Oil-Water Separation Experience from a Large Oil Field

Abstract

Abstract This paper discusses challenges related to emulsions that have been encountered in a large Saudi Arabian field. The field produces from several different reservoirs with a range of fluid properties. These properties provide an interesting case of operational challenges in oil-water separation including increased incidents of shorting in the separator, tripping of equipment and increased demulsifier consumption. This paper presents the results of a comprehensive study that was initiated to understand the main causes of emulsion formation in the field and ways to optimize oil-water separation. The effect of several recommendations that were implemented by operations engineering in the field were evaluated. These include the conversion of a two-phase separator into a three-phase separator, splitting of the demulsifier injection between offshore producing platforms and onshore wet crude handling facilities, and field trials with promising chemicals. The demulsifier costs have been reduced by over 50% by the implementation of retrofitting and proper demulsifier injection strategies. The results presented in the paper provide invaluable operational experience and many lessons learned are applicable to any crude-oil treating facilities.