Guidance Notes to Operators of UK

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DECC OPRC OPEP Guidance

July 2012


1






Guidance Notes to O
perators of UK

Offshore Oil and Gas I
nstallations

(including pipelines)

on

Oil
Pollution

Emergency Plan

Requirements






DECC OPRC OPEP Guidance

July 2012


2

Contents

1

Introduction

................................
................................
................................
...........

4

1.1 Legislative Background

................................
................................
......................

4

1.2 Offences

................................
................................
................................
............

5

2

Definitions an
d Abbreviations

................................
................................
...............

6

2.1 Definitions

................................
................................
................................
..........

6

2.2 Abbreviations

................................
................................
................................
.....

8

3

OPEP Funct
ion and Scope

................................
................................
.................

10

4

Categories of Installations Requiring an OPEP

................................
..................

11

4.1 Types of Installations Requiring an OPEP

................................
.......................

12

5

Pollution Incident Scenario and Hazard Identification

................................
.........

14

5.1 Introduction

................................
................................
................................
......

14

5.2 Pollution incident Scenario Identification

................................
..........................

14

5.3 Worst Case Scenarios

................................
................................
.....................

15

5.4
Well Flow Rates

................................
................................
...............................

16

5.5 Modelling

................................
................................
................................
.........

16

5.6 Environmental Impact Assessment

................................
................................
..

17

5.7 Socio
-
economic Impacts

................................
................................
..................

18

5.
8 Areas of Potential Impact Outwith UK Waters
................................
..................

18

6

Pollution Incident Assessment

................................
................................
............

20

6.1 Volume and Tracking of Oil Pollution

................................
...............................

20

6.2 Oil Modelling During Oil Pollution Incidents

................................
.....................

21

7

Dispersant and Aerial Surveillance Requirements

................................
..............

22

7.1 Introduction

................................
................................
................................
......

22

7.2 Minimum
Response Requirements

................................
................................
..

22

8

Response Strategy and Implementation

................................
.............................

26

8.1 Introduction

................................
................................
................................
......

26

8.2 Response Tiers

................................
................................
................................

26

8.3 Respon
se Strategies

................................
................................
........................

27

8.4 Response Initiation

................................
................................
..........................

33

8.5 Government Interfacing Plans
................................
................................
..........

33

9

Oil Pollution Incident Reporting

................................
................................
...........

35

10

EPC Regulation Requirements

................................
................................
.......

36

10.1 Personnel

................................
................................
................................
.......

36

10.2 Roles and Responsibilities

................................
................................
.............

36

10.3 Emergency Response Procedures

................................
................................

36

10.4 Location of OCU

................................
................................
............................

37

10.5 EPC Exercise Requirements
................................
................................
..........

37

11

Training and Competency Requirements

................................
........................

38

12

Exercise Requirements

................................
................................
...................

39

DECC OPRC OPEP Guidance

July 2012


3

12.1

Offshore OPEP Exercise

................................
................................
...............

40

12.2 Offshore Deployment of Tier 1 Dispersant Spraying Equipment

....................

40

12.3 Offshore Deployment of Tier 1 Oil Recovery Equipment

...............................

40

12.4 Onshore ERC Installations and Procedures

................................
..................

40

12.5 EPC Exercises

................................
................................
...............................

40

12.6 Industry Deployment of Tier 2/3 Oil Response Equipment

............................

41

12.7 Recording of Exercises

................................
................................
..................

41

13

OPEP Content and Layout

................................
................................
..............

42

13.1 Combined Offshore and Onshore Plan

................................
..........................

42

13.2 Separate Offshore and Onshore Plans

................................
..........................

42

13.3 OPEP Content

................................
................................
...............................

42

14

Justification Information

................................
................................
..................

47

15

OPEP Submission

................................
................................
..........................

48

15.1 New submissions

................................
................................
...........................

48

15.2 Cha
nges affecting existing OPEP

................................
................................
..

48

15.3 Review

................................
................................
................................
...........

49

15.4 Quality Control

................................
................................
...............................

49

15.5 Pre

submission process

................................
................................
.................

50

15.6 Consultation and Approval

................................
................................
.............

51

16

OPEP Approval

................................
................................
...............................

54

17

Post OPEP Approval

................................
................................
.......................

55

17.1 O
PEP Maintenance

................................
................................
.......................

55

18

References

................................
................................
................................
......

57


DECC OPRC OPEP Guidance

July 2012


4

1

Introduction

This document aims to provide operators of offshore installations with guidance on the
provision of oil
pollution incident
planning and response for their exploration and
production
installations
.
It
replaces earlier
guidance previously issued by

Department of
Energy and Climate Change (DECC) in April 2009

and
incorporates
all additional
information a
nd
clarification
communica
ted to oil and gas operators via letters and
DECC’s website during 2011/12
as an initial response to the Gulf of Mexico Deepwater
Horizon incident review.
This builds
on
ex
perience gained since
the
implementation of
the Merchant Shipping (Oil Pollution
Preparedness, Response and Co
-
operation
Convention) Regulations 1998 (OPRC)

[1]
.


The OPEP is
a

legally required emergency
response document whic
h should aid
the
operator and any appropriate users
to

implement a robust, effective and tested
emergency response procedure.

It should

set out the “arrangements for responding to
incidents which cause or may cause marine pollution by oil, with a view to

preventing
such pollution or reducing or minimising its effect”.

It is available to the public from
DECC and is owned and implemented by the operator.


The
guidance
provide
s

operators with
guide
lines

to enable them to produce

an OPEP
which is
a
fit for purpose operational
document
that
sets out

clear procedures for
responding to offshore
oil
pollution
incidents f
rom oil and gas installations.
This

guidance does not dictate which strategy
should

be used as any response will vary
according to the n
ature of the incident, the environmental sensitivities and the time of
year.


E
ach
OPEP

must take into account operator
specific

procedures and requirements

for
example

the specific
installation
(
s
)

involved in any response and the specific

environmental
sensitivities which may be impacted

as a result of any oil entering the
sea.


It is the operator’s responsibility to ensure that the OPEP clearly identifies the
potential release scenarios, the potential environmental impacts, and how they would
respond to

mitigate those impacts.


Operators are reminded that in the event of
an
oil

pollution incident

it is the
OPEP

and
the
personnel
involved in the response
that

will determine the success of any

response.
Therefore

operators must ensure the
ir

OPEP
’s are

writ
ten

clearly

and
concisely

to
ensure ease of use and understanding.


All staff
with duties/responsibilities during oil
pollution incident

response
must be

train
ed
and competent in
their specific role
and in
the

use

of
an

OPEP.

In particular
,

operators
who are subcontracting
any

of their operations must have in place adequate systems to
ensure

that response arrangements are in place
. All personnel must be

trained
in
accordance with this guidance
and
be
aware of the
ir

specific

response requirem
ents
.

1.1

Legislative B
ackground

The International Convention on Oil Pollution Preparedness, Response and
Cooperation
[2]

was adopted by the International Maritime
Organiz
ation (IMO) in 1990.

The
Oil Pollution Preparedness, Response and Cooperation

Convention
(OPRC
DECC OPRC OPEP Guidance

July 2012


5

Convention)
came into force in the U
nited
K
ingdom (UK)

on 16 December 1997 and
was implemented through
OPRC
Regu
lations 1998.



