Introduction

The marine engineering industry has offered TSC a variety of complex challenges. The company has been involved with projects on heavy lift barges, pipe lay barges, heavy construction dive support vessels in arctic waters, as well as LPG trestles and offshore tanker loading facilities.

ACFM inspection equipment has been used by topside teams, divers and ROV's from the warm waters of the Carribean and Persian Gulf, to the frozen Sea of Othosk.

U21 instrument (ROV mounted)

8 channel manipulator mounted rigid array probe

The TSC rigid array ACFM system, deployed by work class ROV, was used for weld inspection of subsea connections on Fulmar SALM between November 06 and November 10 1998. All inspection was carried out from the M/S ‘Torungen' at the Ardal Mekaniske Verk yard at Vikaneset in Norway.

Operationally, probe placement was achieved successfully and data acquisition was rapid. There were however several areas where access was limited and successful manipulator access was not possible. As it was specified that only 15% of the actual welds were to be inspected, the probe was normally moved to a position on the weld where a full run representing 15% of the total length could be accomplished in one operation.

Marine loadiing Terminal inspection

U19 AMIGO system

Standard underwater weld probe 5KHz with 50m cable

ACFM inspection was used to inspect designated welds on a deep water marine terminal jetty, Jamnager, India. The jetty is 5km long and situated in a depth of 22 meters of sea water. Several berths were selected for inspection, together with the knuckle platform, service platform and riser platform. ACFM was chosen as the primary method of inspection so that the paint coating may be left intact.

All welds inspected were located both subsea and above sea level. ACFM was used to determine the presence or absence of surface breaking defects.

Arctic SALM inspection

U21 subsea system

Standard underwater weld probe 5KHz with 50m cable

Sakhalin Energy made world history in July 1999 with production start-up from its Vityaz Production Complex offshore Sakhalin Island in the arctic Russian waters of the Sea of Okhotsk. The project represented an innovative concept for the development of a remote field location lacking offshore infrastructure and experiencing a harsh environment. Severe storms and high ice loads combined with intense wind and wave loads and significant seismic activity characterize the areas climate.

The Molikpaq, a caisson platform structure was retrofitted to become Russias first offshore oil production facility. "Okha" a new-build Floating Storage Offloading (FSO) unit  was commissioned and a Single Anchor Leg Mooring (SALM) Buoy was connected to the FSO with an associated flowline from Molikpaq.

TSC were involved in the initial stages of this project. After the installation of the SALM buoy, a severe winter storm caused damage to the associated flowline, and a thorough internal and external inspection was carried out on the buoy prior to commissioning, in order to assess it's integrity. Surface and subsea ACFM systems were used for the inspection.

All welds inspected were located both subsea and above sea level. ACFM was used to determine the presence or absence of surface breaking defects.