Up to now, two BT-3500 tender drilling units, one well intervention unit, one BT-4000 light workover unit and two tender drilling barges have been constructed for Atlantica Tender Drilling, Helix ESG and Etesco. All of them on time and on contracted deck payload capacity. In addition to this, we have developed full basic designs for a BT-UDS drillship and a BT-5000 midwater drilling semi. We have also developed a wind power jack-up intended for offshore applications for MarCon


BT-5000 Midwater Drilling Semi

In November 2014, Bassoe Technology was contracted by CIMC Raffles to perform the basic design of a BT-5000 Midwater Drilling Semi. Bassoe Technology had, during 2014, developed the BT-5000 concept in close cooperation with CIMC OEI (Offshore Engineering Institute) and CIMC Raffles now placed the order in anticipation of the rising market demand for replacing the aging fleet of midwater drilling units. The BT-5000 MWS was CIMC Offshore’s next strategic semi-submersible product. In 2016, the basic design of was completed.

BT-5000 at sea (rendering) BT-5000 at sea (rendering) BT-5000 living quarter(rendering)

BT-4000 Etesco Interventor

In 2013, Bassoe Technology, was contracted by DSIC for basic design of the BT-4000 unit, a concept specifically designed to meet Petrobras light work over unit requirements, aiming to reduce well intervention cost and further increase well productivity in deep water environment. Brazilian contractor Etesco will carry out light workover operations offshore Brazil in Campos and Santos Basin on a four-year charter with start 2016 at delivery of the BT-4000 LWO semisubmersible Etesco Interventor.

Etesco Interventor Etesco Interventor Etesco Interventor

BT-UDS Ultradeepwater Drill Ship

Bassoe Technology UDS

In 2012, Bassoe Technology was contracted by a STX for a basic design of the BT-UDS concept. The BT-UDS was to be built for Sigma Drilling, a company with major shareholders Skeie Technology and Vantage Drilling. In addition to the contracted drillship, Sigma Drilling Ltd. had obtained options from STX for the construction of four additional BT-UDS vessels.

Due to the yard’s financial problems, the project was terminated in 2013. At this point, however, BT had completed the basic design of the BT-UDS which represents the latest generation drillships – more versatile and effective with higher payload, capacities and transit speed than competing designs.

Read more under Designs

BT press release

Vantage Drilling press release

STX press release

The BT-UDS for Sigma Drilling

Cameron Sense Dual Activity Derrick

The BT-UDS for Sigma Drilling was to be designed with a Cameron Sense dual activity derrick with two top mounted heave compensators for efficient drilling and workover. The main drill center, which additionally features an active heave drawworks, would have had 1,250 tons (true) hook-load below the top-drive. The auxiliary drill center could be used for top hole drilling, building of long casing strings, coiled tubing operations through completion riser and other operations.


The Sigma Drilling drillship would feature two 15,000 psi (1,035 bar) seven ram Cameron 18¾” blow out preventer (BOP) stacks including systems for parallel operations and testing of the BOP stacks, including a back-up acoustic control system.

Sigma Drilling had further options for both the first and all four optional drill-ships to upgrade all relevant systems, including the two BOP stacks, to 20,000 psi (1,380 bar) capability.


For pipe, riser and material handling design included two redundant column rackers, three TTS Group 100 tonnes knuckle boom cranes, one pipe handling knuckle boom crane, one riser gantry crane and a TTS Group 165 tonnes heave compensated knuckle boom crane for handling subsea lifts of equipment down to the sea-floor in water depths down to 12,000 ft.

Helix Well Intervention Semi-submersible Unit

Helix Q5000 at sea

Bassoe Technology has developed and designed next generation Well Intervention ultra deepwater Semi-submersible Unit for operator Helix ESG.

The Well intervention Semi, the Q5000 is designed for Gulf of Mexico, Brazil and W of Africa environmental conditions and is design with operational capabilities, as well as Health-Safety-Environment, in focus.

The Q5000 being built by Jurong Shipbuilding in Singapore, is designed for full time intervention, top hole drilling, well testing, subsea construction, open water completions, through-tube well intervention services.

Bassoe Technology has performed concept and basic design engineering for the Unit, and detail engineering including motion, station keeping, stability analyses, structural global and local analyses, marine outfitting, and marine system design.

The Q5000 is designed in accordance with ABS +A1 Column-stabilized Drilling Unit 2012 MODU rules and shall meet IMO rules and regulations.

