New Metering Station measures oil from Veslefrikk

News from Norwegian Society for Oil and Gas Measurement

3/2000 - Oktober 2000

Turbine meters soon to be history?

by Kåre Kleppe, Statoil
During the docking period of the Veslefrikk offshore rig (Summer 99) a new metering station was installed to measure the quantity of oil exported from Veslefrikk. There were two reasons for installing a new station:

	partly because of increased capacity and
	partly because of increased danger for scaling (deposit).

The philosophy behind this is that, compared to turbine meters, ultrasonic meters are less sensitive to barium sulphate. The metering station consists of a 10" metering line with one complete 5-beam KROHNE ultrasonic meter and additional pressure, temperature and density transmitters for condition monitoring.

This station is installed in series with a conventional turbine meter station with 3 x 4" metering tubes and appropriate ball prover. Every 4th day a calibration of the USM meter is performed. This is done by routing the oil into the turbine meter station, calibrating the turbine meters with the help of a ball prover, and then doing a comparison between the turbine meters and the ultrasonic flowmeter during a period of at least two hours. The KROHNE meter was configured to send pulses in the same way as a turbine meter to a metering computer.

The average deviation between the new ultrasonic flowmeter and the turbine meter stations for the period September 1999 to September 2000 was 0.0514 %. Another KROHNE 5-beam meter has been installed to measure condensate from Huldra (start-up October 2001). This meter will also be calibrated against the VFR turbine meter station. After a period when we can say with a great margin of safety that we now trust both of the meters, we will send an application to OD to exchange the turbine meter station (today serving as a master only) with a new master USM. So far the KROHNE meter has functioned very satisfactory.

Overview of the installation.

Key Words: Flow, ultrasonic, oil, turbine, mobile drilling barge
AP0089