Seawater Cooling System Return Pipe Repair

Case Study: Oil Refinery Repair Leaking Underground GRP Seawater Return Pipe

A rapid epoxy putty repair made to an underground 3000mm GRP return pipe in a seawater cooling system cut downtime at an oil refinery to just two days of reduced production. The refinery would otherwise have needed to shut the pipe off for three weeks whilst awaiting fabrication and installation of a replacement section.

Case Study Overview

Site Oil refinery
Location Saudi Arabia
Repair Type No pressure leak repair
Defect Cracks in an underground 3000mm GRP seawater cooling system return pipe

Repair Products

Superfast Copper Epoxy Putty,
Sylmasta AB Original Epoxy Putty

Case Study PDF

Download Seawater Cooling System GRP Pipe Repair Case Study PDF

Case Study Details

The oil refinery was one of the biggest in the Middle East, processing approximately 400,000 barrels per day. Various processes at the site relied upon the seawater cooling system, which extracted water from the Red Sea and transported to and from the refinery.

This was done via a network of underground 3000mm GRP (glass reinforced plastic) lines. Whilst such large pipes enabled vast quantities of seawater to be moved around, any failure would have a hugely detrimental impact on the efficiency of the system and cause massive water loss unless attended to as a matter of urgency.

A potential problem with the return line was first flagged when the ground above a section of buried pipe was noticed to be wet. The line was taken out of service and excavation organised, leading to a hole being dug to access the top 50 percent of the vast pipe.

The earth surrounding the pipe was thoroughly saturated, indicating a significant leak. When pressure was then turned back on, so much water escaped from several areas that the hole was instantly flooded. This water had to be pumped out to regain access to the line.

*So much water escaped the line when pressure was restored that the hole dug to access the pipe became heavily flooded*

Clearly, the pipe could not go back into service leaking so much water. This was problematic for the refinery, who needed the line in operation for oil to be produced at full capacity. For this reason, replacement of the damaged section was not considered an option, as it would have left the line out of action for up to three weeks.

With a rapid repair required, it was decided to use two epoxy putties to seal the seawater cooling system return pipe. For the smaller cracks on the line, Superfast Copper Epoxy Putty was chosen. Although designed for copper pipe repair, it adheres to all materials and comes with a fast work time.

Epoxy putty applied to repair a seawater cooling system return line at an oil refinery in Saudi Arabia — *Superfast Copper applied to seal the smaller cracks in the pipe*

Superfast Copper is supplied in a 114g stick containing pre-measured resin and hardener. The required amount of putty was cut from the stick, kneaded by hand, and then pushed into the cracks on the GRP line whilst soft.

The heat of Saudi Arabia accelerated the five-minute cure time of Superfast Copper so that within a couple of minutes, the putty began to set to a material as hard as steel, permanently filling the cracks and starting to seal the line.

*Sylmasta AB Original was used for the larger cracks because of its extended cure time*

For the bigger cracks, a putty with a longer work time was needed so that greater quantities could be mixed and then applied over larger areas without the threat of premature curing.

Sylmasta AB Original Epoxy Putty was used for its two-hour cure.. Both AB Original and Superfast Copper achieved maximum properties after 24 hours. Applying the epoxy putties to all leak areas took less than four hours. A day later and the system was turned back on.

Completed repair of a leaking 3000mm FRP seawater cooling system return pipe using epoxy putty at an oil refinery in Saudi Arabia — *The line was successfully sealed using epoxy putty*

Once it had been established that no water was now leaking from the pipe, the line was reburied. Whilst the repair was carried out, the refinery had to operate below full capacity for only two days with all the required materials costing under £100 – a far cry from the disruption and expense which would have come with replacing the damaged pipe.