SHELL OFFSHORE INC.

3601 C Street, Suite 1000

Anchorage, AK 99503

DRILLING ICE MANAGEMENT PLAN

Chukchi Sea, Alaska

Submitted to:

U. S. Department of the Interior

Bureau of Safety and Environmental Enforcement

Alaska Outer Continental Shelf Region

Submitted by:

Shell Gulf of Mexico Inc.
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Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 2 July, 2014

DRILLING ICE MANAGEMENT PLAN

Approval: Approved for the Alaska Asset

Effective This document is effective per the latest approval date above. 

Expires In force until revised and/or superseded.

Custodian Alaska Marine Manager

Author Ice Management Lead (July, 2014 Revision)

Reviewers Principal Arctic Marine Facilities Advisor

VP Alaska BOM

VP Arctic HSSE

VP Alaska Operations

Alaska Maritime Assurance Manager

Alaska Wells Operations Manager

Arctic Execution Manager

Offshore Regulatory Team Lead

Shell Exploration & Production Company Approved Date

VP Wells Arctic & Industry Regulatory Affairs Signature on file 7/9/2014
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Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 3 July, 2014

Topic Define the method and system to ensure the safe departure of the drilling

unit from the well site due to incursion of hazardous sea ice.

Purpose/Scope The purpose of this Drilling Ice Management Plan is to provide a

consistent, safe method for full compliance with the Alaska Venture

operating / permitting requirements with regard to the Critical Operation 

Curtailment Plan which encompasses the Drilling Ice Management Plan. 

Applies to This document applies to all Shell employees and contractors conducting 

operations on behalf of the Shell Alaska Venture.

Primary

Responsibility

Alaska Venture Maritime & Logistics supervision shall be responsible for

assuring that this plan is provided and that operators are instructed to use

this procedure prior to all marine drilling operations in Arctic waters

where sea ice incursion is expected.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 4 July, 2014

Table of Contents

I. INTRODUCTION.............................................................................................................5

A. Scope ..................................................................................................................5

B. Drilling Ice Management Plan Objective...............................................................6

C. Drilling Ice Management Principles ......................................................................6

II. DEFINITIONS..................................................................................................................6

A. Roles and Responsibilities ...................................................................................6

B. Definitions and Abbreviations...............................................................................7

III. VESSELS COVERED BY THE DRILLING ICE MANAGEMENT PLAN .........................10

A. Drilling Units.......................................................................................................11

B. Ice Management Vessels...................................................................................12

1. Primary Ice Management Vessels ..........................................................12

2. Secondary Ice Management Vessels / Anchor Handlers ........................13

IV. SHELL ICE AND WEATHER ADVISORY CENTER ......................................................13

A. SIWAC ICE DATA INPUTS................................................................................14

B. Data Transmission.............................................................................................14

V. ICE ALERT LEVELS AND PROCEDURES...................................................................16

A. Ice Alert Levels ..................................................................................................16

B. Ice Alert Roles and Responsibilities ...................................................................16

VI. ICE MANAGEMENT PHILOSOPHY..............................................................................19

A. Proper Equipment..............................................................................................20

B. Skilled People ....................................................................................................20

C. Appropriate Information......................................................................................20

D. Work Process ....................................................................................................21

VII. WELL SUSPENSION PROCEDURES ..........................................................................21

A. Well Suspension Options ...................................................................................21

VIII. MOORING SYSTEM RECOVERY / DISCONNECTION................................................23

A. Conditions Present to Initiate Mooring System Disconnection or Recovery........23

B. Disconnection / Recovery Options .....................................................................23

C. Mooring System Release / Recovery .................................................................23

IX. MOVING ONTO OR RETURNING TO THE DRILLSITE ...............................................23

X. TRAINING.....................................................................................................................24

XI. ATTACHMENTS ...........................................................................................................25

Attachment 1 – Extract from Critical Operations Curtailment Plan .................................25

Attachment 2 – Vessel Description................................................................................26

Attachment 3 – Shell Ice and Weather Advisory Center ................................................52

Attachment 4 – Ice Alert Logs........................................................................................53
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 5 July, 2014

I. INTRODUCTION

A. Scope

A Critical Operations Curtailment Plan (COCP) is in place for the Shell Gulf of Mexico Inc. 

(Shell) Chukchi Sea Exploration Drilling Program. As part of the COCP, this Drilling Ice 

Management Plan (DIMP) has been developed. The description of notification of curtailment (an 

excerpt from the COCP) is presented in Attachment 1.

Drilling operations in the Chukchi Sea will be conducted using two drilling units operating 

simultaneously. The drilling units are the “Noble Discoverer” and the “Polar Pioneer”. Both 

drilling units will operate according to this Drilling Ice Management Plan

The DIMP addresses the following activities:

 Vessels 

 Shell Ice and Weather Advisory Center (SIWAC), located in Anchorage

 Ice Alerts and Procedures

 Ice Management Philosophy

 Well Suspension Contingencies

 Mooring System Recovery and Release

 Moving onto or returning to the Drill Site

 Training

The DIMP:

 Defines Roles and Responsibilities 

 Establishes Alert Levels

 Establishes Responses to Alert Levels

The DIMP facilitates appropriate decision-making and responses to the threat of hazardous ice 

and procedures set forth in the DIMP to prevent damage or harm to personnel, assets, or the 

environment.

Nothing in this document takes away the authority and accountability of the Master(s) of the

vessels for the safety of their personnel and vessels, and for protection of the environment.

This plan is not a substitute for good judgment.

Guidance Note: This document is not intended to contain detailed procedures. Detailed 

procedures are contained within the vessel-specific operating manuals and the Shell Ice

Management Guidance and Procedures manual.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 6 July, 2014

B. Drilling Ice Management Plan Objective

 The objectives of the DIMP are to detect and monitor sea ice conditions, identify 

hazardous ice and determine manageability as per the DIMP and Alert System in 

order to ensure risk to personnel, drilling units, vessels or wells is reduced to ALARP.

 The Ice Alert System is central to the function of the DIMP. It is based on five

progressive alert levels. Each level defines operational status, roles, responsibilities 

and actions required.

C. Drilling Ice Management Principles

 Early detection of ice features

 Assessment of the ice regime

 Identification of Hazardous Ice

 Assessment of Ice Management Vessel (IMV) capabilities to manage ice

 Calculation and monitoring of Hazardous Ice arrival at drill site, Hazard Time (HT)

 Continuous assessment of time required to secure the well, Secure Time (ST)

 Continuous assessment of time required to move rig off location, Move Time (MT)

 Alert Level assignment which triggers the appropriate responses

 Development of ice management strategy

 Monitoring effectiveness of strategy

 Predefined roles and responsibilities

II. DEFINITIONS

A. Roles and Responsibilities

Responsibilities have been defined for key on-site personnel in Section V. In addition to the 

defined personnel the following onshore positions have a role to play in the DIMP.

Wells Operations Manager

Shell’s Wells Operations Manager is the senior Shell shore-based manager responsible 

for all Shell well operations offshore Alaska.

Wells Operations Team Leads

The Wells Operations Team Leads are responsible for Shell well operations at a specific 

well site. There is a Wells Operations Team Lead ashore for each drilling location who 

will update the OEMT on Ice Alert Status or changes to the Ice Alert Level. 
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 7 July, 2014

Ice Management Lead Anchorage

The Ice Management Lead heads the ice management team and works with the offshore 

Ice Advisors (IAs) stationed on vessels to develop daily strategies and designate areas or 

ice features which are of concern. The Ice Management Lead liaises with the Shell Wells 

Operations Team Lead, SIWAC and the OEMT. 