In summary, the OPRC Convention aims to facilitate international co
-
operation and
mutual assistance in preparing for and responding to a major oil pollution incident and
to encourage states to develop and maintain an adequate capability to
deal with oil
pollution emergencies. Specifically, it requires that the UK has national and regional
systems in place for oil
pollution incident

preparedness and response and that ships

and operators of offshore
installations
under UK jurisdiction have oil

pollution
emergency plans which are coordinated with its National Contingency Plan (NCP)

[3]
.



The OPRC Convention Regulations define "oil pollution emergency plan" as
contingency plans (other than the
NCP
) setting out arrangements for responding to
incidents which cause or have the potential to cause marine pollution by oil, with a view
to preventi
ng such pollution or reducing or minimising its effect.


Additional requirements
in relation to prevention of pollution are
included in Section 3 of
the Pollution Prevention and Control (PPC) Act 1999

[4]
,

which is implemented through
the Offshore Installations (Emergency Pollution Control) Regulations 2002 (EPC
)

[5]
.


They give the Government power to intervene in the event of an incident involving an
offshore installation where there is or there may be
a risk of significant pollution.
OPEP’
s

must include arrangements to reflect the potential in
volvement
of the Secretary
of S
tate Representative (SOSREP)

(
See Section
10
)
.


DECC is the regulatory approving authority for Offshore Oil and Gas Installation
OPEPS and the review, assessment and approval process is conducted by DECC’s

Offshore Environmental Inspectorate which is part of the
Energy Development Unit
(Offshore Environment and Decommissioning)
.


1.2

Offences

Under the
OPRC Regulations
offence
s include:
fail
ure

to submit, maintain or implement
a
n
OPEP

or

fail
ure

to report an oil

pollution incident
.

Existing reporting requirements
remain unchanged. Penalties are specified for all such offences upon conviction

[1]
.


Under the provisions of the Offshore Petroleum Activities (Oil Pollution Prevention and
Control) Regulations 2005 (OPPC)

as amended
[8]

any
release o
f oil made to sea
is
an
offence. As such it is the operators’ responsibility, under the provisions of these
Regulations, to minimise the likelihood of an accidental
release
of o
il to sea.


Due to the nature of oil and gas production activities the risk of oil pollution to sea
exists. Should there be an oil pollution incident,

then damage to the environment, the

reputation of an operator and/or the industry may
occur.
To reduc
e these risks, the
operator
’s main action is to
undertake offshore operations in a manner that prevents
pollution incidents from occurring in the f
irst place. A
s a secondary measure, mitigation
techniques should be employed to prevent the discharge of oil
to sea through the
implementation of containment measures.

C
ontainment measures may include

effective deployment or presence of
physical barriers,
modified
operation of
installations, and
any other mitigation
measures taken to contain any oil on the
instal
lation to prevent the discharge of oil to sea
[4]


DECC OPRC OPEP Guidance

July 2012


6

2

Definitions and
A
bbreviations

2.1

Definitions

Appraisal well

Well drilled after the discovery of oil

or gas to establish the
limits of the reservoir, the productivity of wells in it and the
properties of the oil or gas.

Development well

A well drilled for the extraction of reservoir hydrocarbons.

Exploration well

A well drilled into a geological
structure not previously
drilled.

Offshore
installation

OPRC Regulations:
[1]


Any fixed or floating offshore installation or structure
engaged
in gas or oil exploration or production activities, or
loading or unloading of oil;

i
ncludes drilling rigs, offshore
platforms, Floating Production Storage and Offloading
vessels and Floating
Storage Units.
Installations exploring
for or producing gas are
also included.

PPC Act
[4]

Any structure or other thing (but not a ship) in or under
-


(a)

United Kingdom territorial waters, or

(b)

any waters mentioned
in section 7(9)(b) or

(c)

which is used for the purposes of, or in connection
with, the

exploration, development or production of
petroleum.

Oil


For the purposes of ensuring a robust response to potential
oil pollution operators must take account of oil
which will
include substances included within the following:


OPRC Regulations:
[1]


Petroleum in any form including crude oil, fuel oil, sludge,
oil
refuse and refined products


Offshore Petroleum Activities (Oil Pollution Prevention
and Control) Regulations 2005 (OPPC)

as amended
:
[8]

l
iqui
d hydrocarbon or substitute liquid hydrocarbon,
including dissolved or dispersed hydrocarbons or substitute
hydrocarbons that are not normally found in the liquid phase
at standard temperature and pressure, whether obtained
from plants or animals, or miner
al deposits or by synthesis.


Offshore Chemical
s

Regulations 2002 (OCR)

as
amended

[6]

Hydrocarbon chemicals, and substitute hydrocarbon
DECC OPRC OPEP Guidance

July 2012


7

chemicals
, controlled under OCR

Oil handling
facility

OPRC Regulations

[1]


A facility which presents a risk of an oil pollution incident
and includes, inter alia, an oil terminal, pipeline and any
other facility handling oil but does not i
nclude an offshore
install
ation.

Oil
Pollution
E
mergency
P
lan
(OPEP)

OPRC Regulations

[1]


An emergency

plan (other than the National Contingency
Plan) setting out arrangeme
nts for responding to incidents
which cause or may cause marine pollution by oil, with a
view to preventing such pollution or reducing or minimising
its effect.

Oil pollution
incident

An occurrence or series of occurrences having the same
origin, which
results or may result in a discharge of oil and
which poses or may pose a threat to the marine
environment, or to the coastline or related interests of the
United Kingdom and which requires emergency action or
other immediate response.

Operator

EPC Regul
ations
[5]

In relation to an offshore installation means any person who
operates the offshore installation and includes any person
who owns it at the time any powers conferred by these
Regulations are e
xercised in relation to the offshore
installation.

OPRC Regulations
[1]


In relation to an oil handling facility a person having, for the
time bei
ng, the management of such facility in the United
Kingdom, and in relation to an offshore installation, includes
any person having the management of the installation.

Petroleum
Operations Notice
Number 1

PON1


The petroleum operation notice which is used

by
operators of offshore oil and gas installations to notify
regulatory and response authorities of incidents or
accidents involving oil or chemicals with the potential to
cause pollution of the marine environment.

Pollution

EPC Regulations
[5]

includes pollution by oil or any other substance liable to
create hazards to human health, to harm living resources
and marine life, to damage amenities or t
o interfere with
other legitimate uses of the sea, or by any other substance
listed in the Schedule to the Merchant Shipping (Prevention
of Pollution: Substances Other than Oil) (Intervention) Order
DECC OPRC OPEP Guidance

July 2012


8

1997.


Offshore Petroleum Activities (Oil Pollution
Prevention
and Control) Regulations 2005 (OPPC)

as amended
:
[8]

means the introduction by man, directly or indirectly, of
substances or energy into

the

relevant
area

which results,
or is likely to result, in hazards to human health, harm to
living resources and marine ecosystems, damage to
amenities or interference with other legitimate uses of the
sea.

Well
workover
and
intervention
operations

Operations involving entry to the well bore, with or without
removal of the Xmas tree and including well workover and
well servicing operations such as those involving wire
-
line
and coiled tubing techniques.

