COMPANY: EMAS-AMC (SUBCONTRACTOR)
PROJECT TITLE: Liwan Deepwater Project
CLIENT: Husky Oil China
VESSEL: Pipe Lay Barge (DLB) Lewek Centurion
Lewek Centurion is a self-propelled DP2 S-lay pipeline installation vessel, The vessel measures 146.5m long by 30m wide (35m wide included the external thrusters), with mean operating draft of 7.8 m. The pipe lay ramp is located on the center of the barge and runs the entire length of the barge.
The vessel is equipped with one pipe transfer crane and one shipboard crane. The pipe transfer crane has a maximum capacity of 36MT at 30m radius, and the shipboard crane has a maximum capacity of 20MT at 25m knuckle boom. The main crane is a 300 MT Kenz crane at 15-16m radius.
LCE is also equipped with 300mT A-Frame and retractable Hang off Platform at port side with 300mT capacity at maximum retraction.
All of the vessel accommodation is located above the main deck, and is fully air conditioned with a mess hall and recreational facilities. A helideck is located over the bow superstructure and is capable of accommodating an S61 helicopter.
MULTI SUPPORT VESSEL (MSV): Volantis
During jumper installation LCE will be assisted by two (2) units of ROV onboard a MSV provided by CONTRACTOR.
SCOPE OF WORK:
SUBCONTRACTOR’ installed 2x of the following jumpers:
8 inch vertical jumper: EM-RJ-04
8 inch vertical jumper: LH-RJ-01
Works performed by SUBCONTRACTOR were CVC jumper lifting, deployment landing onto receiver hubs, spreader bar and jumper rigging recovery.
ROV operations prior to the installation i.e. hub cleaning, etc. ;during jumper lowering i.e. MEG gel dummy hub release, etc. ;and after the installation i.e. soft landing with running tools, running tools recovery, etc. were not included in the SUBCONTRACTOR scope of work. The word “spool” and “jumper” used here are interchangeably but they refer to the CVC jumpers above.
I was on board to install both jumpers
EMAS-AMC was subcontracted by Saipem to perform the installation of pipelines as part of Liwan 3-1 Area Facilities Development Project. The works involved installation of two (2) pipelines including its pipeline end terminals (PLET’s), four (4) in total, and lifting support of two (2) spools which will be installed offshore in South China Sea, approx. 300 km south from Hong Kong in a water depth range from 1100 to approx. 1400 meter. EMAS-AMC mobilized its pipelay vessel, the Lewek Centurion, end of March 2014 in Singapore for an arrival date of 28th April 2014 at latest in Shekou, China, for inward clearances and pipe load out. The installation activities were estimated to last approximately two (2) months
|Size||[-]||219.1mm OD x 11.1mm WT(12.7mm WT at bend)|
|Material||[-]||DNV 450 (SMLS) + CRA 625|
|Associated Spreader Bar Size||[-]||36” OD x 59m||48” OD x 59m|
|Location||[-]||EM – PLET P7
|WELL – PLET P8 (1123m WD)|
|Max. weight in air (water)||[MT]||21.2 (14.4)||20.3 (15.6)|
|Total jumper length||[m]||55.2||61.3|
|Rigging weight in air:|
|· Jumper lower rigging including buoys, tugger lines||[MT]||5.4||5.4|
|· Spreader bar weight (59m Length)||40.8||52.0|
|· Spreader bar upper rigging and tugger lines||3.0||2.5|
|· Rigging weight in water:|
|· Jumper lower rigging including buoys, tugger lines||3.0||3.0|
|· Spreader bar weight (59m Length)||35.||45.2|
|· Spreader bar upper rigging and tugger lines||2.6||2.6|
|Total deployment weight in air (water) [including contingency factor of 1.1]||[MT]||77.4 (61.1)||88.9 (72.7)|
|Total spreader bar recovery weight in air (water) [including contingency factor of 1.1]||[MT]||54.1 (45.2)||68.6 (55.5)|
|Attachment: CVC Running Tool weight in air (water)||[MT]||5.1 (4.4) each||5.1 (4.4) each|
|Weight tolerance in air (water)||[MT]||± 0.81 (0.49)||± 0.51 (0.31)|
|Length tolerance||[m]||± 8.0||± 5.0|
Recommended weather limitations used of Cranemaster for the jumper installation are shown in the table below. OCM assessed sufficient weather window prior to start of operation, at least up to the spreader bar disconnection.
