2 Metocean

7/30/2019 2 Metocean

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Metocean

Questions covered in this session

Metocean What is it all about?

How does Metoceanbenefit the oil & gasbusiness?

How big are Metocean 100 year design values?

How are Metocean data collected?

How does Metoceansupport Oil & Gas

Operations? Examples of where Metocean impacts the

Business

Objectives of this training module

To introduce you to Metocean Engineering and

its application in oil & gas

To motivate you to appreciate Metocean& findout how to improved design using Metocean.

After completion of this module, you will:

Be able to summarise what Metocean is all about and to

name the key metocean variables that affect design andoperations;

Have an overall picture of where Metocean Engineeringimpacts the business specifically as it relates to data

collection & Metocean input to engineering, safety andeconomics.


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Part 1: Metocean - What is it?

Sakhalin Molikpaq Platform in ice

Hurricane & Its Calling Card

Heavy Seas!


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Metocean and key metocean variables

Meteorological

WindsAir temperature

Air pressureHumidity

PrecipitationSuperstructure icing

Cloud cover/heightVisibilityDaylight hoursDust storms

Oceanographic

WavesCurrentsSea temperatureSalinityTide and water levelStorm surgeSea ice

Sea Spray icingIcebergs

Sediment transport

Metocean is about: describing the conditions, deriving design criteria,

providing operational statistics, and providing forecasts

Critical for both Design and Operations are adverse combinations of the above

The key deliverables

Information on the climate and

metocean environmentOperability and downtimestatistics

Forecasts of weather, wavesand currents

Design criteriaNumerical modeling of the

offshore environment and theresponse behavior ofstructures, floaters and

pipelines.

WAVES


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WAVE

SOUTH CHINA SEA TYPICAL DESIGN WAVE HT VS DEPTH

CURRENT PROFILE 1/7TH POWER

WIND


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The key application areas

Offshore fixed structures: platforms,jack-ups.

Offshore floating structures: FPSOs,

other floating productions systems,drilling rigs, barges, vessels, ships.

Pipelines (offshore & onshore).

Coastal planning and management:dykes, breakwaters, sewage outlets,hydrodynamic transport of

sediments, pollutants and oil spills.Coastal, river and land installations.

FPSO when is it safeto offload

The key sources of metocean info.

Literature searches National and international sources of data (government

agencies) Bespoke field metocean data collection campaigns Numerical modeling: hindcasting (i.e looking back in

time up to 50 or even 100 years) of winds, waves,

currents and water level

Numerical modeling: forecasting (looking ahead in timeup to 10 days or more and now also seasonally),primarily for weather, wave and water level conditions

but also increasingly for current conditions.

Part 2: How Metocean contributes to the business?

Fulmar Platform,

Central North Sea

Refining MetoceanDesignCriteria over the Field LifeCycle


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Metocean input to project life cylcle: Phase 1




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Refine Metocean design criteria



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Part 3: Metocean 100 year Design Values?

Squall-line over Port Hedland

Metocean conditions around the world

Definitions of Rough, Moderate and Mild

*N.B. The Sign ifi cant Wave Height value is approxi mately 54% of thecorresp onding Maximum Wave Heigh t (i.e. Hmax = 1.86 Hs)


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Metocean Categorisation by Area

Most likely sourse ofsevere events:S Extra tropical storms

E Earthquakes

C Hurricanes / Typhoons/Cyclones (winds/waves)M Monsoons (waves)I Ice

W Extra tropical storms (swell)R Currents

Metocean Categorisation by Area

Most likely sourse ofsevere events:S Extra tropical storms

E EarthquakesC Hurricanes / Typhoons/

Cyclones (winds/waves)M Monsoons (waves)I Ice

W Extra tropical storms (swell)R Currents

DESIGN WAVE & RETURN PERIOD


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Metocean Criteria Depends on Application

ISO 19901-1 - MetoceanDesign and Operating Cond

Further information: Metoceanconditionsaround the world then take a look at ISO19901-1 MetoceanDesign and OperatingConditions.

