Transcript Slide 1

Oil & Gas UK
Supplementary Guidance On The
RIDDOR Reporting Of Hydrocarbon
Releases
Technical Presentation
Hydrocarbon Release Reporting Agenda
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Objectives of the Workgroup
Structure of Guidance
Regulatory Requirements
Reporting Methodology
Technical Assessment
Reportable Limits
Additional Rules
Reporting of Non Petroleum Hydrocarbons
Objectives of Workgroup
• Produce supplementary guidance that is
– Fully aligned with RIDDOR 2013 requirements
– Well-understood by the industry
– Consistently applied by the industry
• Primarily focussed on petroleum hydrocarbon releases
• Also includes assessment on non-petroleum
hydrocarbon releases
Petroleum Hydrocarbon Releases
Reportable Limit
Major
Significant
Previous Guidance
2014 Guidance
Minor
Reportable
Limit
Not Reportable
Number of releases
Structure of Guidance
• Regulatory Requirements
– Review of DO relating to Hydrocarbon Releases (HCR)
• Methodology for Assessing RIDDOR Reporting of Petroleum
Hydrocarbon Releases
– Define key words and phrases
– Reporting flow chart
• Technical Assessment
– Defines Reportable Limits
• Case Studies
– Worked Examples
• Appendices
– Consequence Analysis
– Application of Methodology to Non-Petroleum Hydrocarbon Fluids
– High Water Content Liquids
Regulatory Requirements – RIDDOR 2013
Release of petroleum hydrocarbon
75 The unintentional release of petroleum hydrocarbon on
or from an offshore installation which –
(a) results in –
(i) a fire or explosion; or
(ii) the taking of action to prevent or limit the
consequences of a potential fire or
explosion; or
(b) could cause a specified injury to, or the death
of, any person.
Technical Assessment – Potential for
Death or a Specified Injury
• Petroleum Hydrocarbons
– Well Fluids, Natural Gas, Natural Gas Liquids, Condensate,
Crude Oil
• Continuous & Discrete Releases
• Gas, Vapour, Mist, Liquid
• Consequence Analysis
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Continuous Release - Jet Fire
Continuous Release - Pool Fire
Discrete Release - Fireball
Discrete Release - Pool Fire
Flash fire, Explosion, Toxic Cloud, Asphyxia, Narcosis - See
Guidance
RIDDOR DO 75 Assessment Flowchart
Release of
Petroleum
Hydrocarbons?
No
Yes
Confirmed?
No
Yes
Unintentional?
No
Yes
Fire or Explosion?
Yes
No
Automatic
Executive
Action?
Yes
HCR is RIDDOR
DO 75 Reportable
No
Other
Action & Potential
for Death or a Specified
Injury?
No
Yes
HCR is NOT RIDDOR
DO 75 Reportable
Technical Assessment
• Continuous & Discrete Releases
• Consequence Analysis
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Continuous Release - Jet Fire
Continuous Release - Pool Fire
Discrete Release - Fireball
Discrete Release - Pool Fire
• Additional Guidance
Continuous And Discrete Releases
• Continuous release – A continuous release is a loss of
containment from a system which occurs, or has the
potential to occur, for an extended period of time (minutes)
prior to plant stoppage or action being taken to depressurise
the system. For continuous releases, the release rate is the
important factor in determining if a HCR has the potential to
cause death or a specified injury.
• Discrete release – A discrete release is a loss of
containment from a system with a fixed mass inventory
where the hydrocarbon is released over a short period of
time (seconds rather than minutes) and where the initial
mass released has a greater hazard potential than any
following continuous release.
Continuous Release - Jet Fire
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Jet fire flame length ≥ 1m
Criterion – person must be in the flame
Mass flow rate for 1m flame length = 3 kg/hour
Equivalent gas concentration 20% LFL at 0.5m
• Conservatisms
– Jet fire flame length correlation
– Adopted gas concentration criterion
Continuous Release - Pool Fire
• Pool fire flame diameter ≥ 1m
• Criterion – person must be in the flame
• Mass flow rate for sustained 1m diameter
pool = 100 kg/hour
• Conservatisms
– Lowest burn rate adopted for all liquids
– Adopted reportable limit lower than calculated
Discrete Release – Fireball
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Transient analysis
Criterion – thermal dose ≥ 1000 tdu
Surface Emissive Power = 300 kW/m2
Mass of hydrocarbons for 1000 tdu = 0.15 kg
• Conservatism
– Assume person exposed to constant heat flux
Discrete Release – Pool Fire
• Transient analysis
• Pool fire grows with time
• Criterion
– An escaping person is caught in the flame
– The thermal dose received during escape ≥1000 tdu.
