NEL’s EPAT Facility –

Experiences,

Challenges and Future

Developments

Chris Mills, NEL

25 April 2018

– INTRODUCTION

– EPAT FACILITY

– CHALLENGES

– EXPERIENCES

– FUTURE DEVELOPMENTS

Content

Brief history

• 2011: NEL completed R&D with Coriolis meters for a number of O&G

operators at elevated temperatures.

• 2012: NEL formulated a Joint Industrial Project (JIP) exploring influence of T,

P, and viscosity.

• 2014: JIP completed and concluded that:

– calibration under conditions similar to the field required

– lack of traceable calibration facilities that can operate at elevated

temperature, pressure, and viscosity

• 2014 – 2016 NEL designed & built a new flow loop operating at Elevated P

and T (EPAT) & Fully accredited to UKAS

• 2016 - present: This presentation focus now on Experiences, Challenges

and Future Developments

Introduction

Current regulations

• UK Oil & Gas Authority (OGA) Guidelines

Introduction

The facility:

EPAT Facilities

EPAT Facilities

Specification:

Item Spec

Maximum Pressure: 100 bar g

Minimum Pressure: 4 bar g

Pressure Control: +/- 0.5 Bar

Maximum Temperature: 80 °C

Minimum Temperature: 20 °C

Temperature Control: +/- 0.5 °C

Maximum Flow: 100 l/s

Minimum Flow: 0.5 l/s

Fluid Density: 0.810 kg/l

Maximum Fluid Viscosity: 6 cP

Minimum Fluid Viscosity: 2 cP

Test Section Pipe Size: 1 – 10 inch OD

Test Section Pipe Length: 10 metres

Measurement Uncertainty: ± 0.08 (k=2)

EPAT Facilities

EPAT Facilities

Operation & calculations

• DUT calibrated against Turbine Master Meters

– Master Meters are proved at every flowrate, pressure and temperature

– Typical sequence – (Prove, 3 DUT Repeats, Prove)

• Calculations

– CTSp and CPSp both used

– CTLp and CPLp (CTPL) are not used

CPSpCTSpBPVCTPL

CTPLV

mmp

provemmp

EPAT Facilities

Operation & calculations

• DUT calibrated against Turbine Master Meters

– Master Meters are proved at every flowrate, pressure and temperature

– Typical sequence – (Prove, 3 DUT Repeats, Prove)

• Calculations

– CTSp and CPSp both used

– CTLp and CPLp (CTPL) are not used

– API values are not robust for NEL test fluid

CPSpCTSpBPVVmmp

provemmp

CPSpCTSpBPVCTPL

CTPLV

mmp

provemmp

EPAT Facilities

Prover calculations

– API values are not robust for NEL test fluid

Error may be up to 0.1 % up to 49 bar(a), undefined above, [Glen N., O&G FG,

Dec 16]

Challenges

Density characterisation

– API values are not robust for NEL test fluid

– Requires fluid to be characterised at T&P

– Stable density is critical for facility uncertainty

– Water contamination was an issue

CPSpCTSpBPVVmmp

provemmp

Challenges

Demonstrating equivalence

• Intra-comparison

– Compared EPAT system with NEL gravimetric for low pressure and temperature

– Achieved equivalence but only at low P&T conditions.

Challenges

Demonstrating equivalence

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

0.0 2.5 5.0 7.5 10.0 12.5 15.0

%E

rr (R

ef.

Ma

ss

)

Ref. Total MFlow , kg/s

Temperature 20°C, Pressure 5 bar.g

Gravimetric Compact Prover

Challenges

Demonstrating equivalence

• Inter-comparison

– Compared EPAT system with West Lab for high pressure

– Achieved equivalence with manufacturer supplied meter

– Additional customer supplied data allowed comparisons at T&P to be made

Challenges

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

0 10 20 30 40 50 60 70 80 90 100

%E

rr (R

ef.

Ma

ss

)

Ref. Total MFlow , Tonne/hr

Temperature 68°C, Pressure 14 bar.g

NEL West Lab

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

0 250 500 750 1000

%E

rr (R

ef.

Ma

ss

)

Ref. Total MFlow , kg/s

NEL 10 bar.g NEL 40 bar.g West Lab 10 bar.g West Lab 40 bar.g

Demonstrating equivalence

Challenges

Demonstrating equivalence

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

0 10 20 30 40 50 60 70 80 90 100

%E

rr (R

ef.

Ma

ss

)

Ref. Total MFlow , Tonne/hr

Temperature 68°C, Pressure 14 bar.g

NEL West Lab

Challenges

Customer data

• Calibrated large number of Coriolis meters

– All manufacturers

– Variety of sizes and models

Experiences

-2.00

-1.75

-1.50

-1.25

-1.00

-0.75

-0.50

-0.25

0.00

0 50 100 150 200 250 300 350

%E

rr (R

ef.

Ma

ss

)

Ref. Mass Flow, T/hr

Kerosene 20degC 3cSt Gas Oil 20degC 8cSt Gas Oil 20degC 8cSt (R) EPAT 25degC 10bar.g

EPAT25degC 20bar.g EPAT 25degC 20bar.g R EPAT 25degC 40bar.g

Customer data

Experiences

Customer data

-2.00

-1.75

-1.50

-1.25

-1.00

-0.75

-0.50

-0.25

0.00

0 5 10 15 20 25 30 35 40 45

%E

rr (R

ef.

Ma

ss

)

Ref. Pressure, bar.g

Kerosene 20degC 3cSt Gas Oil 20degC 8cSt Gas Oil 20degC 8cSt (R)

EPAT 25degC 10bar.g EPAT 25degC 20bar.g EPAT 25degC 40bar.g

Experiences

Customer data

Linear Pressure Effect

Experiences

Calibration procedure

1. Zero device at operating temperature and pressure

2. Calibrate device at operating temperature and pressure ‘as found’

3. Additional pressure compensation calibration at ± 10 bar.g to derive pressure

compensation

4. Can then perform an ‘as left’ calibration if required

Experiences

EPAT Facility

– MeterVue is fully operational

– Excellent feedback with users from Europe, Middle East and South East

Asia in the past year

– Live uncertainties are calculated for the results

– DAQ system uses EPAT UB for all calculations and reporting

– History for revising facility uncertainty

– Pressure stability ± 0.5 bar.g up to 100 bar

– Increase / decrease temperature by 10°C in 15 minutes

– Increase / decrease pressure by 20 bar in 5 minutes.

Experiences

EPAT Facility

– Meters can be zeroed at T&P but as T drops, P drops significantly.

– RTD on board Coriolis flowmeters measures tube temperature as opposed to

fluid temperature (response lag)

– If zeroing at elevated temperature, it is important to allow time for stabilising

– Zero value can change by end of calibration. Possibly due to expansion /

contraction of facility with T&P over time.

Experiences

• DDAT

– Collating all calibrations (both master meters & customer)

– Enable master meter calibration curves to be used

– Use customer data to revise Coriolis ISO 10790

• Direct Proving

– Not UKAS at present but work is ongoing

– Reduced uncertainty

– Quicker calibration

• Online Density

– Installing a CDM that has been characterised at NEL

Future Developments

Chris.Mills@tuv-sud.co.uk

Contact Details