Alarm Management Experience on Shearwater Dave Gisby and Ian - - PowerPoint PPT Presentation

Alarm Management Experience on Shearwater

Dave Gisby and Ian Dunsmuir

Shell U.K Exploration and Production

Contents

• Overview of the Shearwater project
• Alarm system configuration
• Alarm system performance and operating benchmarks
• Alarm Configuration Manager (ACM) usage
• Summary and Conclusions

Shearwater

Shearwater Co-Venturers

Shearwater Location

Shearwater Aerial View

Shearwater Overview

• Shell/Exxon-Mobil/BP North Sea offshore installation
• Defined as HP/HT production
• First Condensate / Gas Oct 2000
• Production Conditions - 850 Bar THP - 190 DegC
• 6 well-slot bridge linked installation to Main Topsides
• Capacity:

– Gas 11,600,000 m3/d (410 million Scfd) – Condensate 18,400 m3/d (116,000 BPD) – Gas Export Quality = Domestic quality

Shearwater Process Flow Sheet

Condensate Export 90,000 bpd Gas Export 410 MM scfd NGL stabiliser LT separator LT HEXS 2nd stage NGL o/head compression LP/MP compression 1st stage T E G heat cool cool heat Turbo expander/ re-compressor Regen Regen Meter Meter

A M I N E

Contents

• Overview of the Shearwater project
• Alarm system configuration
• Alarm system performance and operating benchmarks
• Alarm Configuration Manager (ACM) usage
• Summary and Conclusions

Studies have identified Three main Problem Areas

• Too many alarms with too High Priority
• Excess Standing Alarms
• Alarm Flood Effects During Process Upsets

Intelligent Alarm Management

• Three Pass Study
• 1. Personnel Safety
• 2. Financial Loss
• 3. Environmental Damage
• Highest single classification determines alarm priority and

classification

Alarm Prioritisation By Consequence

Standing Alarms

• Studies have shown that 90% of standing alarms are due to

incorrect system configuration and Poor alarm Strategy: – Incorrect Use of Off-Normal Alarming Facilities – Alarms Still Enabled on Out of service Equipment – Alarms Still Enabled on Known Faulty equipment

Alarm Flood

• Alarm Flood Effects directly attributable to the normal shutdown of

equipment

• Alarm Flood Occurs at worst possible time for CRO
• Alarms should only be valid when equipment is running
• Intelligent alarm annunciation Strategy required
• HSE have identified “alarm flood” as an issue when investigating

incidents

Alarm Prioritisation - History

• Priorities defined using Shell Expro tool for all alarms and

implemented Oct 2002

• Database – 22,800 alarms:

– Emergency - 136 – High - 3876 – Low - 7839 – Journal – 10,949 – Above defined in database as Px, P3,P2 and P1 respectively

• Two panel operators normally
• Future – one operator normally and two for Start-Up

Alarm Database

Total number of configured alarms

7839 3876 136 1000 2000 3000 4000 5000 6000 7000 8000 9000 Low Priority (P2) High Prority (P3) Emergency (Px) Number of alarms

Contents

• Overview of the Shearwater project
• Alarm system configuration
• Alarm system performance and operating benchmarks
• Alarm Configuration Manager (ACM) usage
• Summary and Conclusions

Alarm Performance - History

• Database – 22,800 alarms
• Bad actors (events) being worked on a weekly basis.
• Alarm activations:

– 1200 per hour (Sept 2001) – 370 per day (Sept 2002) – 288 per day (March 2003)

• Standing alarms:

– Emergency 12, High 200, Low 140 (Aug 2002) – Emergency 2, High 71, Low 184 (Oct 2002) – Emergency 0, High 26, Low 60 (Feb 2003)

Standing Alarm History

Standing alarms

20 40 60 80 100 120 140 160 180 200 Pre Alarm Database Post Alarm Database 6-Jan-03 14-Mar-03 Target Number of alarms Emergency High Priority Low Priority

Alarm Classification - Now

• CP – Change Process being used as vehicle for funding
• 30 Consoles in ACM = 30 TPS Units in use
• Issue with Low and Journal alarms due to sub picture design.
• Sub picture change to allow alarms to be journalled and be seen
• n graphics.

Alarm Classification – Next Steps

• Complete remaining consoles including F&G
• Review bad actors on a weekly basis and after trips using “Event

Analyst”

• “User Alert” to be integrated into alarm management
• Alarm flooding hierarchy i.e. equipment trip, package trip, SPS, -

being investigated

SGS Benchmark

Number of configured alarms per operator

(Fire & Gas and Journal alarms excluded) 500 1000 1500 2000 2500 3000 3500 4000 4500 Shearwater On-shore gas processing unit Complex refinery unit Shearwater target

Contents

• Overview of the Shearwater project
• Alarm system configuration
• Alarm system performance and operating benchmarks
• Alarm Configuration Manager (ACM) usage
• Summary and Conclusions

Why use ACM?

• ACM allows the active alarm configuration to be monitored and

controlled.

• The alarm “enforcement” process and reports gives the operator a

good view of the current alarm configuration.

• The Master Alarm Database contains an audit trail of all parameter

changes – particularly useful if a trip point is being frequently changed.

• The underlying ACM equipment model allows groups of points to be

managed separately (e.g. to disable alarms for shutdown equipment).

ACM Configuration

NT/2000 NT/GUS NT/APP

ACM Administrator Client Alarm Enforcer Client

Process Control Network Process Network

Alarm Enforcer Server TPN Server

NT/2000

Alarm Manager Client

NT/2000

Master Alarm Database Alarm Manager Server CL Server AM

Note that multiple functions can coexist in

• ne box

Overview – Console + Operating Unit

Honeywell TDC3000 Control System Console(1) Console(2) Console(3) Console(34) Process Unit WA Process Unit CW Process Unit CI Well SWA01 Well SWA04 Well SWA08 P4831 Booster Pump C2110 Contactor Process Unit GS P4821 Booster Pump

PT

Low Flow Alarm

PT ESD DCS

Low Flow ESD Trip

FT FT

Low Discharge Press Alarm

Low Discharge Pressure ESD Trip

STOP

Alarm Flood

PT ESD DCS FT FT STOP PT

Local Stop Activated

ACM

Dynamic Alarm Suppression

ACM Usage

• System being used to ensure alarms are controlled.
• If alarm found to require re-prioritising then change process
• ffshore used to provide trail.
• Equipment Groups Configured to match Existing TDC3000

Keyword – Reduced Engineering Costs

• Alarm Configuration Changes logged so are Auditable
• Alarm Enforcement can be carried out either on demand or periodic

scheduled activity

• Wish to be able to Import / Export the database

Contents

• Overview of the Shearwater project
• Alarm system configuration
• Alarm system performance and operating benchmarks
• Alarm Configuration Manager (ACM) usage
• Summary and Conclusions

Summary and Conclusions

• ACM Enabled control to be placed on the PCS Alarms.
• Change process required to re-prioritise Alarms
• ACM software added to mask Standing Alarms
• ACM software added to mask Dynamic Alarms
• All Changes to ACM database are logged and are auditable
• Alarm Enforcement history and changes are available to view as

post event reports

Acknowledgements

• Honeywell, Aberdeen office for its commitment to the challenging

quantity of alarms for masking.

• Shell Expro, Exxon-Mobil and BP for Approval of this presentation

NO ALARM

JOURNAL LOW HIGH

EMERGENCY R1 R0 SLE0 SLE1 SLE2 SLE3 SLE4 J0 J1 A1 A2 START

Alarm Classification By Consequence