Shell Ice and Weather Advisory Center (SIWAC)

Based in Anchorage Alaska SIWAC develops ice and weather forecasts and analysis for

Shell Management and the marine fleet. A full description is available in section IV.

SIMOPS Coordinators

The SIMOPS Coordinators working under the direction of the OEMT, will assist in coordinating 

the cascading activities of the entire fleet from the consequences of having to relocate a drilling 

unit(s) per the DIMP.

Operations Execution Management Team (OEMT)

The OEMT, comprised of leadership from each business function and representation 

from support functions, implements the control and recovery of the 7-day operational 

Integrated Activity Plan (IAP) in accordance with the Integrated Operations Management 

Procedures (IOMP). The scope of the IOMP is to support field operations by maintaining 

up-to-date information, providing resources as needed, coordinating activities, and to 

bring decision-makers together to coordinate exploration and support activities.

B. Definitions and Abbreviations

AHTS anchor handling tug supply

Aiviq MV Aiviq – Secondary IMV and anchor handling vessel

APD Applications for Permit to Drill

AT Alert Time - The result of (HT) – (T-Time) which translates to Alert Level

API American Petroleum Institute

bbl barrel(s)

BHA Bottom Hole Assembly

BOP Blowout preventer

BSEE Bureau of Safety and Environmental Enforcement

CFR Code of Federal Regulations

CIS Canadian Ice Services

cm centimeter(s)

COCP Critical Operations Curtailment Plan

Dia. diameter

DNV Det Norske Veritas
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 8 July, 2014

DP Dynamic Positioning

ea each

Fennica M/V Fennica – Primary IMV

ft foot/feet

FTP file transfer protocol

FY First-year ice. Sea ice of not more than one winter’s growth, developing from 

young ice; 12 inches (in.) (30 centimeters [cm]) or greater. It may be subdivided 

into thin FY 30-70 cm – sometimes referred to as white ice, medium FY 70-120

cm and thick FY >120 cm up to 2 m.

gals. gallons

GFS Global Forecast System

GIS Geographic Information System

Hazardous Ice Ice, which due to its size, stage of development, concentration, set and drift is 

considered to be a threat to the safety of personnel, the drilling unit and well 

operations. Close proximity of an ice feature regardless of its set and drift may

determine it to be hazardous ice.

Guidance Note: Sea state as well as visibility may influence what is categorized as 

hazardous ice.

HOS Hang-off Sub

hp horsepower

HT Hazard Time. The estimated time it will take for hazardous ice to reach the drill 

site.

Hz hertz

IA Ice Advisor

IAP Integrated Activity Plan

IOC Integrated Operations Center

IOMP Integrated Operations Management Procedures

IMO International Maritime Organization

DIMP Drilling Ice Management Plan

IMV Ice management vessel. Any ice class vessel tasked with ice management duties 

in support of the drilling unit. This includes the primary ice management vessel 

(IMV) and the ice class Anchor Handling Tug Supply (AHTS)

in. Inch(es)

kg kilogram(s)

kW kilowatt(s)

lb pound(s)
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 9 July, 2014

LMRP Lower Marine Riser Package

m meter(s)

m

2

square meter(s)

m

3

cubic meter(s)

MHz megahertz

MODU Mobile Offshore Drilling Unit. MODU’s are facilities designed or modified to 

engage in drilling and exploration activities. The term MODU includes drilling 

vessels, semisubmersibles, submersibles, jack-ups, and similar facilities that can 

be moved without substantial effort. These facilities may or may not have selfpropulsion equipment on board and may require dynamic positioning equipment 

or mooring systems to maintain their position.

mt metric tons

MT Move-off Time. The time required to clear decks on the anchor handler recover or 

release moorings conventionally and move off the drill site in an orderly fashion.

M/V Motor Vessel

MY Multi-year ice. Old Ice (OI) up to 3 m or more thick which has survived at least 

two summers’ melt. Hummocks are smoother than on SY and the ice is almost 

salt-free. Where bare, this ice is usually blue in color. The melt pattern consists of 

large interconnecting, irregular puddles on the surface in summer and a welldeveloped drainage system.

NOAA National Oceanic and Atmospheric Administration

Noble Discoverer Turret-moored drilling vessel (MODU)

Nordica M/V Nordica – Primary IMV

OCS Outer Continental Shelf

OEMT Operations Execution Management Team

OI Old ice. Sea ice which has survived at least one summer’s melt. Topographic 

features generally are smoother than FY. It may be subdivided into Second-year 

(SY) ice and Multi-Year (MY) ice.

OIM Offshore Installation Manager

OSR Oil Spill Response

OSV Offshore Supply Vessel

PIC person in charge

Polar Pioneer Column stabilized semi-submersible drilling unit (MODU).

psi pounds per square inch

RAR rig anchor release

RP Recommended Practice
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 10 July, 2014

RPM revolutions per minute

SAR Synthetic Aperture Radar

Shell Shell Gulf of Mexico Inc.

SIMOPS Simultaneous Operations

SIWAC Shell Ice and Weather Advisory Center 

Support Vessels Includes all vessels defined in this plan (IMV/OSR/AHTS/OSV).

SWL Safe Working Load

SY Second-year ice. OI which has survived only one summer’s melt. Thicker than FY

with thickness up to 2.5 m, it stands higher out of the water. Ridged features as a 

result of melting during the preceding summer attain a smooth rounded shape. In 

contrast to MY ice, summer melting produces a regular pattern of numerous small

puddles. Bare patches and puddles are usually greenish-blue.

ST Secure Time. The time required to secure the well, disconnect the LMRP from the 

BOP, recover and secure the riser.

TD Total depth

T-Time Total Time. The sum of ST + MT

Tor Viking II M/V Tor Viking II – Secondary IMV and anchor handling vessel

UHF ultra high frequency

U.S. United States

USCG United States Coast Guard

VMT Vessel Management Team. This team is headed by the drilling contractor’s 

Master / OIM and includes the drilling contractor’s Rig Manager / OIM, and the 

Chief Engineer/Barge Captain and Shell’s Drilling Supervisor and IA

Wx weather

III. VESSELS COVERED BY THE DRILLING ICE MANAGEMENT PLAN

 Drilling Unit – “Noble Discoverer”

 Drilling Unit – “Polar Pioneer”

 Primary Ice Management Vessel (IMV) – “M/V Fennica”

 Primary Ice Management Vessel (IMV) – “M/V Nordica”

 Secondary Ice Management Vessel (IMV) and Anchor Handler – “M/V Tor Viking II”

 Secondary Ice Management Vessel (IMV) and Anchor Handler – “M/V Aiviq”

Guidance Note: The term “drilling unit” is used throughout this document and refers to both the 

“Noble Discoverer” a self propelled drilling vessel and the “Polar Pioneer” a non self-propelled 

semi-submersible. Both units are defined as MODU’s. The final authority with regard to safety 

onboard a drilling vessel is the Master. The final authority for safety onboard a non selfpropelled semi-submersible is the OIM 
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 11 July, 2014

A. Drilling Units

All planned exploration drilling in the identified lease blocks will be conducted with the Noble

Discoverer and the Polar Pioneer. 

The Noble Discoverer is a turret moored self-propelled drillship. Station keeping is 

accomplished using a turret-moored, 8-point anchor system. The underwater fairleads prevent ice 

fouling of the anchor lines. Turret mooring allows orientation of the vessel’s bow into the 

prevailing metocean conditions to present minimum hull exposure to drifting ice. The vessel is 

rotated around the turret by hydraulic jacks. Rotation can be augmented by the use of the fitted 

bow and stern thrusters. Ice-strengthened sponsons have been retrofitted to the ship’s hull.

