Boskalis Westminster has worked on a wide variety of contracts and projects over many years. We have learned to manage complexity, mitigate risks and simplify execution. Whatever the requirements - whether it is standard maintenance dredging, a complex project requiring different engineering and design elements, or long term services - Boskalis Westminster can tailor innovative and competitive solutions.

Projects

Project

Shell Gumusut Kakap

Gumusut Kakap is a deepwater oil discovery in offshore Sabah, Malaysia where Sabah Shell Petroleum Company is the designated Operator. This development employs Malaysia’s first deepwater semi-submersible production system. The 44,000 t FPS is to be located about 200 km off the shore of Sabah (East Malaysia) in the South China Sea in water depth about 1,200 m. The project has allowed Shell to share deep-water expertise with Malaysian energy companies, assisting in the Malaysian government’s goal to create an offshore industry hub. The platform was built in Malaysia by Malaysian Marine and Heavy Engineering Sdn Bhd (MMHE). Boskalis was awarded a contract by MMHE for the provision of the Heavy Transport Vessel (HTV) for the load-out, float-off and tow-back package of the Project which includes the load-out of the Integrated FPS from MMHE fabrication Yard onto the HTV, Dry-transport to Desaru, Float-off, Tow-back and Re-delivery at MMHE fabrication yard. Boskalis was responsible for the load-out-, transport- and float-off engineering and execution of the Gumust Kakap FPS. This included the design of HTV grillages, skid beams and seafastening as well as the design, fabrication and delivery of a ground reaction type Buoyance Tank(BT). The scope also included the mobilization and readiness of HTV Blue Marlin, HTV ballasting during the skidded load-out operation and the provision of the marine spread required for the float-off operation and HTV and BT demobilization. HTV Blue Marlin arrived at the load-out yard end of March 2013. The fabrication yard started with the installation of the grillage required for the load-out of the FPS. The outfitting of the HTV main deck was completed mid-April. Since the draft of the FPS, once afloat, would be more than the maximum water depth over the HTV main deck, a draft reduction mechanism had to be designed. For this purpose Boskalis had designed and fabricated a Buoyance Tank (BT). This BT was designed to fit between the FPS bottom plating and the top of the HTV grillage. On the BT fabrication yard the BT was loaded onto a charted barge, transported to Pasir Gudang, where it was loaded-in for storage until the FPS was ready for the load-out. On April 16th 2013 the BT was load-out by SPMT’s onto the barge that would be used for positioning the BT between FPS bottom and HTV grillage. On May 3rd the FPS was skidded to just before the HTV (land-pull) to start the load-out the next day. As a result of the skidding system used, the tolerances were very small, which resulted in a slow skidding speed. The FPS was in its final position in the early morning of May 5th. Once in position the securing of the FPS started, the link beams were removed and the HTV de-ballasted to BT load-out conditions. On May 9th the barge with BT were moored against the HTV. The next day the load-out of the BT started and on May 11th the BT was in the correct position. HTV and BT were now prepared and tested for the dry-tow and the subsequent discharge operations. On May 14th the loaded HTV shifted from Pasir Gudang to the offload location near Desaru where it dropped anchor. Various preparatory work on the FPS and seafastening removal had to be done and on May 21st all was ready for the discharge of the FPS with the BT under it. The FPS and BT were towed off the HTV by 1 AHT and 4 inshore tugs. After this discharge the HTV de-ballasted and shifted back to the yard for main deck reinstatement. The FPS needed to be offloaded from the BT which started early morning of May 22nd by ballasting of the BT. The FPS was towed off the BT that same afternoon and re-delivered to client. The BT was de-ballasted and towed back to Pasir Gudang for reinstatement. To ensure that the FPS could achieve the required float-off draft, the BT, which is technically a ground reaction barge is required for the discharge operation. Boskalis was responsible for ensuring that the BT was designed, constructed and delivered to ensure the safe and successful execution of this complex discharge. The BT design was unique, having its own power, sophisticated ballast system, tank gauging system, ballast air compressors, hydraulics etc. which had to be thoroughly examined and dry tested before the operation. Also, ground reaction barge operations require flat hard seabed. Intensive research was carried out including bottom survey of several areas around the coast before suitable location with hard sand at required depths was found off Desaru area. The success of the project was due to the strong cooperation between all parties. The project had schedule challenges but the close working relationship between the project management teams of MMHE and Boskalis ensured that the project was still executed in a safe, operationally sound and timely manner.

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Project

Wintershall RAVN and A6-A

Wintershall Noordzee B.V. installed a new remote platform RAVN as a crude production tie-back to A6-A. RAVN is a remote and unmanned crude well unit. Utilising a dry-tree design, all control, power and metered injection for the well will be via the 18.2-km control umbilical between the new satellite platform RAVN in the Danish sector and the operational platform A6-A in the German sector. The umbilical forms the entire link between the remote platform, supplying and controlling all functions and ensuring continual feedback and monitoring of RAVN. The umbilical supplies all the necessary input data, control and feedback to eliminate the usual day-to-day requirements of direct human contact. The umbilical was installed from RAVN first end to second end pull-in at A6-A end. Platforms are located in the Danish territorial waters in the North Sea (RAVN) and German territorial waters in the North Sea (A6-A). The umbilical was connected/pulled into RAVN via a J-tube and internal conductor to the RAVN topside -TUTA. RAVN - first end with pull-in to topside deck via a J-tube - was laid in corridor separate from the 8-inch pipeline between RAVN and A6-A and second end pull-in using the quadrant method at the A6-A platform. SCOPE OF WORK Prepare project planning for Boskalis’ scope of work. Survey work, including post-burial survey. Perform route engineering and installation engineering to optimize the performance of the installation scope, including Orcaflex analysis for laying, pull-ins, loads and dynamics, as well as a detailed burial assessment study (BAS). Prepare platform on RAVN and A6-A. Define umbilical length together with the client. Umbilical load-out at Hartlepool (UK) onto the installation vessel Ndurance. Installation and hang-off of umbilical termination heads – topsides. Crossing 36- & 40-inch live gas pipelines. Pull-in at RAVN & A6-A platforms – direct from vessel as part of SIM-OPS. Umbilical lay and bury scope – minimize on seabed exposure. Mobilize and demobilize all installation spreads for Boskalis’ scope. Provide engineering support during the offshore umbilical installation, including simultaneous burial. Provide QHSE management for Boskalis’ scope. Process and deliver as-built data. Mobilize and demobilize all installation spreads for Boskalis’ scope.

