Maersk Tyra Field Offshore Denmark. Exposing Access for Tyra Tie-Ins.8” & 26” Gas Pipeline.
ExcavationTool: Sea Axe Control Flow Subsea Excavation System
Location: Maersk Tyra Field, Offshore Denmark
Water Depth: 50 meters
Soils: Mixed medium strength sands and clay up to 3mtrs depth below natural seabed. Pipeline buried 1.5 meters below natural seabed.
Client: ITech Services assisting Subsea 7
JBS Fabrication Ltd was contracted onboard Seven Arctic, offshore Denmark for Post excavation operations at Tyra.
The Operational procedure was to assist client to excavate areas over 8”, 12” & 26” Gas pipelines and create safe access exposing the Gas pipelines for Diver operations morgrip Installation below natural seabed complete various Tie-In scopes at Maersk Tyra.
The Sea-Axe spread, and operations team was mobilised onboard the Seven Arctic in Invergordon then sailed to location in the Maersk Tyra Field, offshore Esbjerg for field operations.
On arrival at location and prior to Sea-Axe operations inside the designated areas we were instructed to carry out a test trench run. This familiarised all personnel and vessel with Sea-Axe deployment and recovery procedures and to prove the Sea-Axe’s performance in conditions deemed comparable to the seabed areas where post excavation access was to be executed in project proper.
Sea-Axe was over boarded by the vessels crane and positioned over the designated pipelines after a pre-survey had been completed. This was this case on each location prior to excavation and followed by a post survey run where recorded data was combined with our own Sea-Axe multi beam recordings to prove achieved client specifications.
These scopes required close communication and collaboration with the vessel bridge and DP officers and was a crucial part of this challenging project to achieve safe access for diver operations.
Two 8” pipelines, North and South were excavated and cleared 30mtrs x 8 mtrs x 2.5mtrs in depth for diver operations. Two 12” pipelines cleared North and South 30mtrs x 10-12 x 3mtrs in depth. The 26” pipeline was cleared for diver access 30mtrs x 14mtrs x 3mtrs in depth. We were also required to open an area to allow an ROV to fly in and fit a clamp around the 12” line. This was also achieved quickly and safely before recovering and securing Sea-Axe to deck.
Sea-Axe’s power and enhanced stability combined with our inner vortex chamber proved again that it allows us to concentrate the water column more accurately and directly above the target areas. This is essential when excavating a major safety factor clearance area for diver’s operations below natural seabed.
All client designated access areas were cleared safely, quickly and to client specification allowing the divers to carry out and complete their Tie In work scopes without obstruction and complete confidence in the workspace provided. The competence and experience of our operational team and close working relationship with vessel personnel and survey team proved a winning formula. Showcasing Sea-Axe’s ease of deployment, stability, power and accuracy once again. A perfect client choice for a perfect collaboration and successful project outcome.