routing selection

1Offshore pipeline scope & Offshore pipeline scope &

routing selectionrouting selection

DR. IR. RICKY LUKMAN TAWEKALDR. IR. RICKY LUKMAN TAWEKAL

BANGUNAN LEPAS PANTAI II (SUBSEA PIPELINE ENG.)BANGUNAN LEPAS PANTAI II (SUBSEA PIPELINE ENG.)

topicstopicstopicstopicstopicstopicstopicstopics

Routing Development & SelectionRouting Development & Selection

Marine SurveyMarine Survey

Bottom RoughnessBottom Roughness

ROUTING SELECTION & MARINE SURVEYROUTING SELECTION & MARINE SURVEY

2EXPECTATIONEXPECTATIONEXPECTATIONEXPECTATIONEXPECTATIONEXPECTATIONEXPECTATIONEXPECTATION

Understand the routing selection criteriaUnderstand the routing selection criteria

Know the routing desktop studyKnow the routing desktop study

Know the radius curvatureKnow the radius curvature

Know the routing selectionKnow the routing selection

Know the main marine survey methodsKnow the main marine survey methods

Know the survey equipment used and the data Know the survey equipment used and the data can be obtained can be obtained

Know which survey operation to perform at Know which survey operation to perform at each stage in the installation of pipelineeach stage in the installation of pipeline

Route Selection CriteriaRoute Selection Criteria

Route StudyRoute Study


Route Selection and OptimisationRoute Selection and Optimisation

routing developmentrouting developmentrouting developmentrouting developmentrouting developmentrouting developmentrouting developmentrouting development

3routing development steprouting development steprouting development steprouting development steprouting development steprouting development steprouting development steprouting development step

Marine RouteSurvey

Seabed profile

BottomRoughness

Mix Data & Compare

Route Study

DesignAllowable

SpanLength

ModifyRoute

Select Final Route

OK

NO

Route Selection Criteria

Route Selection Criteria:Route Selection Criteria:

Rules of Thumb for RoutingRules of Thumb for Routing

RegulationsRegulations

Clients NeededClients Needed

Route selection criteriaRoute selection criteriaRoute selection criteriaRoute selection criteriaRoute selection criteriaRoute selection criteriaRoute selection criteriaRoute selection criteria

4RULES OF THUMB:RULES OF THUMB:

The Shortest The Shortest -- Straight line is idealStraight line is ideal

Minimise materialsMinimise materials

Minimise pressure lossesMinimise pressure losses

Minimise installation riskMinimise installation risk

Easiest for installationEasiest for installation

The Safest, minimize risk & impactThe Safest, minimize risk & impact

Minimize CostMinimize Cost


Easiest for InstallationEasiest for InstallationTo be able to lay the pipeline, minimize installation difficultiesTo be able to lay the pipeline, minimize installation difficulties

The Safest, minimize risk & impactThe Safest, minimize risk & impact The selection of pipeline route is to minimize potential risks of damage The selection of pipeline route is to minimize potential risks of damage

to the pipeline during installation and operation phases. to the pipeline during installation and operation phases. The optimum pipeline route is to be selected based on the detail The optimum pipeline route is to be selected based on the detail

survey result within the specified pipeline corridorsurvey result within the specified pipeline corridor Perpendicular approach to the landfall, to contour linePerpendicular approach to the landfall, to contour line


5 Straight line never happens cause:Straight line never happens cause:

Seabed Features/Geohazard PresentSeabed Features/Geohazard Present

Existing FacilitiesExisting Facilities

Third PartiesThird Parties

Shore Crossings Shore Crossings

Installation ConstraintsInstallation Constraints

Environmental ConsiderationsEnvironmental Considerations


Geohazard RiskGeohazard Risk

Routing Routing Routing Routing Routing Routing Routing Routing -------- seabed featuresseabed featuresseabed featuresseabed featuresseabed featuresseabed featuresseabed featuresseabed features

6 Seabed UndulationSeabed Undulation Difficult soils (hard clay, very soft silt)Difficult soils (hard clay, very soft silt) Sand wavesSand waves Wrecks, debrisWrecks, debris Mine FieldsMine Fields Seabed slopesSeabed slopes Active FaultsActive Faults Landslide/mudslideLandslide/mudslide Shallow gasShallow gas PockPock--marksmarks Boulder fieldsBoulder fields Rock/coral outcropsRock/coral outcrops Soil depressionSoil depression Gas hydrate accumulationGas hydrate accumulation ScarpScarp Mud VolcanoesMud Volcanoes SubsidenceSubsidence Seismic ActivitiesSeismic Activities Seabed CurrentSeabed Current



7Routing Routing Routing Routing Routing Routing Routing Routing -------- seabed featuresseabed featuresseabed featuresseabed featuresseabed featuresseabed featuresseabed featuresseabed features

WHY??WHY??

Subsea to BeachSubsea to Beach

Preferred Development OptionPreferred Development Option

Scarp is in the wayScarp is in the way

Shortest RouteShortest Route

Reduced pressure dropReduced pressure drop

Smaller DiameterSmaller Diameter

Smaller UmbilicalSmaller Umbilical

Defer compressionDefer compression

Save MoneySave Money

scarpscarpscarpscarpscarpscarpscarpscarp

A steep slope or long cliff that results from erosion or faulting A steep slope or long cliff that results from erosion or faulting and separates two relatively level areas of differing elevations. and separates two relatively level areas of differing elevations.

