Fabrication and Installation of Hydraulic Pipework for DBA 90t AHC Winch
Fabrication and Installation of Hydraulic Pipework for new 90t AHC Winch on Derrick Barge “Azerbaijan”
From late 2015 into early 2016, Laser Gulf Fabrication were awarded a contract to fabricate and install high pressure (HP) and low pressure (LP) carbon steel pipe spools as part of a new 90t hydraulic Active Heave Compensation (AHC) winch on the heavy lift vessel Derrick Barge “Azerbaijan” (DBA), operating in the Azeri sector of the Caspian Sea.
The winch was to be installed on the roof of the DBA’s main crane in order to fulfil the requirements for controlled installation of high value subsea X-mas Trees (XTs) for Shah Deniz 2 Full Field Development.
LGF’s workscope can be subdivided as follows:
- Full 3D survey of DBA main crane roof and subsequent development of 3D model to locate manufacturer equipment items (HPU, EPU, winch) and design routing and support locations for hydraulic pipework
- Marking of 96-off bolt hole locations on newly installed AHC winch foundation plate
- Fabrication, NDT, blasting and painting of HP and LP carbon steel spools in LGF workshop
- Management of the pressure testing, chemical cleaning and hot oil flushing of fabricated spools at LGF subcontractor’s facility to ensure internal cleanliness of NAS 6 achieved
- Nitrogen priming and individual capping of spools for transportation offshore to DBA
- Mobilization of one team of LGF fitters and surveyors to DBA during its offshore campaign, to complete installation of pipework (excluding closing spools) and precision drilling of 96 holes for eventual mounting of AHC winch
- Survey and subsequent fabrication, painting, chemical cleaning, flushing and installation of all closing spools when DBA arrived back into port guaranteeing first time fit
- Assistance in the installation of 90t winch on foundation plate
- Survey, fabrication and painting of fire-fighting system pipe spools with subsequent installation on board
Laser Gulf Fabrication’s successful involvement in a significant portion of the complex, intricate project for installation of the 90t AHC winch onboard the DBA is accentuated by the following achievements:
- Defect-free welding on all fabricated spools produced in Laser Gulf Fabrication’s workshop (including heavy wall thickness HP pipes with operating pressure 330bar)
- Efficient and safe installation of spools offshore when DBA was fully operational and main crane in use
- Successful survey, marking and precision drilling of 96-off bolt holes on AHC winch foundation plate resulting in a successful first time fit and significant time savings in the Client’s project schedule
- Successful accelerated fabrication of closing spools and first time fit
- The works that LGF were responsible for executing were completed within tight timescales successfully and to the satisfaction of the Client