Problems as well as profits for oil firms

The days when the Middle East – a zone of cheap and available supply – produced most of the West’s oil are firmly over. Oil explorers are pinning their hopes on up-and-coming oil patches such as the Caspian and offshore West Africa.
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But a lot of the increase in profits in recent years has been the result of efficiency gains, rather than exploitation of the market. ExxonMobil, for example, has cut its workforce by almost one-fifth in the past five years, and its return on capital has doubled to 20%.

BBC