Erosion Effects in Flowmeters - Subsea UK · •Install in water/ sand erosive flow facility. Run...

NEL Slide 1 SUBSEA UK CONFERENCE, ABERDEEN 15-02-18

Erosion Effects in

Flowmeters

John Peters, NEL

Tariq Boussouara, NEL

Subsea EXPO 2015 Conference, Aberdeen 11-12th February 2015

Presentation Contents

• Project Objective

• Flowmeter Details, Test Programme

• Overview of Erosion Facility

• Factors Which Affect Erosion

• Results and Conclusions

• Recommendations

• CFD Erosion Modelling

• Summary


Energy, Oil & Gas Low Carbon Technologies Environment

• Holds UK National Standards for fluid flow & density measurement

• A global centre of excellence in flow measurement, flow systems and fluid

dynamics

• World class research, development, modelling, calibration, consultancy,

measurement and testing


NEL

Sand Particle Erosion, - Damage, Wear

• A major issue world-wide in oil & gas

exploration & production piping systems

• Causes major wear, damage to piping,

equipment, components

• Potentially significant errors in flow

metering systems


• National Measurement System

• Supported the project:

• ‘To assess the effects of erosion on flowmeters using

performance and diagnostic data’.

• Undertaken by NEL

• This presentation outlines the results, findings, conclusions


NMS Flow Programme Project

• 3 different meter types supplied for operation in erosive flow conditions

Test Group 1:

• Turbine meter- 50 DN, nitrite coating

• Venturi meter- 50 DN Βeta ratio 0.75, st/steel

Test Group 2:

• Two 80 DN Coriolis meters ( A & B)

– Bent measuring tubes (different internal designs)

– One meter (A) had Diagnostic parameters through advanced signal

condition monitoring.


Flowmeters

• Determine flow meter performance using clean water with calibrated

reference meters.

• Install in water/ sand erosive flow facility. Run the meters under

controlled accelerated erosive flow conditions

– sand concentration ~6% by weight

– Graded semi-rounded sand, D50 particle size ~275 microns

– Particles range from <125 microns up to 550 microns

• Clean meters, repeat calibration on clean water.

• Process then repeated

• Review, assess meter performance, Report findings


Test Programme


NEL Erosive Flow Facility

Mixing Tank

Clean water tank

Control Valve

Sample Point

Meter B

Electromagnetic ref meter

Meter A

Pump 1 Pump 2


Factors Which Affect Erosion


Erosion Basics – Particle Velocity

• Erosion highly dependent upon particle impact velocity ...

E = K.f V2.6

• Particle velocity; wear = f (velocity)2.6

• Particle size

• Materials of construction

• Particle Impact Angle

• Quantity (mass) of sand, sand concentration, duration

• Sand shape, sharpness, hardness

• Fluid flow regime - liquid, gas, multiphase

• Piping configuration, flow path profile, shape, complexity

• Equipment, component design


Factors Affecting Erosion Levels


Results

Venturi Meter- Erosion results


Test 1 Test 2 Test 3

90 hrs 55 hrs 52 hrs

1136 l/min 1050 l/min (rev) 1214 l/min

-0.55% -0.55% -1.1%

Discharge Coefficient (Cd) drift

• Pressure-tappings eroded internally

(edge not sharp); -ve shift in Cd

• Throat diameter 0.1mm increase

• Divergent section 0.4mm increase

• Slight evidence of ripple erosion

marks on parts of wall.

• Pressure tapping erosion most

significant factor.

0.980

0.985

0.990

0.995

1.000

0 500 1000 1500

Dis

ch

arg

e C

oeff

icie

nt

Flowrate (l/min)

Before test 1 After test 1

After test 2 After test 3

Turbine Meter- Erosion results


Clean water End Test 1

Meter factor 14.3 pulses/l 13.8 pulses/l

Shift in K factor - -3.5%

Test 1: 44hrs @ 1050 l/min, 6% sand

Blades eroded badly

Bearing support badly eroded

13.6

13.7

13.8

13.9

14.0

14.1

14.2

14.3

14.4

0 250 500 750 1000 1250 1500

Tu

rbin

e k

fa

cto

r (p

/l)

Flowrate (l/min)

