Crude oils found in the major Chinese offshore petroliferous basins can be classified into four categories based on their maturity, i. e. immature, low mature, mature and high mature oil.

• 中国近海海域主要含油气盆地目前找到的原油,依成熟程度可分为未成熟、低成熟、成熟和高成熟原油四大类。