oil lead
2.Water Quality of Offshore Marine Areas In 2001, the water quality in the offshore marine areas was mainly affected by the activated phosphate and inorganic nitrogen. The key pollutants in some marine areas include COD, oil and lead. The offshore sea water is mainly at Grade II and exceeds Grade IV.
7.In the process of drilling oil and gas wells, the casing inwall wear will happen owing to the friction between drill string and casing, thus reducing the collapsing strength of wearing casing, which direct consequence will be the decrease in oil/gas well servoice life, more serious, will lead to the well’s being partially or wholly abandoned.


