美國石油儲量達到1975年以來峯值

US proven oil reserves last year rose to their highest level since 1975, official figures have shown, in the latest sign of how the shale revolution has transformed the country’s energy supply outlook.

官方數據顯示，去年美國已探明石油儲量攀升至1975年以來的最高水平。這一數據又一次顯示了頁岩革命如何改變了美國的能源供應前景。

Proven reserves — oil that is expected to be recoverable with existing technology at current prices — were in decline in the US up until 2009, when companies began experiments with producing oil from the Bakken shale of North Dakota.

已探明儲量指的是預計可以用現有技術、在現有油價下開採的石油儲量。直到2009年，美國已探明儲量始終在下降。2009年，多家企業啓動了從北達科他州巴肯(Bakken)頁岩中開採石油的實驗，從而扭轉了下降勢頭。

Rising reserves are an indication that higher US oil production, which has risen about 80 per cent since 2008, can be maintained in the longer term, although the recent slump in oil prices is expected to lead to cutbacks in activity and a slowdown in output growth over the coming months.

雖然最近油價的暴跌預計會導致石油開採活動萎縮，並在之後幾個月內導致石油產量增長放緩，然而不斷攀升的石油儲備仍然表明：美國石油產量能在較長時期內維持在較高水平。自2008年以來，美國石油產量已增長了大約80%。

Crude has fallen nearly 40 per cent since June, on the back of surging US production combined with slowing global oil demand. Brent, the international benchmark, fell 18 per cent last month alone as Opec, the producers’ cartel, decided not to cut output. Brent was trading just below $70 a barrel on Thursday afternoon.

由於美國產量的激增，再加上全球石油需求的放緩，原油價格自今年6月以來已經下跌了近40%。石油輸出國組織(Opec, 簡稱歐佩克)決定不縮減產能，作爲國際基準的布倫特(Brent)原油僅上個月就下跌了18%。週四下午，布倫特基準原油的價格略低於每桶70美元。

Last year companies in the US produced about 2.7bn barrels from their reserves, but added 5.5bn in new discoveries, according to the government’s Energy Information Administration.

根據美國政府能源情報署(Energy Information Administration)的數據，去年石油企業在美國的石油開採量大約爲27億桶，而新發現的儲量則爲55億桶。

As a result, the US ended 2013 with about 36.5bn barrels of proven oil reserves: a rise of 9.3 per cent over the year, and one of the highest levels ever reported in records that go back to the 19th century.

這意味着，2013年底美國已探明石油儲量約爲365億桶，全年增長9.3%，是這19世紀以來最高水平之一。

The peak came in 1970, when the industry reported proven reserves of 39bn barrels of crude oil.

目前，美國已探明石油儲量最高的一年是1970年，當時其石油產業報出已探明原油儲量爲390億桶。

However, the US is today still well behind Russia and Canada in terms of proven reserves, and also behind most Opec members.

不過，以已探明儲量而言，今日的美國仍然遠遠落後於俄羅斯和加拿大，也落後於大多數歐佩克成員國。

Saudi Arabia’s proven oil reserves, the world’s largest conventional ones, were 266bn barrels at the end of last year, according to the BP Statistical Review.

沙特阿拉伯是全球常規石油儲量最大的國家，根據《英國石油公司世界能源統計年鑑》(BP Statistical Review of World Energy)的數據，去年底該國已探明石油儲量是2660億桶。

The largest additions to US reserves were in the Bakken shale, which gained 1.68bn barrels in 2013, and the Eagle Ford shale of south Texas, which gained 805m barrels.

對美國來說，石油儲量的最大增長來自巴肯頁岩和德克薩斯南部的鷹灘(Eagle Ford)頁岩。2013年，前者爲美國增加了16.8億桶儲量，後者爲美國增加了8.05億桶儲量。

The additions in the Bakken are equivalent to the discovery of what would be known in the industry as a “giant” field, and are larger than any single field discovered worldwide in 2013.

巴肯頁岩帶來的儲量增長等價於發現一個業內所說的“大”油田，也大於2013年全球發現的任何單個油田的儲量。

US proven reserves of natural gas also grew strongly in 2013, rising 9.7 per cent to 354tn cubic feet.

2013年，美國已探明天然氣儲量也增長強勁，增長了9.7%，達到354萬億立方英尺。

The EIA’s estimates are based on companies’ reports of their proven reserves, which reflect their plans for drilling over the next five years.

美國能源情報署的儲量估計是基於各公司已探明儲量報告得出的，這些報告反映了這些公司未來五年的鑽井計劃。

The 2013 estimate is based on an average oil price of about $97 per barrel for US benchmark crude. Crude’s fall to about $67 this week means that some previously reported proven reserves will become uneconomic.

另外，對2013年儲量的估值，基於美國基準原油價格爲大約每桶97美元的假設。而就在本週，原油價格下跌至每桶67美元左右，意味着此前報出的部分已探明儲量的開採會變得不再經濟。

That fall will have only a “moderate” effect on estimates this year, the EIA said. Companies use average prices when assessing their reserves, and the decline has come only at the end of the year, so the average price for 2014 as a whole will be higher.

美國能源情報署表示，油價的下跌只會對今年的儲量估計帶來“很弱”的影響。石油企業在評估儲量時使用的是平均油價，而油價的暴跌只是年底的事，2014年全年平均油價總體上應該會更高一些。