问答题 翻译：Gas lift is the method of artificial lift that uses an external source of high-pressure gas for supplementing formation gas to lift the well fluids. The primary consideration in the selection of availability and compression cost of gas.

问答题 翻译：THE OPEC oil cartel is about to turn 40, and the mood in the run-up to the grand heads-of-state party in Venezuela in less than three weeks time is jubilant. Not quite two years ago,oil was $10 a barrel and the cartel was on the brink of collapse. Now the oil price is well above $30 a barrel, and it shows little sign of coming down.

问答题 翻译：In these early days, as lamp oil, was the important product and the main objects of refining was to extract as much of it as possible from the crude. Lubricants and some fuel oil were also sold, but gasoline was burnt off as unwanted and bitumen was also largely useless.