November 12, 2019May 15, 2020 by Kristin Øye Gjerde

Climbing on Statfjord

By Kristin Øye Gjerde, Norwegian Petroleum Museum

Statfjord A, B and C have been subjected to a heavy battering throughout their producing lives. Stringent safety standards call for constant inspection and maintenance of these platforms. Many of the areas to be monitored are hard to get at – inside piping in the shafts or at the tip of the flare boom, for instance. Climbers – rope access technicians – have been used since the 1990s to reach the most inaccessible places.

— Photo: CAN AS

CAN AS, which was established as a Norwegian company in 1993, has been hired for a number of such jobs by Scana Industrier as the contractor for surface treatment on Statfjord.

During the 1990s, rope access technicians were permanently stationed on the field as part of the scaffolding teams. Such specialists always had to be available. Rope access techniques were both efficient and cost-saving as an alternative to erecting scaffolding for a small job and then dismantling it.

Rope access technicians were eventually also hired for special assignments, such as work on the flare boom or entering seawater and ballast water pipes when production had been shut down for a maintenance turnaround. Equipment which was otherwise in operation then became accessible.

Maintenance work on Statfjord C in 2000. Photo: CAN AS

CAN had 103 employees in 2011. The company puts together teams for jobs on Statfjord, for instance, which vary in composition to perform the work required. Personnel need to have rope access expertise at levels 1 to 3. To reach the highest level, which is a certified safety leader, the operative must have taken a course and carried out about 800 logged hours of rope access work. This corresponds to roughly three years of experience, and the person concerned will then be able to lead an access team.

Training gives heavy emphasis to safety and rescue, and double security must be provided in all work. Equipment has to be in top condition, and the user must be familiar with the way it functions and have received frequent practical training.

A standard rope access team comprises a safety leader and two operators. In addition to expertise in climbing with ropes, CAN’s employees are qualified mechanics, electricians, sheet metal workers, welders, pipefitters, riggers, insulators, scaffolders or surface treatment personnel. That makes it possible to put together a number of multidisciplinary rope access teams.

The company’s personnel not only conduct inspections, but also carry out improvement and maintenance work such as surface treatment, pipework, insulation and welding, as well as upgrading sprinkler and fire-alarm systems. In addition, they can undertake fabrication in areas without crane cover and support subsea operations.

Inspecting pipes

Piping inspection on Statfjord B. Photo: CAN AS

Large pipes on Statfjord are used to transport seawater for cooling, ballast and firewater. They run through the shafts from the base of the platform and up to the topside process facilities. Entry and exit points can be up to 150 metres apart in height.

CAN has sent inspectors through this type of piping to conduct internal inspection. The smallest access technicians are normally detailed to do such work in the narrowest pipes, where small trolleys may also be used to simplify access. Movement can be very restricted. The inspectors can remove rust and coatings to get the best possible view. A robot is generally unable to do the same.

Not all the pipes are equally narrow, and the access technician can then carry out internal repairs, such as welding on patches or anodes and surface treatment.

Flare booms/towers

The biggest flare towers are generally up to 100 metres long, and have huge dimensions. Inspecting them involves a combination of various corrosion scanning methods at nodes and fixings. Findings are usually visualised with the aid of magnetic particle (MT) or liquid penetrant (PT) testing. A welder and a surface treatment specialist are normally included in the team, so that repairs can be conducted as wear and tear are identified.

Drilling derrick and equipment

Inspection of crane at Statfjord A in 2010. Photo: CAN AS

Access technicians have conducted systematic inspection of derricks since 1996 to prevent dropped objects. This work concentrated earlier mostly on removing loose objects, but has also been extended in recent years to cover checks on permanently installed and moveable equipment at a height. The access technicians can also check bolts in the derrick when the customer requires this.

In all the jobs, findings are reported to the customer and improvements carried out as required. All inspections are documented in reports sent to the customer when the work has been completed. [REMOVE]