8 GeohazardsGeohazards Turbity CurrentsTurbity Currents Mud SlidesMud Slides Scarp FailureScarp Failure Triggers (Seismic / Metocean)Triggers (Seismic / Metocean)

Large Free SpansLarge Free Spans Steep SlopesSteep Slopes Large Diameter PipelineLarge Diameter Pipeline Installation CapabilitiesInstallation Capabilities

Flow AssuranceFlow Assurance Sand TransportSand Transport SluggingSlugging

Slope FailureSlope Failure 3 deg slopes3 deg slopes Seismic eventSeismic event Soil typeSoil type Debris Flow / Turbidity CurrentDebris Flow / Turbidity Current

Loads on the PipelineLoads on the Pipeline

Scarp Scarp Scarp Scarp Scarp Scarp Scarp Scarp the challengesthe challengesthe challengesthe challengesthe challengesthe challengesthe challengesthe challenges

Mapping the Risks:Mapping the Risks:

Survey (Geophysical and Geotechnical)Survey (Geophysical and Geotechnical)

Data Acquisition on Steep SlopesData Acquisition on Steep Slopes

Age dating of flowsAge dating of flows

Modelling of GeohazardsModelling of Geohazards

Pipeline Routing:Pipeline Routing:

Avoid Failure Prone SlopesAvoid Failure Prone Slopes

Avoid Soil RunAvoid Soil Run--out Areasout Areas

Probability and Consequence ModellingProbability and Consequence Modelling

Scarp Scarp Scarp Scarp Scarp Scarp Scarp Scarp geohazard challengesgeohazard challengesgeohazard challengesgeohazard challengesgeohazard challengesgeohazard challengesgeohazard challengesgeohazard challenges

9 Existing facilitiesExisting facilities

Pipelines & Cables (crossings, proximity/distance Pipelines & Cables (crossings, proximity/distance between existing & new line, lay in corridors)between existing & new line, lay in corridors)

Cables (power, telecommunication, fiber optic)Cables (power, telecommunication, fiber optic)

Wellheads (exploration and production)Wellheads (exploration and production)

Platforms / FPSOs (available riser slots, dropped Platforms / FPSOs (available riser slots, dropped objects)objects)

Subsea structuresSubsea structures

Access for tieAccess for tie--ins (existing / future)ins (existing / future)

Drilling rig legs/anchorsDrilling rig legs/anchors

Coastal protectionCoastal protection

Generally want 500m clearanceGenerally want 500m clearance

Routing Routing Routing Routing Routing Routing Routing Routing existing facilitiesexisting facilitiesexisting facilitiesexisting facilitiesexisting facilitiesexisting facilitiesexisting facilitiesexisting facilities

International boundariesInternational boundaries Other exploration licencesOther exploration licences Fishing area (commercial & recreational)Fishing area (commercial & recreational) MilitaryMilitary Shipping lanes (ASL & Local), Type & intensity of shippingShipping lanes (ASL & Local), Type & intensity of shipping Dredging & Dumping (dredged materials, waste, ammunition) areasDredging & Dumping (dredged materials, waste, ammunition) areas Marine/Nature ReservesMarine/Nature Reserves Mineral depositMineral deposit Archaelogical siteArchaelogical site HeritageHeritage Anchorage Area/Anchoring ZoneAnchorage Area/Anchoring Zone Iceberg plow marksIceberg plow marks

Routing Routing Routing Routing Routing Routing Routing Routing -------- third partiesthird partiesthird partiesthird partiesthird partiesthird partiesthird partiesthird parties

10

Social impact (fishermen)Social impact (fishermen)

Land usage Land usage proximity to peopleproximity to people

Minimise shore approaches (pipeline stability)Minimise shore approaches (pipeline stability)

Maintain adequate Maintain adequate clearance from adjacent islandsclearance from adjacent islands

Onshore routing / destinationOnshore routing / destination

Environmental parameters (waves, tides, scour, coast erosion, Environmental parameters (waves, tides, scour, coast erosion, beach movement, topography, geology, environmental beach movement, topography, geology, environmental sensitivity) sensitivity)

Environmental constraints Environmental constraints conservation, coral conservation, coral

Routing Routing Routing Routing Routing Routing Routing Routing shore crossingsshore crossingsshore crossingsshore crossingsshore crossingsshore crossingsshore crossingsshore crossings


11


BEACHPULLBEACHPULL

Installation methodInstallation method

Minimum curvatureMinimum curvature

Vessel anchor patternsVessel anchor patterns

Vessel minimum operating draftVessel minimum operating draft

Lay tolerances (+/Lay tolerances (+/--10m, corridor 5010m, corridor 50--100m wide)100m wide)

Platform approachesPlatform approaches

Routing Routing Routing Routing Routing Routing Routing Routing installation constraintsinstallation constraintsinstallation constraintsinstallation constraintsinstallation constraintsinstallation constraintsinstallation constraintsinstallation constraints

12

BS 8010, page 8, Sect. 4.1.6.4:BS 8010, page 8, Sect. 4.1.6.4:

The pipeline should be installed within The pipeline should be installed within 100m100m of the of the selected pipeline route and never installed outside selected pipeline route and never installed outside the survey corridor. The limit of deviation from the the survey corridor. The limit of deviation from the selected pipeline route should be reduced in selected pipeline route should be reduced in congested area.congested area.

