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P MURALIDHARAN General Manager Swinton Technology Middle East

• Working with Swinton Technology for the past 1 year and responsible for overall Middle East Business

• Total 34 years experience in Process Control Industry of which 22 years experience in Middle East, handling Custody Transfer Flow Products (Orifice, Turbine, PD, Ultrasonic, Coriolis), Flow Computers & Metering Systems

• Bachelor of Technology in Electronics Engg

Orifice Meter Diagnostics

– ConocoPhillips Field Tests

P Muralidharan General Manager

Swinton Technology Middle East

(Richard Steven, DP Diagnostics LLC)

Agenda

• Introduction

• Field Tests-Conoco Phillips

• Conclusions

• Questions and Answers

Introduction

• Orifice flow meters are popular as they are simple, generally inexpensive & reliable

• Current practice of accuracy validation is by routine scheduled inspections

• A diagnostic system (CBM) is desirable as it:

– Guarantees performance therefore reducing exposure to measurement error

– Avoids risky routine inspection – Provides Alerts & identifies problems

flow

P2 P1

DPt

H L

‘Traditional’ Meter

DP (P1-P2)

3 of 40

DP Diagnostic Method

flow

P2 P3 P1

DPt DPr

H L H L

‘Traditional’ Meter

DP (P1-P2) ‘Recovered’ DP

(P3-P2)

3 of 40

DP Diagnostic Method

flow

P2 P3 P1

DPt DPr DPppl

H L H L H L

‘Traditional’ Meter

DP (P1-P2)

‘Recovered’ DP

(P3-P2)

Permanent

Pressure Loss DP

(P1-P3)

3 of 40

Four pairs of ‘normalised’ diagnostic results

plotted as 4 points inside a ‘Normalised

Diagnostic Box’ (NDB).

All points inside the box indicates good meter

performance (each result is within allowable

uncertainty).

10

Simple visualisation

Any point outside of the box means that actual meter

performance is not agreeing with expected and there is

potentially a non-compliance or a fault producing an error

in meter flow rate prediction.

Pattern of diagnostic results provides indication of cause of alarm.

11

Simple visualisation

12

Issues Detected Include:

An Orifice Plate Installed Backwards

A Worn or Damage Orifice Leading Edge

Incorrectly Spanned DP Transmitter.

Orifice Blockage

Meter Incorrectly Installed

Incorrect Inlet or Throat Diameter In Use

Two-Phase Flow

Excessive Upstream Disturbance

Contamination Build-Up

Blocked Impulse Lines

Saturated DP Transmitter

Drifting DP Transmitter

A Buckled Orifice Plate

Agenda

• Introduction

• Field Tests-Conoco Phillips

• Conclusions

• Questions and Answers

ConocoPhillips Field Tests

• ConocoPhillips (CoP) has field tested ‘Prognosis’ on a

live 10” orifice meter at the Franklin gas station in Texas,

USA

• CoP deliberately induced known controlled problems to

test and verify the diagnostic system. The response of

Prognosis to the correctly operating orifice meter is

shown before the response of Prognosis to the various

induced problems are presented.

• Baseline (10”, 0.46 beta, dry gas orifice) ConocoPhillips Field Tests

Measurement error of between -15% and -20%!!

• Backwards installed plate

• Leaking 5-way manifold (DP reading error)

Actual DP 64.57 inH20

DPt drifts -5.4%, DPt read 61.08 inH20

Flow Error -2.7%

• Blocked impulse line (upstream)

Pressure at P1 is ‘stuck’, 2 DPs are affected and hence all

results are affected.

No doubt that there exists a DP integrity issue!!

• Incorrect Orifice Diameter Keypad Entry

-11% bias in flow rate prediction

Actual d = 4.5”

Keypad entered d = 4.25”

• Incorrect inlet diameter keypad entry

<+1% bias in flow rate prediction

Actual ID = 9.75” (schedule 80)

Keypad entered ID = 9.562” (wrong schedule)

Agenda

• Introduction

• Field Tests-Conoco Phillips

• Conclusions

• Questions and Answers

Conclusions

• Swinton Technology & DP Diagnostics have developed and proven an Orifice Meter diagnostic tool called “Prognosis”

• Prognosis can

– Assure correct Orifice Meter Operation

– Reduce exposure to mis-measurements

– Increase productivity of field technicians by reducing inspection visits

Conclusions

• Prognosis has been field tested at

– BP CATS,

– CoP TGT and Franklyn

– Rosneft Polar Lights Field ( Russia)

• Prognosis is procured by

BP, Conoco Phillips, Petronas, Yanpet ( Exxon/Saudi Aramco) , MaerskOil,

Encana, UK National Grid Talisman

• Concept is now included in

– UK governments DECC “ Guidelines for Petroleum Measurement

– The Canadian regulators “ Directive 17”

– QP Measurement Guidelines

Thank You.

Questions?

muralidharan@swintontechnology.com

Enquiries.stme@swintontechnology.com

http://www.swintontechnology.com/