Sakhalin Energy Investment Company Ltd contracted FSDS Russia with the aim to undertake a Weldability Assessment for the installation of sucrificial anodes at the "Molikpaq Offshore Platform". FSDS Russia in its turn subcontracted Arc Subsea. Arc Subsea entrusted Marex Subsea Welds Ltd to perform the Weldability Assessment in its Hellenic branch premises in Athens.
Marex Subsea Welds' role was to carry out weldability trials in order to qualify a procedure to enable welding of S275JR sacrificial anode straps to the primary structure (Molikpaq Offshore Platform) which comprised of a high carbon content EH36 base material.
The prerequisites and document preparation for the Diving Operations and Evaluation of Marex Subsea Welds as a Diving Contractor in order to perform the Weldability Assessment, was conducted initially by a Diving Representative of Shell. The Diving Pre-Audit Check was completed by a Senior Subsea Inspector and Maintenance Engineer.
The Weldability Assessment's duration was approximately three weeks. Marex had to provide apart from the suitable premises and equipment according to OGP rules, the appropriate materials (EH36 and S275JR+AR), documentation (prerequisites documents for the asessment, clariffications and proposals, dive project plan, risk assessment, welding method statement) and the working team (engineers, coded welders, diving team, HSE) for the assessment.
Throughout the duration of the weldability assessment trials, over eighteen (18) specimens both on butt and fillet welds in PB (2F), PG (3F) and PD (4F) positions were welded and more than one hudrend (100) laboratory tests were done. Non-Destructive & Destructive tests were performed by G.A.T.S. Ltd (NB#1935-GR) and Element Material Technology (NB#0891-UK) laboratories. After the completion of the Weldability Assessment, all companies involved, issued Evaluation Letters to Marex for its quality of services.