Routing Routing Routing Routing Routing Routing Routing Routing tolerancestolerancestolerancestolerancestolerancestolerancestolerancestolerances

Routing Routing Routing Routing Routing Routing Routing Routing installation constraintsinstallation constraintsinstallation constraintsinstallation constraintsinstallation constraintsinstallation constraintsinstallation constraintsinstallation constraints

13

A surprising number of factors have to be taken into account:A surprising number of factors have to be taken into account:

Water Depth (Avoid extremely shallow depth & extremely deep water)Water Depth (Avoid extremely shallow depth & extremely deep water)

Seabed Features (SeaSeabed Features (Sea--bottom undulation, Very hard seabed, Very soft seabed, Sand bottom undulation, Very hard seabed, Very soft seabed, Sand waves, Soil depression, Boulder fields, Wrecks, Debris, Rock outcrops, Mine fields, waves, Soil depression, Boulder fields, Wrecks, Debris, Rock outcrops, Mine fields, Active Faults, Pockmarks, Landslide/Mudslide areas, shallow gas, seabed slope, Active Faults, Pockmarks, Landslide/Mudslide areas, shallow gas, seabed slope, subsidence, seismic activity, seabed current) subsidence, seismic activity, seabed current) -- GeohazardsGeohazards

Existing Facilities (Existing platforms and risers, Minimized crossings of existing Existing Facilities (Existing platforms and risers, Minimized crossings of existing pipelines & cables, spacing between pipelines, subsea structures, subsea wellheads, pipelines & cables, spacing between pipelines, subsea structures, subsea wellheads, coastal protection)coastal protection)

Third Parties (Submarine exercise areas, Fishing area, Dredging, Dumping grounds Third Parties (Submarine exercise areas, Fishing area, Dredging, Dumping grounds (dredged material, waste, ammunition), Avoidance of Shipping Lane (dredged material, waste, ammunition), Avoidance of Shipping Lane -- ASL & Local, ASL & Local, Marine/Nature Reserves, Mineral Deposit, Archaeological Site, Heritage, Military, Marine/Nature Reserves, Mineral Deposit, Archaeological Site, Heritage, Military, Avoidance of zones exposed to anchor damage, Avoidance of zones exposed to Avoidance of zones exposed to anchor damage, Avoidance of zones exposed to droppeddropped--object damage, Iceberg plow marks (site specific))object damage, Iceberg plow marks (site specific))

Shore Crossings (Shore Crossings (Environmental constraints Environmental constraints conservation, Social impact (fishermen, conservation, Social impact (fishermen, pearl worker), Land usage pearl worker), Land usage proximity to people, Beach mobility, Minimise shore proximity to people, Beach mobility, Minimise shore approaches (pipeline stability), approaches (pipeline stability), Maintain adequate clearance from adjacent islands,Maintain adequate clearance from adjacent islands,Onshore routing / destination)Onshore routing / destination)

Installation constraints (Installation method, Installation constraints (Installation method, Minimum curvature, Vessel anchor Minimum curvature, Vessel anchor patterns, Vessel minimum operating draft, Lay tolerances, Platform approaches)patterns, Vessel minimum operating draft, Lay tolerances, Platform approaches)

Future Marine Development & ActivitiesFuture Marine Development & Activities

PoliticsPolitics


Start and DestinationStart and Destination

Gather all available informationGather all available information

Naval ChartsNaval Charts

Projects in the RegionProjects in the Region

Seismic DataSeismic Data

Environmental ConstraintsEnvironmental Constraints

Block OwnershipBlock Ownership

ROUTE STUDYROUTE STUDYROUTE STUDYROUTE STUDYROUTE STUDYROUTE STUDYROUTE STUDYROUTE STUDY

14

Propose Preliminary Routes (Rules of Thumb)Propose Preliminary Routes (Rules of Thumb) The shortestThe shortest

The safest (Risk & Impact)The safest (Risk & Impact)

Easiest to InstallEasiest to Install

CostCost

Define Scope of Work for Route (Marine) SurveyDefine Scope of Work for Route (Marine) Survey GeodeticalGeodetical

GeophysicalGeophysical

GeotechnicalGeotechnical

HydroHydro--OceanographyOceanography

Visual (optional)Visual (optional)

One day offshore will pay for months of office engineering timeOne day offshore will pay for months of office engineering time


Optimal route selection at the outset of an offshore pipeline project has the potential to Optimal route selection at the outset of an offshore pipeline project has the potential to minimise subsequent design challenges and dramatically reduce construction costs. The minimise subsequent design challenges and dramatically reduce construction costs. The critical importance of routing decisions is recognised in our approach, which combines critical importance of routing decisions is recognised in our approach, which combines extensive experience with rapid and effective analysis tools to screen candidate routes. extensive experience with rapid and effective analysis tools to screen candidate routes.