The Noble Discoverer is classed by Det Norske Veritas (DNV) as a Mobile Offshore Drilling 

Unit (MODU) for worldwide service. It is a “1A1 Ship-Shaped Drilling Unit l” and is capable of 

performing drilling operations offshore Alaska. The Noble Discoverer has been issued with a 

DNV Appendix to Class stating:

“The structural strength and material quality of the ‘Ice Belt’ formed by the sponsons below the 

8,950 mm A/B level, have been reviewed against the requirements for the DNV ICE-05 

Additional Class Notation and found to meet those requirements (as contained in DNV Rules for 

Classification of Ships, Pt 5 Ch 1, July 2006) for a design temperature of -15 degrees C.”

The Polar Pioneer is classed by Det Norske Veritas (DNV) as a Mobile Offshore Drilling Unit 

(MODU) for worldwide service. It is a non-self-propelled, “SPM thruster assisted” (TA) 

semisubmersible offshore drilling unit of twin-hull configuration. The rig is a “+ A1 Column 

Stabilized Unit” and is capable of performing drilling operations offshore Alaska. 

Positioning is accomplished with a combination of an eight-point all chain catenary mooring 

system and dynamic positioning system. 

Polar Pioneer was built in 1985, with unlimited operation area, in accordance with the 

“Norwegian Maritime Directorate” and to “Det Norske Veritas regulations,” current at that time. 

While operating in Norwegian waters, the installation, with its inventory, equipment, crew and 

machinery was required to comply with current rules and regulations for operation on the 

Continental Shelf of Norway. 

The drilling units will undergo inspections by BSEE and Det Norske Veritas (DNV) for 

certification before entering the theater. The DNV certificates will be forwarded to BOEM.

The drilling units will comply with all of the regulations of DNV, the International Maritime 

Organization (IMO), and the U.S. Coast Guard (USCG). All exploration drilling operations will 

be conducted under the provisions of 30 CFR Part 250 Subpart D, and other applicable 

regulations and notices including those regarding the avoidance of potential drilling hazards, 

safety and pollution control. 

Procedures for monitoring and reacting to ice in the prospect areas are provided in the Critical 

Operations and Curtailment Plan (COCP) and the Drilling Ice Management Plan (DIMP)
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 12 July, 2014

Drillship Principal Dimensions

Dimensions “Noble Discoverer”

Length Overall 514 ft 156.7 m

Transit Draft 27 ft 8.2 m

Drilling Draft 25.12 ft 7.67 m

Breadth 85 ft 26 m

Drill Rig Principal Dimensions

Dimensions “Polar Pioneer”

Length Overall 400 ft 122 m

Breadth over all 292 ft 89 m

Transit Draft 30 ft 9.15 m

Drilling Draft 75.44 ft 23 m

Survival Draft 62.32 ft 19 m

B. Ice Management Vessels

Ice management support to the drilling units will be provided by the Fennica, Nordica, Tor

Viking II and Aiviq. The drill units will be supported by these IMVs from the beginning of the

campaign until the vessel departs the area. A description of these vessels is provided in

Attachment 2.

Ice Management Vessel Principal Dimensions

Dimensions Fennica & Nordica

DNV Icebreaker 

Polar-10

Tor Viking II

DNV Icebreaker 

Ice-10

Aiviq

ABS A-3 

Icebreaker

 Length Overall 380 ft (116 m) 275 ft (83.7 m) 361 ft (109.9 m)

 Draft 27 ft (8.4 m) 20 ft (6.0 m) Ice Max 25 ft (7.62 m)

 Breadth 85 ft (26 m) 59 ft (18.0 m) 80 ft (24.38 m)

 Bollard Pull 230 tonnes 200 tonnes 200 tonnes

1. Primary Ice Management Vessels

The Fennica and the Nordica are designated as the primary IMVs. Both vessels are classed by 

DNV as +1A1 Tug Supply Vessel Icebreaker Polar-10. Designed for ice management, 

maintenance and service of offshore oil wells, the 380-ft (116-m) Fennica and Nordica are

multi-purpose vessels specialized in marine construction and icebreaking. The Fennica and

Nordica are equipped with diesel-electric propulsion systems and their innovative combination 

of capabilities, based on extensive design and engineering work, facilitates use of these systems 

in arctic conditions.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 13 July, 2014

2. Secondary Ice Management Vessels / Anchor Handlers

The Aiviq is designated as a secondary IMV and anchor handler. The Aiviq is classed by ABS as 

A1, A3 (Icebreaker). Designed for ice management, anchor handling, and maintenance and 

service of offshore oil wells, the 361-ft (109.9-m) Aiviq is a multi-purpose vessel specialized in 

anchor handling and icebreaking.

The Tor Viking II is designated as a secondary IMV and anchor handler. The Tor Viking II is 

classed by DNV as +1A1 Supply Tug Icebreaker Ice-10. Designed for ice management, anchor 

handling, and maintenance and service of offshore oil wells, the 275-ft (83.7-m) Tor Viking II is 

a multipurpose vessel specialized in anchor handling and icebreaking.

Guidance Note: Ice Management Vessels supporting the drilling units may be deployed to assist 

other vessels or assigned to assist other Shell drilling units as operations and ice conditions 

dictate. Diverting ice management resources away from the drilling units may require a 

curtailment of activities. The decision to curtail activities as a result of diverting ice management 

resources away from the drilling vessel shall be made jointly by the Shell Drilling Supervisor 

and the Drilling Vessel Master/OIM. The onshore Shell Wells Operations Team Leader (in 

consultation with the drilling contractor’s Rig Manager) will endorse the plan or set priorities if 

agreement cannot be reached at the field level.

IV. SHELL ICE AND WEATHER ADVISORY CENTER

SIWAC is an integrated forecasting service staffed 24/7 by industry-leading specialists under 

Shell contract in Anchorage, Alaska. SIWAC’s primary function is to provide present and 

forecast ice and weather conditions directly to field operations and planning managers during the 

operational season. SIWAC provides information to decision makers and field principals to help 

them minimize risks when operating in the presence of ice. To provide quality and accurate 

information, SIWAC depends on skilled forecasters, subscription and public satellite imagery, 

numerical models, field observations, Geographic Information System (GIS) software tools, and 

a robust communication network. 
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 14 July, 2014

A. SIWAC ICE DATA INPUTS

Ice forecasts are developed and issued daily. The Lead Ice Analyst compiles available data from 

subscription, specialized, and public services in ArcMAP (GIS Software) such as:

 MDA RadarSat 2 imagery

 MODIS satellite

 Canadian Ice Services

 National Ice Center

 Contract weather services

 Field observations

 IceNav images

B. Data Transmission

Effective communication of SIWAC ice and weather guidance and reciprocal feedback and field 

observations requires a robust and capable data network. The drilling units and IMVs are 

equipped with high-speed data and voice satellite service that has been proven to perform well in 

the U.S. Chukchi and Beaufort Seas. 

Data, including satellite imagery and observations, are relayed through a file transfer protocol 

(FTP) site between SIWAC and the field vessels using automated processes. This keeps both the 

field and forecasters continuously refreshed with the latest information. In addition, SIWAC 

maintains a secure website that allows direct, on demand access to all forecast reports and data 

products. Additional information about SIWAC is provided in Appendix 3.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 15 July, 2014

Ice Information Flow Chart

NOTE: This graphic depicts the constant two-way communication that would occur between the 

various components of the system.