Before erosion

After Erosion

Coriolis Meters- Erosion results overall-Volumetric Error


-10

0

10

20

30

40

50

60

0 50 100 150 200

Vo

lum

etr

ic E

rro

r (%

)

Erosion Hours

Coriolis Meter ACoriolis Meter B

Test 1 Test 2 (reverse)

Test 3

Test 1 Test 2 Test 3

90 hrs 55 hrs 52 hrs

1330 l/min 1050 l/min (rev) 1214 l/min

Test 1: Meter A, Tube velocity 13.2 m/s

Meter B, Tube velocity 8.7 m/s

• Meter B drifts much less than A

• Rate of Drift proportional to velocity

• Meter A stopped working in Test 3-

later found severe erosion damage

of measuring tubes.

Coriolis Meters- Mass Flow Error Drift

Mass Flow Error Drift - Meter A

• Clean, within 0.1%

• Test 1, +16% drift


• Test 3, meter fails- eroded through

Mass Flow Error Drift – Meter B



• Test 1, +2.7% drift



0

2

4

6

8

10

12

14

16

18

20

0 5 10 15 20 25 30

Ma

ss f

low

Err

or

(%)

Flowrate (kg/s)

after test 2

After test 1

Specification

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0 5 10 15 20 25 30

Mass F

low

Err

or

(%)

Flowrate (kg/s)

After test 3

after test 2

After test 1

Specification

Coriolis Meters- Density Error

Density Error Drift - Meter A


• Test 1, -15% drift

• Test 2, -17% drift


Density Error Drift – Meter B


-18

-16

-14

-12

-10

-8

-6

-4

-2

0

2

0 5 10 15 20 25 30

Density E

rror

(%)

Flowrate (kg/s)

Specification

After test 1

After test 2





0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

0 5 10 15 20 25 30

Den

sity E

rro

r (%

)

Flowrate (kg/s)

After test 3

After test 2

After test 1

Specification

Coriolis Meters- Volume Error Drift

Volume Error Drift - Meter A





Volume Error Drift – Meter B



• Test 1, -0.55% drift



0

5

10

15

20

25

30

35

40

45

50

0 500 1000 1500 2000

Vo

lum

etr

ic F

low

Err

or

(%)

Volume Flowrate (l/min)

After test 2

After test 1

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

0.8

0 500 1000 1500

Volu

metr

ic F

low

Err

or

(%)

Volume Flowrate (l/min)

After test 3

After test 2

After test 1

Diagnostic Data- Coriolis Meter A

SCP-S Stiffness Diagnostic Parameter

SCP-S Sensitive to erosion wear rate within

meter

• Clean, 0% deviation

• During Test 1, -7% deviation

• During Test 2, -1% change,-8% deviation total

SCP- A Asymmetry Diagnostic Parameter


SCP-A Sensitive to Difference in amplitude

between inlet and outlet sensor

• Clean, 0% Deviation

• During Test 1, -4.5% deviation

• During Test 2, +0.5% change,

-8

-7

-6

-5

-4

-3

-2

-1

0

1

% D

evia

tio

n (S

CP

-S)

Erosion Test 1Calibration Erosion Test 2

Diagnostic Data -Coriolis Meter A

PCP-M Multiphase Condition Parameter

PCP-M Multiphase Condition Parameter

• Clean, 0 reading

• 5-6% sand concentration, 800-1000 reading

NEL Slide 20 SUBSEA UK CONFERENCE ABERDEEN 15-02-18

0

200

400

600

800

1000

1200

0 2 4 6

PC

P-M

Readin

g

Sand Concentration (%)

Coriolis Meter A- Inspection end of Tests


Erosion grooves along inside

wall of measuring tube Inlet tube Outlet tube

Severe wear on outer radius of tube.