15

Gulf of Aqaba Crossing, 2003Gulf of Aqaba Crossing, 2003

The 36 pipeline passes from Taba in The 36 pipeline passes from Taba in Egypt to Aqaba in Jordan, crossing the Egypt to Aqaba in Jordan, crossing the 860m deep Gulf of Aqaba: a depth record 860m deep Gulf of Aqaba: a depth record for a large diameter pipeline. Both sides for a large diameter pipeline. Both sides of the gulf are extremely steep, with of the gulf are extremely steep, with numerous gullies and unstable slopes, and numerous gullies and unstable slopes, and delicate corals at the shore approaches. delicate corals at the shore approaches. Any preAny pre-- or postor post--lay intervention would lay intervention would have been very costly, with no scope for have been very costly, with no scope for trenching or rock cover. Identifying a trenching or rock cover. Identifying a suitable route was particularly suitable route was particularly challenging, requiring sophisticated challenging, requiring sophisticated numerical analysis to minimise span numerical analysis to minimise span lengths and avoid landslide runlengths and avoid landslide run--out zones. out zones.


Gulf of Suez, 2005Gulf of Suez, 2005

Offshore and Onshore Support for pipeline Offshore and Onshore Support for pipeline routed in shallow waters with extensive routed in shallow waters with extensive reefs and rocky areas off the east coast of reefs and rocky areas off the east coast of Egypt. Pipeline route optimized to avoid Egypt. Pipeline route optimized to avoid excessive spanning, relax installation excessive spanning, relax installation tolerances, and avoid severe cross slopes tolerances, and avoid severe cross slopes to ensure lateral stability. . to ensure lateral stability. .


16

The minimum radius of curvature, R is based on the following The minimum radius of curvature, R is based on the following bending stress equation;bending stress equation;

where,where,

yy == radius of steel pipe (mm)radius of steel pipe (mm)

EE == modulus of elasticity for steel (modulus of elasticity for steel (MPaMPa))

SS == specified minimum yield stress (SMYS) (specified minimum yield stress (SMYS) (MPaMPa))

ff == factor of safety, taken as 5%factor of safety, taken as 5%

Radius of curvatureRadius of curvatureRadius of curvatureRadius of curvatureRadius of curvatureRadius of curvatureRadius of curvatureRadius of curvature

SfEyR

=

.

2.E DR f SMYS=


R

aaaa

y

x1x2

L

xt

3;

4mod ;

5 10%

sin ( / 2) / 2( )1(2 )

2(2 )

(2 )

EDR faE ulus of ElasticityD pipe diameterfa design factor x SMYSdesign factorSMYS Minimum Yield Strength

y Ry R y

xy R y

yRx

y R y

xt y R yL R

=

=

=

=

=

=

=

=

=

=

=

aaaa

Pipeline components (e.g. valves, tees) in particular Pipeline components (e.g. valves, tees) in particular should not be located on the curved route sections should not be located on the curved route sections of the pipelineof the pipeline

Jansen VHJansen VH ((This section calculate radius natural bend based on moment curvature (section pipeline design calculation for elastic curve pipe)

17


.

2.E DR f SMYS=

R

Turning Point (TP) - 1

Turning Point (TP) - 2

Inflection Point (IP)


Based on tension laying capacity:

( )subTR SF

i W=

T = Bottom Tension (residual lay tension) (kg)i = Lateral pipe/seabed friction coefficient ~ 0.5 Wsub = Pipe Submerged Weight (kg/m)SF = safety factor, 2 (considered appropriate)

18

Survey are for finding information about:Survey are for finding information about:

Geodetic Survey:Geodetic Survey:Geodetical parametersGeodetical parameters

Geophysical:Geophysical:The seabed along the pipeline route (contours)The seabed along the pipeline route (contours)

Geotechnical:Geotechnical:The nature of soilThe nature of soil

HydroHydro--Oceanography:Oceanography:Meteorology & Environmental LoadMeteorology & Environmental Load

Visual:Visual:Real Time Monitoring (by ROV, AUV, DIVER)Real Time Monitoring (by ROV, AUV, DIVER)

Marine surveyMarine surveyMarine surveyMarine surveyMarine surveyMarine surveyMarine surveyMarine survey

Data Processing of Pipeline Route Survey Flow Chart Data Processing of Pipeline Route Survey Flow Chart

Bathymetry

SideScanSonar

SubBottomProfile

Magneto

Soil

Interpretation

Contouring Topography Map

LaboratoryAnalysis

Thematic Map

Description

Thematic Map DrawingMap

REPORT

Description

GeneralDescription

marine survey marine survey marine survey marine survey marine survey marine survey marine survey marine survey geophysical & geotechnicalgeophysical & geotechnicalgeophysical & geotechnicalgeophysical & geotechnicalgeophysical & geotechnicalgeophysical & geotechnicalgeophysical & geotechnicalgeophysical & geotechnical

19

Offshore Geodetic Survey:Offshore Geodetic Survey:

DGPSDGPS

Static Global Positioning System (GPS) & Real Time Static Global Positioning System (GPS) & Real Time Kinematic (RTK) SurveyKinematic (RTK) Survey

TraverseTraverse

Profiling & CrossProfiling & Cross--Section LevelingSection Leveling

Advance contour mapping with fast, accurate and Advance contour mapping with fast, accurate and flexible result for planning, design and constructionflexible result for planning, design and construction

Marine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) survey

Offshore Geophysical Survey:Offshore Geophysical Survey:

BathymetryBathymetry

Side Scan SonarSide Scan Sonar

SubSub--bottom profilingbottom profiling

Grab samplesGrab samples

MagnetometerMagnetometer

Marine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) surveyMarine (route) survey

20

Medium ResolutionMedium Resolution Single beam enchosounderSingle beam enchosounder

Hull MountedHull Mounted

750m wide swathe750m wide swathe

Best Best 8m footprint size8m footprint size

High ResolutionHigh Resolution Multi BeamMulti Beam

Towed close to seabedTowed close to seabed

Much narrower swatheMuch narrower swathe

marine survey marine survey marine survey marine survey marine survey marine survey marine survey marine survey -------- geophysicalgeophysicalgeophysicalgeophysicalgeophysicalgeophysicalgeophysicalgeophysical

BathymetryBathymetry


21

Used to find seabed profile, wrecks, wellhead, rock Used to find seabed profile, wrecks, wellhead, rock outcrops etcoutcrops etc

Towed fishTowed fish


Side scan sonarSide scan sonar


Seabed feature from side scan sonar recordSeabed feature from side scan sonar record

22


Seabed feature from side scan sonar recordSeabed feature from side scan sonar record

SANDY CORAL

DIRECTION OF SHIP MOVEMENT

HIGH REFLECTIVITY

HIGH REFLECTIVITY120 Meter CORAL DOMINATED BUT SAND ALSO EXHIBITED

50 Meter

General purpose pingerGeneral purpose pinger

Seismic structure of top 10Seismic structure of top 10--15m of seabed15m of seabed

Looking for reflector horizonsLooking for reflector horizons

Acoustic signatureAcoustic signature

Can use AUV Can use AUV

(autonomous underwater vehicle)(autonomous underwater vehicle)


SubSub--bottom profilerbottom profiler

23


Seabed profile from subSeabed profile from sub--bottom profilerbottom profiler

SUB BOTTOM PROFILER RECORD

SEABED SURFACE

LAYER 1

LAYER 2

LAYER 1

LAYER 2LAYER 2

SEA WATERSEA WATER

LAYER 1

500 Meter

100 Meter

80 Meter

60 Meter

120 Meter

140 Meter

160 Meter

180 Meter


Seabed profile from subSeabed profile from sub--bottom profilerbottom profiler

183 Meter

SEABED SURFACE

SEABED SURFACE

ROCK OUTCROP

ROCK

LAYER 1

LAYER 1LAYER 1

LAYER 2

LAYER 2

LAYER 2

SEA WATER

SEA WATER

Line ESC

10 Meter

20 Meter

30 Meter

40 Meter

24

Frequency of sampling varies for trenched vs onFrequency of sampling varies for trenched vs on--bottom bottom pipeline (500m to 5km), typical one was per kmpipeline (500m to 5km), typical one was per km

Offshore Geotechnical Survey:Offshore Geotechnical Survey: SamplingSampling

Gravity CoresGravity Cores Box CoresBox Cores Cone Penetrometer (CPT)Cone Penetrometer (CPT) VibrocoreVibrocore DrillingDrilling

Field Test:Field Test: Deep Boring Test Deep Boring Test Undisturbed Soil SamplingUndisturbed Soil Sampling Standard Penetration TestStandard Penetration Test Vane Shear TestVane Shear Test Dutch Cone Penetration Test Dutch Cone Penetration Test

Laboratory Test:Laboratory Test: Specific Gravity Specific Gravity Content Content Grain Size Analysis Grain Size Analysis Atterberg LimitAtterberg Limit Shrinkage LimitShrinkage Limit

marine survey marine survey marine survey marine survey marine survey marine survey marine survey marine survey -------- geotechnicalgeotechnicalgeotechnicalgeotechnicalgeotechnicalgeotechnicalgeotechnicalgeotechnical

Soil sample from drop coringSoil sample from drop coring


Soil sample from CPTSoil sample from CPT

Soil sample from vibrocoreSoil sample from vibrocore

25

Data interpretationData interpretation

Types of soil or rock at or below seabedTypes of soil or rock at or below seabed

Thickness of layerThickness of layer

Engineering characteristic: unit weight, water content, liquid & Engineering characteristic: unit weight, water content, liquid & plastic limit, grain size, carbonate content, strength, density, plastic limit, grain size, carbonate content, strength, density, porosity etcporosity etc

Shear strength parameters (intact and remoulded undrained shear Shear strength parameters (intact and remoulded undrained shear strength for clay, and angle of friction for sands)strength for clay, and angle of friction for sands)

