“Man cannot discover new oceans unless he has the courage to lose the sight of the shore”

Overview

- Health Assessment of Underwater Effluent Disposal Pipeline at a depth of 25 meters at Dahej, Gujarat.
- Pipeline – 20” diameter with 70 mm Reinforced concrete quote buried under 1-1.5 meters silt.
- Inspection of underwater pipeline at a depth range from 10 meters upto 25 meters.
- Identification & Health checkup of underwater Diffuser (Outfall Point) 3 kilometres in the Sea.
- Remaining Thickness Measurement/Corrosion Mapping.
- Leak detection/Pressure Test of underwater Pipeline.
- Cathodic Protection Survey of underwater Pipeline.

Challenges

- Turbidity too high for any underwater activity.
- The currents and turbulence makes the Dahej Sea one of the roughest sea to work in India.
- The undercurrents of Gulf of Khambhat make the underwater visibility to absolute zero.
- Identification & marking of the pipeline & diffuser with the given coordinates with zero visibility.
- Removal of silt and pipe excavation manually.
- No damage to the pipeline to be ensured.

The Approach

We recognized at once that we had to look beyond the conventional technique as well as inspection method. Considering the challenges, we started with the basic processes clubbed with the finest technology and created a mix of a customized solution for this complex challenge.

The Solution

The Team

We collaborated with our expert Marine Team, Ex-Navy with more than 15 years of diving expertise. Equipped with latest diving tools and global sea diving norms, we explored the path for underwater inspection.

Resources – Dumb Barge, Tug Boat, Gemini Boat, Survey Boat, DGPS, Dredger, a team of expert divers with latest diving tools and PEC Inspection team.

The Technology

UNDERWATER & SPLASH ZONE PULSED EDDY CURRENT PROBE

We reached out to the Technical Associates. Through a detailed technical discussion with them, we were able to bring one of the best technical innovative solution for deep underwater inspection.

Underwater PEC probes are specifically designed to detect corrosion hidden under marine growth and/or coatings, without surface preparation, in offshore applications such as risers, jetty piles, caissons, underwater piping systems, and conductor inspections.

- Underwater thickness measurement and corrosion mapping up to 100 meter depth.
- Inspection without removal of Insulation/Coating.
- No surface preparation required.
- Inspects through the marine growth as well.
- Wall Thickness - Up to 100mm (4 in)
- Insulation/Coating thickness (liftoff) - 0-300mm (0-12 in)
- Footprint at zero liftoff - 100mm (4 in)
- Watertightness -100 meters - (330 ft)
- Maximum surface temperature – Direct contact operation 70*C (158*F)

The Results

With the dedicated experienced Team and innovative technique we could achieve the desired results which a few thought to be impossible.

The Client was contemplating to replace the 20 year old pipeline. However, with these results, we helped them extend the life of pipeline with nominal repair works and thereby ensuring Great Savings.

Successful underwater inspection (thickness measurement) of 360* X 500 mm patch at various locations without removal of 70 mm Reinforced concrete coat.

Corrosion mapping of inspection locations.

Not only just inspection but we successfully detected leak underwater and reported which was the best solution to their never ending issues.

All the nozzles of the Diffuser were removed and re-fitted after health check-up. The blockages of the diffuser were cleaned and the effluent could regain its discharge pressure.

Our Team