2.2

Abbreviations

BA
O
AC

Bonn Agreement
Oil
Appearance Code

CCW

Countryside Council for Wales

CEFAS

Centre for Environment, Fisheries & Aquaculture Science

CMRA

Coastal and Marine Resource Atlas

CPB

Counter Pollution Branch (MCA)

DECC

Department
of Energy and Climate Change

DEFRA

Department
for
Environment, Fisheries and Rural Affairs

E&P

Exploration and Production

EA

Environment Agency

EIA

Environmental Impact Assessment

EMS

Environmental Management System

EPC

Offshore Installations (Emergency Pollution Control) Regulations
2002

ER

Emergency Re
sponse

ERC

Emergency Response Centre

GPS

Global Positioning System

HMCG

Her Majesties Coastguard

IMO

International Maritime
Organi
z
ation

IPIECA

International Petroleum Industry Environmental Conservation
Association

ITOPF

International Tanker Owners
Pollution Federation Limited

JNCC

Joint Nature Conservation Committee

LA

Local Authorities

LSA

Life Saving Appliances

MAGIC

Multi
-
Agency Geographic Information for the Countryside

MCA

Maritime

and Coastguard Agency

DECC OPRC OPEP Guidance

July 2012


9

MMO

Marine Management Organisation

MODU

M
obile Offshore Drilling Unit

MS
-
ML

Marine Scotland


Marine Laboratory

NE

Natural England

NCP

National Contingency Plan

NGL

Natural Gas Liquid

OCR

Offshore Chemical
s

Regulations 2002

OCU

Operations Control Unit

OGUK

Oil and Gas UK

OIM

Offshore
Installation Manager

OPE
P

Oil Pollution Emergency Plan


OPPC

Offshore Petroleum Activities (Oil Pollution Prevention and
Control) Regulations 2005

OPRC

Merchant Shipping (Oil Pollution Preparedness, Response and
Co
-
operation Convention) Regulations 1998

OPRC Convention

The Oil Pollution Preparedness, Response and Cooperation
Convention

PON

Petroleum Operations Notice

PPC

Pollution Prevention and Control Act 1999

SEPA

Scottish Environment Protection Agency

SG
-
MD

Scottish Government


Marin
e Directorate

SNCA

Statutory Nature Conservation Agency

SNH

Scottish Natural Heritage

SOSREP

Secretary of State
’s

Representative

SRC

Shoreline Response Centre

UK

United Kingdom

UKCS

United Kingdom Continental Shelf

DECC OPRC OPEP Guidance

July 2012


10

3

OPEP Function and Scope

W
HAT DOES AN OPEP DO?

Operators are responsible for, and must be able to respond to, pollution incidents
relating to their installations or infrastructure. The OPEP Guidance

notes

requires
operators to produce a fit
-
for
-
purpose, operational document, that clearly sets out the
procedures for responding to offshore oil pollution incidents in an effective and efficient
manner, and in co
-
ordination with the UK’s National Contingency Plan.


The scope of an OPEP will cover many different activities and functions. When
developing the

OPEP, it is therefore essential that a multi
-
disciplinary team approach is
used to capture operational, response and environmental requirements. Team
members may include, but not be limited to, senior management, offshore and onshore
operational personne
l (including relevant contractors), offshore and onshore response
personnel (including relevant contractors), Health, Safety and Environment (HS&E)
advisors, insurance advisors etc. If contractors or environmental consultants are
employed to develop and w
rite the OPEP, relevant information must be provided and
reviewed by appropriate personnel employed by the operator

and responsible for
incident response
, to ensure that a robust and fit
-
for
-
purpose document is produced.




DECC OPRC OPEP Guidance

July 2012


11

4

Categories of Installations Requ
iring an
OPEP

DO I NEED AN
OPEP
?

All installations, infrastructure and activities that could give rise to an oil pollution event
on the UK
CS must be covered by an OPEP
.
T
his requirement applies to fixed and
floating installations, including MoDUs

(Mobile Offshore Drilling Units)
; gas, condensate
and oil pipelines; and subsea facilities, including any connect
ed third party
infrastructure that is not the subject of a separate OPEP. If there is any doubt as to
whether an OPEP is required, operators
should contact the DECC Offshore
Environmental Inspectorate.


More detailed guidance about the categories of installations and types of activity
requiring an OPEP is provided in the following sections. A summary is presented in
Table
4
.1.


Table 4.
1
:

Types of installations requiring an OPEP

Type of Activity

Requirements

Ref Section

Single installation

One OPEP required

4
.1.1

Group of Installations


One OPEP acceptable

4
.1.2

Pipelines

Combined platform (or handling facility) and pipeline
OPEP, or separate pipeline OPEP

4
.1.3

Subsea Tie back

Incorporated into host platform OPEP

4
.1.4

3
rd

party subsea tiebacks

New OPEP required if subsea operator takes responsibility
otherwise can be incorporated in host platform OPEP

4
.1.5

Exploration wells

OPEP required unless addressed within scope of an
existing plan

4
.1.6

Appraisal wells

As per exploration wells

4
.1.6

Development Wells

OPEP required unless addressed within scope of an
existing plan

4
.1.6

Decommissioning

Incorporation into existing OPEP

4
.1.7

Well intervention

/ Well
workover

Incorporation into existing OPEP

4
.1.7

Well abandonment

Incorporation into existing OPEP

4
.1.7

NGL/Gas Storage import and
export stations

One OPEP acceptable

4
.1.8


OPEPs are therefore required for all
oil and gas activities

undertaken on the UKCS

which could give rise to an offshore pollution incident.


Offshore oil and gas operators, MoDU operators and Well Intervention Vessel
operators should note that a Shipboard Oil Pollution Emergency Plan (SOPEP) covers
floating production facilities, MoDUs
and well intervention vessels when they are in
transit, but are not relevant once the vessels are engaged in oil and gas activities
authorised by DECC. When undertaking such activities, an OPEP that has been
approved by DECC must therefore be in place bef
ore the activities commence.


The facilities and activities covered by the OPEP must be clearly stated in the
submission, and be consistent throughout the document. Where appropriate, a
schematic should be included to identify the infrastructure covered b
y the submission,
supported by the data in a table format.


DECC OPRC OPEP Guidance

July 2012


12

To ensure compliance with
OPRC
,
OPEP’s

must be submitted by operator
s

for
approval to
DECC

at least 2 months prior to the start of activities

(
see

Section

15.1
)
.


4.1

Types of Installations R
equiring an
OPEP

4.1.1

Single Installation

All single installations must have an OPEP. This

may include a complex of bridge
linked instal
lations.


4.1.2

Groups of installations

G
roups of installations
may be included within one OPEP
provided all the actions
required
in respect of each individual installation are clearly identified and the
geographical location of the installations is within a reasonable distance so that the
potential environmental impact of a
pollution incident

from within the group
can be
treated as
comparable
.
In most cases groups of installations will be
physically

joined by
infrastructure

and

may include offshore installations, subsea tie backs and pipelines
associated with a host installation.

Where an
OPEP

covers more than one installation
operators must ensure the
document contains specific information relating to each installation thus ensuring that
personnel using the document can clearly identify response arrangements associated
with their installation.

Operators should be aware that
OPEP

r
equirements associated with groups of
installations will be
assess
ed on a case by case basis
to ensure

that individual aspects
associated with the developments, environmental sensitivities and response
arrangements can be taken into account. Operator
s
may
contact
DECC

to discuss
individual circumstances if required.



4.1.3

Pipelines

Pipelines
engaged in the transportation of
oil,
condensate
,

wet gas
, or gas
must
be
covered by
an
OPEP.


Pipeline operators (both in
-
field and trunk export)
may have

a separate pipeline plan or

a combined host installation and pipeline plan.