|Tp [s]||Limiting Sea States – Hs [m]|
|Deployment Criteria –
|Deployment Criteria– In Depth||Landing Speed Criteria
|EM-RJ-04 & LH-RJ-01||EM-RJ-04 & LH-RJ-01||EM-RJ-04||LH-RJ-01|
Installation Tolerance and Target Location
Both jumpers was installed onto each connection hub. Prior to installation, each jumper was sized according to the results of jumper metrology. Target co-ordinate and installation tolerances for the jumper installation are presented in the table below:
|CVC RT Landing tolerance:|
|Max landing speed||[m/s]||0.8|
|Max angular misalignment of RT for landing on hub||[deg]||1.5|
|Max angular misalignment of connector in RT for jumper connection to hub receiver||[deg]||1.5|
|Max total angular misalignment between connector and hub for final connection||[deg]||3 (1.5 + 1.5)|
|Max allowable hub receiver inclination from vertical||[deg]||+/- 5|
|Max lateral misalignment in any direction||[inch]||+/- 6.75 (~171mm)|
|Landing position – Well LH 34-2-1||[-]||N/A||E 351800.41m N 2217148.18m
|Landing position – PLET P8||[-]||N/A||E 351846.97 m N 221732.30m
|Landing position – East Manifold Hub HT5||[-]||E 337712.6m N 2205876.8m
|Landing position – PLET P7||[-]||E 337755.43m N 2205895.97m
Material & Equipment List
The table below lists items and quantities for 1 batch of 2 jumpers transported on 1 cargo barge. This list was for jumper lifting, lowering and landing only.
|Ref.||Material and Equipment||Qty||Remarks|
|1.||Vertical Jumper||2 nos.||CONTRACTOR Provided|
|2.||CVC Running Tools (2 nos. pre-installed on each jumper)||4 nos.||CONTRACTOR Provided|
|3.||Spreader Bar with Upper and Lower Rigging, including clumpweight & temporary buoy for landing, where applicable||2 sets||CONTRACTOR Provided|
|4.||Working platform for Spreader Bar Upper Rigging Connection||2 sets||CONTRACTOR Provided|
|5.||Work class ROV||2 nos.||CONTRACTOR Provided, onboard MSV|
|6.||Cranemaster (4.5m stroke length) equipped with rigging – 150MT SWL
|7.||EMAS Transfer Rigging||1 set||SUBCONTRACTOR|
|8.||SAIPEM Transfer Rigging||1 set||CONTRACTOR Provided|
|9.||Load Control Lines Rigging||1 set||SUBCONTRACTOR|
Cranemaster was selected to be used as passive heave compensation system for the jumper installation. Prior to deployment of each jumper, the Cranemaster’s gas pressure was set according to the specific characteristic of each jumper.
It is noted that the Cranemaster unit to a certain extent functions as a swivel as long as the piston rod was extracted from zero position which in this case, eased ROV orientation during jumper lowering.
|Cranemaster Unit||[-]||CM2-150T-4500-A (max stroke length = 4.5m)|
|Safe Working Load||[MT]||150|
|Max water depth||[m]||3000|
|Size||[mm]||Length 6340 to 10840mm (zero to full stroke) Diameter 660mm|
|Weight with shackles in air (water)||[MT]||6.321 (4.603)|
|Mounting direction||[-]||Piston road pointing down|
General Installation Scenario
The installation of two (2) 8 inch vertical jumpers with Lewek Centurion commenced from lifting each jumper from CONTRACTOR’s material barge, lowering through splash zone, releasing MEG gel dummy hubs and landing on the connection hubs. The general sequence is as summarized below:
Pre-Installation Activities by CONTRACTOR/Initial Status on Site
- Pre-installation survey and verification of the status of connection hubs ensuring no potential obstacles for the jumper installation
- Preparation on the connection hubs was performed by CONTRACTOR hub cleaning, removal of pressure cap, sticks injection, debris cap installation and survey of jumper route.
