Subsea infrastructure / 2025
Two hundred and fourteen kilometres of pipeline inspected without a single diver in the water.
- Client
- Ardmore Midstream
- Vessel
- SOUNDER
- Duration
- 51 days
- Position
- 58.1147 N / 1.9042 E
0
Network inspected
Three deployment windows
0
Segments cleared
More remaining life than modelled
0
Diver hours
Across the entire campaign
The brief
Ardmore operates an ageing gathering network with a regulatory inspection obligation and a maintenance budget that assumed the worst about every span it could not see.
The brief was blunt: inspect all of it, rank it honestly, and do not come back with a report that says everything needs attention. A list where everything is urgent is a list nobody can act on.
The approach
SOUNDER ran the full network in 51 days across three deployment windows, holding a 40 centimetre standoff on structure in currents that peaked at 2.6 knots.
Wall thickness was gauged ultrasonically at 1,840 discrete points selected from the sonar return rather than from a fixed interval, so the sampling followed the anomalies instead of the calendar.
Free spans were measured against the as-laid record rather than the design drawing. The two disagree almost everywhere, and the design drawing is the one that is wrong.
What the returns showed
Eleven free spans exceeded allowable length. Nine of those were not in the previous inspection record because the previous inspection interpolated between fixed waypoints.
Wall loss across the network was substantially better than modelled. Sixty-eight percent of segments carry more remaining life than the maintenance plan assumed.
Two cathodic protection anodes were fully consumed at a junction the plan listed as low priority. That junction is now the highest priority item on the network.
The useful half of the report was the part that told us to stop spending money. Nobody had produced that before.
Similar water
Ardmore Field took 51 days and produced findings the client would rather not have had. That is the point of paying for a survey.