Utilization of Heat and Centrifuge Technology to Recover Crude for Sales from Slop Oil

Abstract

Abstract The exploration and production of heavy oil often results in the formation of tight water in oil and oil in water emulsions that are stabilized further by the presence of paraffin, asphaltene, scale, corrosion inhibitors and other fine solids. This emulsion in its most stable form can be very difficult to break and often requires more than gravity separation and treatment with emulsion breakers. It is a well-established practice in the oilfield to utilize heater treaters in combination with emulsion breaker chemicals to treat slop oil. However some emulsions are so stable due to the presence of fine solids that they cannot be broken without the use of additional heat and centrifugal forces. This paper looks at a case study of the use of a process skid that utilized heat and two centrifuges: to treat stored slop oil that could not be separated to give saleable crude quality of <2%BSW. The stored slop oil was tested in the laboratory to ascertain the impact of emulsion breakers, heat and a combination of both emulsion breakers and heat. However none of these solutions by themselves were found to be successful. The process skid utilizing heat and two centrifuges was successful in application in the field and stored slop oil was treated at a range of 600-800 bpd with an average rate of recovery of 42% saleable crude being achieved. This paper describes the process skid utilized and the challenges encountered in its operation and maintenance. It outlines the lessons learnt and the steps that were taken to optimize its usage to get the best rate of recovery of saleable crude in the shortest time possible.