Relevant deformation characteristicsRelevant deformation characteristics


&HEIGHT & PERIOD OF WAVE

WAVE TRANSFORMATION

TIDAL

CURRENT VELOCITY

WIND SPEED

PHYSICAL

CONDITION

Marine survey Marine survey Marine survey Marine survey Marine survey Marine survey Marine survey Marine survey

HydroHydroHydroHydroHydroHydroHydroHydro--------oceanography surveyoceanography surveyoceanography surveyoceanography surveyoceanography surveyoceanography surveyoceanography surveyoceanography survey

26

Location 1Dari Ke

0558.9 LS 0556.1 LS

106.58 BT 106.11.7 BT

1 100

Parameter Metocean Simbol Unit

Kecepatan Angin

Angin 60 menit-an W60 m/s 3.89 11.55

Tinggi Gelombang

Tinggi Gelombang Signifikan Hs m 0.14 3.2

Periode Gelombang Signifikan Ts s 2.17 7.42

Panjang Gelombang Signifikan Ls m 7.35 85.93

Elevasi Muka Air

Mean Sea Level (MSL) m

Higher Water level (di atas MSL) m

Lowest Water level (di bawah MSL) m

Kecepatan Arus

Kecepatan Total (karena pasut dan angin)

0 % dari kedalaman V0 m/s 0.252 0.480











Kedalaman Perairan (m)

Periode Ulang

Posisi

1

Panjang Pipa (m) 12373

Lokasi

10.5

0.59

0.35

0.60

Metocean dataMetocean dataMetocean dataMetocean dataMetocean dataMetocean dataMetocean dataMetocean data

BOTTOM ROUGHNESSBOTTOM ROUGHNESS

ANALYSISANALYSIS

Bottom Roughness analysis is performed to assess the Bottom Roughness analysis is performed to assess the requirements for seabed preparation and span correction.requirements for seabed preparation and span correction.

The study is accomplished by performing following tasks:The study is accomplished by performing following tasks:

Review of seabed profile using the pipeline alignment Review of seabed profile using the pipeline alignment drawings and identify the segments of the pipeline route drawings and identify the segments of the pipeline route that require detailed investigations;that require detailed investigations;

Perform bottom roughness using specialist software, such Perform bottom roughness using specialist software, such as OFFPIPE, SAGE, etc, and determine locations of as OFFPIPE, SAGE, etc, and determine locations of significant free spans and number of free spans that require significant free spans and number of free spans that require span correction;span correction;

27

GeneralGeneral

Determine areas that may require preDetermine areas that may require pre--lay correction;lay correction;

Determine areas that may require postDetermine areas that may require post--lay correction;lay correction;

Review alternative methods of remedial corrections, and Review alternative methods of remedial corrections, and propose remedial actions that are cost effective.propose remedial actions that are cost effective.

Bottom Roughness AnalysisBottom Roughness Analysis

Specialist finite element or finite difference software is normally Specialist finite element or finite difference software is normally used for this analysis.used for this analysis.

The bottom roughness analysis is performed for empty, hydrotest The bottom roughness analysis is performed for empty, hydrotest and operational conditions. and operational conditions.

The computer model for the bottom roughness analysis The computer model for the bottom roughness analysis incorporates following information:incorporates following information:

Properties of the pipeline, including weight of concrete weight Properties of the pipeline, including weight of concrete weight coating and content.coating and content.

Seabed profile is simulated using xSeabed profile is simulated using x--y coy co--ordinates along the ordinates along the pipeline route under investigation.pipeline route under investigation.

Surface soil is simulated in the analysis to determine level of Surface soil is simulated in the analysis to determine level of settlement for different design conditions, i.e. empty and flooded settlement for different design conditions, i.e. empty and flooded with seawater.with seawater.

28

Hydrotest pressure is included for the pipe in hydrotest Hydrotest pressure is included for the pipe in hydrotest condition for bottom roughness analysis to determine if condition for bottom roughness analysis to determine if the pipe stresses and predicated spans are within design the pipe stresses and predicated spans are within design allowable. This determines if the pipeline can be allowable. This determines if the pipeline can be hydrostatically tested before span correction. hydrostatically tested before span correction.

For analysis in operation condition, design pressure and For analysis in operation condition, design pressure and temperature is included in the analysis. temperature is included in the analysis.

The predicted free spans are then compared with The predicted free spans are then compared with recommended allowable free spans for each design condition. recommended allowable free spans for each design condition.

Also stresses in the pipeline are checked to ensure they are Also stresses in the pipeline are checked to ensure they are within the design allowable for all design conditions.within the design allowable for all design conditions.

Bottom Roughness AnalysisBottom Roughness Analysis

Interpretations of FindingsInterpretations of Findings

As the input for seabed profile coAs the input for seabed profile co--ordinates are of certain intervals, ordinates are of certain intervals, span can be predicted to an accuracy of plus or minus the spacing span can be predicted to an accuracy of plus or minus the spacing of the pipe nodes. The number of the spans reported in the above is of the pipe nodes. The number of the spans reported in the above is therefore subjected to that accuracy. therefore subjected to that accuracy.

The estimated number of spans reduces when the pipeline is The estimated number of spans reduces when the pipeline is flooded. This is due to increase in weight which results in (1) further flooded. This is due to increase in weight which results in (1) further settlement/collapse of soil due to increased external load and (2) settlement/collapse of soil due to increased external load and (2) increase in pipe sag which will reduces pipe span.increase in pipe sag which will reduces pipe span.