Guidance Note:

Additional information regarding ice may be requested by the Master of the drilling units. Any 

means appropriate to the circumstances, shall be used to provide this information. Where this 

information is to be obtained by aerial reconnaissance, the Ice Management Lead in Anchorage

will liaise with Shell Logistics to provide the appropriate resources.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 16 July, 2014

V. ICE ALERT LEVELS AND PROCEDURES

These procedures define five Alert Levels that are linked to the time that hazardous ice is 

forecast to be at the drilling location, and the time required to secure the well and move the 

drilling unit off location if it becomes necessary. Roles, responsibilities, and actions required are 

specified according to the Alert Level. 

A. Ice Alert Levels

ALERT 

LEVEL TIME CALCULATION STATUS

Green Alert Time is greater than 24 hours Normal operations

Blue Alert Time is greater than 12 hours Less 

than 24 hours

Initiate risk assessment Validate secure 

times (ST) & move time (MT)

Yellow Alert Time is greater than 6 hours Less 

than 12 hours

Limited well operations in line with COCP, 

Commence securing well

Red Alert Time is less than 6 hours Well securing operations completed.

Commence anchor recovery operations.

Black Drillsite evacuated Move drilling unit to a safe location

HT = Hazard Time 

MT = Move Time

ST = Secure Time

T-Time (Total Time) = ST + MT

AT = Alert Time 

AT = HT – T-Time

Guidance Note:

If the Alert Time (AT) value becomes negative at any time well securement and drillsite 

evacuation contingency plans will be initiated. Ice Alert Roles and Responsibilities 

The following tables summarize roles, responsibilities and actions required for key on-site 

personnel for each Ice Alert Level. 
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 17 July, 2014

ROLES AND RESPONSIBILITIES FOR ALL 

ALERT LEVELS

Drilling Unit 

Master / OIM

Shell Ice Advisor

Drilling Unit

Shell IMV 

Ice Advisor IMV Master 

Rig Manager –

Noble Drilling

OIM –

Transocean 

Drilling Unit

Shell Drilling 

Supervisor

Drilling Unit

The Master / OIM 

is the person in 

charge (PIC) of 

the drilling unit. 

He is the final 

authority in 

regards to safety 

of the vessel, 

crew and 

compliment. All 

changes of Alert 

Level are issued 

by the Master /

OIM. 

The responsibility 

to evacuate the 

drillsite in 

response to a 

hazard rests with 

the Master / OIM.

Evaluates 

information from 

SIWAC, IAs and 

Vessel 

Management 

Team (VMT).

Establishes MT 

in conjunction 

with the AHTS 

Masters.

Establishes Ice 

Alert Level on 

advice from IA 

and is 

responsible for

ice 

management 

operations.

Ensures Alert 

Level status is 

broadcast to 

fleet and 

internally 

throughout 

drilling unit at 

intervals 

dependent on 

Alert Level or at 

change of Alert 

Level.

Collates and 

evaluates

information from 

the SIWAC, IMV 

IAs and VMT.

Advises Master / 

OIM on 

establishing Ice 

Alert Level.

Directs ice 

management 

operations as 

required.

Correlates 

Secure Time 

(ST) and Move 

Time (MT) with 

information from 

rig operations.

Establishes 

Hazard Time 

(HT) in 

conjunction with 

IMVs and 

advises Master /

OIM and VMT.

Works in 

conjunction with 

IAs on IMVs to 

develop and 

establish 

effective ice 

management 

strategies and 

advises Master / 

OIM.

Ensures current 

ice drift is 

broadcast to 

fleet, and liaises 

with SIWAC.

The IA is Shell’s 

IM 

representative 

onboard the 

IMVs and is the 

primary contact 

for all 

communications 

with the Master

/ OIM. He 

advises the IMV 

Master in 

executing the 

ice 

management 

strategies.

Works in 

conjunction with 

Master of IMVs 

to determine the 

local ice 

conditions and 

hazardous ice.

Works in 

conjunction with 

drilling unit IA 

and IMV Master 

to develop and 

implement 

effective ice 

management 

strategies.

Provides 

feedback on 

effectiveness of 

strategy and 

reports any 

anomalies 

pertaining to 

ice.

The Master is 

the PIC of the 

IMV. He is the 

final authority 

in regards to 

safety of the 

vessel, crew 

and 

complement.

Evaluates 

advice from 

SIWAC and 

IAs (drilling 

unit and 

IMVs).

Works in 

conjunction 

with IA on 

drilling unit

and IA of IMV 

to develop and 

execute 

effective ice 

management 

strategies 

within the 

capability of 

the vessel.

Provides 

feedback on 

effectiveness 

of the strategy 

to the IA on 

the IMV.

Reports to 

IMV IA any 

condition 

which inhibits 

vessel 

performance.

The Rig Manager 

/ OIM is the 

drilling contractor 

on-site supervisor 

responsible for all 

drilling-related 

operations aboard 

the drilling unit.

Establishes (ST)

and informs VMT 

of (ST) and well 

conditions.

Validates drilling 

team is aware of 

their duties under 

present Ice Alert 

status.

Validates well 

secure 

contingency 

plans.

The Drilling Supervisor

is the senior on-site 

Shell supervisor with 

responsibility for 

overseeing drilling and 

well operations and for 

initiating spill response 

as the Onsite Incident 

Commander for spills 

originating from the well 

site.

Validates well ST in 

conjunction with the Rig 

Manager / OIM. Informs 

Master / OIM regarding 

ongoing and upcoming 

critical operations and 

curtailment plans.

Communicates status of 

well and Ice Alert level to 

Shell shore 

management and 

SIMOPS coordinator

Under the authority of 

the Shell Wells 

Operations Team Lead, 

the Shell Drilling 

Supervisor may raise the 

Ice alert level at any 

time. He may order the 

suspension of drilling 

operations, and securing 

of the well.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 18 July, 2014

Alert Conditi

on

VMT

Meeting 

Frequency

Drilling Unit 

Master / OIM

Shell Ice 

Advisor

Drilling Unit

Shell IMV Ice 

Advisor IMV Master 

Rig Manager –

Noble Drilling

OIM –

Transocean 

Drilling Unit

Shell Drilling 

Supervisor

Drilling Unit

Green

Alert 

Time is 

greater 

than 24 

hours. 

Every 24 

hours, or 

more 

frequently 

as needed.

Discharges 

duties as per 

accountabiliti

es

Discharges

duties as 

per 

accountabili

ties.

Discharges 

duties as per 

accountabiliti

es.

Discharges 

duties as per 

accountabiliti

es.

Discharges 

duties as per 

accountabilities.

Discharges 

duties as per 

accountabilities.

Blue

Alert 

Time is 

greater 

than 12 

hours 

and 

less 

than 24 

hours.

Every 12 

hours, or 

more 

frequently 

as needed.

Ensures

readiness to 

execute 

contingency 

plans. 

Ensures

primary IMV

is available 

to execute 

Ice 

Management 

strategies for 

the given ice 

regime.

Ensures 

AHTS / IMV 

readiness for

ice 

management 

and anchor 

handling 

operations.

Establishes

Ice 

Manageme

nt 

Strategies 

in 

conjunction 

with IMVs 

and IA 

onboard 

IMVs.

Directs ice 

manageme

nt 

operations

Proposes

appropriate 

Ice 

Management 

Strategies 

based on real 

time 

assessment 

of the Ice 

Regime and 

advises IMV 

Master and 

drilling unit 

IA.

Validates

readiness of 

IMV to 

execute ice 

management 

strategy.

Executes Ice 

Management 

Strategies in 

conjunction 

with IA on 

IMVs. 

Establishes

and states 

readiness of 

IMV to 

execute ice 

management 

strategy.

