All-flexible and hybrid solutions for Ultra Deep Water Simplified - PowerPoint PPT Presentation

All-flexible and hybrid solutions for Ultra Deep Water Simplified presentation SUT July 2006 Jean-Paul Ferraz

Contents � Flexible pipe capabilities � Hybrid Catenary Riser (HCR) � Free Standing Hybrid Riser (FSHR) 2

Flexible pipe capabilities � Objective Define maximum water depth vs pipe internal diameter � Assumptions Bottom risers and flowlines Rough bore pipes Sweet & sour services Design pressure (differential) / temperature : 3000 psi / 90°C Radii ≥ 2 x pipe natural radius (flowlines) 1.25 DAF during installation (flowlines) Limited Deep Blue VLS tension capacity Current manufacturing limits (weight, diameters, bending stiffness, etc.) 3

Flexible pipe capabilities � Driving design issues Collapse Lateral buckling Reverse end-cap effect (high strength tapes) Installation top tension for flowlines & utilization factor x damaging pull � Maximum water depth as a function of pipe internal diameter curves were removed from this simplified presentation. 4

UDW flexible pipes qualification, DIP tests Vessel offset: 40 m 0 Pipe follower First mark (reference point for the TDP for the dry annulus test condition). Test sample Dead weight Seabed 1800 m TDP at the second mark (flooded annulus condition) depth 5

UDW flexible pipes qualification, DIP tests 6

UDW flexible pipes qualification, DIP tests � 18 different structures tested offshore Brazil � 13 campaigns of the Sunrise 2000 laying vessel � ~100 m long samples tested in dry and flooded annulus conditions � WD from 1080 m to 2100 m � ID from 4” to 11” � 9” pipe qualified for 2100 m water depth 7

Contents � Flexible pipe capabilities � Hybrid Catenary Riser (HCR) � Free Standing Hybrid Riser (FSHR) Free Standing Hybrid Riser (FSHR) � 8

Hybrid Catenary Riser (HCR), an observation � Simple free hanging configuration: very localized high curvature variations Riser Top 0,25 0,20 Curvature 0,15 Touch Down Point 0,10 0,05 0,00 Riser Top Riser Base Position along riser TDP 9

Hybrid Catenary Riser (HCR), features � Riser concept (Technip’s patent) for Ultra Deep Water applications Flexible Flexible jumper at top side Rigid pipe as intermediate section Flexible pipe at TDP � General technical benefits: Rigid Flexible pipe allows a much smaller SCR bending radius at the TDP HCR Much steeper configurations Reduced top and bottom tensions Flexible Avoid use of flex or stress joints 10

Hybrid Catenary Riser (HCR), advantages � Global configuration similar to that of Flexible Riser Small hang-off angle Small bending radius at the TDP Same behaviour as common flexible free hanging configuration � Horizontal vessel motions induce little dynamic loads � Vertical vessel motions induce most of dynamic response Transferred to the bottom section of the riser If motions are important a small buoyant wave shape can be included 11

Hybrid Catenary Riser (HCR), advantages � Flexible-rigid connections outside high curvature zones � Flexible pipe bending deformations locally absorbed Flexible pipe curvature variations at connections much smaller than at TDP No large moments induced in the rigid pipe � Simple connection design Standard flanges Small bending stiffeners (more for handling than for dynamic behaviour) at intermediate connections No special design required for rigid pipe � All configuration (flexible + rigid) can be installed with Deep Blue vessel 12

Hybrid Catenary Riser (HCR), driving parameters � Decoupled and optimized designs Top riser flexible jumper: design driven by fatigue however with reduced tensions Intermediate rigid section: reduced stress due to curvature variation absorbed by flexible pipe Bottom flexible section: design typically driven by collapse and compressive loads 13

HCR vs SCR vs flexible risers study case � Water Depth 2750 m; offshore West Africa environmental conditions � Spread moored FPSO � Free hanging configuration � HCR, SCR, flexible riser designs SCR 4000 m long (15 deg hang-off angle) HCR & flexible 3000 m long (4 deg hang-off angle) � The HCR consists of: 8” Gas Injection riser 10’’ Water Injection riser 30 m of flexible pipe 30 m of flexible pipe 2520 m of rigid pipe 2520 m of rigid pipe 450 m of flexible pipe 450 m of flexible pipe Reference : DOT paper by Technip, New Orleans, November 2000 14

HCR vs SCR vs flexible risers study case � The HCR reduces the tensions Max Top Tension (te) At the top Flexible HCR SCR 500 � Simplifies the hang-off 360 355 345 285 � Reduces required payload capacity 210 of floaters with small water crossing areas 8" GI Riser 10" WI Riser At the bottom Max Bottom Tension (te) � Avoids the need of a riser base Flexible HCR SCR anchor 240 150 80 80 80 55 8" GI Riser 10" WI Riser 15

HCR vs SCR vs flexible risers study case � The HCR reduces the fatigue issues in the rigid pipe The maximum occurring stress is smaller The stress range is smaller Max Stress Range in Rigid Pipe (MPa) Max Stress in Rigid Pipe (MPa) +140 MPa +117 MPa Flexible HCR SCR 215 417 177 300 Flexible HCR SCR 238 175 75 44 8" GI Riser 10" WI Riser 8" GI Riser 10" WI Riser 16

HCR vs SCR vs flexible risers study case � The HCR reduces the seabed congestion Suspended Length of pipe (m) The riser length is smaller +720 m 3580 3580 The horizontal projection of the riser is 2860 2860 2860 2860 smaller The zone in which the TDP moves is smaller Flexible HCR SCR Horizontal Projection (m) 8" GI Riser 10" WI Riser 1900 1900 Flexible HCR SCR Length of TDP Zone (m) +450 m 700 700 670 670 670 670 Flexible HCR SCR 250 250 250 250 8" GI Riser 10" WI Riser 8" GI Riser 10" WI Riser 17

Contents � Flexible pipe capabilities � Hybrid Catenary Riser (HCR) � Free Standing Hybrid Riser (FSHR) 18

Free Standing Hybrid Riser (FSHR) components Near surface top-tensioned rigid riser � Compartmentalised air can � Flexible Jumper Air can uplift 400 to 500 t � Air Can Air can depth of 150 to 200 m Taper Joint � Bottom connection taper joint / flex � joint Steel Riser Flexible jumper 300 to 450 m long � Gooseneck connection at can with � bend stiffener Classic connection at FPU (EF / bend � stiffener) Taper / flex Joint 19

Free Standing Hybrid Riser (FSHR) advantages � Weight reduction at FPU � Flowline / riser installation and pre-commissioning independent from FPU arrival � Fatigue issue eliminated due to FPU motion decoupling � Air can depth of 150 to 200 m wd ⇒ waves excitation mitigation � Suitable for big diameter pipes � Highly insulated lines (e.g. PiP) � Flow assurance improvement � Inspection and integrity monitoring implemented into the system design 20

Free Standing Hybrid Riser (FSHR) cross section IPB flexible jumper 21

Free Standing Hybrid Riser (FSHR) fabrication & installation � Air can Pre-fabrication of air can in modules and testing Final air can assembly mounting prior to load out on transportation barge � Riser J-Lay on Deep Blue 22

Free Standing Hybrid Riser (FSHR) installation � Installation of jumper with standard laying vessel 23