For more information see Upstream, and Offshore Engineer Digital Archive Special Supplement October 2012 (requires login).

Helix Q5000

BT-3500TSV Atlantica Delta

In 2013, Bassoe Technology was contracted by DSIC for the basic design of a second BT-3500 unit. The unit will be operated by Atlantica Tender Drilling for Total Congo in the Moho Nord exploration and production project - the largest oil project ever in Congo.

In September 2016, the Atlantica Delta unit begun running drilling riser on the first of 17 wells in the well development program. Atlantica Delta will operate alongside the Moho Nord TLWP. Processing will be made on the floating production unit Likouf.

BassDrill Delta in field

BT-HTB Atlantica Gamma

Atlantica Gamma at sea

In 2012, Bassoe Technology was contracted by DSIC for the basic design of a Heavy Tender Barge to be operated west of Africa by Atlantica Tender Drilling.

In May 2014, The BT-HTB Atlantica Gamma was successfully undocked at DSIC, Dalian. However, the modular mast equipment package under construction in the US fell well behind the original schedule and as a direct consequence, Atlantica Tender Drilling terminated the construction contract of the BT-HTB with DSIC.

For specifics regarding the BT-HTB design, read more here.


MWP Mark II at sea

Bassoe Technology was selected by Marcon Windpower AB to develop a jack-up platform for wind power systems offshore. The design of the jack-up wind power platform is based on a 3.6 MW wind power package for the UK sector in the North Sea.

Bassoe Technology has calculated the dynamic response for the jack-up, due to waves and winds in water depths of 45 m.

Maximum spud can reaction forces was calculated and structural strength analyses was performed for the two water depths. Structural analyses were performed both in open water conditions and in ice operation conditions.

A Jack-Up unit gives several advantages, it can be fully commissioned at the building site, offshore installation site activities are minimized with no lifting actions, decommissioning is easily performed as a reverse installation operation, After the planned service period the Jack-Up can be used for renewed service at another location.

The first unit installed was designed for wind measurement at the South Midsjo Banks in the Baltic Sea. This jack-up unit is equipped with a 90 m high tower for wind data collection.

BT-4900N Harsh Environment Accommodation Unit

Bassoe Technology BT-4900N at sea

Bassoe Technology has developed and designed a New Generation Accommodation Unit for Norwegian operator Sirius Offshore.

The BT-4900N harsh environment accommodation unit is design with Health-Safety-Environment in focus.

The health aspect is a growing factor in an increasingly competitive offshore labor market of skilled workers. The BT-4900N Accommodation Unit offers attractive and comfortable offshore living standards and a high quality off-time experience for the guests. The architecture and interior design includes high quality single-birth cabins with daylight, atrium above the mess area, spacious recreation areas for sport activities, Spa area and auditorium for entertainment and training.

Safety aspects including a hull design with an inherent reserve buoyancy and latest type of freefall lifeboats in accordance with DNV-OS-E406. Lifeboats are located on the opposite side from the host platform and are protected by the living quarters. Increased DP reliability in connection with potential hazardous gas release on the host installation is achieved with a new design combustion air intake arrangement (patent pending) to diesel generators. Personnel safety during transport of people between the BT-4900N and the host platform is achieved by a passage inside the deck box to the gangway tower and sheltered gangway. To improve safety of crane operations all material handling, including galley provision containers, is made with direct line of sight for the crane operator.

Environmental care is among other things achieved by a state-of-the-art drain handling and treatment system to ensure zero discharge. Engine exhaust gas NOx reduction by use of SCR in accordance with IMO Tier III is provided for emission control.

With optimized hull geometry, large airgap, the BT-4900N accommodation is designed for operations in the harshest environments including the Northern North Sea and West of Shetland, as well as in low temperature areas.

The operability of the Unit is paramount for a harsh environment unit. Focus has been given to high up-time of gangway and heli deck access with helicopters. Spacious working deck areas on upper deck with workshops and client stores are supported by two large cranes, one 100T knuckle-boom crane and 100T offshore lattice crane.

The BT-4900N is designed in accordance with DNV +1A1 Column-stabilized Accommodation Unit (N) Class Requirements with the following class notations; CLEAN, ECO, E0, CRANE, HELIDECK-SH, F-AM, DYNPOS AUTRO, POSMOOR ATA V, UKVS and shall meet NMD, Norwegian PSA, UK HSE and IMO rules and regulations.