4.1.4

SubSea

Tieb
acks

All subsea tie backs must
be included within an
OPEP.

They

may

be

incorporated
within a host installation
OPEP

or have a
separate
OPEP.




4.1.5

3
rd

P
arty
S
ubsea
T
ie
backs

For subsea tiebacks where the operator of the subsea facility differs from that of the
host installation, the responsibilities in terms of oil
pollution incident

reporting and
response
must
be clearly defined a
nd
agreed between the operators and
DECC
.

Where the operator of the host installation takes responsibility

for reporting and/or
response
, the existing
OPEP

for the installation
must

include the tieback. W
here the
operator of the subsea facility takes responsibility, a new
OPEP

will
be developed

and
the host installation
OPEP

must be updated to include
these changes.


4.1.6

Exp
loration/appraisal/development W
ells

All exploration/appraisal/development drilling and production
operations conducted on
an installation
must be
cover
ed within
an approved
OPEP
.



DECC OPRC OPEP Guidance

July 2012


13

From f
ixed

production

i
nstallations
: p
rovided
the
operation
s
are

from a fixed
installation with an existing approved
OPEP

covering these activities
,

all
exploration/appraisal/development
operations

will be
covered w
ithin the existing
OPEP.



From m
obile
d
rilling
units
:

a
ll

e
xploration/appraisal/de
velopment
operations

carried
out

from a mobile

drilling unit

must be included within an OPEP.

Where the mobile
drilling unit is within the vicinity of a fixed production installation the activities can be
covered in an addendum to the existing fixed installation OPEP. Each addendum will
require separate approva
l, see Section
15.3.



Each new exploration/appraisal/development operation will require an assessment to
ensure that local environmental sensitivit
ies and contingency arrangements have been
addressed. The assessments must be included in the addendum
.


If an OPEP covers a number of wells, for example if there is a three
-
well drilling
programme, all the wells must be identified in the submission. If

only one of the wells is
identified in the OPEP, DECC will assume that there is an outstanding submission for
the other wells, even if the OPEP mentions a multiple
-
well drilling programme, and this
will inevitably delay the determination of the OPEP, and
could delay the determinations
of other related environmental submissions
.


It is not acceptable to submit an
addendum
to an obsolete exploration

/

appraisal

/

development drilling
OPEP.



Operators should not
assume

that an
addendum

to a plan will be reviewed and
approved within a shortened time period

(
see Section
15.3
).


4.1.7

Well Intervention, Well Workovers, Well Abandonment and
Decommissioning operations

Well intervention, well workovers, well abandonment and decommissioning
operations
require to be included within the scope of an OPEP

where there is a risk of oil pollution.
These activities may be incorporated into an existing
OPEP

and operators are
encouraged to include these activities when submitting an
OPEP

for initial
approval
.


4.1.8

N
atural
G
as
L
iquid

(NGL)
/Gas Storage import and export stations

All NGL/Gas Storage import and export stations require an
OPEP.


DECC OPRC OPEP Guidance

July 2012


14

5

Pollution I
ncident

Scenario and Hazard Identification


WHAT
INFORMATION DO
I
NEED PRIOR TO WRITIN
G AN
OPE
P
?

5.1

Intro
duction

To allow for an effective response o
perators must

prepare
an inventory of the oils

present on their installation to identify the potential for
oil
pollution incidents a
nd
allow
an assessment of the a
ssociated environmental hazards.

5.2

Pollution
incident

Scenario Identification

In order to manage and respond to oil
pollution

incidents operators must produce an
installation
specific

hydrocarbon

inventory
that
identif
ies

the various types and volumes
of
hydrocarbons

present on the
ir

installation

tog
ether with their dispersion
characteristics
.

H
ydrocarbon
s

must be categorised in accordance with

the

ITOPF
category groupi
ng
as
summari
s
ed

in Figure
5
.1.


Figure
5
.1 ITOPF category grouping for hydrocarbons

[9]


Key for oil types
:

1 = ITOPF category Group I SG

< 0.8 e.g. Kerosenes / Gasolines

2 = ITOPF categor
y Group II SG

0.8
-
0.85 e.g. light crude, gas oils

3 = ITOPF category Group III SG

0.85
-
0.95 e.g. medium crude

4 = ITOPF category Group IV S
G
> 0.95 or P
our
P
oint

>
30
degrees


Operators must, then, identify potential
worst case
scenarios which could give rise to
an oil pollution incident to sea from their
installations such as well
blowout or diesel
tank rupture

or from operations involving a third party, such as offloading of fluids via
tanker/ship.


This information will be used to determine the correct response strategy and
subsequent management of any oil pollution incidents.

O
p
erators must identify
potential
situations

which could give rise to a

pollution incident, including

worst
-
case
scenarios
.

A
n effective OPEP will allow operators to respond effectively

and efficiently

to all identified oil pollution incident scenarios
.


All

OPEPs associated with
existing installations and production wells,
exploration,
appraisal and development (production) drilling operations, or work
-
over and
intervention operations on hydrocarbon producing wells that are undertaken on the
UKCS must assess

and provide for an effective response to an identified worst
-
case
scenario where all containment barriers have failed resulting in a blow
-
out
.

The
response would normally
require the drilling of a relief well
.

The OPEP must in addition
consider
the worst
-
case scenario relating to the total loss of the installation’s
hydrocarbon inventory
.
Worst case scenarios must be accurately identified and
assessed using the guidelines below

(Section 5.
3
)
.



Operators of oil pipelines must have in place the capability to
detect
loss of inventory
from their pipelines.
Total loss of pipeline inventory is determined as the worst case
pipeline scenario.
Any pipeline OPEP must make reference to specific pipeline
DECC OPRC OPEP Guidance

July 2012


15

e
mergency procedures and provide details of the time required to shut down and the
potential quantities that may be released.
Detection limits for main trunk lines must be
provided within the justif
ication document
(see
Section
1
4
)
.


5.3

Worst Case Scenarios

The following information
must

be taken into consideration when preparing the OPEP
submission:




Well and reservoir information relevant to the scale of potential releases of
hydrocarbons, including information relating to the nature of the hydrocarbons and

the well flow characteristics; the potential daily release rate; and the total quantity of
hydrocarbons that could be released during the maximum time that it could take to
stop the release. If there are reservoir characteristics relevant to this informa
tion,
such as High Pressure and High Temperature (HP/HT) conditions, this information
must be included.





Identification of the worst
-
case scenario in relation to the potential release of
reservoir hydrocarbons. For all operations relating to exploration,

appraisal and
development wells (i.e.
normal production operations,
drilling, well intervention, and
well abandonment) the worst
-
case scenario will be the quantity of reservoir
hydrocarbons that could potentially be released if all containment barriers fa
iled, i.e.
a well blow
-
out with total loss of containment. The scenario should be directly
related to the particular circumstances of the installation, the proposed activities,
and the reservoir characteristics, and should be consistent with the informati
on
used by other operational departments, e.g. well engineering. For example, if the
operation involves the drilling of a dry gas well, and no oil or condensate is
expected; or there is insufficient reservoir pressure for a well to flow unaided; or if
the

flow rate is likely to reduce significantly during the period of any release, this
should be reflected in the OPEP as it is likely that will affect the pollution response
strategy and the assessment of any potential environmental impact. If the OPEP
cove
rs a number of wells, the highest flow rate well should be used to identify the
worst
-
case scenario, and this should be explained in the OPEP and related
environmental submissions as it may conflict with the information provided in
applications relating to

the other wells.