Establishes ST 

and assesses 

upcoming well 

operations for 

changes to ST

with regard to 

COCP.

Informs VMT of 

ST and well 

conditions.

Validates 

securing 

contingency 

plans. 

Validates ST in 

conjunction with 

the Rig Manager 

/ OIM. 

Informs Master / 

OIM regarding 

ongoing and 

upcoming critical 

operations and 

COCP.

Reports Alert 

changes to Shell 

shore-based 

management

and SIMOPS 

coordinator

Yellow

Alert 

Time is 

greater 

than 6 

hours, 

and 

less 

than 12

hours.

Every 6 

hours, or 

more 

frequently 

as needed.

Establishes 

and 

Validates 

MT. 

Establishes 

departure 

strategy.

Ensures 

Alert status 

is broadcast 

to fleet and 

internally at 

1-hour 

intervals or 

at change of 

Alert Level.

Establishes 

HT, and 

advises 

Master / 

OIM and 

VMT. 

Works in 

conjunction 

with IA on 

IMVs to 

initiate ice 

manageme

nt 

strategies.

Directs ice 

manageme

nt 

operations

Ensures 

current ice 

drift is 

broadcast 

to fleet.

Implements 

ice 

management 

strategies as 

directed by 

drilling unit IA 

in conjunction 

with IMV 

Master.

Provides 

feedback on 

effectiveness 

of strategy.

Executes ice 

management 

strategies as 

directed by 

drilling unit

IA.

Provides 

feedback on 

effectiveness 

of the 

strategy.

Commences

securing well in 

accordance with 

agreed plan. 

Informs VMT of 

progress.

Monitors Well 

Securing 

Operations and 

effectiveness of 

ice management 

operations.

Communicates 

overall drilling 

unit status to 

Shell shore 

management

and SIMOPS 

coordinator
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 19 July, 2014

Red

Alert 

Time is 

less 

than 6 

hours.

Every 

hour.

Initiates

departure 

plans 

following

confirmation 

from Rig 

Manager / 

OIM that the 

Lower 

Marine Riser 

Package 

(LMRP) has 

been 

retrieved and 

secured and 

guide wires 

are released. 

Ensures

Alert status 

is broadcast 

to fleet and 

internally.

Directs 

AHTS 

activities.

Assesses

effectivenes

s of Ice 

Manageme

nt Strategy 

in line with 

ongoing 

operations.

Directs ice 

manageme

nt 

operations 

and assists

Master / 

OIM as 

needed. 

Ensures 

current ice 

drift is 

broadcast 

to fleet 

during 

anchor 

recovery 

operations.

Continues to 

implement 

ice 

management 

strategies in 

support of 

drilling unit 

and anchor 

recovery 

operations. 

Executes ice 

management 

strategies as 

directed by 

drilling unit 

IA. 

Conducts 

activities 

associated 

with releasing 

the drilling 

unit from 

moorings as 

directed by 

Master or 

OIM. 

Confirms well is 

secured and 

that LMRP is 

disconnected, 

retrieved and

secured.

Commences

securing drill 

floor for 

departure from 

site. 

Monitors rig 

securing 

operations and 

departure plan.

Communicates 

status to Shell 

shore 

management

and SIMOPS 

coordinator

Organizes 

additional 

support as 

needed for site 

departure 

operations (for 

example 

logistics).

Black

Drill

site 

evacua

ted

As 

needed.

Directs 

operations 

leading to 

safe 

departure 

from drill site 

to preagreed safe 

area.

Complies 

with all 

regulatory 

reporting 

requirements 

(internal and 

external).

Works with 

VMT and IA 

and IMVs to 

establish 

further 

course of 

action. 

Continues

to monitor 

ice 

conditions. 

Works in 

conjunction 

with IMV

IAs to plan 

a route to 

safe area 

and passes 

routing to 

Master. 

Provides

Master / 

OIM and 

VMT with 

information 

to aid 

further 

decision 

making.

Advises IMV 

Master on 

operations 

leading to 

safe transit 

from drill site 

to pre-agreed 

safe area.

Provides 

information to 

drilling unit 

Master /OIM 

to aid further 

decision 

making.

Works under 

direction of 

the drilling 

unit Master 

and IMV IA 

during transit. 

Confirms drill 

floor and 

associated 

areas are 

secured and 

ready to depart 

drill site.

Provides 

information to 

Master / OIM 

and VMT to aid 

further decision 

making.

Informs Shell 

shore 

management 

and SIMOPS 

coordinator of 

evacuation.

Complies with all 

regulatory 

reporting 

requirements 

(internal and 

external).

Provides 

information to 

Master / OIM

and VMT to aid 

further decision 

making.

VI. ICE MANAGEMENT PHILOSOPHY

An effective Drilling Ice Management Plan is designed to enable execution of the exploration 

program, with the appropriate barriers in place to manage and mitigate against risks associated 

with ice. Additionally, it also identifies the worst case scenario that is caused by the failure of 

barriers and addresses the procedures to deal with consequences of escalation.

The worst case scenario for the purpose of the DIMP is the forced and uncontrolled departure of 

the drilling unit from the drillsite by incursion of hazardous ice. This section addresses the 

activities associated with ice management as a barrier to this worst case scenario. The strategy to 

prevent this event is to have the following elements as effective barriers:
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 20 July, 2014

 proper equipment,

 skilled people,

 appropriate information, and

 work processes

The key elements identified above are discussed herein.

A. Proper Equipment

 The Primary IMVs will have the appropriate ice class with ice breaker capabilities and 

have been contracted to support the exploration campaign.

 IceNav: The drilling units and IMVs will be outfitted with IceNav Equipment (Enhanced 

radar imaging of ice and geo-synchronized satellite imagery).

 Tor Viking II and Aiviq are high specification anchor handling vessels and have been 

designated as the secondary IMVs and anchor handling vessels.

 Ice reconnaissance aircraft capability

B. Skilled People

 The drilling units and all IMVs will carry specialist IAs, in addition to the regular crew 

complement.

 The drilling units will have two IA’s onboard for 24/7 coverage.

 The Primary IMVs will have two IA’s onboard providing 24/7 coverage.

 The Secondary IMVs will have one IA onboard.

 The IAs supporting the exploration campaign will have documented experience of having 

performed ice management activities associated with supporting offshore exploration.

 SIWAC will be staffed with world-class industry-acknowledged experts in weather, 

satellite, and Ice Synoptic analysis.

 Qualified and experienced ice observers for ice reconnaissance flights.

 IMVs will have crews who are experienced operating in ice.

C. Appropriate Information

A multi-layered, systematic approach is taken to provide relevant information from SIWAC with 

a feedback loop from the vessels using:

 Wide Area Satellite Imagery

 High Resolution Satellite Imagery

 Meteorological Buoys

 Field Observation from IMV ice reconnaissance 

 Numerical Models

 Local Radar

 Vessels are outfitted with Fit for Purpose Data and Communications link
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 21 July, 2014

D. Work Process

A systematic approach for risk mitigation is adopted by developing effective work processes.

 Development of effective ice management strategies based on available information 

(Global and Local) 

 Deployment of assets to deliver strategy:

 Threat Sectors identified

 Assess manageability of ice feature (preferably by trial breaking as this is the only way to 

determine manageability)

 Appropriate management of ice feature (breaking/deflecting)

 Primary Icebreaker deployed at an effective perimeter to reduce floes to manageable size 

in advance of Hazardous Ice triggering an increase in Alert Level

 Scheduled VMT meetings (Frequency Dictated by Alert levels)

 Planning/Coordination meetings with specific focus on Ice Alert Levels

VII. WELL SUSPENSION PROCEDURES

Effectiveness of the DIMP is dependent upon being able to accurately establish HT, ST and MT. 