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Project

Wintershall L8-P4

Wintershall Noordzee B.V. installed a new remote platform at L6-B as a gas production tie-back to L8-P4. L6-B is a remote and unmanned gas well unit. Utilising a dry-tree design, all control, power and metered injection for the two wells will be via the 19.5-km control umbilical between the new satellite platform L6-B and the operational gas platform L8-P4. The umbilical forms the entire link between the remote platforms, supplying and controlling all functions and ensuring continual feedback and monitoring of L6-B. The umbilical supplies all the necessary input data, control and feedback to eliminate the usual day-to-day requirement of direct human contact. The umbilical was installed from L8-P4 first end to second end pull-in at L6-B remote end. Both platforms are located in Dutch territorial waters in the North Sea. The umbilical was connected/pulled in to L6-B via a J-tube and internal conductor to the L6-B topside - TUTA. The umbilical will be installed from L8-P4 - first end with pull-in to topside deck via a J-tube, laid in corridor separate from the 8-inch pipeline between L8-P4 and L6-B. FACTS AND FIGURES Water depth 30-35 meters Challenging North sea conditions. Challenging soft seabed. Fast-track project, with a short lead-time between award and installation – Feb 2014, July/Aug installed. Stepped phase process of pull-in, laying and burial ops. Completed on time, with no incidents. Umbilical loaded quickly and safely. Umbilical length 19.5 km. Burial scope of single pass burial of umbilical minimum requirement of 1m TOC (top of cover). SCOPE OF WORK Prepare project planning for Boskalis’ scope of work. Survey work, including a pre-burial, as-laid and post-burial survey. Perform route engineering and installation engineering to optimize the performance of the installation scope, including a detailed burial assessment study (BAS). Prepare platform on L8-P4 and L6-B. Define umbilical length together with the client. Umbilical load-out at DUCO Newcastle (UK) onto the installation vessel Ndurance. Hang-off of umbilical end. Crossing 36-inch live gas pipeline Callantsoog. Pull-in at L6-B & L8-P4 platforms – direct from vessel as part of SIM-OPS. Mobilize and demobilize all installation spreads for Boskalis’ scope. Provide engineering support during the offshore umbilical installation, including burial. Provide QHSE management for Boskalis’ scope.

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Project

Eastbourne Beach Recharge

Due to erosion by wind, waves and rising sea levels, the beach front at Eastbourne needed to be reinforced. The previous campaign to improve coastal defence was carried out in 1998 and in 2011 the shoreline no longer fulfilled the design criteria for safe coastal protection.Eastbourne Borough Council (EBC) developed a scheme comprising the recycling of existing material, particularly in environmentally sensitive areas (SSSI – Beachy Head) and the importing of bulk quantities for the rest of the beach frontage. The sequence of the works was to execute the recycling first and subsequently fill the groyne bays to the required profiles with imported shingle. The site stretched over a total length of 5.5 km, from Beachy Head in the west, along the whole of Eastbourne front, to Langney Point in the east. The design profile varied over the length of the site, with the aim of achieving a design crest width and height with seaward slopes of approximately 1 in 9. All dry earth moving was subcontracted to Ovenden who executed the works with up to 3 excavators, 4 bulldozers and 10 dump trucks working at the same time. The imported shingle was mainly dredged at Owers Bank /Area 435. The material supplied complied with the design requirements, having a D50 in the order of 16m. As this material had to be pumped ashore via an 1100m long sinker line, a heavy duty dredger with substantial installed power was needed. The Prins der Nederlanden was therefore mobilised, with a total of 19,000 kW installed capacity, every one of which was required during pump ashore.

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Project

Eastoke Nourishment Works

Hayling Island is fronted by a shingle beach, spanning its entire southern shoreline. Regular storm wave attack and the consequential threat of overtopping dictates the need for constant management in order to prevent flooding of properties in the lee of the beach. Eastoke, situated at the eastern end of the frontage, is particularly prone with properties located immediately behind the beach crest. Natural sediment transport along the beach, combined with localised tidal flows had created an accretion of gravel at the entrance to Chichester Harbour. This presented a hazard to shipping, with Chichester Harbour Conservancy (CHC) keen to maintain navigable water. Havant Borough Council, responsible for the coastal protection, initiated discussions in order to combine the dredging of the harbour entrance with the renourishment of their beach. The beneficial reuse of this material (a total of 75,000m³) had several advantages: no sediment was lost from the system; no disposal at sea; it was a very cost effective solution (saving approx 60% compared to sourcing from the nearest licensed area) as the dredging cycle time was very short and two clients benefited from the single operation. Boskalis Westminster is keen to promote the reuse of dredged material, with several similar schemes completed to date.

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