- Material barge with both vertical jumpers were on Both jumpers are pre-rigged with CONTRACTOR’s rigging (spreader bar, upper and lower rigging) and CVC RT’s on both ends in soft land up configuration, were ready to be lifted.
Pre-Installation Activities by SUBCONTRACTOR
- LCE located in Safe Handling Zone (SHZ)
- Set-up Cranemaster to the required pressure
- Rig-up and overboard the Cranemaster below A-frame
- Paid out A&R winch to deploy Cranemaster into water
- Moored material barge alongside LCE
- Inspected jumpers and associated rigging
- Connected transfer rigging to first jumper’s spreader bar
- Attached control lines to pre-rigged tugger rigging on spreader bar
- Performed final inspections, as required and complete/ fill pre-deployment checklis
Installation Activities by SUBCONTRACTOR
- When the material barge was alongside LCE, main crane was used to connect transfer rigging to the first jumper on working platform.
- Lifted the first jumper using LCE main crane and deploy through splash zone to approximately 40m water depth and disconnected control line
- Continued lowering the jumper until 90 metres (elevation of jumper lower connector) water depth for load transfer from main crane to A&R winch. Connected winch ROV hook to transfer rigging.
- Load transferred from main crane to A&R winch;
- Disconnected transfer rigging from LCE main crane using CONTRACTOR provided ROV
- Waited for CONTRACTOR to operate valves on ROV back seal test panel on jumper and dummy hub
- Continued lowering jumper in SHZ until approximately 50m from seabed
- Moved vessel from SHZ towards jumper installation location
- When jumper was close to the landing area, in an area free from any existing or future structures released the MEG
- Once in position, waited for ROV (CONTRACTOR) to remove debris cap on hubs, and clean hub
- ROV orientated the jumper and lower winch to land jumper onto respective hubs
- Waited for CONTRACTOR to carry out connector soft landing at both end
- ROV performed a fix on both hubs. Coordinates was recorded in installation checklist (CONTRACTOR).
Post Installation Activities
- Disconnected rigging from jumper, recover Spreader Bar to material barge and prepare for subsequent jumper lift
- ROV operations: Install gasket, connect jumper to the hubs and recover Running Tools at both ends (by CONTRACTOR)
- As-installed survey (by CONTRACTOR).
Summary of Work Plans
Step #1 Pre-Installation Activities by SUBCONTRACTOR
Step #2 Jumper Lifting, Deployment and Landing
Step #3 Recovery of Jumper Rigging and Preparation for Subsequent Jumper Installation
Step #1 Pre-Installation Activities by SUBCONTRACTOR
- Radio communication between vessels was established.
- Vessels were in Safe Handling Zone.
- Scope of each vessel was clearly identified and is known onboard each vessel.
- Confirmed with CONTRACTOR that ROVs on MSV are ready to dive.
- Pressure caps was removed (by CONTRACTOR).
- Corrosion inhibitor and dye sticks was injected into hubs (by CONTRACTOR).
- Connection hubs was checked free of obstacles (by CONTRACTOR).
- Hubs was cleaned and were covered with a debris cap/inhibitor injection cap.
- MSV and Material Barge were in vicinity (by CONTRACTOR).
- SIMOPS Procedure with MSV in place.
- HIRA Stage 3 was completed.
- PTW/ toolbox talks/ JSA with relevant personnel were in place.
- Weather forecast was assessed.
- A&R wire 109mm OD re-routed through A-Frame sheave with the open spelter socket reinstated.
- A-Frame set to the required angle.
