Large Deck Load Capacities

The BT-3500 TSV is designed with a special focus on large deck load capacities. The deck and column payload capacity in operation and survival conditions is 4,400 tonnes. The total payload in operation and survival conditions is 5,800 tonnes and in transit condition 2,900 tonnes.

Increased Hydrodynamic Performance and Flexibility

The BT-3500 semi-submersible is characterized by its excellent motions and flexibility. A special focus on hydrodynamic performance has led to a unit with increased operability and workability, especially crane operations and gangway handling. The unit's flexibility allows it to be used for various host platforms, such as fixed jackets, Spars and TLPs in water depths up to 2,000 meters (6,600 ft.) in offshore Brazil, Gulf of Mexico, South East Asia and West of Africa.

Improved Safety

The gangway route between the host platform and the BT-3500 leads directly into the deck box of the BT-3500. This means improved safety for the workers since no passage to/from the host facility is on open deck.

For detailed technical data on the BT-3500 TSV please download the brochure here.

For more information about BassDrill Beta, see Projects.

For more information about Atlantica Delta, see Projects.

The BT-HTB is designed to transport a complete derrick set to the location and erect the drilling package on the deck of the fixed installation using the large crane onboard. The unit supports the fixed installation during drilling and workover operations. It contains drilling liquid mud in pits, bulk and cementing storage and handling facilities, pipe and tubular storage which are supplied to the derrick set during operations. The BT-HTB accommodates 140 people with corresponding catering and safety facilities onboard. For detailed technical data on the BT-HTB please download the brochure here.

For more information, see Projects.

The BT-LTB is designed to transport, erect and support a Derrick Set during drilling and workover operations. The unit will support the derrick set with drilling mud and bulk handling facilities, cementing facilities, pipe and tubular storage. The BT-LTB is moored with the stern towards a fixed installation with an 8-point wire-rope mooring system. This enables both erection of the drilling set onto the fixed installation using the large crane as well as providing equipment and fluids during drilling and workover operations. The BT-LTB is designed for accommodation of up to 100 people onboard. Bassoe Technology has performed a basic design for the unit with a full class approval by ABS in accordance with class notation +A1 Barge, Unrestricted Services. Model tests were performed for the BT-LTB in March 2008.

Safe and Cost-Efficient Structural Configuration

The structural configuration of the BT-5000 MWS is both robust and proven. Redundant structural members increase safety as do the buoyant upper hull deck-box by providing reserve buoyancy in case of large heel accidents. Furthermore, the structural configuration of the BT-5000 MWS is recognized to be cost efficient during construction and as it has a minimum of bracings and critical fatigue sensitive hot-spot the risk for fatigue cracks and inspection is reduced.

Operations

The BT-5000 MWS is designed for both exploration and production drilling with a special focus on completion operations thanks to the introduction of large cellar deck areas around the moon-pool for handling of various subsea related equipment, such as BOP stack, X-mas trees, various umbilical reels and an upper deck layout designed to include ample space for various third party equipment. The drill-floor area has been designed to allow a quick change over between different drilling activities with dedicated areas for pre-rigging of coiled tubing and other third party equipment.

Optional Equipment and Outfitting

The BT-5000 MWS is in its basic version arranged with the equipment required to provide a cost efficient drilling tool but the Unit can also be tailor designed to meet specific owner preferences and requirements with regard to optional equipment and outfitting. The basic version is arranged with a 8-line chain mooring system with four thrusters intended for self-contained thruster assisted mooring up to 500/610 m (1,640/2,000 ft, harsh/moderate environments) water depth and with wire or polyester mooring-line inserts the Unit will be able to carry out drilling operations in up to 1,500 m (5,000 ft). The Unit is also pre-arranged for a 12-line mooring system for operations in hurricane/cyclone prone areas where thruster assist cannot be used.

The work was a joint project where Bassoe Technology defined the hull and developed a technical specification including General Arrangement, Marine, HVAC and Drilling flow sheets and single line diagram. Bassoe Technology also performed motion and station keeping analyses, weight and stability analyses, as well as loading conditions for the unit. DSME developed structural drawings and supporting analyses for receiving an ABS AIP approval. In discussions with clients 2010, requests for meeting the latest GOM requirements were presented. DSME asked Bassoe Technology to design a new hull for a DSME7000 DP-3 ultra deepwater drilling unit and also to develop a General Arrangement and perform motion and station keeping analyses, loading condition calculations, a DP-3 single line diagram and updated flow sheets to enable a tender bid. For more information, see Projects or download brochure here.

The BT-7000 DP mild environment unit is built for operations in water depths up to 2,400 m (7,880 ft) and drilling depths up to 30,000 ft. However, the design is developed to allow for a maximum operational water depth of 3,050 m (10,000 ft) and drilling depths of 40,000 ft.