Identification of the worst
-
case scenario in relation to the potential release of the
installation

/ MODU / Vessel

hydrocarbon inventory, which will normally be the total
diesel fuel inventory, although other inventories such as drilling

fluid base oil may
be relevant.




Although it is not relevant for well operations, the worst
-
case assessment of pipeline
releases should be based on the total volume of liquid hydrocarbons present in the
isolated pipeline and, in the case of major trunk li
nes, the modelling should assess
three potential release locations, at the offshore installation; at the mid
-
point; and at
a location as close to the landfall location as can be accommodated by the model.



Although the OPEP must always address the worst
-
case scenarios, operators are
reminded that comparatively small releases of certain types of oil, or small releases in
DECC OPRC OPEP Guidance

July 2012


16

sensitive areas, or small releases in certain circumstances, have the potential to result

in a significant environmental impact and may therefore require a substantial response.

5.4

Well Flow Rates

W
ell flow
-
rate should be specific to the well
(s)

that is the subject of the OPEP or OPEP
Addendum
.
If the OPEP covers more than one well, details of ea
ch wells flow rates
should be included to allow the user to gain a quick understanding of potential release
rates in the event of a well incident. The well with the maximum flow rate should be
used for modelling purposes and to determine adequate response

recourses.


The flow rate should
be based on information relating to the particular
installation,
activity and
reservoir
, and
should be provided in cubic metres per day or hour and the
units clearly stated.

The flow rate should be consistent with information included in the
PON15 and any other
relevant
regulatory submissions, or
any
discrepancy should be
explained.

The selected flow rate should be used to calculate the
predicted total loss of
hydrocarbons du
ring the period covered by the modelling, and during the estimated
time taken to stop the release,
and the calculated volumes s
hould be clearly stated.

5.5

Modelling

When developing an OPEP oil pollution modelling must be used to determine the
impact of potent
ial oil pollution with results providing an indication as to the
trajectory

and

likely fate

(weathering and transport) of the oil.


Deterministic and stochastic modelling must be carried out based on the identified
installation specific worst
-
case
release

scenarios

to determine the fate of the released
liquid hydrocarbons
.

The output should be considered alongside relevant
environmental sensitivities, to inform the response strategy.


Stochastic models
should be used
to determine the areas that could be i
mpacted
using

data that is relevant to the hydrocarbon types and the estimated uncontrolled flow rate.
If the depth of the release beneath the sea surface could significantly affect the
dispersion and fate of the released hydrocarbons, this should be take
n into
consideration in the study if it is a feature of the selected model, as it is likely to be
relevant to the environmental impact assessment. However, the deepwater release
assessment cannot be relied upon for the purpose of developing a robust respo
nse
strategy that accommodates all release scenarios, so it would also be necessary to
separately model an equivalent surface release.


The m
odels must be run for a period of time that is sufficient to identify the potential
directions of travel and the ar
eas likely to be at risk. As a minimum, the models must
be run for a period of 10 days
under
worst
-
case
liquid
hydrocarbon release

conditions,
or until there are no released
hydrocarbons
remaining
on the sea surface (i.e. until
they
have evaporated,
dissi
pated or beached). If the minimum

10
-
day
modelling
period
does not clearly identify the potential areas at risk, then the
modelling
period must be
extended.


Trajectory modelling must use the same inputs as the stochastic modelling.

Trajectory

modelling must be carried out using a 30 knot onshore wind to determine the likely
scale and impact to the UK and 30 knot wind blowing towards the closest median line in
order to determine the scale and impact to Ireland, Norway and Continental European
DECC OPRC OPEP Guidance

July 2012


17

s
eas and coastlines. For stochastic modelling the most persistent hydrocarbon should
be used.


Conclusions of both the deterministic and stochastic modelling should include:



Likelihood of impacts on environmental sensitivities (such as bird populations,
con
servation areas or other users of the sea) and the scale of that impact
at
different times of the year;



T
he identification of the areas that could be impacted as a result of any release,
including potential UK beaching locations, and the waters and potenti
al beaching
locations of adjacent States, and the likely time
-
frames for hydrocarbons to
beach or cross a median line
;






If the oil will
not

beach, within what time scale is the oil likely to disperse
completely and how close to the shore will the oil becom
e

prior to dispersion;
and

Please note that
no counter pollution measures should be taken into consideration

when assessing the impact.


For oil installations
deterministic modelling should be carried out for both diesel and
oil and stochastic modelling should be carried out for oil.


For gas and condensate installations

deterministic modelling should be carried out
for diesel and gas/condensate and stochastic
modelling should be carried out for
diesel.


In all cases, the modelling must be undertaken using relevant weather, current and
temperature data obtained from scientifically
-
validated historic data sources, and the
origin of this information must be fully

referenced.


DECC has determined that currently
-
available models are capable of meeting the
above requirements, to enable operators to develop a competent response strategy
that adequately addresses all potential release scenarios.

5.6

Environmental Impact

As
sessment

Operators must carry out an assessment of the

potential

environmental impacts
associated with the
ir

identified
oil
pollution
scenarios

to ensure that

a

timely and
adequate oil pollution response

is developed
within th
e
OPEP.



The OPEP should
contain a

brief summary of the predicted environmental and socio
-
economic impacts of the worst
-
case release of liquid hydrocarbons, taking account of
the results of the modelling undertaken to identify the areas that could be impacted as a
result of any li
quid hydrocarbon release and sensitivity data relevant to those areas

(
see Section 5.6
)
.


Details of environmentally sensitive areas that could be impacted by a release should
be obtained from
appropriate contacts, such as
the relevant fisheries authoritie
s, e.g.
the MMO or Devolved Authority; the relevant inshore pollution authorities, e.g. the
Environment Agency or the Scottish Environment Protection Agency; and the relevant
Statutory Nature Conservation Agencies, e.g. the Joint Nature Conservation Commit
tee

DECC OPRC OPEP Guidance

July 2012


18

(JNCC)
, and Natural England or Scottish Natural Heritage

or
Countryside Council for
Wales
.


A

base line description of the surrounding environment highlighting sensitive
components

with seasonal variations

and
all
environmental
sensitivities

at risk
in UK
coastal waters

and
if threatened
those of
Ireland or Continental
Europe

should be
included in all OPEP submissions.

Where required, a

S
horeline Protection Plan must
be pr
epared and
submitted to DECC

in accordance with
the OPEP G
uidance
, and
the
relevant local authorities

should be contacted in addition to the bodies detailed above to
en
sure that
comprehensive
and up
-
to
-
date environmental information is included in the
plan.


5.6.1

Coastal and Marine Resour
ce Atlas

The Coastal and Marine Resource Atlas (CMRA)

[11]

is a publicly available on
-
line
resource contai
ning geographical information which may

be
us
ed when developing
an
OPEP

e.g. seabird vulnerability to surface oil
pollution
, sensitive fish areas, protected
areas, oil industry infrastructure, etc. The Atlas is a sub
-
topic within the interactive map
feature of MAGIC (Multi
-
Agency Geographic Inf
ormation for the Countryside),

[10]

(select 'Interactive Map' and then 'Coastal and Marine Resource Atlas' within Step 1).
Please refer to
http://www.magic.gov.uk/camra.html

for more information on the
background of the Atlas and data management. The website is managed by Natural
England on behalf of DEFRA, and the Atlas is being improved under the d
irection of a
steering group. Any queries should be directed to
support.magic@defra.gsi.gov.uk
.



