Observation Class ROV: A Better Alternative to Saturation Divers
Several years ago in an Australian oil field, the choke inside a subsea manifold was leaking crude out.
The system was shut down and a
Saturation dive spread was brought in to
change out the choke. This was at a large
cost to the company.
Once this was repaired the field was back
online however NOPSEMA then put in
place that all the chokes in this manifold
would have to be UT (NDT) quarterly.
Working together with an engineer, Dive
Works Managing Director, Andrew Ford
helped to develop a method of conducting Ultrasonic Thickness Testing (UT) of the chokes inside the manifold by modifying an observation class ROV.
This eliminated the need for saturation
divers to conduct the UT tests of the
chokes being inside the manifold.
The ROV Pilot flew the ROV inside the
manifold with the system that was
created for the non destruction testing of the chokes. The ‘Falcon’ ROV was then used as another view of the operation
from outside of the manifold. The chokes
were tested during the project.
The outcome was successful and saved
the Client $7 million per quarter on not
using saturation divers. This equated to a
savings of AUD $28 million per annum.
Using the ROV was a safer alternative to
saturation divers and reduced the company’s risk exposure.
The company was then able to meet the
requirement of NOPSEMA and provide
quality ongoing reporting of the situation.