Station keeping is achieved by a DP system according to ABS DPS-2 requirements, including 8 x 3,300 kW thrusters. With relatively small modifications, the arrangement can be redesigned to meet ABS DPS-3 requirements. Basic design including structural drawings, global performance analyses, flow sheets and layout drawings for machinery and utility systems and drilling systems are being provided for an early fabrication start. Bassoe Technology have developed a Technical Contract Specification for DSOC for signing a contract between the shipyard and a drilling contractor. For more information and detailed technical specification download brochure here.

The BT-MDS is designed with a beam of 32.20 m (105’-8”) to meet the maximum requirement of Panamax sized vessels. With a length of 184.55 m (605’-6”), the vessel has a displacement of 53,700 tonnes and a payload of 20,000 tonnes. The main objective for the design is a purposed designed, robust vessel includes a high degree integration of drilling equipment into the hull, with a simple, easy layout to inspect and maintain.

The arrangement of the vessel includes an accommodation for 184 people with a galley and mess for serving half crew in one seating. Forward of the moon pool area is the riser storage located in a hatch-less hold supported by two knuckle-boom cranes and a catwalk machine. Aft of the moon pool is the drill pipe storage located on upper deck, supported by two knuckle-boom cranes. A large, 41.60x 11.20 m (136’-6” x 36’-9”), moon pool is located amidships. Above the moon pool is a drill floor and substructure arranged supporting a 210 ft derrick.

Station keeping for the BT-MDS is achieved by a DP system in accordance with IMO requirements for DP Class 2 vessel, including 6 thrusters, 2 large thrusters aft and 4 retractable thrusters amidships/forward. The power generation plant in two engine rooms includes six gen sets of 5,500 kWe each, total of 33.0 MWe. Transit speed is achieved using the two aft thrusters with the remaining 4 thrusters retracted into the hull. The vessel can be modified to meet IMO requirements for a DP class 3 vessel, dividing the power plant in three engine rooms.

A Maximum of Efficiency and Operational Flexibility

The BT-UDS is designed for exploration and production drilling, completion operations, workover and intervention operations. The drilling area, developed in close cooperation with Skeie Technology, is designed for maximum efficiency and a minimum of down-time, with off-line preparation of next coming operations and rigging of various equipment, such as casing strings, down-hole assemblies and coiled tubing assemblies. This, together with a large free moon pool area for handling and stacking of multiple X-mas trees (up to 12 trees can be stored onboard), handling of subsea umbilicals and related reels, as well as storage of various third party equipment and containers, will make the drillship specifically well suited for development drilling.

Zero Discharge

The BT-UDS has been designed for zero discharge to allow operations in environmentally sensitive areas. Special emphasis has been placed on drain collection to minimize the risk for spillage of liquids into the sea and the BT-UDS features a state-of-the-art drain treatment system.

Improved Storage Capacity

The mud system features large storage capacity with three segregated systems having dedicated pits, tanks and pumps for oil-based mud, water-based mud as well as completion fluids.

High Performance – Small Size

The BT-UDS, with a length and breadth of 228 x 38 meter, which is smaller or similar as competing designs, will have a payload of 25,000 tonnes which is above competing designs. This has been achieved by effective utilization of its hull with integrated riser storage and mud handling. The vessel has space for six mud pumps.

Superior Transit Speed

Six 5.0 MW azimuthing thrusters together with the Bassoe Technology developed and model tested hull-form will provide a transit speed up to 16 knots, which is higher than competing designs, allowing faster and more efficient mobilization between drilling locations.

Reduced Environmental Footprint

The BT-UDS combines DP Class 3, which is the highest redundancy dynamic positioning class, a highly efficient twin-skeg hull and a well developed drain philosophy. It also features DNV’s class-notation for Enhanced Reliability, DYNPOS-ER, which leads to more effective utilization of the six diesel generators. Altogether, this leads to a reduced environmental footprint.

For more information, see Projects.

The arrangement of the vessel includes an accommodation for 212 people with a galley and mess for serving half crew in one seating. The riser storage is located in a hatch-less hold forward of the moon pool, supported by two knuckle-boom cranes and a catwalk machine. The drill pipe storage located on upper deck aft of the moon pool is supported by two knuckle-boom cranes and a catwalk machine.

A large, 37.6 x 12.8 m (123’-4” x 42’-0”), moon pool is located amidships. Above the moon pool is a drill floor and substructure arranged supporting a 210 ft dual derrick.

Station keeping for the SWS-1200 is achieved by a DP system in accordance with IMO requirements for DP Class 3 vessel, including six 4.5 MW thrusters. The power generation plant in three engine rooms includes six gen sets of 7.3 MWe each, total of 43.8 MWe.

For detailed technical specification please download the SWS-12000 brochure here. For more information, see Projects.