Offshore CompoSol Encap

North Sea 1" Off Take Valves

An offshore platform operator in the North Sea had an integrity issue with an off take valve. A 24” Prover Loop System had a severely corroded 1” off take valve. External corrosion had caused wall loss down to 1mm and it was not thought possible to carry out hot work surface preparation on the significantly reduced wall thickness without the risk of perforating the substrate. IMG Composites were approached to provide a solution, CompoSol Encap.

IMG Composites technologies allow repairs to be undertaken using surface preparation standards St 2 to SA 2.5. This technology means that the repairs can be carried out without causing further damage to already weakened systems. A saddle repair was designed using the CompoSol Encap repair system. This repair was carried out while the line was still “Live", eliminating the need for any loss of production through shutdown.

Offshore CompoSol Flat

Composite flat surface coatings are beneficial as they both protect steel substrates from corrosion deterioration and also reinforce the plate to reinstate load bearing capacity lost through deterioration. Composites are light weight, flexible and strong. High quality fibre reinforced polymer composites also have good impact resistance, as the fibre-matrix interfaces act as crack stoppers and crack deflectors. Below is a cast study of CompoSol Flat application to a pipe deck container loading bay on a platform in the North Sea.

Stage 1 - Initial Inspection

Initial inspection highlighted various through wall defects across the operational area of the loading bay. Approx. 80% of the deck area had severe wall thinning, measuring between 0 and 3 mm in certain areas. This conformed to inspection information. Existing anti slip patched were noted to be in a very poor condition and required to be uplifted for further investigation.Upon removal of the anti slip tiles, additional defects were exposed beneath.

Stage 2 - Surface Preparation

The substrate was prepared toST 3 standard – Power Tool Cleaning – to remove all rust scale, loose paint and loose rust using wire brushes and air driven grinders with non-sparking abrasives. Upon completion of the surface preparation the substrate was inspected to ensure it was free from oil, grease, dirt and any other contaminants. The application area was treated by applying IMG Composites Ferroblock to convert the rust to a stable compound and seal the metal from moisture. Once Ferroblock had reached full cure, the through wall defects were addressed by the application of patch repairs utilising IMG Composites Reinforced Epoxy Paste and CompoSol Flat.

Stage 3 - Self Levelling Compound

Quality checks were carried out on to ensure the IMG Composites Ferroblock together with the patch repairs were adequately cured. Temperature readings were taken and the minimum application temperature of 10°C was achieved. After recording the temperature rating, IMG Composites Self-Levelling Compound was applied over the complete surface area of the loading bay and left to dissipate. Once cured, the self-levelling compound provides a level area on which to commence application of the complete composite repair.

Stage 4 - Composite Reinforcement

Initial quality checks were conducted to ensure the IMG Composite Self Levelling Compound had achieved full cure. The first application of the IMG Composites Reinforced Epoxy Paste and CompoSol Flat was then applied in accordance with the repair design. All materials applied are batch coded and documented within the quality documentation so that they are traceable. This application is allowed to cure before continuing to build up with CompoSol Flat.

Stage 5 - Composite Build-up

Quality checks were conducted and recorded throughout the layer build up. The continuous build up of the IMG Epoxy and Laminate increases the strength characteristics of the composite, whilst giving the repair the flexibility to dissipate any impact forces from normal operational conditions. Once the full build-up of the complete composite system has been achieved, the repair was left to cure before the final anti slip coating was applied.

Timetable of Repair

• Day 1: Arrive Platform, Check Worksite, Habitat, Progress Permits
• Day 2: Prep Deck Area using air powered tools and non sparking disks, ensuring compliance with HAVS and Platform regulations, to a ST2/ST3 standard. Apply deck levelling compound.
• Days 3-11: Apply Lightweight Kevlar Reinforcement Compound / Lay Up Kevlar Laminate
• Days 12-13: Lay Anti Slip Coating
• Day 14: Tidy Site, Final Inspection, Complete Documentation, Pass Back to Platform
• Day 15: Depart Platform

Offshore CompoSol Pipework

North Sea Platform Process Gas Line

An offshore platform operator in the North Sea had an issue with a 4” Process Gas Line that had suffered 75% wall loss due to external corrosion. The operator was planning a shut down in 9 months and needed to keep the line operating till this time. IMG Composites were contacted and asked to provide the solution, CompoSol Pipework.

At 153bar this was possibly the highest pressure composite repair in the North Sea. An engineered design was generated by the technical team, in line with the guidelines set out in ISO 24817. Due to the substrate weakness, surface preparation was carried out to St. 2 standard. CompoSol Reinforced Epoxy Paste was used to reinstate the pitting corrosion back up to the surface. 21 layers of CompoSol Pipework repair material was applied along 3 feet of the axial extent of the pipe. The repair was applied live and on line with no reduction in the operating pressure. The pipe remained in service for the required 9 months till the next shut down.

Offshore Composol Vessel

Sharjah Floating Oil Storage Unit Vessel Repair

An offshore oilfield operator in Sharjah were interested in finding a permanent solution for a corroded deck plate areas on their “FSU”-Floating Oil Storage Unit main top deck. The FSU is a 250,000 ton converted tanker which has been specially converted to store the field oil production and the corroded deck area in question was the top part of the storage tank.

