Application of Innovative Chemical and Mechanical Processing for Treatment of Difficult Production-Waste Sludge

Abstract

Abstract East Kalimantan Indonesia has a history of challenges and difficulties in the management and treatment of emulsions, slop oils, slurries and tank bottoms which accumulate in process vessels and tanks. These unresolved production streams, collectively termed "sludge" incorporate strong oil and water emulsions, chemically bound by metal-carboxylate soaps and various mixtures of stabilizing fine sand, scale, and wax. Previous disposal methods used or considered for use range from very crude methods such as open burning and land-spreading to sophisticated techniques such as slurry fracture injection. However, such options did not provide for oil recovery and posed severe environmental or regulatory problems. The process proven most viable in treatment of sludge employs an aggressive system of heat, customized chemical demulsification, settling, and various means of mechanical/centrifuge separation. In the last several years, more than 500,000 barrels of sludge have been successfully reclaimed at Lawe Lawe and Santan Terminals. Whilst the sludge treatment program overall has been successful, there have also been serious technical challenges and cost-impacts. These difficulties have provided significant lessons learned for both operator and contractor in terms of optimization of key physical, chemical and mechanical separation techniques; as well as for minimizing costs. A case study of a recent treatment program for over 220,000 barrels of sludge at Santan Terminal will be used to highlight significant implementation and management experience including: Critical equipment selection and design parameters,Chemical treatment requirements,Successful (and unsuccessful) methods for optimization of treatment rate and improving oil recovery,Mechanical challenges for the removal of stabilized fine solids,Key parameters for project tracking, andA realistic assessment of treatment costs. The results to date illustrate how an effective sludge treatment and reclamation program can provide commercially and environmentally superior results in terms of cost and impacts.