Study On Recovery And Purification Technology Of Diesel Oil In Waste Oil - Based Drilling Fluid

The problem of environment caused by waste oil-based drilling fluid is arousing more and more people’s attention due to it is widely used in complex formation drilling for oil and gas field. Waste oil-based drilling fluid with very stable and complex components would result in a very bad impact on the environment, if directly discharged without treated. Waste oil-based drilling fluid with high levels of diesel has the value of recycling. Hence, it is great significant for the environment protection, energy conservation and sustainable development of oil-gas field development to perform research on diesel recovery purification technology in the waste oil-based drilling fluid.Recovery and purification technology of the diesel in waste oil-based drilling fluid were carried out.The recycling technology experiment results of diesel in waste oil-based drilling fluid indicated that X-BL62 was the optimal demulsifier, X-JLHL and X-JBXA were the best demulsification additives. The optimum diesel recovery process experimental parameter was determined through single factor optimizing experiment and orthogonal experiment. Under the optimal condition, the recovery rate of diesel up to 82.50% was obtained from waste oil-based drilling fluid. Analyzing the basic properties of recycling diesel from waste oil-based drilling fluid, found that the diesel contains a large number of impurities need to further purify. Through one-step solidifying treatment waste residue mixture which came from diesel recovery purification process.The optimized purification process, flocculation-pickling-caustic washing-white clay adsorption, was confirmed, after single factor optimizing experiment and orthogonal experiment research of waste diesel. In addition, the diesel recovery rate up to 80.15% and the major physicochemical properties of purification diesel meet the level 3 of 0# diesel standard (GB 19147-2009) under the optimized purification technology conditions. Meanwhile, once controlling the ratio of purified diesel to 0# standard diesel of 3:1, the blend diesel with all indexes meet the level 3 of 0# diesel standard could be used to automobile diesel fuels or prepare oil-based drilling fluid repeatedly. According to the FT-IR analysis of diesel, the effect of purifying waste diesel is very ideal through the flocculation-pickling-caustic washing-white clay adsorption purification technology process. Additionally, purified diesel mainly contains saturated and unsaturated alkanes, and the ingredients of purified diesel approximately are the same as commercially available 0# diesel.According to the results of test in laboratory and field conditions, recovery purification process design of diesel oil from waste oil-based drilling fluid was carried out. In addition, the economy of recycling purification diesel technology was analyzed, and results showed that the cost of waste diesel oil recovery purification process is reasonable, recycling has the good economic efficiency, and the technology has a certain application prospect.