Traditional methods of welding steel plates onto the affected area had been considered, however, there were two distinct disadvantages. Firstly, an additional weight problem from the 15mm thick plates required, would have added significant loads onto the existing substructure. Secondly, the preparation for cutting and welding additional re-enforcement plates, would have necessitated that all the affected storage tanks be drained, gas freed, then purged, a time consuming and costly procedure. Traditional methods would have also reduced storage capacity and have inhibited field production during the repair duration.

The operator contacted IMG Composites who carried out an initial site survey and then designed a repair which would be lightweight and could be applied without emptying the storage tanks. The ability of the composite reinforcement to move and flex with the tanker deck and the structural strength provided by such a repair method was also a crucial factor in operator’s decision.

The major advantage to the operator is that these repairs can be undertaken whilst the system or pressure containment vessel is still ‘live’. Using traditional methods the operator would have to decant product from the vessel, prior to gas freeing and then purging out all before welding on re-enforcement plates internally or externally.
Using this new IMG Composite Repair procedure, there is minimal disruption as there is no hot-work involved. Once completed, the reinforced area can be painted over to blend back into the rest of the paint system used.

A 25 square metre top plate deck area was reinforced and took 4 days to install without any disruption to operations.

The operator commented that: “The repair method selected proved to be innovative, and has enabled us to continue normal un-interrupted operations without impacting safety, production or the total storage capacity.

The final composite repair has also proven to be simple, strong, and durable, and will provide a permanent solution to an otherwise difficult and complex problem, when compared to repair using traditional methods. Traditional methods would have undoubtedly have been more expensive, time consuming, and could have severely impacted field crude oil production and reduced oil storage capacity during any repair outage”.

Offshore CompoSol Subsea

Equatorial Guinea Riser

A platform situated in the Gulf of Guinea had serious problems with the corrosion of a riser beneath the water-line. The pipeline had already been repaired with a competitor wrap repair system; however this repair had de-bonded from the substrate and was therefore no longer offering corrosion protection. IMG Composites were contacted and asked to provide a solution. With a Composol Subsea repair solution the corrosion was arrested and the substrate was protected for a warranted service life of 20 years.

The riser had a relatively high operating temperature. Although the temperature was within the operating limits of a cured CompoSol Subsea repair, it increased the likelihood of an improperly cured repair, and was also potentially harmful to the applicators. Consequently, the riser was shut down during application. However, there was little loss in production as flow was diverted through a separate pipeline for the duration of the application.

The application procedure required the riser to be sandblasted by divers to remove marine growth and surface corrosion so the surface of the substrate was prepared to SA2.5 standard. 400mm of the axial extent of the competitor repair was removed to assess the potential of adhesion of the repair to the substrate. Following surface preparation, reinforced epoxy paste was applied to form a smooth surface. Application of the CompoSol Subsea laminate was performed by divers who wrapped the full circumference of the pipeline. It required a 50% overlap of the wrap to ensure adequate compression and that all excess air and water was expelled from the repair. The entire operation, from survey to cured repair, took ten days. After repair the pipeline was returned to service and the repair had a warranted service life of 20 years.

Onshore CompoSol Encap

Middle East Oil Terminal Stubs

IMG Composites technologies allow repairs to be undertaken using surface preparation standards St 2 to SA 2.5. This technology means that the repairs can be carried out without causing further damage to already weakened systems.

A major Middle East oil terminal had problems with corrosion around stubs and off take valves. Severe corrosion had taken place and the operator was concerned with the integrity of the stubs. IMG Composites were approached and tasked with providing a composite solution that would enable the operation of the plant to continue. The answer was provided in the form of CompoSol Encap.

As the stubs had already suffered significant wall loss due to severe corrosion it was vital that the surface preparation method employed would not be overly damaging to the substrate. IMG Composites technologies allow repairs to be undertaken using surface preparation standards St 2 to SA 2.5. This technology means that the repairs can be carried out without causing further damage to already weakened systems.

Onshore CompoSol Pipeline Case Study

Middle Ease Gas Pipeline

A major Middle Eastern Gas Operator had severe corrosion problems on its National Transmission Pipeline Grid. As most of the pipeline was over 20 years old, the Operator decided on a preventative maintenance and rehabilitation programme. An Intelligent Pigging programme was launched to identify all wall defects and a rehabilitation schedule was initiated to repair and reinforce the worst of the anomalies.

Traditional techniques such as welded sleeves were costly and difficult to install and involved hot work. IMG Composites was awarded the contract to provide both a technically sound and cost effective solution with its COMPOSOL PIPELINE system. All COMPOSOL Composite repairs are designed and engineered in line with ISO 24817 and ASME PCC-2 and are carried out under Cold Work Permits.

Application is manual with light hand tools, which is important in remote areas as no heavy equipment or cranes are required. IMG Composites' composol cold work repairs are carried out online with no disruption to production by locally available, qualified applicators. The COMPOSOL PIPELINE system can be applied seamlessly for any length required at the work site.

For example, this 20inch diameter pipeline required reinforcement over a range of lengths, including 1metre, 3metre, 7metre and over 10metre sections. The concept is simple, just wrap the COMPOSOL PIPELINE system components around the pipe and allow to cure. When designed, and applied by trained applicators, in line with internationally recognised standards, it is possible to replace the strength and integrity of any pipe wall material lost due to corrosion or erosion. Repairs can be designed to have a life expectancy between 1 year and 20 years.

IMG Composites supplies an Engineered and Designed Composite Repair System for use on pipelines suffering from either internal or external corrosion, including through wall defects or mechanical damage.