5.6.2

Summary of
Pollution I
ncident

Scenario and
Environmental Impact

Assessment

Full
pollution incident

scenario and
environmental
assessment
information

may
provide
too much detail

in

the final
OPEP

document and
may
not
add value

during any
response and should

be summarised
in a
ccordance with the guidance con
tained in
Section 12.3
.
6.

Full details of the as
sessment must be included within the
OPEP

application in a separate Justification Document for approval
(See Section

13
)
.

5.7

Socio
-
economic Impacts

Any significant
potential
socio
-
economic impacts that could have a bearing on the
response strategy should be
summarised in the OPEP. For example, in certain areas
,

it may important to ensure that fishermen and
/or

fish farmers are regularly advised o
f

the location and direction of
movement of
a s
pill;

or it may be important to avoid using
dispersants in areas whe
re there would be a possibility of
dispersed oil
contaminating
harvested or farmed shellfish stocks; or it may be necessary to take specific measures
to prevent oil coming ashore in areas with a high amenity value. It is not necessary to
try to quantify t
he economic impact, but any significant potential impacts should be
identified and clearly linked to the response strategy.

5.8

Areas of Potential Impact Outwith UK Waters

Where the modelling indicates that a hydrocarbon release could impact areas outwith
UK
waters, the OPEP should provide details of the pollution control authorities in the
relevant State

or States
, and any
relevant
international response agreements, such as
the
NORBRIT

Agreement. The OPEP should also provide details of where the
operator wou
ld intend to obtain access to relevant information to assess the potential
DECC OPRC OPEP Guidance

July 2012


19

environmental and socio
-
economic impacts, including reference to any communication
with the relevant bodies.


DECC OPRC OPEP Guidance

July 2012


20

6

Pollution Incident

Assessment

During a pollution incident a
n
assessmen
t must be
carried out

to determine an effective
response strategy.

All efforts must be made to identify the volume and type of oil
discharged to help determine the dispersion characteristics
,

fate
and likely impact

of the
oil.

A
rrangements

must

be in place to monitor the movement, spreading and
emulsification of any oil
discharged

to allow an assessment of the potential threat to the
environment to be made.

An initial assessment may be performed by visual inspection
from the

installation or stan
dby
vessel;

however
,

this may have limitations if the
extent
of the pollution
is large or moving away from the installation. Therefore
,

aerial
surveillance and oil
pollution
modelli
ng may be required to allow the extent,

trajectory

and
fate of the oil to b
e
more accurately
observed and predicted.


Details of the
procedures and
mechanisms used by

operators
to assess any
oil
pollution
must be included within the O
PEP
.
The level of assessment required will be
determined in accordance with the circumstances and

severity of any pollution incident
when it occurs.


6.1

Volume and Tracking of
Oil Pollution


Efforts
must

always be made to quantify the maximum t
otal volume lost using
measured or

calculated

data

from
operational

or production losses. Where this is not
possible the Bonn Agreement
Oil Appearance
Codes
(BAOAC)
must be used to
estimate losses from a visual assessment and/or aerial surveillance of oil on the sea
surface. A maximum and minimum figure shall be provided
where B
A
OA
C

are utilised
in order to allow a suitable assessment of potential pollution
,

in accordance with
DECC

PON1 Guidance
[12]
.


Initially oil

pollution

will be tracked using visu
al assessment, where possible.
An early
estimation of the movement of oil on the surface can be calculated using manual
trajectory estimations.


During pollution events it is necessary to have procedures and mechanisms to estimate
the volume of oil
discharged to
sea and

its trajectory as detailed above. These sh
ould
be included within the OPEP
.


6.1.1

Aerial surveillance

The use of aerial surveillance

in the monitoring of oil
pollution
allows an accurate
picture to be formed and assists in the development of targeted response options.


Aerial surveillance will allow:



oil
pollution

to be tracked;



the size and nature of any slick to be determined;



an
estimation of the

volume

of oil

to be made;



the
trajectory

and

fate of the oil to be determined i.e. is the oil dissipating

or
emulsifying;



identification of any environmental se
nsitivities i
.
e
.

rafting seabirds or

other users
of the sea
.


DECC OPRC OPEP Guidance

July 2012


21

All operators holding an
OPEP

must have the capability to mobilise aerial surveillance
in accordance with the
Minimum Response Requirements

detailed in Table
7
.1
.
Thereafter flight frequency will be assessed during each incident

as part of the
response str
ategy
.


Methods used may include helicopters or dedicated aerial surveillance aircraft.
Operators should note that although an initial assessment can be made using
crew
change
helicopters, if available in the field at the time of the
oil pollution inciden
t
,
reliance on crew change helicopters for
pollution

assessment
thereafter
is not
acceptable. Effective aerial surveillance requires observers to be fully trained and
competent in techniques for detecting oil, both visually and through interpretation of a
range of remote sensing technologies.



As a minimum, the following should be available on surveillance aircraft:



Infrared Scanner imaging equipment;



Ultra Violet Scanner imaging equipment;



Suitable navigation equipment including Global Positioning Syste
m (GPS) to
ensure the accurate display of search areas and spray patterns and to control
the activities of other resources under its control during counter
-
pollution
operations;



Suitably trained and experienced aircrew and other trained staff to ensure an

adequate, continuous response capability.


Operators should be aware that
DECC
/
MARI
TIME

AND COAST
GUARD

AGENCY
(MCA)

may, at their discretion, undertake their own independent aerial surveillance
flights.


6.2

Oil M
odelling

During Oil Pollution Incidents

During actual oil pollution incidents operators must have oil pollution modelling
capabilities available as part of their response arrangements. Real time parameters will
be used to assist in predicting the
t
r
ajectory

and
fate of hydrocarbons and
areas of
the
environment at risk
to
help
determine a targeted response strategy.

DECC OPRC OPEP Guidance

July 2012


22

7

D
ispersant and Aerial Surveillance Requirements

7.1

Introduction

Once the oil
pollution incident

scenarios and environmental
sensitivities

have been
identified the next stage is to identify suitable response options.
In the event of an oil
pollution
incident operators
must have the capability

to respond to the
pollution
.
It is not
possible to produce a standard
O
PE
P

therefore

each plan must
be developed to reflect
operator, installation, incident and environmental specific criteria.


The following identifies
the
minimum

dispersant and aerial surveillance
response
requirements.

7.2

Minimum Response Requirements

7.2.1

Installations

outside any block w
holly or partly within 25 miles of the
coastline

Response arrangements are based on an expectation that they will be relevant to the
characteristics of the oil

pollution
, the prevailing

metocean

conditions, geographic
location and environmental sensitiviti
es.


W
here the nature of the produced hydrocarbons is already known it may be acceptable
to provide targeted response provisions based upon kno
wledge of the hydrocarbon
type
as detailed in the installation hydrocarbon inventory
.

If
, during categorisation
,

in
accordance with the ITOPF category grouping
as
summarised

in Figure
5
.1,
diesel
is
categorised
higher than
Group

1 please refer to Section
8
.3 for further information

on
response options
.



