The bioremediation of oily sludge in Daqing oilfield was treated by natural compost and two Enhanced Composting Techniques.To compare the change of the physical and chemical paramnters and degradation of total petroleum hydrocarbons(TPHs)and establish optimal composting system.The results show that in the three compostingmethods,the content of organic carbon decreased and the total nitrogen content increased.The strengthened composting can prolong the high temperature time of composting and petroleum hydroc...