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Alarm Management Experience on
Shearwater
Dave Gisby and Ian DunsmuirShell 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
AMINE
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
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
Low Priority (P2) High Prority (P3) Emergency (Px)
Nu
mb
er
of
ala
rms
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
0
20
40
60
80100
120
140
160
180
200
Pre Alarm
Database
Post Alarm
Database
6-Jan-03 14-Mar-03 Target
Nu
mb
er
of
ala
rms
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
on 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)
0
500
10001500
2000
2500
30003500
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/GUSNT/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
one 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
offshore 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