If the reservoir area is

unexplored a different level of resp
onse provision will be required
to deal with the potential for a
n

oil pollution incident

involving
unknown hydrocarbons
until such time as the characteristics of the hydrocarbons being produced can be
assessed.


Providing the
installations covered by the
OPEP

are located outside any block wholly or
partly within 25 miles of the coastline, t
he
hydrocarbon inventory

generated in Section
5
.2

will allow the operator to use
Table
7
.
1

-

Minimum response requirements for
oil
pollution incident
s from exploration
and production activities

to
determine the minimum
response times and levels required for both dispersant capability and aerial
surveillance
.



Note
:

response

time is counted from the time the incident occurred or was discovered
.


The
minimum standards
,

required for oil
pollution incident

response
for installations
out
with
any block wholly or partly within 25 miles of the coastline
,

detail
ed in
Table
7
.
1
should aid

in the
planning
of

response measures
. T
hey do

not dictate which strategy
must be used
during
a
ny

real
pollution event
.



Table
7
.
1

should be used in conjunction with
Table
7
.
2

-

Dispersant combat rate
requirements

which lists the dispersant combat rate recommended for responding to
oil
DECC OPRC OPEP Guidance

July 2012


23

pollution

ranging from 0 to >500

tonnes.

It
takes into account the increased response
times necessary to deploy equipment associated with larger
pollution incident
s.
However, when using the table, it should be noted that response levels are
cumulative
, for example during an oil
pollution incident

of

>500 tonnes the
requirements for
oil pollution incident
s of 100


500 tonnes plus the requirements for
oil
pollution incident
s of 25


100 tonnes and the requirements for
oil pollution incident
s of
0
-
25 tonnes would
all

be required during the response and

not just “Monitor and
dispersant within 18 hours as required for
oil pollution incident
s >500

tonnes.



If the dispersibility of hydrocarbons cannot be demonstrated other strategies must be
identified to ensure an effective response. This may include
measures for containment
and recovery.


DECC OPRC OPEP Guidance

July 2012


24

Table
7
.1
Guidance on minimum standards required for oil pollution incident response
from installations out with
any block wholly or partly within 25 miles of the coastline
.
This guidance has been developed in consultation with DECC, MCA,
MS
-
ML
, JNCC, oil
pollution incident response specialists and industry and should be used in conjunction
with Table
7
.
2
-

Dispersant combat rate requirements
.

The Block Specific Vulnerability

refers to seabird vulnerability with Category 1 being

very

high vulnerability and
Category 2,

3, and 4 being high, moderate and low vulnerability respectively.


Note
: time is counted from the time the incident occurred or was discovered.



Table
7
.2
Dispersant combat rate requirements for oil pollution incidents
ranging from 0 to >500

tonnes.








Response Times

Oil Quantity
(Estimate)

Oil Type

Aerial
Surveillance

Capability

Block Specific Vulnerability


(JNCC 1999) (Ref
4)



1

All other categories

0 to 25 tonnes

1

Within 4 hours

Monitor and

natural dispersion


(dispersant requirement
assessed on case by
case

basis)

Monitor and natural
dispersion
-

No
dispersant
requirement


2; 3 and 4

Monitor and dispersant
within 1 hour


Monitor and
dispersant available
but no “within 1 hour
requirement”

25 to 100 tonnes

1

Monitor and

natural dispersion


(dispersant
requirement
assessed on case by
case basis)

Monitor and natural
dispersion
-

No
dispersant
requirement


2, 3 and 4

Monitor and dispersant
within 2 hours

Monitor and
dispersant available
but no “within 2 hour
requirement”

100 to 500 tonnes

1

Monitor
and

natural dispersion


(dispersant requirement
assessed on case by
case basis)

Monitor and natural
dispersion
-

No
dispersant
requirement


2; 3 and 4

Monitor and dispersant
within 6 hours

Monitor and
dispersant within 6
hours

>500 tonnes

1

Monitor and

natural dispersion


(dispersant requirement
assessed on case by
case basis)

Monitor and natural
dispersion
-

No
dispersant
requirement




2; 3 and 4

Monitor and dispersant
within 18 hours

Monitor and
dispersant within 18
hours

Estimated oil pollution quantity

Average combat rate

0 to 100 tonnes

10 tonnes per hour

100 to 500 tonnes

50 tonnes per hour

>500 tonnes

More than 50
tonnes per hour

DECC OPRC OPEP Guidance

July 2012


25

7.2.2

Installations

in any block wholly or partly within 25 miles of the
coastline

In addition to the oil
pollution incident

response requirements det
ailed in Section
7
.2.1

and shown on
Table
7
.1
, the fo
llowing additional responses may

be
required for

installations

operating in any block wholly or partly within 25 miles of the coastline

dependent on the hydrocarbon inventory and
oil pollution incident

scenarios identified
in Section
5
.2
.


1.

The presence near the facility at all times of a ves
sel:

a.

with the
capability of spraying dispersant within 30 minutes of an oil
pollution
incident

notification
;

b.

Has a stock of dispersant sufficient to deal with a
n

oil pollution incident

of 25

tonnes, and if required
, have the capability (equipment and capa
city) of
recovering
any
oil likely to be lost from the insta
llation under a Tier 1 scenario
(
See Section
8
.2
)
;

2.

In the event of a Tier 2 incident, Tier 2 resources must

be
available on scene within
half the time taken for the oil to reach shore in 30 knot
wind conditions
.
;

3.

Details of resources to deal with a Tier 3 incident (i
.
e
.

an oil
pollution incident

that
cannot be controlled by Tier 1 or 2 resources), including sources transport and
delivery system
;

4.

A
Sh
oreline Protection Strategy Plan
,

(
see

Section
8
.
3.
7
)
.


DECC OPRC OPEP Guidance

July 2012


26

8

R
esponse

Strategy and Implementation


WHAT
MUST BE CONTAINED IN

A

RESPONSE STRATEGY

AND HOW WILL THIS
BE IMPLEMENTED
?

8.1

Introduction

A range of factors will affect the response to an oil
pollution incident
. These include
, but
may not be limited to,

the quantity of oil discharged to sea
, the type of oil, the location
of the
pollution incident
, the water depth, the distance to shore, the prevailing weather
and tides, the time of day or year, the environmental sensitivity of the area, the
organisationa
l structure of the operator, the availability and adequacy of equipment and
the level of training of personnel. The oil
pollution incident

response
strategy selected
depends upon knowledge of
the oil pollution incident itself,
the quantity and
type

of the
oil released
,
the
transport,
tra
jectory
and fate of the
released
oil and the presence of
sensitive receptors.
Each

response

is
,

therefore
,

unique and
varies
with the nature
and
circumstances
of the incident.


The aim of a response strategy is to minimise
the severity of any impact on
environmental sensitivities and
to
hasten
the recovery
process and return to normality
.

8.2

Response Tiers

Oil
pollution incident
s must be classified according to the response levels they are most
likely to require and

NOT

the
volume

of
oil pollution,

unless this is supported by a
location specific risk assessment. For example, if a
pollution incident

requires the use
of resources from a regional centre, this would be used to classify the necessary
response level, irrespective o
f its size.

If in doubt, a default principle of over
-
classification is more desirable than under
-
classification and escalation.


For consistency with the
NCP
, the following Tier definitions apply:



Tier 1

Local (within the capability of the operator

on site
)
;



Tier 2

Regional (beyond the in
-
house capability of the operator)
;



Tier 3

National (requiring national resources)
.