Erosion scars on outlet bend

of inner measuring tubes

Coriolis meters- Conclusions

• Mass Flow = f.(Stiffness)

• Erosion reduces stiffness, increases twist in

tubes, +ve drift in mass flow

• Density = f(stiffness/mass)

• Density drift highly dependent upon meter

design, where erosion occurs

• Both meters drifted in opposite directions

• Erosion = f (velocity )^2.6

• Velocity in Meter A tubes (13.2 m/s)

approx 1.5 times higher than Meter B

• This equates to ~ 3 x rate of erosion of

Meter B


Before

Erosion

After

Erosion

↓

Thickness

↓

Mass

↓

Stiffness

Coriolis meters: Conclusions- Diagnostic Data -Meter A

• Three Diagnostic parameters monitored : – Flow tube stiffness,

– Flow asymmetry

– Multiphase (multicomponent condition) of the fluid

• All sensitive to erosive conditions, wear rate and sand content in the meter

• Potentially use diagnostics to determine when wear has reached a critical

level before risk of rupture

• Diagnostics can potentially detect the presence of sand in the flowstream.


Accelerated Test v Field Conditions


Equivalent Field Erosion Conditions

Duration (hrs) Sand conc. by

weight (%)

Accelerated NEL

Erosion Test (1)

90 6

Potential Field

Condition (1)

540 1

Potential Field

Condition (2)

5400 0.1

Recommendations- for flowmeters in erosive flows

• Consider a meter’s maximum operating velocity

• Operate meters at lower velocities to reduce wear rate

• Increase meter size to locally lower velocities through meter

• Use erosion resistant materials to minimise wear

• Perform bench-mark erosion tests on other meter types, designs, – e.g. ‘straight’ Coriolis designs

– Venturi with lower Beta value

• Consider using diagnostics in meters (where possible)


• Erosion testing of equipment, components is very beneficial. A good

performance on test is a good omen for a good performance in the field.

• Testing is essential to test seals, bearings and all moving parts

• Accelerated field conditions are simulated under controlled conditions

• Testing quickly identifies any design weak points

• Testing identifies any local erosion hot-spots

• Testing may show surprises, not evident from CFD modelling


Benefits of Erosive Flow Testing

CFD Erosion Modelling


e.g. DNV RPO501- Bend erosion equation

n

pipet

lsand UKG

A

CFmerosion ...

.

).sin().(.

bend geometry

particle size effect

material properties

Particle velocity

mass of sand

n.~ 2.6


Example Erosion Equation

Test

CFD


CFD View: Cone Flowmeter – Water/Sand Erosion

Summary


• Flowmeters may wear significantly in erosive flow conditions – Potentially significant shifts in error

– Potential for significant wear of meter internals, loss of meter integrity.

• Wear greatly influenced by meter design, local particle velocities and operating

conditions.

• Erosive flow testing is often essential to understand the wear characteristics of

components and validate equipment performance

• CFD can optimise designs for erosion; predict the wear life of components in

field conditions

• Part of the tool-box for equipment and pipeline integrity, risk and maintenance

management


Summing Up

Thank You for Listening

Any Questions?

[email protected]


NEL Contacts


Audit & Allocation Alick MacGillivray [email protected]

CFD Neil Bowman [email protected]

Densitometers Norman Glen [email protected]

Erosion John Peters [email protected]

Flow Consortium Phil Mark [email protected]

Heavy Oil Chris Mills [email protected]

Measurement Consultancy Craig Marshall

Chris Mills

[email protected]

[email protected]

Measurement Uncertainty Alick MacGillivray [email protected]

Meter Diagnostics Craig Marshall [email protected]

MeterVue Jess Burke [email protected]

Multiphase Holly Ramsay [email protected]

PPDS Norman Glen [email protected]

Single Phase Metering Sarah Pedley [email protected]

Training John Dods [email protected]

Umbilicals Lisa Aagesen [email protected]

Valve Testing John Dods [email protected]

Wet Gas Emmelyn Graham [email protected]

NEL Contact Tel: + 44 (0) 1355 202222

For general queries contact the sales team on [email protected]

Forthcoming Training Courses

• Principles and Practice of Flow Measurement Training Course

12-14 May, East Kilbride

NEL Slide 34 SUBSEA UK CONFERENCE ABERDEEN 15-02-18

Contact us

+ 44 (0)1355 220222

[email protected]

www.tuvnel.com

Erosion Effects in Flowmeters - Subsea UK · •Install in water/ sand erosive flow facility. Run...

Documents

Transcript of Erosion Effects in Flowmeters - Subsea UK · •Install in water/ sand erosive flow facility. Run...