically viable. As a further option, the gas is now sometimes re-[[wikt:inject|injected]] into the formation for [[enhanced oil recovery]] by pressure maintenance as well as miscible or immiscible flooding. Conservation, re-injection, or flaring of natural gas associated with oil is primarily dependent on proximity to markets (pipelines), and regulatory restrictions.

Natural gas can be indirectly exported through the absorption in other physical output. The expansion of shale gas production in the US has caused prices to drop relative to other countries. This has caused a boom in energy intensive manufacturing sector exports, whereby the average dollar unit of US manufacturing exports has almost tripled its energy content between 1996 and 2012.<ref>{{Cite journal |last1=Arezki |first1=Rabah |last2=Fetzer |first2=Thiemo |date=January 2016 |title=On the Comparative Advantage of U.S. Manufacturing: Evidence from the Shale Gas Revolution |url=http://cep.lse.ac.uk/pubs/download/dp1399.pdf |journal=Journal of International Economics |publisher=Centre for Economic Performance |issn=2042-2695 |archive-url=https://web.archive.org/web/20160701075547/http://cep.lse.ac.uk/pubs/download/dp1399.pdf |archive-date=2016-07-01}}</ref>

A "master gas system" was invented in [[Saudi Arabia]] in the late 1970s, ending any necessity for flaring. Satellite and nearby infra-red camera observations, however, shows that flaring<ref>{{Cite web |date=2007-08-29 |title=Bank-Led Satellite Imagery Sheds More Light on Gas Flaring Pollution |url=http://go.worldbank.org/W33BPE31S0 |access-date=2017-11-24 |website=The World Bank – News & Broadcast}}</ref><ref>{{Cite web |last=Ethan |date=2007-11-09 |title=Will eyes in the sky end natural gas flaring? |url=http://www.ethanzuckerman.com/blog/2007/11/09/will-eyes-in-the-sky-end-natural-gas-flaring/ |access-date=2017-11-24 |website=Ethan Zuckerman's online home}}</ref><ref>{{Cite web |date=2007-11-09 |title=Composite image of gas flares in 1992, 2000 and 2006 by NGDC |url=http://www.ethanzuckerman.com/blog/wp-content/2007/11/flares.jpg |access-date=2011-02-06 |website=Ethan Zuckerman's online home}} [https://www.ngdc.noaa.gov/ National Geophysical Data Center (NGDC)]</ref><ref>{{Cite web |title=Composite image of the earth at night |url=https://nssdc.gsfc.nasa.gov/planetary/image/earth_night.jpg |access-date=2017-11-24 |via=Ethan Zuckerman's online home}}</ref> and venting<ref>{{Cite news |last1=Abnett |first1=Kate |last2=Nasralla |first2=Shadia |date=2021-06-24 |title=Gas infrastructure across Europe leaking planet-warming methane |language=en |work=Reuters |url=https://www.reuters.com/business/environment/exclusive-gas-infrastructure-across-europe-leaking-planet-warming-methane-video-2021-06-24/ |access-date=2021-12-18}}</ref> are still happening in some countries.

Natural gas is used to generate electricity and heat for [[desalination]]. Similarly, some landfills that also discharge methane gases have been set up to capture the methane and generate electricity.

Natural gas is often stored underground [references about geological storage needed]inside depleted gas reservoirs from previous gas wells, [[salt domes]], or in tanks as liquefied natural gas. The gas is injected in a time of low demand and extracted when demand picks up. Storage nearby end users helps to meet volatile demands, but such storage may not always be practicable.

With 15 countries accounting for 84% of the worldwide extraction, access to natural gas has become an important issue in international politics, and countries vie for control of pipelines.<ref>{{Cite web |last=Jürgen Wagner |date=2007-06-19 |title=The Contours of the New Cold War |url=http://www.imi-online.de/2007/06/19/thecontoursofthe/ |access-date=2011-02-06 |publisher=IMI}}</ref> In the first decade of the 21st century, [[Gazprom]], the state-owned energy company in Russia, engaged in disputes with [[Ukraine]] and [[Belarus]] over the price of natural gas, which have created concerns that gas deliveries to parts of Europe could be cut off for political reasons.<ref>{{Cite web |title=Gazprom and Russian Foreign Policy |url=<!--http://www.npr.org/templates/story/story.php?storyId=99026745-->https://www.npr.org/series/99026745/gazprom-and-russia-s-foreign-policy |access-date=<!--2011-02-06-->2017-11-24 |website=NPR}}</ref> The United States is preparing to export natural gas.<ref>{{Cite web |last=Sumit Roy |date=2014-06-23 |title=U.S. Natural Gas Export Era Begins In 2015, Fueling Upside In Prices |url=http://seekingalpha.com/article/2282733-u-s-natural-gas-export-era-begins-in-2015-fueling-upside-in-prices |access-date=2015-06-11 |website=Seeking Alpha}}</ref>

