Crude oil is tested before export to make sure it complies with the standards of the refinery it is being shipped to. Crude oil from different fields can be identified according to a series of chemical signatures, including levels of sulfur and nitrogen, acidity and viscosity.
通常原油出口前要进行检验，保证其符合接收该原油的炼油厂的标准。不同油田出产的原油可以根据一系列化学成分加以识别，包括硫含量、氮含量、酸度以及粘度。