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Pipelines testing or calibrating multiphase or wet gas viscosity on the performance of both cases it was likely to exceed the perfor- ex-test separator gas measurement meters. NEL supports the use of substitute single phase and multiphase meters, and mance of installed meters. device as well providing additional fuids because of the improved uncertainty the effect of gas entrainment on the perfor- “As with any type of black box tech- measurements during critical well testing in calibration calculations, compared with mance of ostensibly single phase meters. nology, assurance around meter perfor- operations.

that achievable with live fuids. Making

The use of diagnos- mance is implicit from key parameters or

GE sure that testing and calibration facilities tics parameters, avail- meter diagnostics,” the presenters said. can replicate as closely as possible both able from the more “As is current industry practice, with e.g. GE’s Anusha Rammohan and Baskaran modern technologies, ultrasonic meter technology, it is possible Genesan, GE Global Research – USA, operating pressures and temperatures is also high on the agenda, be it for wet gas, gives you access to to benchmark key meter performance presented their insights into multiphase much more than a parameters during factory calibration / fow through ultrasound doppler. multiphase or single phase. “One of the big drivers for industry and Multiphase fow could be fully character- straight-forward fow function tests and use these to establish vendors, is trying to fnd solutions for low ized and measured if the velocities and signal.” a baseline for performance monitoring / cost multiphase fowmeters,” Mark says. phase fractions of all the components in

NEL, based near verifcation in the feld.”

Phil Mark

Pearson also described the proto- “At the moment they are very high cost, at the fow were available through sensor

Glasgow, Scotland, typing of a SONAR technology meter several hundred thousand of dollars (each), measurements, they say. For a three-phase is looking at how changes in diagnostic fow, for example, this involves which potentially limits the number of parameters, can be used to monitor measuring six independent applications. If a multiphase meter could the performance of the fow meter, parameters. “Since this is an be made less expensive, whilst delivering in order to move to condition- almost impractical expecta- the same or similar performance, it would based monitoring and calibration, tion, in reality only a subset of open up a bigger market.

instead of time-based monitoring. “Other challenges facing the indus- The organization, which is the these measurements is available try include the effect of increasing oil custodian of the UK’s National Flow to a fow meter,” the pair say. “For example, not all compo-

Measurements Standards, is also nent velocities can be directly looking at how the data gathered measured. The burden then falls from such devices can be inter- on the fow meter algorithm to preted in a rigorous and reliable fll in the missing pieces with an fashion. appropriate model.”

Last year, NEL invested in the

Flow models typically perform development of its high pressure well, as long as the fow condi- wet gas facility, now the UK’s tions are within the ranges for only independent commercial test which they have been built, but facility that can test meters to fow their extrapolative capabilities rates over 2000cu m/hr under wet are questionable making their per- gas conditions and is capable of formance and accuracy unreliable using oil and water components

NEL’s new high pressure wet facility and unpredictable in the feld, say simultaneously. near Glasgow. Image from NEL.

Rammophan and Genesan.

The event also heard from a

The ultrasound Doppler tech- number of suppliers and operators: nique is used to measure veloci-

BP ties based on the scattered signals

Bill Pearson and Samir Ismayilov, from small particles or bubbles in from BP Azerbaijan-Georgia-Turkey the fow. Scatterers could be gas – Azerbaijan, presented the devel- bubbles or oil or water bubbles in opment and feld trials of SONAR the liquid mixture /emulsion. “The technique works based on

Meter Technology.

SD Sonar 10in. Expro fow meter.

Images from BP.

the relationship between the mea-

The project was a collabora- diagnostic interface from which mea- sured Doppler shift in the signal frequency tion between BP AGT Region and Expro surement stakeholders can verify meter and the scatterer velocity,” say the present-

Meters, part of Expro Group. BP required performance. In the event that meter ers. “There is ample evidence in literature retrospective, non-intrusive fow mea- performance becomes sub-optimal on the ultrasound Doppler method being surement in a number of “allocation” used to measurement velocity in fows diagnostics expert support can be sought metering applications. For two applica- with a very small amount of gas (low gas and, where necessary, the clamp-on tions, a clamp-on SONAR fow meter was volume fractions). Under such conditions, meter components can be readily trialled, including feld cabling, transmit- the fow exhibits a predominantly bubbly changed under permit to work without ter, mounting clamp, transducer module, fow regime, which is conducive for the the need for shutdown and dependence and cover assembly. The ActiveSONAR

Doppler measurement with the small gas on isolations for workforce safety.

meter was EX ‘d’ Zone 1 certifed.

bubbles acting as the scatterers.”

The results indicated that clamp-on The trial sites included a crude oil

SONAR technology, as a non-intrusive reception line at the Sangachal Terminal, However, GE has looked at the applica- retroft meter technology, was at least Azerbaijan, where offshore oil and gas is tion of the ultrasound Doppler technique comparable with other type of technol- processed prior to export. ActiveSONAR to a much wider range of three phase ogy, such as ultrasound or differential was also used as a secondary measure- fow conditions, with varying water cut pressure producer meters, and in some ment tool to verify an existing legacy and gas volume fractions. oedigital.com March 2015 | OE 53 052_OE0315_pipelines1.indd 53 2/22/15 11:10 AM