ST is time taken to secure the well, disconnect and retrieve the LMRP.

As part of securing the well, well suspension procedures have been established. These 

procedures will be contained within the drilling unit operating procedures. Return to the drill site 

following exit due to the threat of Hazardous Ice is covered in Section IX. 

A. Well Suspension Options

Securing and suspending the well can be accomplished by several means. The base case is to 

suspend the well with mechanical and/or cement plugs. This method is to be used for Ice Alert 

Level calculations. Should ice or well conditions develop where ST must be reduced, the 

following contingencies and options or combination thereof can be chosen. The option or 

contingency will be dependent upon well conditions, environmental conditions and (or)

equipment limitations. Shell will employ the most effective suspension procedure under the 

specific circumstances at the time.

Relevant information associated with well suspension will be documented in the daily drilling 

reports. The BSEE field representative will be apprised, and relevant records will be submitted 

to BSEE. Potential well suspension options are listed in the following table.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 22 July, 2014

Mechanical Plugging Drill pipe Hang-off Pull Out of Hole Shearing Drill 

Pipe Dropping String

Time Required / 

Preference

Requires most time. Is the 

base case procedure for 

securement and for Ice 

Alert Level calculation.

Less time than 

plugging.

Potentially less time, depending upon 

position in hole.

Least amount of 

time. Stuck pipe 

contingency.

Comparable to shearing 

drill pipe. Contingency to 

cope with mechanical 

hoisting failure.

Provides 

wellbore Isolation

Yes Yes (blind/shears 

closed)

Yes (blind/shears closed) Yes (blind/shears 

closed)

Yes (blind/shears closed)

Hang-off Sub

(HOS) Required

No Yes (Emergency 

Drill Pipe Hang-off 

Tool)

No No No

Packers / Bridge 

Plug Required

Yes No No No No

Potential to 

Leave String in 

Hole

Yes, if suspended below 

packer.

Yes No Yes, but access 

to pump through 

sheared string is 

questionable.

String in hole but requires 

fishing trip and overshot to 

circulate.

Remarks Mechanical plugs are 

preferred method in cased 

hole.

In this case, no 

down hole plugging 

has been assumed.

This method is acceptable in 

situations where casing has been run 

and cemented, but not drilled out yet. 

Pipe can be pulled and blind/shears 

closed without further containment.

Contingency for 

stuck pipe 

situation.

Contingency to cope with 

mechanical hoisting failure.

Advantages Provides complete 

wellbore isolation. 

Equipment readily 

available.

Provides wellbore 

isolation via blind/

shear rams. 

Equipment readily 

available. Can be 

done in a timely 

manner. Leaves kill 

string in place for 

potential well 

control 

requirements.

Requires less time in situations where 

casing has been run but not drilled 

out, or if already out of the hole as 

noted above, for logging or changing 

the Bottom Hole Assembly.

Quickest way to 

secure the well 

and prepare for 

move-off.

Next to shearing, quickest 

way to prepare rig for 

move-off. Also leaves the 

top of the string in the hole 

undamaged and ready for 

recovery or circulating via 

overshot and packoff.

Disadvantages Takes longer. Packers 

require additional tripping. 

Cementing requires

mixing/ pumping time and 

introduces potential for 

contamination.

No down hole

wellbore isolation.

Not a preferred method with open 

hole conditions because no pipe is 

left in the hole for potential well 

control methods. No down hole

wellbore isolation.

Potential to leave 

a deformed pipe 

profile 

complicating 

fishing and 

circulating 

operations.

No down hole isolation is 

accomplished.

Requires fishing trip to 

reestablish down hole

circulation.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 23 July, 2014

VIII. MOORING SYSTEM RECOVERY / DISCONNECTION

A. Conditions Present to Initiate Mooring System Disconnection or Recovery

This section addresses mooring disconnection / recovery operations if ice conditions have 

triggered an Ice Alert Level of yellow and escalated to a red. The following discussion assumes

the well has been secured and all recoverable well related equipment has been retrieved and 

secured.

B. Disconnection / Recovery Options

Mooring System disconnection / recovery can be accomplished by several means. The base case 

is to recover moorings in the conventional manner. This method and the resultant MT is to be 

used for the determination of the Ice Alert Level. In the event conditions develop where the 

drilling unit must reduce MT, the selection of a specific contingency option and the execution of 

the procedures rests with the drilling unit Master / OIM who informs the VMT. Potential options

and contingencies are listed in the table below.

Guidance Note: Conventional recovery for the Noble Discoverer refers to the disconnection of 

the drilling unit mooring lines from the pre-laid anchor system by an anchor handler. For the 

Polar Pioneer conventional recovery refers to recovery and racking of the complete anchor 

system

C. Mooring System Release / Recovery

Contingency Mooring Release Options

Conventional Mooring 

Recovery

Rig Anchor Release 

(RAR) Running off Wires

Time Required 

/ Preference

Requires most time. Is 

the base case 

procedure for recovery

Less time than 

conventional recovery

Contingency plan if RARs fail to 

activate.

Advantages

System is intact. 

Ready for 

redeployment.

Reduced MT Allows disconnection of mooring 

system in event of RAR failure.

Disadvantages None

Increased 

redeployment time. 

Requires back up 

equipment. Relies on 

actuation by acoustic 

release.

Complicates redeployment. High

potential for seabed fouling. 

Potential to compromise the 

mooring system.

Guidance Note: The drilling units will have a RAR release command unit onboard. A second 

RAR release command unit will be onboard the IMV / anchor handler.

IX. MOVING ONTO OR RETURNING TO THE DRILLSITE 

The authority to move on to or return to the drillsite will be issued by the Shell Wells Operations 

Team Lead with the concurrence of the OEMT Shell Drilling Supervisor and Rig Manager / 

OIM. Relevant regulatory authorities will be notified in accordance with the requirements.

A thorough reconnaissance of ice regimes in the vicinity will be conducted and hazardous 

features plotted prior to commencing mooring operations.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 24 July, 2014

An Ice Alert Level of green, together with a favorable ice condition forecast is required before 

mooring commences. 

Recognizing HT will be the only argument available for the Alert Level calculation before 

mooring, a minimum HT of 60 hours and a minimum distance of 30 miles to Hazardous Ice is 

required to give a reasonable period of time to set moorings and stay within Green Alert at 

completion of mooring.

Upon authorization by the Shell Wells Operations Team Lead, the final decision to move on to 

or return to the drillsite is dependent upon the drilling unit Master or OIM who is advised by the 

VMT. The Master / OIM and VMT will assess the various operational, weather and ice 

parameters with input from the drilling unit IA supported by the IMV Masters and the IAs to 

determine the practicality of the decision. A decision to commence mooring operations assumes 

a realistic expectation that the drilling unit will be able to stay on location and commence drilling 

operations for a productive length of time. The OEMT will be informed of all decisions as they 

are made.

X. TRAINING

All personnel will be made aware of their roles and responsibilities within this DIMP through a 

training session on each vessel. This training will also include a Table Top Exercise, which will 

be executed prior to beginning operations, providing exposure to and test communications and 

procedures of the COCP, and the DIMP. Participants at the table top exercise will include:

 Shell and Wells leadership

 Rig Crews (both Drilling and Marine Contractor staff)

 Oil Spill Response (OSR) representative

 SIWAC representatives

 BSEE Operations representatives 

 IMV Masters or Senior officers

 IAs

 Alaska Logistics ( Marine and Aviation ) Representatives

 SIMOPS Coordinators

Observations from the Table Top Exercise will be documented.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 25 July, 2014

XI. ATTACHMENTS

Attachment 1 – Extract from Critical Operations Curtailment Plan

Per Section 8 of the COCP:

Notification of the decision for curtailments to Shell, USCG and BSEE agency representatives 

will be made as soon as practical, but in a manner that does not interfere with the safety of the 

crew, environment, or vessel. All operations curtailment decisions will be documented on the 

Shell Daily Operations Report and conveyed to the on-site BSEE representative as they develop. 