After hydrotesting and dewatering of the pipeline, the collapsed soil After hydrotesting and dewatering of the pipeline, the collapsed soil will remain in the collapsed state. However, as the pipeline is now will remain in the collapsed state. However, as the pipeline is now lighter, the pipe span will increase. The actual span length cannot lighter, the pipe span will increase. The actual span length cannot be predicted but would be somewhere between that for an empty be predicted but would be somewhere between that for an empty condition and for a flooded condition.condition and for a flooded condition.

29

Interpretations of FindingsInterpretations of Findings

If the span corrections is carried out only after pipeline If the span corrections is carried out only after pipeline has been hydrotested and dewatered, then the expected has been hydrotested and dewatered, then the expected number of span correction corresponding to operation number of span correction corresponding to operation condition can be expected to be less, but this is also condition can be expected to be less, but this is also depend on the soil condition.depend on the soil condition.

Estimation of spans is based on the assumption that the Estimation of spans is based on the assumption that the pipeline is laid exactly on the route. However, as pipe pipeline is laid exactly on the route. However, as pipe cannot be laid exactly on the planned route, and seabed cannot be laid exactly on the planned route, and seabed varies due to route deviation, the number of spans and varies due to route deviation, the number of spans and span length predicted are merely indicative. Actual span length predicted are merely indicative. Actual postpost--lay survey is required to determine the actual span lay survey is required to determine the actual span lengths and numbers of spans requiring correction.lengths and numbers of spans requiring correction.

Remedial ActionsRemedial Actions

Commonly used remedial measures for span correction Commonly used remedial measures for span correction are:are:

TABLE 1 TABLE 1 -- PIPE SPAN ABOVE DESIGN ALLOWABLE DURING PIPE SPAN ABOVE DESIGN ALLOWABLE DURING OPERATION CONDITIONOPERATION CONDITION

Type of Anomaly Type of Anomaly Required Remedial ActionsRequired Remedial Actions

High spots causing excessive High spots causing excessive pipe stress and unacceptable pipe stress and unacceptable spans spans

High spots to be removed prior High spots to be removed prior to pipe laying (Preto pipe laying (Pre--lay corrections) lay corrections)

Unacceptable spans but pipeline Unacceptable spans but pipeline stress within allowable limits stress within allowable limits

Either remove source of span Either remove source of span before pipe laying or correct span before pipe laying or correct span after pipe laying (Postafter pipe laying (Post--lay lay correction) correction)

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Remedial ActionsRemedial Actions

The typical viable alternatives for correcting spans are:The typical viable alternatives for correcting spans are:

For soft soil, preFor soft soil, pre--sweeping to clear minor seabed ripples using a tug sweeping to clear minor seabed ripples using a tug dragging a chain or pipe at stern to clear the ripples and smoothen dragging a chain or pipe at stern to clear the ripples and smoothen seabed. A few tug runs would be required.seabed. A few tug runs would be required.

For isolated areas where separation between the bottom of the pipe For isolated areas where separation between the bottom of the pipe and seabed is significant (1m or more), or where localised stresses and seabed is significant (1m or more), or where localised stresses are unacceptable, a dredger or similar equipment could be mobilized are unacceptable, a dredger or similar equipment could be mobilized to remove these.to remove these.

PostPost--lay intervention jetsled, which is already required for trenching lay intervention jetsled, which is already required for trenching in the near shore area, is very viable for span correction. in the near shore area, is very viable for span correction.

Using conventional groutbags,Using conventional groutbags,

Alternatively, span correction using a combination of jetting and Alternatively, span correction using a combination of jetting and placement of conventional grout bags/concrete mattresses may be placement of conventional grout bags/concrete mattresses may be adopted. adopted.

Analysis ExampleAnalysis Example

Pipeline Data:Pipeline Data:

~65m Water Depth~65m Water Depth

Undulating seabed with soft clayey soil and presence of Undulating seabed with soft clayey soil and presence of buried corals.buried corals.

Calculated allowable span:Calculated allowable span:

InstallationInstallation HydrotestHydrotest OperationOperation

Allowable Static Span (m)Allowable Static Span (m) 9191 5454 4646

Allowable Dynamic Span (m)Allowable Dynamic Span (m) 4848 4444 3838

Recommended Allowable Span (m)Recommended Allowable Span (m) 4747 4343 3737

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22" Pipeline - Installation Condition

-74

-73

-72

-71

-70

-69

-68

3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000Horizontal Distance (m)

Ele

va

tion

(m

)

0

10

20

30

40

50

60

70

80

90

100

%SM

YS

Seabed ProfilePipeline ProfilePipe Stress

Pipeline Spanning (L =72m)

Recommended allowable span (Installation) = 47mRecommended allowable span (Installation) = 47m

Analysis Example Analysis Example Installation CaseInstallation Case

Analysis Example Analysis Example Hydrotest CaseHydrotest Case

22" Pipeline - Hydrotest Condition

-74

-73

-72

-71

-70

-69

-68


Ele

vat

ion

(m

)

