Research On Evaluation And Treatment Technology Of Waste Oil Based Drilling Fluid

Waste oil-based drilling fluids are a very common pollutant in the process of oil and gas extraction.Because of its difficult handling,serious pollution,but also the state of hazardous waste,so the urgent need to solve the current environmental problems.In this paper,the treatment of waste oil-based drilling fluid produced in Shengli Oil Field is carried out.The method of chemical elution + curing is mainly adopted.The basic physical and chemical properties of the waste oil-based drilling fluid are 70.9%,the moisture content is 15.5%,the oil content is 13.6%,the content of cadmium is 55.7 mg/kg,the content of copper is 140 mg/kg,the content of lead is 18.7 mg/kg,the content of chromium is 20.3 mg/kg between 1.9 ~ 2.0 g/mL,the sedimentation ratio is 86%,the demulsification voltage is 642 V,the solid particle size is mainly between 10 ~ 100 μm,The viscosity of the funnel is 680 s,the apparent viscosity is 421 mPa·s,and its correlation relation model is established.The maximum relative error is 8.79%.Surfactant screening experiments were carried out to obtain five better surfactants.Single factor experiment,to determine the impact of the various factors on the apparent oil removal rate of the basic trends and the best conditions.Using the Design expert software,a response surface experiment was designed using the Box-Behnken method.The regression equation is established and the optimal experimental combination scheme is predicted.The relative error of the experiment is less than 2.8%.The optimum conditions were as follows: ultrasonic time 33.05 min,demulsifier PE2040 addition amount 3%,initial temperature 59.99℃,elution water addition amount 25 mL,the apparent oil removal rate reached the maximum value of 93.2%.The curing experiment used both the fly ash and cement curing agent to optimize the amount of fly ash added.The compressive strength was obtained with a maximum compressive strength of 502 kPa,and the optimum amount of fly ash was 15%.The experiment of the leaching solution verifies the effectiveness of the curing treatment,and the leaching solution meets the requirements of the national standard.