The process for disposing the acid sludge can reduce the cost of acid-removal, improve the acid-removal efficiency and improve the quality of recoveredoil sludge.
该处理石油酸渣的工艺可以降低除酸成本，提高除酸效率并提高回收油渣的质量。
2
Of course, there is far more oil underground than can be recovered.
当然，地下的石油远比可回收的多。
3
The price of gas has not recovered as quickly as that of oil in recent months, in part thanks to the success of firms like XTO in producing more of the stuff.