0

10

20

30

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50

60

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%SM

YS


Span Length reduces in Hydrotest(L = 38m)

Collapsed soil due to weight of pipeline in

Hydrotest

Recommended allowable span (Hydrotest) = 43mRecommended allowable span (Hydrotest) = 43m

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Analysis Example Analysis Example Operation CaseOperation Case

22" Pipeline - Operation Condition (Corroded Pipe)

-74

-73

-72

-71

-70

-69

-68

3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000

Horizontal Distance (m)

Ele

va

tion

(m

)

0

10

20

30

40

50

60

70

80

90

100

%SM

YS


Span Length increases due to lighter pipe content but less

than that of installation (Lope = 60m)

Collapsed soil remain collapsed

Recommended allowable span (Operation) = 37mRecommended allowable span (Operation) = 37m

Analysis Example Analysis Example High Spot LocationHigh Spot Location

22" Pipeline - Operation Condition

-74

-73

-72

-71

-70

-69


Ele

va

tion

(m

)

0

10

20

30

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60

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100

110

%SM

YS


High spot causing Overstress and adjacent

long pipeline span

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Analysis Example Analysis Example Possible Prelay Span Possible Prelay Span Correction by DredgingCorrection by Dredging

22" Pipeline - Operation Condition

-74

-73

-72

-71

-70

-69


Ele

va

tion

(m

)

0

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110

%SM

YS


Possible Dredged Profile to remove high spots and

long spans

Analysis Example Analysis Example Use of Typical Grout Use of Typical Grout Bags for Span CorrectionBags for Span Correction

NOTES:

ELEVATION VIEW

GROUT BAGS

FOR SPAN CORRECTIONS

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Review Survey DataReview Survey Data

Refine Preliminary RoutesRefine Preliminary Routes

The shortestThe shortest

The safest (Risk & Impact)The safest (Risk & Impact)

Easiest to InstallEasiest to Install

CostCost

Bottom Roughness AssessmentBottom Roughness Assessment

Software tools to predict spansSoftware tools to predict spans

Optimise routesOptimise routes

Route selection & optimizationRoute selection & optimizationRoute selection & optimizationRoute selection & optimizationRoute selection & optimizationRoute selection & optimizationRoute selection & optimizationRoute selection & optimization

Mass PreMass Pre--excavation excavation PSL JetpropPSL Jetprop

PrePre--lay lay -- DiverlessDiverless

Post Lay Post Lay -- DiverlessDiverless

Strakes Strakes --CRPCRPMattsMatts

Grout BagsGrout Bags

ROV TrenchersROV Trenchers

SupportsSupportsPloughsPloughs

interventioninterventioninterventioninterventioninterventioninterventioninterventionintervention

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1.1. Very rugged seabedVery rugged seabed

2.2. Very high tidal currents across the Very high tidal currents across the

possible pipeline routes means the possible pipeline routes means the

seabed is very mobileseabed is very mobile

3.3. 3 pipeline routes need to be fitted in3 pipeline routes need to be fitted in

4.4. LNG tanker terminal and shipping LNG tanker terminal and shipping

traffictraffic

Routing study case 1Routing study case 1Routing study case 1Routing study case 1Routing study case 1Routing study case 1Routing study case 1Routing study case 1

1.1. Due to the shore approach section of the pipeline, the Due to the shore approach section of the pipeline, the pipeline installation startpipeline installation start--up will probably be initiated from up will probably be initiated from the Balongan onshore facilities end.the Balongan onshore facilities end.

2.2. From the Balongan onshore end, the pipeline would then From the Balongan onshore end, the pipeline would then headed generally in the Northheaded generally in the North--East direction toward the East direction toward the new PLEM.new PLEM.

3.3. It is proposed that the submerged pipeline shall be postIt is proposed that the submerged pipeline shall be post--trenched to a minimum burial depth of 2.0m from the top trenched to a minimum burial depth of 2.0m from the top of pipe of pipe

4.4. The onshore pipeline shall be buried with minimum burial The onshore pipeline shall be buried with minimum burial depth of 1.0m from the top of pipe.depth of 1.0m from the top of pipe.

5.5. Total pipeline length is 10.46 km.Total pipeline length is 10.46 km.


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Installation subsea pipeline from Teluk to Muara



Ormen Lange Ormen Lange -- LangeledLangeled

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Ormen Lange Ormen Lange Langeled ConceptLangeled Concept


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Ormen Lange Ormen Lange Langeled RoutingLangeled Routing

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Narrow & Steep LandfallNarrow & Steep Landfall


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Ormen Lange Ormen Lange -- LangeledLangeled


Steep Landfall & Sharp CurveSteep Landfall & Sharp Curve

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Route Selection CriteriaRoute Selection Criteria

Route StudyRoute Study


Route Selection and OptimizationRoute Selection and Optimization

Bottom RoughnessBottom Roughness

Routing DevelopmentRouting DevelopmentRouting DevelopmentRouting DevelopmentRouting DevelopmentRouting DevelopmentRouting DevelopmentRouting Development

SEKIAN..SEKIAN..

TERIMA KASIH

routing selection

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