Metocean Design and Operating

Conditions in the ArcticAreas: Alaska, Canada, Caspian, Norway,RussiaEnvironment: Onshore, Deepwater, Heavy Ice, ShallowWaterMetocean Conditions: mostly Rough; some ModerateWinds: 30 to 40 m/s (58 m/s gust)Air Temperature: -50C to +43CWaves Hmax: 3 to 31 metresSurface Currents: 1.5 to 2 m/sWater Depth: North Caspian 4m +0.8m/-1.8mStorm Surge: +/-0.5 to 2 mSea Surface Temperature: -1.9C to +30CLevel Ice: 1.5m, Rafted Ice: 3m, Drift 2.5 m/s(Sakhalin)

First-year and Multi-year Ice (e.g. Alaska, Canada,Shtokman)Ridges & Hummocks: Sail 6m, Keel 26m, Gouging:1.6m (Sakhalin)

Stamukha: L=150m, W=40m, Thickness=11m(Sakhalin)Icebergs Scour: L=650m, W= 25m, D= average 0.3m(E. Canada)


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Part 4: Metocean Support to Operations.

Sakhalin MolikpaqPlatform in high waves

ApplicationsSurveys: Seismic & Sea bottom surveysDrilling:

Rig selection Logistics, Oil Spill Vortex Induced Vibration (VIV);Field Development Concept Selection:

Towage of structures to site

Installation of jacket, topsides, float-over, floatermoorings & risers, subsea equipment, pipelines

Production operations; e.g shuttle tanker offloading Marine and aviation logistics

Production Operations: Off-loading downtime Emergency MOB and Oil Spill Modeling / prediction Marine and aviation logistics Maintenance, e.g. diversAband on ment:

Weather window for abandonment operations

FPSO and Shuttle Tanker offloading

Main Metocean parameters

Winds (speed and direction) Waves (wave height, wave period, wave

direction) Currents (speed and direction over the whole

current profile) Meteorological Conditions n(fog, air

temperature, sea temperature)


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Metocean statistics

Monthly and seasonalpercentage exceedenceabove thresholds;

Monthly persistence statisticsabove and below thresholds forvarious durations;Variability in exceedence andpersistence statistics from oneyear to the next; distinguishingbetween a good year anda badyear.

Examples of Wind Rose and Monthly

Significant Wave Height Exceedence

Plots

Real-Time Metocean Data

are provided by:

Metocean stations

Remote systems on

Data Buoys

National network of

land and coastal

meteorological

stations

National data buoy

network

Weather and Ocean Forecasts

Forecasts are:

For3 to 7 days ahead

Area or site-specific

For aviation: specific format

Growing need for forecasts

of currents

Example Forecast P lots from Oceanweather.com


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Arctic Operational Issues

Summer Operations: Length of Summer Opr Window Variability in Onset of Thaw Early Freeze Up

Winter Operations: Variabili ty in Onset of Freeze Up Length of Winter Opr Window Icebreak: Ridges, Mult i-year ice Severity of Wint er (Impact onLogistics)

Fog: Impact on Helicopter Flights,Hovercraft and Marine Activities

Evacuation: In variety of adverse weather/iceconditions.

Arc tic Cond iti ons pro vi de ad ded

Dimension(s) to normal Operations

Part 5: How are Metocean Data collected?

Metocean Data Buoy

ready for deployment

Metocean Stations typical parameters

Wind speed, wind direction, atmospheric pressure, airtemperature, humidity, rainfall, visibility, cloud cover;

Significant wave height, maximum wave height, meanzero crossing period, peak period;

Profile (with depth) values of current speed, current

direction, temperature and salinity

Metocean Stations integrate the real-time collection,

processing, quality control, display, exporting (i.e.transmission) and archiving of meteorological andoceanographic information in one system. Typical

parameters are as below:


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Purposes of Metocean stations

Anemometer

Real-time information in support ofsafe and efficient operations (e.g.helicopter flights, drilling, heavy lifts,float-overs, etc.);

Near real-time information to theforecast agencies to improveaccuracy of forecasts;

Archive data for generating climaticstatistics for operational planning(i.e. downtime assessments) andmetocean design criteria.

Remote Deployments

Remote Deployment of Oceanographic Equipment

Numerical Modelling

Source: Oceanweather Inc. web site


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Satellite Data

Source:European Space Agency (ESA)

National Databases

Further information: US National Oceanographic Data Center archiv es

How Much MetoceanData are there in the Oil &

Gas Industry MetoceanData Bank?

World map showing areascovered by hindcastJ IPstudies.

Source:http://www.oceanweather.com/metocean/


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Weather and Ocean Forecasts

Part 6: Examples of where Metocean impacts

the business

North Caspian Off shore

Metocean Station

How Metocean contributes to Business 1


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How Metocean contributes to Business 2

METOCEAN

Documents

2 Metocean