Northern Endeavour Mooring Chain Inspection

The Northern Endeavour FPSO owned by Northern Oil & Gas Australia (NOGA) is operated and maintained by Upstream Production Solutions (UPS). The FPSO is remotely located in the Timor Sea on a permanent set of mooring chains supported by holdback anchors all tensioned to a Riser Turret Mooring (RTM). Over a period, the mooring chains and subsea structures receive marine growth and corrosion, detrimental to the integrity of the assets. Furthermore, the mooring chain links cause abrasion between the crown of the links.

Bhagwan Marine provided Inspection Services to UPS from the DP2 DSV Bhagwan Dryden. The work class ROV FCV600 was utilised to perform Close Visual Inspection (CVI) surveys of the mooring chain, suction anchors and landing frame. Cleaning techniques were employed, such as high-pressure water jetting and fast rotating brushes. A Cathodic Protection survey was conducted via stab point method on areas of interest. Through the ‘Thrash Zone” and selected areas of interest, the chain links were measured to a high degree of accuracy for wear via use of a Bhagwan Marine designed “Go-No-Go” Gauge.