Micro Motion Guide: Process Solution Guide Separator Water Measurement Using Rosemount Vortex | Micro Motion Manuals & Guides

Process Solutions Guide

Rosemount Key Benefits

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g

maintenance free flowmeter technologies not only reduce cost, but also provide advanced diagnostic capabilities to

Rosemount 8800 has no moving parts and a non clog design which does not require any routine replacement or

Separator Water Measurement Using Rosemount Vortex

• Reduced maintenance and operations cost

• Reduced risk of lost revenue due to gas blow by

• Reduced environmental risk of gas venting

• Improved reliability of separator water

measurement for reservoir modelin

• Improve well availability

Overview

Many oil and gas producers are looking for opportunities to decrease maintenance costs and maximize production.
Eliminating the utilization of older technology, such as mechanical meters, to measure flow provides an opportun ity
to reduce maintenance and operating costs and ensure the reliability of field data to maximize production. Modern

reduce disruption should the meter or well require attention.
Producing wells flow into either a production or test separato r to separate gas from liquids and further separate the

oil from water. This document will focus on water measurement on the separator outlet. Typically on the water leg
of the separator, flow rates are being measured by turbine meters. Due to debris in flow lines and gas blow by,
turbine meters often require extensive maintenance to replace or clean the rotating internals. Many oil and gas
producers report that replacement or cleaning of the internal parts is needed at least once per year. Also, when the
meters fail, the water flow rate is not measured and must be inferred. This failure can be very costly, especially
when the well experiences high water production and well intervention is needed. Also, not having accurate water
production data decreases the reliability of the reservoir model. Some operators also monitor the trends in water
production. A sudden increase in the flow rate or daily volume may indicate a stuck dump valve, and gas is being
vented through the water leg of the separator resulting in lost revenue and environmental hazards.

The Rosemount 8800 vortex flowmeter can significantly reduce flowmeter related maintenance and failures. The
cleaning to maintain performance. The Rosemount 8800 vortex flowmeter ensures an accurate and reliable

measurement providing data to the reservoir model, and can be configured for multi-fluid measurement using the
adaptive digital signal processing to detect a sudden increase in flow rate caused by gas discharge from the water
leg. By setting flow limits in the RTU, this diagnostic tool can be used to shut in the well until corrective action can
be taken reducing lost revenue and decreasing the environmental impact of venting gas to the environment.

© Emerson Process Management, Inc. All Rights Reserved

Rev. B

Separator Water Measurement Using Rosemount Vortex

0.5 (15)

1.0

(25)

65.4

974.1

diameters upstream and 5 straight pipe diameters downstream is required for best measurement results. Vertical

Vertica

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etca ou t g

Hori

Flowmeter Sizing Guide

Process Solutions Guide

Meter Size in Inches
(mm)

1.0 (25) 1.5 (40) 142 2770.7

1.5 (40) 2.0 (50) 240.6 6526.7

2.0 (50) 3.0 (80) 378.2 10757.8

Reducer Meter Size
in inches (mm)

Min Instantaneous Flow
Rate (barrels per day)

Table 1

Max Instantaneous Flow
Rate (barrels per day)

Sizing Considerations

The key to correctly sizing a vortex flowmeter on the water outlet of a separator is understanding what the
instantaneous flow rate is. The instantaneous flow rate is often much higher than the average daily rate and it should
be used to ensure that meter is correctly sized for the application. A snap acting dump valve should be used to
provide the highest flow rate to ensure the flow remains above the low flow cutoff of the meter. The trim size of the
dump valve can often be used to aid in determining the expected flow rate. If configuring the meter for multi-fluid
measurement to detect gas blow-by, it is important not to oversize the meter and select a smaller meter that does
not exceed the maximum flow rate. See the multi-fluid configuration section on the next page for more details. The
sizing chart in Table 1 references water flow rates that can be measured by each meter type and size. For detailed
analysis for your application consult an Emerson representative or the Instrument Toolkit®
be downloaded from www.rosemount.com

.

sizing software which can

Many vortex meter installations require a line size reduction in
order to take advantage of the optimal flow range of the meter.
Rosemount also offers a Reducer vortex meter which has built in
reducers integral to the flanges eliminating the need to modify
piping. The reducer meter has the same lay length as the
standard vortex meter allowing for a drop in replacement should
the flow rates change during the life of the field. Reducer Meter Standard Flanged

Installation Recommendations

The design of the process piping should ensure that the meter body will remain full, with no entrapped air. For best
results the meter should be installed upstream of a snap acting dump valve. A minimum of ten straight pipe

mounting with flow up for liquids is the best orientation, but horizon tal mountin g is also acceptabl e. When mounting
horizontally with fluids with small solids content such as sand, it is recommended to have the flowmeter installed with
the electronics to the side. This will minimize potential measurement errors by allowing solids to flow under the
shedder bar without interrupting the vortex shedding. The Rosemount 8800 vortex meter design is less susceptible
to error and abrasive wear due to sand content than turbine or differential pressure meters, but in applications with
very high sand content it may be necessary to delay installation of the meter until the well stabilizes and sand
production is reduced.

l Mountin

zontal Mounting

Preferred

© Emerson Process Management, Inc. All Rights Reserved

Flow up

Rev. B

Okay