Chris Wicks

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The QuickLists

Christopher Wicks

UK HES Manager

Marathon Oil U.K. LLC



Overview

What are QuickLists?

What do they do for us?

How are they used?

Summary




What Are QuickLists?

Principally

Emergency response and incident management

–Aid the on-site emergency team in:

• Assessing the hazard

• Understanding escalation potential

–Provide guidance and reminders on potential access / egress impairment

issues

Additionally

Reference tool for Operations personnel

Supporting development of Emergency Response Exercises

Communication tool summarising Major Accident Events for

workforce




Background



Background

QRA – Quantified Risk Assessment

Statistical analysis to evaluate the risk to the individuals on the

plant

Complex

Costly

Under used?

What value does it add?




Typical QRA Output…

4.2 x 10-4

One number that defines the risk to an individualDoes this help make anybody safer?

Data presented for example only




Value of QRA?

A

4.2 x 10-4B

9.8 x 10-4

7.2 x 10-4

6.8 x 10-4

Change design to

remove leak sources

Add rated

fire/blast walls

Optimise fire/gas

detection system





Journey Findings/Outcomes




Example




Escalation from Fires

3 0 M i n u t e s

5% Chance Wall Fails

F i r e

Process Area ‘Safe’ Area





0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 20 40 60 80 100 120 140 160 180

P r o b a b

i l i t y

( D u r a t i o n l o n

g e r t h a n )

Duration of event (minutes)

Event Escalation





Example




Escalation from Explosions

0 . 5

B a r g

20% Chance Wall Fails

E x p l o s i o n

Process Area ‘Safe’ Area



http://itmakessenseblog.com/files/2011/03/explosion.jpg

http://itmakessenseblog.com/files/2011/03/explosion.jpg



0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0.0 0.5 1.0 1.5 2.0 2.5 3.0

P r o b

a b i l i t y

( O v e r p r e s s u r e g r e a t e r t h a n )

Overpressure (bar)

Event Escalation





Example




Wind

Gas Concentration

Wind speed and direction displaces

different volumes of air resulting in

varying air change rates


Open Modules



Wind

Wind speed and direction displaces

different volumes of air resulting in

varying air change rates

Gas Concentration


Open Modules



Gas Concentration

Wind Speed 5 knots

10 knots

>15 knots

120

300

160 170

180 190

200

210

220

230

240

250

260

270

280

290

310

320

330

340 350

0 10

20

30

40

50

60

70

80

90

100

110

130

140

150

160 170

180 190

200

210

220

230

240

250

260

270

280

290

310

320

330

340 350

2015

105

Duration to

Concentration <20%LEL (mins)





Gas Concentration

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 5 10 15 20 25 30

P r o b a b

i l i t y

( F l a m m a b l e G a s C l o

u d S t i l l P r e s e n t )

Time (Minutes)

A

B





One Tool…




Graphical Interpretation

Given QuickLists are to be used in

potentially stressful situations they must

be:

Simple to read

Clear and concise

Interpretable with limited ‘experience’

Comprehensive enough to meet the needs ofthe event




Layout Overview – Process Hazards

Escalation

Potential

BlowdownCurves

Gas Detection

Layout and

Inventory

Volumes

Fire Detection

layout and

Module

Boundary Data




Escalation Potential Example – Open Module

1. Select Table A, B or C based on prevailing weather conditions

2. If all critical safety systems (blowdown, isolation etc.) are functioning asexpected, estimate of duration until gas cloud dissipated

Example Wind from 175 degrees at 7 knots – use Table A

All SCEs OK, use 1st column

61% chance gas will be dissipated within the hour, but 39% (i.e. reasonablechance) that it will still be there, certainly in pockets





Escalation Potential Example – Fire

1. If SCE fails (Blowdown, Isolation), high chance of event lasting longer than 1 hour

Possible structural damage and flare boom impact

North end of asset not assessable

Be aware of prevailing weather – combustion products could impair helideck





Blowdown Curves

Blowdown Valve Failed to Open

Blowdown Slower than Expected - Partially Opened Valve?

Blowdown Quicker than Expected - Release from Inventory?

Expected Blowdown



O h MAE /I f i I l d d



Other MAEs/Information Included

Data presented for other Major

Accident Events, including:

Ship Collision

Riser Events

Oil Spills and Response

Chemical Spills

Riser Releases

Ship Collision


S



Summary

Provide a simple guide to incident control team

members (on- and offshore), enabling them to: Identify potential escalation issues

Identify access/egress considerations

Evaluate event severity, likely duration and possible control

measures

Additionally

Provides reference tool for onshore teams

Supporting development of Emergency Response ExercisesCommunication tool summarising MAEs for workforce




Thankyou

Chris Wicks

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