Study of COD Removal from the Waste Drilling Fluid and Its Application Chad Oilfield

Abstract

The increase in the demand for oil and gas in various countries will lead to an increase in the number of oil and gas drilling and the production of waste drilling fluid in the petroleum industry. However, the environmental protection requirements for the discharge of waste drilling fluid in various countries have not decreased, but have become more stringent. Therefore, it is very important to effectively treat the waste drilling fluid in a harmless manner and ensure that it meets the requirements of various countries for the discharge of waste drilling fluid. This article first analyzed the effects of three additives, polyacrylamide (PAM), polyaluminum chloride (PAC) and ferric oxide (FeSO4) on reducing the chemical oxygen demand of waste drilling fluids in Chad, and determined the best of the three additives Dosage. Subsequently, the article further explores the effect of the optimal dosage of the three additives on the treatment of COD of waste drilling fluid in Chad. The results show that when the dosages of the three additives are 50, 8000 and 800 μg/g, flocculation and the removal efficiency of COD are the best, and the removal rate of COD is 72%. The effects of H2O2, Fe2+, pH value, reaction time and irradiation time on COD removal rate were further inspected. The COD removal rate of the filtrate after flocculation was further determined by the addition of 7.0% H2O2, 0.07% ferrous sulfate, pH 3.5 and reaction time 1.0 h. The optimal dosage of the three reagents used in laboratory experiments and the best conditions for the treatment of waste drilling fluid were applied to the Chad site to treat the waste drilling fluid, so that the liquid and solid phases of the treated waste drilling fluid can meet the domestic emission standards of Chad. The solid phase can be used for landfills, roads, at the same time as a fertile soil for plant growth. The liquid phase was used by the apparatus itself for recycling.