EO-Based Ice and Iceberg Monitoring

in Support of Offshore Engineering Design and

Tactical Operations

Desmond Power, C-CORE

ESA Industry Workshop on Satellite EO for the Oil and Gas Sector

Overview

• Operations in ice infested waters

• Ice load analysis– Sea ice– Iceberg

• Ice management– Impact on design loads – Technologies

• Role of EO in Design and Operational Ice Management– Sea ice charts– Iceberg surveillance– Near-real-time services

Oil and Gas Operations in Ice Infested Waters

Ability to operate dependent on a number of factors

• Type of structure• Met Ice Ocean environment• Knowledge of ice conditions

– Icebergs– Sea-ice

• Ability to manage ice conditions

• Knowledge of the ice loading on a particular structure

Sea Ice Design Loads

• Characterization of ice/metocean environment

• Sea Ice Encounter Frequency– floe diameter, thickness, drift velocity,

facility size, concentration

• Ice - Structure Interaction– Structure shape, crushing,

contact area– Ice types, ice clearing mechanisms

• Risk Mitigation– Ice breaking

• Loads– Limit stress – failure of ice (sheet, ridge)– Limit energy – kinetic energy in ice– Limit force – wind/wave driving force

Iceberg Design Loads

• Characterization of ice/metocean environment

• Iceberg Encounter– Iceberg waterline length,

drift velocity, facility size, areal density

• Ice - Structure Interaction– Crushing, spalling, contact area – Ice mechanics, strength

• Risk Mitigation– Modeling detection and towing

• Impact Loads– Global - kinetic energy

(mass, impact velocity), eccentricity, ice pressure, crushing, contact area, penetration

– Local – high-pressure zone, impact duration L

Ut

Structure

Iceberg Management - Benefits

Manage Can’t Manage

OK

Avoid Can’t Avoid

OK HITDisconnect Structure

HIT

Fixed Structure

DetectCan’t Detect

HIT

All Icebergs Potentially Impacting Installation

1 impact / 100 yrs

Influence of Ice Management

1 impact / 10 yrs

Iceberg Design Load

1 impact / 10 yrs

Design load at 10-4 annual probability level*

Iceberg Loads – Influence of Impact Frequency

100

Pro

babi

lity

of E

xcee

denc

e 10-1

10-2

10-3

10-4

* Standard = CAN/CSA-S471-06 and ISO 19906

Iceberg Length Distribution

Waterline length: maximum dimension along waterline – most commonly used metric

Mean – 64.6 mExponential Distribution

L

W

Iceberg waterline length

Pro

babi

lity

of O

bser

vatio

n

Effect of Tactical Avoidance

0

0

1

2

3

4

5

6

7

8x 10

4

Freq

uenc

y

Generic Distributionmean = 44.13

std = 53.1max = 399.95

n = 100000

Length

Freq

uenc

yFr

eque

ncy Population that Hit

Mean length = 6.63m

Generic PopulationMean length = 44m

Larger icebergsthat give

higher loads are avoided

Sea Ice Management

• Icebreaker support– Relieve pressures in confining

pack conditions– Push extreme features away

from rigs – Extend operational season of

floating drill rig

Iceberg Management

SensorIntegration

• Tactical– Ice Detection

• Marine Radar• Satellite SAR• Aircraft and vessel reconn• Drift prediction

– Physical Management• Water cannon• Towing• Multi-vessel coordination• Towing in pack ice• Ice island

• Strategic– Data collection– Data fusion– Data management– Forecasting / threat

analysis / decision-making – Simulation training

Role of EO in Design and Operational Ice Management

• Sea Ice– Ice charts

• Encounter frequency from historical records• Tactical mapping as input into icebreaker support

– Ice regime characterization• First year/multiyear, thin/thick• Ice structure interaction

– Input to forecasting

• Icebergs– Historical aerial density– Population distribution– Drift speed assessment– Strategic and tactical surveillance

• Threat assessment and decision making• Input to drift tracking and forecasting• Supports iceberg physical management

Sea Ice from SAR

• Well known in the ice charting world

• Used for inversion of– Geophysical state: ice type,

concentration– Thermodynamic state

• Medium to low resolution SAR data are useful

– Significant quantity of data in satellite archive for historical quantification

• Multi-parameter SAR (frequency, polarization) more robust for charting

– Fewer ambiguities– More satellites mean more imaging

opportunities

• Available in NRT to support operational charting

– Both charts and image data are useful to ice management service providers

– Many imaging opportunities available in medium and low resolution

Open WaterFirst and Multi

Year Ice

New Ice

Land

L-Band C-BandL-Band C-Band

HV/HV/HH

Example – Historical Sea Ice Regime Characterization

Icebergs from SAR

• Icebergs appear as targets in SAR

• Detection probability a function of

– Iceberg size– Ocean state (wind)– Incidence angle– SAR resolution– Polarization

• Can use low resolution for population assessments

– Compensate for icebergs that are missed

• Available in NRT to support operational charting

– Higher resolution data required

• New SARs with better noise floor have high detection probability

TSX Data © Copyright ©2007 German Aerospace Center (DLR)/Infoterra GmbH

Iceberg Aerial Density from SAR

Ground Station

ENVISAT, RADARSAT-1/2, TSX, CSK

Internet

Level

1

Server

EOVAC

Server

Vessels/Platforms

Image Interp.

ChartQA/QC

Product

Data Fusion

DatabaseSatellite

MetIceOceanVAC

Elements of an Operational EO Service

ClientOps Centre

Client

Probability of Detection - RADARSAT-2

0.570.830.910.970.120.060.320.4320-25

0.950.990.900.380.530.7425-30

0.910.881.000.840.680.610.840.8730-35

0.790.900.820.780.760.930.9435-40

0.970.950.9740-45

15-2010-155-100-515-2010-155-100-5Wind Speed m/s

Incidence Angle

HVHHSCN Mode – 50 m

Medium Iceberg (50-120 metres)

0.740.881.001.000.320.240.520.6320-25

0.950.990.970.600.760.8725-30

0.920.920.990.940.880.810.930.9330-35

0.890.930.990.950.920.960.9635-40

0.950.950.9840-45

15-2010-155-100-515-2010-155-100-5Wind Speed m/s

Incidence Angle

HVHHFine Mode – 8m

Example of Surveillance Scenario

Aye Captain… land ho!!!

Is that an iceberg???