Delayed or shelved exploration projects from offshore West Africa to the Canadian oil sands could lead to a supply crimp in the next few years if and when demand comes roaring back.

• 当市场需求卷土重来之时，西非海岸、加拿大油砂等开采项目的一度推迟和搁置也许会成为今后几年限制石油供应的一道软肋。