Preparation of Rigging
- Assemble transfer rigging on deck (Ref. Appendix 2) – note: use SAIPEM Transfer Rigging to achieve more reserved hook height.Assemble Cranemaster rigging on deck (Ref. Appendix 2)
- LCE located in Safe Handling Zone (SHZ)SHZ has been specified in CONTRACTOR drawings (Ref. Appendix 1) : F12416-SAI-005-IEN-DWG-1990-04 for Jumper EM-RJ-04F12416-SAI-005-IEN-DWG-1990-05 for Jumper LH-RJ-01
- When the load transfer is complete, adjust Cranemaster height to allow personnel on hang-off platform to disconnect main crane stinger from the Cranemaster.SAFETY NOTE: Ensure crane wire is slack before disconnection.
- Remove control lines from Cranemaster, if any attached.
- Retract the hang-off platform.
- Pay out A&R winch to deploy Cranemaster into water depth of approximately 50m (elevation of hook below Cranemaster), sufficiently away from incoming material barge hull.
Connect Main Crane and A&R Wire to Jumper Rigging
- Bring material barge alongside LCE Port Side with the jumper to be lifted closer to main crane. (Refer Appendix 1 F12416-SAI-005-IEN-DWG-2543-01 for material barge jumpers layout)
Keep approximately 5m safe distance between barge stern and LCE stern extruded thrusters (Ref. Appendix 2 16009-AMC-OPS-DWG-251-02)
NOTE: All barge mooring operations, lifting, overboarding (even rigging overboarding), lowering to 50m above seabed should be carried out in safe handling zone
(Refer to Appendix 1 F12416-SAI-005-IEN-1990)
- Transfer relevant personnel to the material barge (equipped with pre-installation checklist), usingthe rigid billy pugh, for rigging connection and inspection of the jumpers.
- Perform final inspection of jumper, rigging and CVC’s prior to lift-off, install secondary locking bolt(by CONTRACTOR). Complete pre-deployment checklist in Appendix 4.
IMPORTANT NOTE: DO NOT OPEN VALVE ON MEG PLUG.
- Dismantle scaffolding on both ends of the jumper.
Use the main crane to bring the transfer rigging to the material barge to connect to the pre-rigged spreader bar rigging on the work platform. (Ref. Appendix 1 F12416-SAI-005-IEN-DWG-2538) (Ref. Appendix 2 16009-AMC-OPS-DWG-404-00 for EMAS Transfer Rigging or F12416-SAI-005- IEN-DWG-2543-05 for SAIPEM Transfer Rigging) – note: it is preferred to use SAIPEM Transfer Rigging to achieve more reserved hook height.
NOTE: A proposed method of connection is to utilize an additional shackle below transfer rigging (item 9 of drawing 16009-AMC-OPS-DWG-404 or item C at the bottom of drawing F12416-SAI-005-IEN-DWG-2543-05) to be connected to the masterlink.
Depending on the availability of the rigging, transfer rigging can also be pre-rigged on the spreader bar at the top of the work platform on material barge, and LCE main crane can hook up the transfer rigging (item 6 of drawing 16009-AMC-OPS-DWG-404 or item E of drawing F12416-SAI-005-IEN-DWG-2543-05)
Step #2 Jumper Lifting Deployment and Landing
- Toolbox talks/ JSA with relevant personnel are in place.
- Radio communication with MSV established.
- Weather forecast has been assessed.
- Cranemaster and rigging attached to the A&R wire.
- Jumper is connected to LCE main crane and control lines.
- CVC Running Tools are connected at each end of jumper.
- Jumper has been checked by CONTRACTOR during step #1 in case there is any issue to give time to CONTRACTOR to carry out required remedial action.
- Confirm with CONTRACTOR that they surveyed landed area and there is no debris or existing structure on landing area before start operation.
- Pre-deployment checklist has been completed (refer Appendix 4)
- With all riggings connected, after CONTRACTOR’s final check and approval, remove jumperseafastening on material barge.
