Serving the Vincent oil field, located off the North West Cape of Western Australia, the FPSO Maersk Ngujima-Yin has a storage capacity of 1.9 MMboe, a production capacity of 120,000 barrels of oil and 100 MMcf/d of natural gas, as well as a water injection capacity of 230,000 bwpd.
Moored in approximately 1,312 ft of water, the massive vessel is designed with a double hull, and measures 1,093 ft long and 190 ft wide.
Four load bearing pads below the cabin of the crane required replacement. This involved cutting away the existing plates before welding in the new pads – all via red hot-work techniques.
One of the main challenges was working at heights – the location of the scope was 40m above deck level and all equipment needed to be manually handled up to the work location. This also posed a significant risk of dropped objects so extra care was taken to ensure the safe handling and placement of all equipment.
The existing scaffold build meant that our technicians had restricted access during installation, and they also had to allow for approximately 20 penetrations from scaffold tubes.
The allocated time frame for this workscope was eight days. In order to meet this deadline, it was determined that the work needed be carried out 24 hours a day with a team of two technicians working back to back 12 hour shifts.
Our project engineer conducted a site survey prior to the scope commencement in order to determine the exact size of the habitat and how it would fit the existing scaffold frame.
Safehouse was required to install a 5m x 4m x 3m hot work welding habitat which encapsulated the entire working area. A pulley system was utilised to move all equipment up and down to the work area. A gas sensing module was used in-line with the habitat air intake, in order to prevent the ingress of any hydrocarbon gas releases.
Outcome and benefits
The habitat installation enabled critical hot work repairs to be completed without having to go into shutdown.
The feedback from the client’s operations and project teams was excellent, with special mention to the positive attitude of the Safehouse technicians and how they assisted all other contractors where possible. All work was successfully completed within the scheduled time frame of eight days, with our experienced technicians overcoming any challenges that they faced.