Coriolis 2-phase liquid meter (TRICOR or...) 1

[engr2GW]

Hi,

I understand that API 5.6 and AGA 11 covers and approved the use of Coriolis meter as a custody transfer quality meter. there are other coriolis technology that are currently being used in the industry like micromotion and (the one I'm interested in) TRICOR meter. are these also covered in the APA and AGA standards since they're also coriolis?

As much as possible, do it right the first time...

 

[MortenA]

I think that you a confusing things - Coriolis flow meter is a "generic" type of technology, and TRICOR meter is an implementation of the principle by a specific vendor (Tricor)

Best regards, Morten

 

[engr2GW]

Thanks MortenA, but you just repeated what I said, TRICOR is using the coriolis technology. but my question was, does the standards cover it since it is using the technology for 2-phase liquid (oil/water), as opposed to a one phase (oil) measurement.

As much as possible, do it right the first time...

 

[controlnovice]

Tricor and MicroMotion are both Coriolis meters, so if API5.6 and AGA11 says Coriolis are approved, then both MM and Tricor are approved.

Not sure about Tricor, but MicroMotion claims they can detect two phase flow and accurately measure the liquid flow. Haven't tried it myself though.

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This is normally the space where people post something insightful.

 

[georgeverghese]

As fas as I know, coriolis meters are true mass meters; volume rates are inferred by input from a densitometer. So it may be possible to infer phase volume rates and mass ratios in this 2phase flow if you have a densitometer and correlations to compensate for operating temp with a little arithmetic jugglery. Coriolis meters are routinely used for custody / fiscal transfer since they can meet the accuracy requirements for such applications in most jurisdictions.

 

[Compositepro]

Coriolis meters will work for two-phase flow only if they behave like a single phase, as in an emulsion. Slugs of liquid with differing density passing through the meter will not read correctly, and the signal will be unusable. Air bubbles also cause problems for coriolis meters.

 

[engr2GW]

Thanks, Georgeverghese, the very first step explanation of what I was looking for.

As much as possible, do it right the first time...

 

[tickle]

MicroMotion has software that can be used with the Coriolis meter for determining the oil cut of a stream. This is typically used on well production streams. I am not sure that it could be used for custody transfer without detailed information on the density of the water and oil; this would be a question for Emerson and / or Tricor.

To expand on what is written above regarding AGA and API; these standards are the requirements for custody transfer for Coriolis meters that the meters should be compared against, whether the meters comply with the standards is a different question.

 

[zdas04]

I first visited MicroMotion's plant in 1994. Ever since that trip I have been hearing about it being a "true" mass flow meter (whatever that means to you). No Coriolis meter can measure a mass flow rate. They measure the amount of displacement and vibration of a bent pipe likely caused by the momentum of the fluid. If you know the density (and it is constant) then from that you can infer a mass flow rate. It also infers a fluid density from vibration frequency of the pipe. The multi-phase flow problem is that the latency of the density sensor is around 20 seconds and multi-phase flow transients are millisecond scale. That makes the meter reflect the density from 20 seconds ago which is multi-phase flow translates into making stuff up. If I don't know the current density, the the displacement of the bent pipe is just numbers.

They are decent liquid meters when the fluid make-up is pretty constant. Not so good for clean dry gas, but can be OK if the pressure (and therefore the density) is high enough. Really crappy (just like every other meter) for multi-phase flow.

David Simpson, PE
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist