Crude oil is commonly classified as light, medium or heavy, referring to its gravity as measured on the American Petroleum Institute (API) Scale.

原油通常分为轻型，中型或重型，所指的是对美国石油学会(API)严重程度的规模衡量。

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Heavy crude oil will cover a larger proportion of petroleum trade in our country with the consuming of light crude oil.

随着中轻质原油可利用量的逐渐减少，稠油在我国石油行业中所占的比例越来越大。

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We are a refiner of heavy high-sulfur crude oil as well as a significant producer of refined petroleum products and gasoline blending components, including biofuels.

我们是高浓度硫原油炼油厂，同时也是成品油和汽油调合组分包括生物燃料的著名生产商。

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James Gibbs, Frontier's chief, has no sympathy for Canadian producers that feel they're getting ripped off on the heavy crude his company buys, 50, 000 barrels a day (just under a third of its total petroleum consumption).

FORBES: Wild Frontier