Operations curtailment decisions will also be formally conveyed to BSEE on a weekly basis via 

the Well Activity Report and at the end of the well operations as part of the End of Operations 

Report. The following chart illustrates the lines of communication in the field and from the field 

to the shore base.

Guidance Note:

Well Suspension procedures are described in step by step detail in a document called Secure 

Times and Procedures contained within Shell Applications for Permit to Drill (APD) which have

been submitted to BSEE under portions of 30 CFR 250 and less so under 30 CFR 550. These 

Secure Times and Procedures were submitted to BOEM under 30 CFR 550.213(g)

The following chart illustrates the lines of communication in the field and from the field to the 

shore base.
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 26 July, 2014

Attachment 2 – Vessel Description

“Noble Discoverer Specifications”

NOBLE DISCOVERER SPECIFICATIONS

TYPE- DESIGN Drillship - Sonat Offshore Drilling Discoverer Class

SHAPE Monohull with sponsons added for ice-resistance1

SHIP BUILDERS & YEAR Namura Zonshno Shipyard, Osaka, Japan - hull number 355

YEAR OF HULL CONSTRUCTION 1965

YEAR OF CONVERSION 1976

DATE OF LAST DRY-DOCKING 2014

NOBLE DISCOVERER DIMENSIONS

LENGTH 514 ft 156.7 m

LENGTH BETWEEN PERPINDICULARS (LBP) 486 ft 148.2 m

WIDTH 85 ft 26 m

MAXIMUM (MAX) HEIGHT (ABOVE KEEL) 274 ft 83.7 m

HEIGHT OF DERRICK ABOVE RIG FLOOR 175 ft 53.3 m

NOBLE DISCOVERER MOORING EQUIPMENT

Anchor pattern symmetric 8 point system. The unit is fitted with Sonat Offshore Drilling patented roller turret 

mooring system giving the unit the ability to maintain favorable heading without an interruption of the drilling 

operations.

ANCHORS Stevpris New Generation 7,000 kilograms (kg) each (ea) 15,400 pounds (lb) ea.

ANCHOR LINES Chain Wire Combination

SIZE/GRADE 2.75-in. wire 3-in. ORQ Chain

LENGTH 2,750 ft (838 m) wire + 1,150 ft (351 m) chain (useable) per anchor

NOBLE DISCOVERER OPERATING WATER DEPTH

MAX WATER DEPTH 1,000 ft (305 m) with present equipment (can be outfitted to 2,500 ft [762 m])
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 27 July, 2014

MAX DRILLING DEPTH 20,000 ft 6,098 m

DRAW WORKS EMSCO E-2,100 - 1,600 horsepower (hp)

ROTARY National C-495 with 49 1⁄2 -in. opening

MUD PUMPS 2 ea. Continental Emsco Model FB-1600 Triplex Mud Pumps

DERRICK Pyramid 170 ft. with 1,300,000 lb nominal capacity

PIPE RACKING BJ 3-arm system

DRILL STING COMPENSATOR Shaffer 400,000 lb with 18-ft (5.5 m) stroke

RISER TENSIONS 8 ea. 80,000 lb Shaffer 50-ft (15.2 m) stroke tensioners

CROWN BLOCK Pyramid with 9 ea. 60-in. (1.5 m) diameter sheaves rated at 1,330,000 lb

TRAVELING BLOCK Continental - Emsco RA60-6

BLOWOUT PREVENTER (BOP) Cameron Type U 18 3⁄4 -in. (48 cm) x 10,000 pounds per square in. (psi)

RISER Cameron RCK type, 21-in. (53 cm)

TOP DRIVE Varco TDS-3S, with GE-752 motor, 500 ton

BOP HANDLING Hydraulic skid based system, drill floor

NOBLE DISCOVERER DISPLACEMENT

FULL LOAD 20,253 metric tons (mt)

DRILLING 18,780 mt (Drilling, max load, deep hole, deep water)

NOBLE DISCOVERER DRAUGHT

DRAFT AT LOAD LINE 27 ft 8.20 m

TRANSIT 27 ft (fully loaded, operating , departure) 8.20 m

DRILLING 25.16 ft 7.67 m

NOBLE DISCOVERER HELIDECK

MAXIMUM HELICOPTER SIZE Sikorsky 92N

FUEL STORAGE 2 ea. 720-gallon tanks

NOBLE DISCOVERER ACCOMODATIONS

NUMBER OF BEDS 140

SEWAGE TREATMENT UNIT Hamworthy ST-10

NOBLE DISCOVERER PROPULSION EQUIPMENT

PROPELLER 1 ea 15 ft 7-in. (4.8 m) diameter, fixed blade

PROPULSION DRIVE UNIT Marine Diesel, 6 cylinder, 2 cycle, Crosshead type

HORSEPOWER 7,200 hp @ 135 revolutions per minute (RPM)

TRANSIT SPEED 8 knots

GENERAL STORAGE CAPACITIES

SACK STORAGE AREA 934 cubic meters (m3)

BULK STORAGE

 Bentonite / Barite 180 m3 - 4 tanks

 Bulk Cement 180 m3 - 4 tanks

LIQUID MUD

 Active 1,200 barrels (bbl)

 Reserve 1,200 barrels (bbl)

 Total 1,200 barrels (bbl

POTABLE WATER 1,670 bbl / 265.5 m3 (aft peak can be used as add. pot water tank)

DRILL WATER 5,798 bbl / 921.7 m3

FUEL OIL 6,497 bbl / 1,033 m3

1 Sponsons designed and constructed to meet requirements of Det Norske Veritas (DNV Additional Class Notation 

ICE-05
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 28 July, 2014

“Polar Pioneer Specifications”
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 29 July, 2014
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Shell Gulf of Mexico Inc. 30 July, 2014
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Shell Gulf of Mexico Inc. 31 July, 2014
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Shell Gulf of Mexico Inc. 32 July, 2014
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Shell Gulf of Mexico Inc. 33 July, 2014
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Shell Gulf of Mexico Inc. 34 July, 2014
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Shell Gulf of Mexico Inc. 35 July, 2014
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Shell Gulf of Mexico Inc. 36 July, 2014
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“Nordica” Specifications
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 38 July, 2014
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Shell Gulf of Mexico Inc. 39 July, 2014
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Shell Gulf of Mexico Inc. 40 July, 2014
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Shell Gulf of Mexico Inc. 41 July, 2014
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“Fennica” Specifications
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 43 July, 2014
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Shell Gulf of Mexico Inc. 44 July, 2014
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Shell Gulf of Mexico Inc. 45 July, 2014
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Shell Gulf of Mexico Inc. 46 July, 2014
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Shell Gulf of Mexico Inc. 47 July, 2014
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Shell Gulf of Mexico Inc. 48 July, 2014

“Tor Viking II” Specifications 

AHTS/Icebreaker Tor Viking II - Main Characteristics

Design: KMAR 808 AHTS/ ICEBREAKER (Now; MOSSMAR)

