Study On Vacuum Distillation And Microwave Treatment Of Waste Oil-based Drilling Fluid

As a new energy,shale gas has been exploited enormously in china.Oil-based drilling fluid is required during the horizontal drilling process,so that plenty of waste oil-based drilling fluid would be generated.Waste oil-based drilling fluid is hazardous,whose oil content must meet the standards of relevant laws and regulations before they are discharged.With the more and more strict of drilling environmental protection,treatment technology of waste oil-based drilling fluid while drilling has become a trend in shale gas development process.The main methods of treating waste oil-based drilling fluid around the world are curing,chemical cleaning,traditional thermal distillation,biodegradation and so on.In order to realize the industrial application,and reach the treatment request of oil based drilling fluid while drilling.The article has selected vacuum distillation technology and microwave desorption technology,then conducts some experimental study.(1)Analysis the sample's physical and chemical properties,such as oil content,water content,solid content and other organic matter contents,which as the foundation for the treatment of waste oil-based drilling fluid.(2)Vacuum distillation treating waste oil-based drilling fluid is designed,and uses BBD response surface analysis method investigate differently factors on the oil removal rate and dehydration rate of waste oil-based drilling fluid and obtains the corresponding prediction model,then gets the optimal experimental conditions: distillation temperature is 420?,distillation time is 80 min and system pressure is 0.02 MPa,the oil removal rate reaches 98.67%.(3)According to the microwave characters,putting forward a new method: using microwave desorption deals with waste oil-based drilling fluid.Analyses the desorption effects factors by response surface,such as microwave power,sample quality,irradiation time and the interaction between them.By the end get the optimum process conditions: microwave power is 900 W,irradiation time is 6min and the sample quality is 35 g,the oil removal rate is 97.75%.(4)Analysis the composition of the solid and liquid products after vacuum distillation and microwave desorption,then compared with the oil in the waste oil-based drilling fluid.The result proves it is feasible that reusing the recoveried oil to oil-based drilling fluid;and the solid phase product doesn't contain harmful substances so as to be treated directly.(5)Bases on the experiment results,this paper has made a conceptual design on microwave desorption treatment while drilling and has a cost analysis.