NOTE: All barge mooring operations, lifting, overboarding (even rigging overboarding), lowering to 50m above seabed will be carried out in safe handling zone(Refer to Appendix 1 F12416-SAI-005-IEN-1990)
- Deploy ROV (s) from MSV.
- Use the pipe transfer (starboard) crane to transfer personnel back to LCE, then haul in \maincrane and lift the jumper clear from the jumper transportation stands on material barge.
- Monitor the weight on main crane.
- Cast off material barge.
- Lower the jumper, when the lower connector touches the water surface, zero the crane payout meter.(Any other reference as substitute is acceptable.)
- Continue to lower the spool using the main crane until the main hook touches the water. At this point, the jumper lower connector will be at approximately 40m water depth (depending on each jumper configuration)
- Disconnect the spreader bar control lines.
- Continue lowering main crane until the jumper lower connector reaches approximately 90m water depth (depending on each jumper configuration). At this point, the main hook will be at 50 metreswater depth.
Connect winch ROV Hook to transfer rigging (Item 7 of drawing 16009-AMC-OPS-DWG-404)
- Lower the main crane gradually until the winch takes up the load.NOTE: Monitor behaviour of Cranemaster during load transfer.
- ROV to disconnect main crane from transfer rigging at the 400 Te ROV hook. (Ref. Appendix 2 16009-AMC-OPS-DWG-404)
- Recover main crane hook to deck.NOTE: The ROV hook will be re-used later for recovery of the spreader bar.
- After disconnection, ROV will, in sequence, open valve on MEG Plug, remove dummy hot stabs and open valves on back seal test panels (by CONTRACTOR).NOTE: MEG valves opening, dummy hot stab removal and jumper back seal panel valve opening shall be done before 90m WD, if possible.
- When main crane is clear, winch continues to lower the spool with ROV following the descent until spool is approximately 50m above seabed.
- Monitor the weight on winch and Cranemaster behavior.
- Step LCE towards the edge of Safe Handling Zone (Ref. Appendix 1) : F12416-SAI-005-IEN-DWG-1990-04 for Jumper EM-RJ-04F12416-SAI-005-IEN-DWG-1990-05 for Jumper LH-RJ-01
Step #3 Recovery of Jumper Rigging and Preparation of Subsequent Jumper Installation
- After both connectors on the jumper have been soft-landed, ROV to disconnect spreader bar lower rigging from the jumper (by CONTRACTOR).
- Haul in on A&R winch to lift the spreader bar away from the jumper up to 50m above seabed.
- Step LCE away from spool location along access route to the safe handling zone. As route shallavoid or limit when not possible, crossing with existing structure, LCE to adjust route if necessary based on last reviewed layout.
Access Route 02 for Jumper EM-RJ-04 (F12416-SAI-005-IEN-DWG-1990-04)
Access Route 01 for Jumper LH-RJ-01 (F12416-SAI-005-IEN-DWG-1990-05)
- Once LCE reached the SHZ, come up on A&R winch to lift the spreader bar to 50 metres waterdepth (main crane elevation).
- Meanwhile, deploy the main crane with 400 Te ROV hook to a water depth of approximately 50m and standby for load transfer.
- ROV to assist the load transfer of spreader bar rigging from A&R winch to main crane. ROV to connect 400 Te ROV hook to the recovery grommet on the transfer rigging. Ref. Appendix 2 16009-AMC-OPS-DWG-404 Item No. #3 and #5Ref. Appendix 2 16009-AMC-OPS-DWG-251-06
- Lower A&R winch wire to transfer load to LCE main crane. When wire is slack, disconnect ROV hook from transfer rigging.
- Assemble load control lines with ROV hooks for recovery of spreader bar. Ref. Appendix 2 16009-AMC-OPS-DWG-422
- Deploy spreader bar load control lines – ROV to connect them onto spreader bar control points on each end.