This leads to the concept of a ‘Tiered Response’ to oil
pollution incident
s. Operators
should seek to develop their response capability in

a way that allows any response to
be escalated from Tier to Tier in response to an escalating

(or diminishing) situation.


The
OPEP

should identify response arrangements according to Tier and the company’s
credible worst
-
case scenarios.


Tier 1
: A Tier 1 response is the lowest response level and requires resources to be
available
locally.

Depending on
the characteristics of the oil
this may or may not include
the use of dispersants. By definition these resources must be at or
near the incident
s
ite. It is expected that these resources will be deployed as quickly as operational
circumstances allow.


Tier 2
: For larger
pollution incident
s, local resources may be insufficient to
deliver

a
proper response. In these cases it may be that resources from

a regional centre will be
DECC OPRC OPEP Guidance

July 2012


27

required. A key component of UK offshore Tier 2 response is that operators are
expected to have this capability mobilised and applied within 2 to 6 hours of
an oil
pollution incident

as detailed within
Table
7
.
1
.


Tier 3
: For ver
y large
pollution incident
s, resources supplied from national and
international sources may be required. A key component of UK offshore Tier 3
response is that operators are expected to have this capability mobilised and applie
d
within
6 to

18 hours of
an
oil pollution incident

as detailed within
Table
7
.
1
.

8.3

Response S
trategies

Response strategies must be developed and included within the
OPEP

according to the
Tiered level of response
(
S
ee Section
8
.2)

taking into account the installation
hydrocarbon invento
ry, worst case
oil pollution incident

scenarios and the potential
impacts on environmental sensitivities.

This may include a response strategy flow
diagram.



Details of the response strategy to conduct an effective and early intervention to protect
the e
nvironment in the event of any liquid hydrocarbon release, including robust and
location
-
specific arrangements based on the outcome of the modelling and the
predicted environmental and socio
-
economic impacts. The information provided should
include detail
s of the pollution prevention and response equipment that the operator
maintains or intends to access for deployment in the event of a release, or a potential
release, and the time that it would take to deploy that equipment


The response strategy will include source control measures to prevent further release
or escalation of release.
Th
is may include
measures that would be taken to stop the
worst
-
case release of liquid hydrocarbons from the reservoir, and an estimate of the
maximum duration of the release. The latter could be a function of natural cessation
related to the nature of the hydrocarbons and well flow characteristics, but will normally
be the time taken to implement appropriate measures to stop or control the rele
ase
(e.g. use of a capping or containment device), and the time taken to drill a relief well.


Where appropriate, details of plans to implement the capping of a well and the drilling
of a relief well to totally isolate the original well

should be included
,

to demonstrate that
there is adequate planning or provision in place for these eventualities



As a rule the
preferred response option
can be described as follows:



Source control should be prioritised where possible to stop any release, prevent
further re
lease or escalation, or to contain released oil.



For incidents such as well blow out where there is a continuous release in to the
marine environment capping and containment devises and relief wells may be
the preferred response option.



If

oil enters th
e marine environment and
there is the option not to intervene in a
n

oil pollution incident

either because it is small and/or a great distance offshore
and likely to dissipate naturally before causing any significant impact on the
environment, then the pref
erred course of action is to monitor
and

review

the
situation
.



If, on the other hand the oil will persist or weather into a persistent residue and
may impact
o
n the coast
line

or on
an environmentally sensitive resource, then
DECC OPRC OPEP Guidance

July 2012


28

intervention should be considered. The most likely intervention is the use of
chemical dispersants to disperse the oil. Containment and recovery of oil may
be necessary if the oil will not disperse.


Although, t
he initial response to any release should on
ly be based on the available
response resources

offshore
. Any that are not immediately available to the operator,
such as additional dispersant spraying capacity, spill containment and recovery
equipment, well capping and containment devices or MoDUs and
equipment that may
be required to drill a relief well,
but can be accessed

if required, should be clearly
identified and a timescale provided for provision of the relevant resources.


8.3.1

Oil

Quantity
Estimation

Although oil
pollution incident
s must be
classified according to the

response levels they
are most likely to require it is
still
important to estimate the
quantity

of oil discharged to
sea
.

Where possible
operational or
production information should be used to
measure/calculate the
quantity

of oil
discharged.


Where this is not possible the
BAOAC

must be used in conjunction with the visual appearance of any

oil
on the sea

to
estimate the

quantity

of oil discharged to sea

[12]
.


8.3.2

Survey and
M
onitor

If

oil
pollution is

not an immediate threat to environmental sensitiv
ities
and surveillance
and modelling predicts that the oil will disperse prior to reaching the coast or any
environmental s
ensitivities
,
the most appropriate response method may be to allow it to
disperse naturally.


If the

oil is dispersing

naturally then it should continue to be
surveyed and
monitored to
confirm the
oil

is diminishing
, to track its course

and
ensure any changes to the nature
of the oil
do not alter its likely impact.


8.3.3

Chemical
D
ispersion

Chemical dispersant use is generally inappropriate in shallow sheltered waters
, in water
depths of less than 20 metres and in waters extending up to
1.15 mil
es (equivalent to 1
nautical mile)
beyond the 20 metre contour
,
or on refined
oil
products such as diesel,
gasoline or kerosene which should disperse naturally prior to reaching the coast or any
sensitive environments. The use of chemical dispersants will
,

therefore
,

be dependent
upon several factors including the
quantity of oil
, oil type
,
sea temperature,
time of year,
prevailing weather and environmental sensitivities.


The objective for any oil
pollution incident

response is to take the most appropriate

action to minimise the impact on the environment. In determining whether the use of a
chemical dispersant is an appropriate response strategy operators must make a
judgement between the environmental impact caused by the use of chemical
dispersants and th
e likely consequences of allowing any oil to disperse naturally.
Several sources can be accessed to aid in the decision process for example
Marine
Management Organisation
(
MMO)

Approval and use of Dispersants in UK

[13]
.


Operators must satisfy themselves that the reservoir hydrocarbons are likely to be
amenable to dispersant treatment, if th
e latter
is identified as a component of the
response
strategy. Where prior testing of dispersant efficacy is possible, it should be
undertaken in accordance with the MMO guidance.

DECC OPRC OPEP Guidance

July 2012


29

If dispersant
treatment
is identified as a
potential
component of the

initial

response
, the
OPEP should confirm the type and qua
ntity of dispersant held onboard the stand
-
by
vessel. If the type of dispersant is critical
,
because of the nature of the reservoir
hydrocarbons, this
should be clearly stated and available sources identified in case the
stocks need to be replenished

or
t
he standby vessel
has to be
relocated
f
or

any reason
.
If the stand
-
by vessel is
replaced,
provision must be made to maintain the dispersant
response capability detailed in the OPEP.

Just because d
ispersant
is available

does not mean that it must be used


Dispersant Product Approval


Only products that have been approved for use in the United Kingdom may be
deployed for the treatment of oil. Further information on the approval process can be
obtained from the
MMO

web site UK Oil Spill Treatment Products
Scheme

[14]

and the
MMO

booklet entitled “The approval and use of oi
l dispersants in the UK”
[13]
.
Approved dispersant products should only be used in accordance with the conditions of
that approval.


Dispersant
E
fficiency

Operators are expected to assure themselves that the dispersants they
use remain
effective against the potential products w
hich
might

be
discharg
ed
from their
installation,
taking into account possible alterations in
oil