The BT-4900N living quarter includes 490 single berth cabins of highest standard, 456 guests and 34 crew cabins. Mess seating capacity is 376 persons.

For more information see the BT-4900N brochure.

BT-MTB BassDrill Alpha

BassDrill Alpha at sea of Congo

Bassoe Technology has developed two Tender Barges for BassDrill Management Ltd, Houston, USA.

Based on the class approved Light Tender Support Drilling Barge Bassoe Technology designed for BassDrill in 2008, a Medium Tender Support Drilling Barge with increased space and capacities for operations in water depths between 5 and 200 m was designed and built based on ABS class approved drawings developed by Bassoe Technology.

The non-propelled barge, BassDrill Alpha, has an accommodation for 112 people onboard. The design is made in accordance with ABS class notation +A1 Unrestricted Service Barges, and the barge is in compliance with the latest amendments to the MODU and Solas codes.

The BassDrill Alpha was fabricated and delivered from Lamprell Energy Ltd facilities in the UAE in 2010 and is now operating offshore Congo, West Africa.

For MTB pictures click here.

BT-3500TSV BassDrill Beta

In 2010, Bassoe Technology was contracted by DSIC for the basic design of a BT-3500 unit to be operated by Atlantica Tender Drilling for Petrobras alongside Petrobras' P61 TLWP (Tension Leg Wellhead Platform) at the Papa-Terra Field Development offshore Brazil.

In April 2013, The BassDrill Beta semi-submersible was successfully floated out from DSIC, Dalian. In November 2014 it had successfully installed its Mast Equipment Package onto the Petrobras P61 TLWP in Campos Basin and in December 2014, it started its operational activities as part of the first development in Brazil using a semi-submersible tender drilling unit.

BassDrill Beta at Papa-Terra Field BassDrill Beta aboard Heavy Lift Vessel BassDrill Beta afloat BassDrill Beta in dock Construction of BassDrill Beta Columns

DSME 6000M and DSME 7000

DSME 6000m/7000

Bassoe Technology was selected by DSME, Korea for the development of their new compact drilling semi-submersible. Inspite of recently built semi-submersible projects, DSME decided to single source the work with Bassoe Technology. The project is based on a concept sizing and optimization of the hull by Bassoe Technology and is jointly developed by DSME and Bassoe Technology. The DSME 6000M is approved by ABS. The DSME 6000M is a deepwater drilling unit based on requirements set forth by Petrobras. The Unit's basic version layout include a DP-2 configuration. However, due to optimized layout of engine rooms and electrical rooms, the Unit can meet DP-3 requirements by small layout modifications.

More information about the DSME 6000M can be found here.

Bassoe Technology was asked by DSME to enhanse the DSME 6000M for operation in deepwater in Gulf of Mexico. The DSME7000 has been increased for larger VDL and water depth capacity. The DSME 7000 is designed for station keeping meeting the IMO DP Class 3.

SWS-12000 Ultra Deepwater DP Drill Ship

SWS 12000 at sea

The Chinese builder Shanghai Waigaoqiao Shipyard has selected Bassoe Technology for developing a 69,000 metric tonnes ultra deep water drill ship. The project is based on a marketing survey made by Bassoe Technology to determine the optimal size for a new drill ship. The SWS-12000 hull geometry is based on the BT-MDS hull, a 50,000+ metric tonnes drill ship for high transit speed.

The SWS-12000 is sized and designed for utilizing a dual activity derrick and offers a large extent of flexibility regarding drilling equipment and crane solutions. A large degree of integration of the drilling equipment in the hull has resulted in a optimized size and resulted in a state of the art drill ship design.

The vessel can handle either NOV, Aker MH or TTS drilling packages, including dual activity derrick, N-line or conventional tensioners and up to six mud pumps for three completely segregated mud systems.

The vessel's station keeping meets the IMO requirements for DP Class 3.

Extensive wind tunnel and model tests have been performed for the SWS-12000, including optimization of the moon pool configuration.

SWS 12000 at sea

Engineering Service Agreement with Aker Solutions AS

Project coordination and structural analysis.

Peab and West Wind

West Wind at sea

Bassoe Technology was contracted by PEAB to design the wind turbine installation vessel for Lake Vänern, Sweden. The design met the DNV requirements and DNV submitted a Maritime Certificate for the vessel.

For pictures during installation of wind turbines in the lake Vänern, click here.