- Recover Cranemaster above the water surface.Lift the Cranemaster below the A-frame using the A&R wire to keep it clear of the yokohoma fender and cargo barge to be moored alongside later. If necessary, bring the Cranemaster to LCE deck with the help of knuckle boom crane.
- Moor material barge alongside LCE.
- Land spreader bar on either LCE deck or material barge deck back to its spreader bar transportation then disconnect spreader bar upper rigging from the main crane transfer rigging. This is so that the transfer rigging can be re-used for lifting the next jumper.Ref. Appendix 2
- Unmoor material barge.
- LCE re-locates for subsequent jumper installation (Ref. Appendix 1) : F12416-SAI-005-IEN-DWG-1990-04 for Jumper EM-RJ-04F12416-SAI-005-IEN-DWG-1990-05 for Jumper LH-RJ-01
- Repeat the jumper installation procedure from Step #1.2.
Failure of LCE DP/DGPS Systems
The installation vessel being DP class 2, if there is a failure of the DP / DGPS during operations, the secondary positioning system ensuring full workability shall take over. In the unlikely event of a failure of both positioning systems causing a DP run-off, the operations shall be stopped and the vessel shall move to the safe handling zone (Ref. Appendix 1 or Ref. /19/) until DP control is recovered.
If the jumper is close to the seabed, it shall be lifted up to 50 m approx. above seabed.
If the jumper is already landed but the A&R wire not yet disconnected, the vessel shall be held in position in manual joystick mode, the A-frame wire shall be paid out in order to remain slack and the jumper rigging shall be disconnected subsea by ROV. Then, the spreader bar shall be lifted up to 50 m approx. above seabed and the vessel shall move to the safe handling zone until DP control is recovered.
A&R Winch Failure
A&R winch is function tested and load tested prior to mobilisation. There are adequate spares and competent winch technicians onboard. In the unlikely event of A&R winch failure, vessel moves to safe handling zone (Ref. Appendix 1 or Ref. /19/) until winch is repaired. Special attention shall be paid to avoid clash with existing subsea structures if the jumper is close to the seabed. If possible, it shall be lifted up to 50m above seabed.
Two (2) ROV’s are to be provided by CONTRACTOR onboard a MSV. Contingencies in the event of ROV breakdown are covered in Ref. /24/.
PHC Cranemaster is properly maintained in the factory and equipment certified prior to mobilisation. There are adequate sprares and competent Cranemaster technician onboard. The Cranemaster air-oil pressure is set for the requirement of jumper installation and during the deployment of Cranemaster there will be periodic check on system pressure onboard.
If PHC system does not activate in water, the jumper landing should be carried out within the jumper landing criteria. The maximum allowable sea-state for landing without the Cranemaster is shown the table below (Ref /32/):
|Allowable Hs for Jumper Landing w/o PHC||Unit||Tp [s]|
Note: At Tp 6s the allowable sea states are limited by deployment criteria in splash zone.
Table 8-1: Recommended weather criteria for Jumper Landing without PHC (Ref. /32/) – limiting landing speed of 0.5 m/s
Impact on Running Tool or Jumper during Lifting/Overboarding
If the Running Tool or jumper impacts the vessel during lifting/overboarding and damage is suspected, the jumper shall be re-landed on its supports on material barge for inspection and approvals by CONTRACTOR.
Failure of MSV DP/DPGS System
The MSV being DP class 2, if there is a failure of the DP / DGPS during operations, the secondary positioning system ensuring full workability shall take over. In the unlikely event of a failure of both positioning systems causing a DP run-off, the operations shall be stopped and the MSV shall move to the safe handling zone until DP control is recovered.
If the jumper is close to the seabed, it shall be lifted up to 50 m approx. above seabed by LCE then LCE shall move to safe handling zone.
If the jumper is already landed but spreader bar not yet disconnected, the LCE shall hold position on DP until the MSV’s DP control is recovered and ROV operations can resume.
Spreader Bar Recovery
In case of bad weather after jumper installation, spreader bar may be stored on seabed, in agreement with CONTRACTOR and COMPANY representatives onboard