Campo de gás natural: diferenças entre revisões

2 393 bytes adicionados ,  19h09min de 20 de agosto de 2011
sem resumo de edição
'''Campo de gás natural''' é um depósito geológico com alto conteúdo de [[gás natural]]. [[Petróleo]] e gás natural são produzidos pelo mesmo processo geológico [[Hipótese|hipotético]] de formação de [[combustível fóssil|combustíveis fósseis]]: a [[decomposição]] [[Digestão anaeróbia|anaeróbica]] da [[matéria orgânica]] em profundidade sob a superfície da [[Terra]]. Como conseqüência, petróleo e gás natural são frequentemente encontrados juntos. Normalmente, depósitos ricos em petróleo são conhecidos como [[Campo de petróleo|campos de petróleo]] e depósitos ricos em gás natural são chamados de '''campos de gás natural'''.
Em geral, sedimentos orgânico enterrados em profundidades de 1.000 m a 6.000 m (a temperaturas de 60 °[[Celsius|C]] a 150 °C) geram óleo, enquanto sedimentos enterrados mais profundamente e a mais alta temperatura geram gás natural. <!-- The deeper the source, the "drier" the gas (that is, the smaller the proportion of [[Natural gas condensate|condensate]]s in the gas). Because both oil and natural gas are lighter than water, they tend to rise from their sources until they either [[Petroleum seep|seep]] to the surface or are trapped by a non-permeable layer of rock. They can be extracted from the trap by drilling.
The largest natural gas field is South Pars/[[Asalouyeh]] gas field, which is shared between [[Iran]] and [[Qatar]]. The second largest natural gas field is located in [[Novy Urengoy]], [[Russia]]. The gas field [[Haynesville Shale]] Louisiana-Texas has been projected bigger than South Pars, since this a new well it has not been officially recorded its overall power.
==Offshore gas fields==
[[Image:Toisa Perseus&Discoverer Enterprise.jpg|thumb|The drillship ''[[Discoverer Enterprise]]'' is shown in the background, at work during exploratory phase of a new offshore field. The Offshore Support Vessel ''Toisa Perseus'' is shown in the foreground, illustrating part of the complex logistics of offshore oil and gas exploration and production.]]
Like oil, natural gas is often found underwater in offshore gas fields such as the [[North Sea Oil|North Sea]], [[Corrib Gas Field]] off [[Ireland]], and the [[Sable Offshore Energy Project|Scotian Shelf]] near [[Sable Island]]. The technology utilized to extract and transport offshore natural gas is different from land-based fields in that a few, very large rigs are usually used, due to the cost and logistical difficulties in working over water.
Rising gas prices have encouraged drillers to revisit fields that, until now, were not considered economically viable. For example, McMoran Exploration has passed a drilling depth of over 32,000 feet (9754 m) (the deepest test well in the history of gas production) at the Blackbeard site in the Gulf of Mexico.<ref>A Famed Dry Hole Gets a Second Shot, Wall Street Journal, July 21, 2008, p.B1</ref> [[Exxon Mobil]]'s drill rig had reached 30,000 feet by 2006 without finding gas; Exxon Mobil abandoned the site.
{{Em tradução|:en:Natural gas field}}
== Ver também ==