Alarm Management Experience on Shearwater - … Management Experience on Shearwater Dave Gisby and...

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