UN-121: Liquid Coriolis(water cut meter, inferred mass proving)

Description

Calculates the uncertainty in mass and standard volume flowrate for a liquid flow through a Coriolis meter with an online prover taking into account the measured density and associated uncertainty to calculate the prover mass and associated uncertainty. Base volume and meter mass uncertainties are determined from proving statistics as per API MPMS 4.2. Pressure, temperature and measured density uncertainties are determined using the technical specification for the transmitters selected from the integrated transmitter selection tool.

General

The General tab is used to enter information, which is saved along with the uncertainty calculation and included in reports which are generated.

The tabs used for inputting data and calculating the uncertainty in the individual components of the uncertainty can be seen along the top of the module window.

The report tab is only visible once the calculation has been run and will not be visible if any parameters are changed until the calculation has been run once more.

Input/output

Options

Pressure units

This section gives the option of entering the pressure as either an absolute value or as a gauge value with reference to atmospheric (barometric) pressure. If Absolute is selected inputs are required for Absolute pressure and Atmospheric pressure and if Gauge is selected inputs are required for Gauge pressure and Atmospheric pressure. This ensures that whichever is chosen both the gauge and Absolute pressure value is available to other sections of the module.

For example: the Density calculation tab may require an absolute pressure to perform an AGA 8 calculation and the Gauge pressure may be used for the pressure transmitter calculation.

Absolute pressure – the Atmospheric pressure = Gauge pressure

Inputs

Pressure

This is the line pressure of the gas stream measured upstream of the Coriolis meter.

Note: As described above, if Absolute is selected inputs are required for Absolute and Atmospheric pressure and if Gauge is selected inputs are required for Gauge and Atmospheric pressure.

The default value for Absolute Pressure is set to 1 standard atmosphere (1.01325 bar)

Temperature

This is the measured temperature of the gas stream.

density

the density of the liquid flowing through the Coriolis meter.

Water Cut

Percentage of water in the flow.

Mass flow rate

This is the mass flow rate through the Coriolis meter.

Outputs

The outputs section shows the calculated flow rate and uncertainty taken from the Coriolis Meter with Oil Prover tab and Net Oil Flow Rates tab.

Calculation Blocks

The following blocks are used within this uncertainty module:

Pressure

Temperature

Measured Density

Water Cut

Liquid Volume Prover

Coriolis Meter with Oil Prover

Net Oil Flow Rates

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