Custody transfer in dynamic fluid measurement is defined as a metering point location, where the fluid is being measured for sale from one party to another. During custody transfer; accuracy and precision are very important and vital to both the company delivering the material and the eventual receiver. Best practices should be made for volume calculation to get near as much as possible to the true value.
To achieve the custody transfer accuracy requirements, Kuwait Oil Company (KOC) uses turbine and PD flow meters at locations designated as custody transfer type to measure the volume of crude oil transferred from one owner to the other. There are several factors that affect the operation of these flow meters, such as the liquid temperature, the pressure in the system, density of the product dispatched, water content….etc These variables are taken into account in order to calculate the "corrected" volume dispatched which is equivalent to the raw volume reported by the flow meters affected by correction factors obtained from established formulas based on the process variables. Established procedures for calibrating and testing the equipment’s required to measure process variables with the aim of obtaining accurate and representative values, are included in various International Standards such as the API, ASTM, ISO, IP Publications.
In KOC, Export Operations (EO) Lab, which holds International accreditation (ISO) IEC 17025 and is the only accredited lab in the country, is responsible to run the analysis required to obtain the required quality values needed to obtain the Gross Standard Volume (GSV) and Net Standard Volume (NSV) of the quantities dispatched to Refineries and Export.