Publications

An oil production surface facility is usually equipped with carefully and periodically calibrated metering tools to ensure accurate measurement of the produced oil. Whilst, the quality of the oil is thoroughly analyzed using the standard laboratory methods and apparatus. This practice is particularly imminent in the case of oil custody transfer rendered in the facility. Currently, based on several studies conducted by LEMlGAS, it is apparent that the lack of proper measuring instruments as well as knowledge of crude oil physical behavior dwarf most of the oil production surface facilities in Indonesia. Hence, the parties involved in a custody transfer often dispute about the disparity of quantity and quality of the oil being transferred, phenomenon commonly referred as ",oil losses",.This paper discusses factors affecting ",oil losses", during the custody transfer in oil production surface facilities in lieu of crude oil physical behavior. Laboratory experiments were conducted using crude oil and water from more than 60 gathering stations. Loss from evaporation is investigated by combining TBP (TJXe Boiling Point) analysis with process simulator to simulate crude oil behavior in storage tanks. Water-oil emulsion behavior (particularly stability) is characterized by correlating specific gravity and BS&W (Bottom Sediment and Water). Effect of volume shrinkage caused by mixing different type of crude oil is numerically formulated on the basis of volume and weight compositional analysis, hence the effect can be transformed into a graphical representation. Using this visual representation one can easily observed the effect of increasing or decreasing the quantity of one or more components in the mixture towards the overall volume change of the mixture. This tool proves to be important in justifying the use of shared storage tanks or shared pipeline among the parties involved in a custody transfer.Finally, this paper concludes that besides of the use of proper measuring system and analysis in a custody transfer of crude oil, a comprehensive knowledge about physical characteristics of the crude oil proves to be a critical factor in minimizing the ",oil losses", phenomenon.