• Mass of hydrocarbons to meet criterion
– Natural Gas Liquids - 3 kg
– Condensate - 10 kg
– Crude Oil - 30 kg
• Conservatism
– Speed of escape
Additional Guidance – Hydrocarbon Liquids
• Water Cut
– Hydrocarbon liquids with ≥ 90% water by mass are not
combustible and are therefore not reportable
• Accumulation
– Liquid releases are only reportable if they can form pools.
– If a liquid release falls to the sea and there is no pool or
coating formed on equipment or the deck, it is not
reportable.
– If a liquid release is routed directly to the drains within 0.5
m of the point of release and does not form a pool, it is
not reportable.
Reportable Limits
Type of Release
Phase
Gas / Vapour / Mist
Hazard
Fluid
Reportable Limit
Jet Fire
Natural Gas
Natural Gas Liquids
Condensate
Crude Oil
3 kg/hour
(0.0008 kg/s)
OR
20% LFL at 0.5 m
Pool Fire
Natural Gas Liquids
Condensate
Crude Oil
100 kg/hour
(0.028 kg/s)
Fireball
Natural Gas
Natural Gas Liquids
Condensate
Crude Oil
0.15 kg
Pool Fire
Natural Gas Liquids
3 kg
Pool Fire
Condensate
10 kg
Pool Fire
Crude Oil
30 kg
Continuous
Liquid
Gas / Vapour / Mist
Discrete
Liquid
Reportable Limits for Petroleum Hydrocarbon
Releases – DO 75 (Appendix B of Guidance)
Confirmed
Release
Phase of
Release
Liquid
Accumulation
Water Content
Type of
Release
Composition
of Release
Reportable
Limit
Continuous
(Section 10.2.1)
Hydrocarbon
Gas/Vapour/Mist
3 kg/hour, OR
20% LFL at 0.5m
Discrete
(Section 10.3.1)
Hydrocarbon
Gas/Vapour/Mist
0.15 kg
Continuous
(Section 10.2.2)
Hydrocarbon
Liquids
100 kg/hour
Natural Gas
Liquids
3 kg
Condensate
10 kg
Crude Oil
30 kg
Gas/Vapour/Mist
Petroleum
Hydrocarbon
Release
Liquid
Is the Water
Content <90% by
Mass?
NO
YES
Did the
Release
Accumulate?
NO
YES
Discrete
(Section 10.3.2)
Not RIDDOR
DO 75 Reportable
Reportable Limits for Non-Petroleum Hydrocarbon
Fluids – DO 77 (Appendix D of Guidance)
Confirmed
Release
Phase of
Release
Hazardous
Liquid
Water Content
Liquid
Accumulation
Type of
Release
Composition
of Release
Reportable
Limit
Continuous
All Flammable
Gasses / Vapours
/ Mists / Sprays
3 kg/hour, OR
20% LFL at 0.5m
Discrete
All Flammable
Gasses / Vapours
/ Mists / Sprays
0.15 kg
Methanol
80 kg/hour
All Other
Flammable
Liquids
100 kg/hour
Methanol
45 kg
All Other
Flammable
Liquids
30 kg
Gas / Vapour
Mist / Spray
Non-Petroleum
Hydrocarbon
Fluid Release
YES
(Mist or Spray)
Liquid
Is the Water
Content <90% by
Mass?
NO
YES
Is the
Release a
Hazardous
Liquid?
NO
YES
(Liquids)
Continuous
Did the
Release
Accumulate?
NO
YES
Discrete
Not RIDDOR
DO 77 Reportable
Regulatory Requirements
RIDDOR 2013
Dangerous Occurrence
RIDDOR
Reportable Limit
OIR/12
Wells
DO 20
No
All releases
Pipelines
DO 21
Yes
(See HSE Website)
Only if release is within
500m zone
Release of petroleum
hydrocarbons
DO 75
Yes
(See Sections 3 & 4)
All RIDDOR DO 75
reportable releases
Release of non-petroleum
hydrocarbons
DO 77
Yes
(See Section 5)
Not required
RIDDOR 2013
Dangerous Occurrence
RIDDOR
Reportable Limit
OIR/12
Wells
DO 20
No
All releases
Pipelines
DO 21
No
Only if release is within
500m zone
Release of petroleum
hydrocarbons
DO 75
No
All fires & explosions
Release of non-petroleum
hydrocarbon fluids
DO 76
No
Not required
Unignited Release
Ignited Release
Guidance on Hydrocarbon Release Reporting