Classification: DnV,+1A1, SUPPLY, SF, TUG ICEBREAKER ICE-10, DK(+) EO HELDK-SH 

DYNPOS-AUTR HL(2,8) W1-OC

Built / Delivered: Havyard Leirvik, Norway - 03/2000

Registered / Flag: Skärhamn, Sweden

Dimensions

Length Over All (LOA): 83.70 metres

Length between p.p.: 75.20 metres

Breadth, moulded: 18.00 metres

Depth, moulded: 8.50 metres

Draught (scantling): 7.20 metres

Draught (design): 6.00 metres

Freeboard (design): 2.50 metres

Dead Weight: 2,528 tonnes

Light Ship: 4,289 tonnes

Gross: 3,382 tonnes

Net: 1,145 tonnes

Capacities

Dry Bulk: 283 m3in 4 tanks - totaling 10,000 ft3

Pot Water: 724 m3

Drill Water / Ballast: 1,205 m3

Brine: 400 m3– SG 2.5

Oil Based Mud: 612 m3– SG 2.8
Drilling Ice Management Plan Chukchi Sea, Alaska

Shell Gulf of Mexico Inc. 49 July, 2014

Base Oil: 242 m3

Fuel Oil: 1,190 m3 Marine Gas Oil (Diesel)

Urea: 94 m

3

Diesel Overflow: 21 m3 with alarm

Diesel Service / Settling: 2 x 20 m3

Deck Load: Abt 1,350 ts

Deck Area: 603 m2/ 40.20 m x 15.0 m

All products in dedicated tanks – no dual purpose tanks

Propulsion

Main Engine: MAK 18,300 BHP - 4 eng (father/son) 2 x 3,840 kW + 2 x 2,880 kW = 13,440 kW

Thrusters: Bow 1,200 BHP in tunnel (Electr) + 1,200 BHP 360 deg retractable = 2,400 BHP: 

Stern 1,200 BHP in tunnel

Bollard Pull: Bollard Pull: 202 continuous (DnV certified) / Abt. 210 max pull

Speed/Consumption: 16 knots – Abt. 42.7 MT / 24 hrs at 6.0 metres draught , 12 knots – Abt. 

25.0 MT

Towing & Anchor Handling Equipment

AHT Winch: Brattvaag towing/anchor handling winch 400 ts pull / 550 ts brake holding caps

AHT Drum: One of 1,400 mm dia. x 3,750 dia. x (1,250 mm + 1,250 mm) length

Wire Capacity: 2 x 1,900 metres of 77 mm wire or 2 x 1,650 metres of 83 mm wire

AH Drum: One of 1,400 mm dia. x 3,750 mm dia. x 3,000 mm length

Wire Capacity: 4,100 metres of 83 mm wire

Winch Control: TOWCON 2000 Automatic Control with printer

Pennant Reels: One off 2 x 1,500 m of 77 mm wire or 2 x 1,300 m of 83 mm wire capacity: One 

off 3,400 m of 77 mm wire or 1 x 3,100 m of 83 mm wire capacity

Large Reel Inner Core: 1,500 mm dia.

Cable Lifters: 2 x 76 mm and 2 x 84 mm onboard

Chain Lockers: 2 x 129 m 3 / giving abt 2 x 6,000 ft of 3 inch chain

Shark Jaws: 2 pairs of Karm Forks arranged for chain up to 165 mm dia. / 750 ts SWL

Inserts for handling of 65, 75, 85, 100, and 120 mm dia. wire/chain

Stern Roller: One of 3,5 metres dia. x 6.0 metres length – SWL 500 ts

Guide Pins: 2 pairs Karm Fork Hydraulic pins – SWL 170 ts

Deck Equipment

Capstans: 2 x 15 ts pull

Tugger Winches: 2 x 15 ts pull

Smit Brackets: One bracket on B Deck Forward – SWL 250 ts

Cranes: 1 hydraulic crane on fore cargo deck giving 6 / 12 ts at 20/10 m arm (360 deg) 

: 1 telescopic crane on aft cargo deck giving 1.5 / 3 ts at 15/10 m arm (360 degr)

: 1 hydraulic crane on for-castle deck for stores etc.

Windlass: 1 hydraulic windlass / mooring winch. 2 declutch-able drums 46 mm K3 chain

Accommodation: Accommodation of a total of 23 persons, including crew.

All accommodation equipped with air-condition and humidification facilities.

Dynamic Positioning

The vessel is equipped with Kongsberg Simrad SDP 21 Redundant DP System – Green DP.
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“Aiviq” Specifications
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Attachment 3 – Shell Ice and Weather Advisory Center

Operational Support Overview

Safe and efficient offshore operations in the Arctic are contingent upon quality and timely ice 

and weather forecasts. Using state of the art satellite technology, large areas of the Beaufort and 

Chukchi Seas are monitored remotely by the SIWAC to track movement of ice and make 

estimates of its type and concentration. 

Synthetic Aperture Radar (SAR) instruments on board the RADARSAT 2 satellite are contracted 

to acquire necessary images of sea ice over areas of interest several times per week. These 

images are transmitted to ground stations, processed, and made available for analysis within 

hours of acquisition. Interpretation of the ice edge and features are performed by experienced 

specialists using powerful mapping software to produce ice charts that are considerably more 

detailed than those available from national ice centers. These charts are then distributed to 

operational personnel and planning managers and can be validated or ground-truthed using actual 

ice regime assessments from the IMV fleet. 

Knowing the location and composition of the ice at any given moment is a valuable tool;

however, it is not enough. It is important to forecast how the ice may change over time. A 

complementary component of ice forecasting is quality weather information. Weather conditions 

in the Arctic are among the most severe on the planet and change dramatically in a short time. 

National weather services do not provide measurements and forecasts that sufficiently resolve 

the conditions over small areas or short time spans in the Arctic offshore. Therefore, dedicated 

meteorologists with Arctic forecasting experience are employed full time to produce accurate 

snapshots of the current conditions and reliable forecasts of weather conditions into the future. 

Using global weather models, such as ECMWF and GFS numerical weather model as a starting 

point, the meteorologists produce a high resolution grid in proprietary modeling software of 

weather parameters, such as atmospheric pressure, wind speed, and wave height, that have been 

corrected based on local observations from Shell’s vessels at sea, meteorological buoys, and 

coastal weather stations. The result is a model that accurately reflects current and forecast 

weather conditions over short distances in the Beaufort and Chukchi Seas, making marine 

operations and vessel transits safer and more responsible. Without this innovative forecast effort, 

weather products from other sources tend to describe the average or general conditions that one 

could expect over large areas, such as the entire U.S. Beaufort Sea, which results in local 

conditions rarely matching what is forecast. 

The wind vectors, which are a set of points indicating the speed and direction of the wind 

distributed over the Beaufort and Chukchi Seas, and other output from the weather model are 

applied to the ice charts in the mapping software. This allows the ice analyst to assess the effect 

of wind and weather systems on the future movement and development of the ice.
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Attachment 4 – Ice Alert Logs

Ice Alert Level Log

ICE ALERT LEVEL LOG

DRILLING UNIT

Date Time HT ST MT T-Time Remarks

Alert 

Level Master
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Ice Alert Level Notification

Notice of Ice Alert Status Change 

Drilling Unit

Date

Time

Previous Ice Alert Level

Ice Alert Arguments

Hazard Time (HT)

Secure Time (ST)

Move Time (MT)

Alert Time (AT)

New Ice Alert

Present Ice and Weather Conditions 

Forecast Ice and Weather Conditions 

Comments

Approved By Master/OIM

Signature

Date & Time
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Well Secure Time Log

WELL SECURE TIME LOG

DRILLING UNIT

Date Time

Well 

Secure Time (ST)

Initials

Remarks

Initials

Rig 

Manager / 

OIM

Shell Drilling 

Supervisor