济阳坳陷郑家王庄油田原油生物降解程度为2 ~ 8级，生物降解是导致原油稠化的主要原因。

The biodegradation extent of viscous crude in Zhengjia-Wangzhuang Oilfield is level 2 ~ 8, the biodegradation is the main cause of oil densification.

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郑慧莹，李建东。 1999 。松嫩平原盐生植被与盐堿化草地恢复。科学出版社，北京。

Zheng huiying & li jiandong. 1999. the saline vegetation and its restoration on the songnen plains. science press, beijing.

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