At present, my country's drilling sewage, oil production sewage and other oilfield wastewater have become the main source of pollution in the petroleum industry, and it is in urgent need of advanced treatment. Due to the different geological conditions, development methods, water injection quality, and gathering and transportation processes of various oil fields in our country, and the use of many inorganic and organic chemical treatment agents in the drilling process, crude oil dehydration, gathering and transportation, and sewage treatment processes, water plugging in oil and water wells, profile control, acidification, and fracturing and other measures cause oilfield wastewater to contain a large amount of polymers and surfactants, and the emulsification degree of oil in sewage is intensified. The above reasons have led to the deterioration of the water quality of oilfield wastewater in our country. At present, the traditional chemical dosing treatment of oil production wastewater makes it difficult for the treated water quality to meet the drainage standards or the water quality requirements of injection water. Therefore, there is an urgent need to develop new high-efficiency and low-cost processes, technologies and corresponding equipment suitable for oilfield wastewater treatment.

This project has successfully developed a high-efficiency combined purification process suitable for the treatment of drilling sewage in oil fields in my country and developed corresponding treatment equipment. It has the technical advantages of modularity, low energy consumption, and high effluent water quality standards.

The main core process of the oilfield drilling sewage treatment combined treatment technology proposed in this project is to strengthen the photocatalytic advanced oxidation combined technology. Since the project team has made major technological breakthroughs in the bottleneck of photocatalytic industrialization, the photocatalytic technology has been greatly reduced. The cost and improvement of photocatalytic reaction efficiency. Therefore, the comprehensive cost of this project is low, and the effluent quality can reach the highest EU sewage discharge and World Health Organization discharge standards.

Application situation or application prospects：This project can be applied in various oil field drilling sites and offshore drilling platform sewage treatment and other fields.

This technology has solved key technical bottlenecks, successfully built a 5t/h pilot treatment unit, and the treated effluent index reaches the EU standard (CODcr 40mg/L).