===Floating liquefied natural gas===
[[Floating liquefied natural gas]] (FLNG) is an innovative technology designed to enable the development of offshore gas resources that would otherwise remain untapped due to environmental or economic factors which currently make them impractical to develop via a land-based LNG operation. FLNG technology also provides a number of environmental and economic advantages:
* Environmental&nbsp;– Because all processing is done at the gas field, there is no requirement for long pipelines to shore, compression units to pump the gas to shore, dredging and jetty construction, and onshore construction of an LNG processing plant, which significantly reduces the environmental footprint.<ref>{{Cite web |title=SEAAOC – NT Resources Week – Informa – NT Government |url=http://www.seaaoc.com/news-old/shell-receives-green-light-for-prelude-flng |url-status=dead |archive-url=https://web.archive.org/web/20120325160619/http://www.seaaoc.com/news-old/shell-receives-green-light-for-prelude-flng |archive-date=2012-03-25 |access-date=2015-06-11 |website=NTRW}}</ref> Avoiding construction also helps preserve marine and coastal environments. In addition, environmental disturbance will be minimised during decommissioning because the facility can easily be disconnected and removed before being refurbished and re-deployed elsewhere.
* Economic&nbsp;– Where pumping gas to shore can be prohibitively expensive, FLNG makes development economically viable. As a result, it will open up new business opportunities for countries to develop offshore gas fields that would otherwise remain stranded, such as those offshore East Africa.<ref>{{Cite web |date=2011-01-28 |title=The Floating Liquefied Natural Gas (FLNG) Market 2011-2021 |url=http://www.visiongain.com/Report/568/The-Floating-Liquefied-Natural-Gas-(FLNG)-Market-2011-2021 |url-access=subscription |url-status=dead |archive-url=https://web.archive.org/web/20150319155339/https://www.visiongain.com/Report/568/The-Floating-Liquefied-Natural-Gas-(FLNG)-Market-2011-2021 |archive-date=2015-03-19 |access-date=2015-06-11 |website=visiongain |id=ENE8974}}</ref>

Many gas and oil companies are considering the economic and environmental benefits of floating liquefied natural gas (FLNG). There are currently projects underway to construct five FLNG facilities. [[Petronas]] is close to completion on their FLNG-1<ref>{{Cite web |date=2015-04-22 |title=Petronas' FLNG Facility to Deliver First Cargo in Q1 2016 |url=http://worldmaritimenews.com/archives/158677/petronas-flng-facility-to-deliver-first-cargo-in-q1-2016/ |access-date=2017-11-23 |website=World Maritime News Staff}}</ref> at [[Daewoo Shipbuilding and Marine Engineering]] and are underway on their FLNG-2 project<ref>{{Cite web |last=Raj |first=Audrey |date=2015-06-16 |title=Steel cut for PETRONAS FLNG 2 |url=http://www.aogdigital.com/component/k2/item/4971-steel-cut-for-petronas-flng-2 |access-date=2017-11-23 |website=Asian Oil & Gas}}</ref> at [[Samsung Heavy Industries]]. [[Shell Prelude]] is due to start production 2017.<ref>{{Cite web |title=prelude starts production |url=https://www.shell.com/media/news-and-media-releases/2017/prelude-arrives-in-australia.html}}</ref> The [[Browse LNG]] project will commence [[Front-end loading|FEED]] in 2019.<ref>{{Cite web |title=Browse Development – We remain committed to the earliest commercial development of the world-class Browse resources |url=http://www.woodside.com.au/Our-Business/Developing/Browse/Pages/Browse.aspx#.WhjzruNFyUl |website=www.woodside.com.au |quote=Woodside continues to target the selection of a Browse development concept in H2 2017 and commencement of front-end engineering and design (FEED) in 2019.}}</ref>