Descaling Product Comparison Onboard an Oil Rig

The Problem

The oil rig was experiencing toilet blockages and despite using dosing pumps and moving them around the rigs to try dislodge any pipe blockages, 70 toilets were still experiencing problems.

To fix the blockages, workers needed to locate the blockage then remove and replace the pipework. In many cases, the cause of the blockage was very small. Small amounts of debris/foreign matter should not shut a whole sewerage pipe system down. However, the pipework had a dense scale build up and due to the growth of scale these small items were getting caught and causing a complete blockage of the mainline. This has a knock-on effect of further issues as people continue to use the toilet system and the lack of vacuum caused by the main line blockage prevents flushing.

This is a blockage example that took 15 man hours to locate and remove. The cause of this blockage was a small door knob off a bathroom cabinet that may have inadvertently fallen into the bowl.

This scale build up was resulting in weekly blockages and the loss of many man hours to locate and repair. Not to mention that the job has obvious bio-hazard exposures.

A section of pipework was removed and cut mechanically into small sections to allow testing of 3 different scale removers. The results were interesting and show the effectiveness of the various products.

Product trials

Each of the pieces of pipework were placed in 1.5 litres of water and 100 ml of the descaling product was added to the water. They were left to soak for two days.

A section of the pipework removed from Void 13

This has been soaking in Triple7 Eco-Scale Plus. Very good result. Marked reduction in pipework scale and increase of internal diameter. Scale is being attacked along all edges and is “retreating” into the pipework away from the cut edge. Strong signs of the product getting behind the scale and remnants can be easily removed with a screwdriver as the scale is softening.

This has been soaking in Product 1. Very poor result. Zero or very little reduction. No penetration between scale and pipework. Scale still hard.

This has been soaking in Product 2 for two days. Product 2 is a product the rig been using for several months. Stopped recently to try a different product Reduction in scale visible. Signs of voids opening between the scale and the pipework. Shows promise if kept up permanently although the cost is prohibitively expensive. Scale still moderately hard.

This has been soaking in a Combination of Triple7 Eco-Scale Plus, Product 1 and Product 2. An additional mix was made up of a mixture of the three products and the results are also good. The photograph shows it to be better than Triple7 but in reality the Triple7 solution is working better. Possibly this is only working because it has Triple7 mixed in. Second place winner!

Product trialed

Triple7 Eco-Scale Plus

Triple7 Eco-Scale Plus is a unique and highly concentrated limescale and calcium remover designed to meet the challenges of the Mining, Oil and Gas Industry. The highly concentrated formulation of naturally derived acids and bio based surfactants provides maximum limescale removal performance without corrosion damage to valuable equipment.
Triple7 Eco-Scale Plus has been formulated with work safety in mind, offering powerful limescale removal performance without introducing dangerous acids into the workplace.

Triple7 Eco-scale Plus requires no PPE, contains no toxic or dangerous ingredients and can be disposed of without risk of environmental damage.

Two other global brands that have traditionally been used in oil and gas environments were compared for performance.

The Results

After six days soaking in the same solution, the sections were removed and compared for the final time. The clear winner is the Triple7 Eco-Scale Plus with the combination containing Triple7 Eco-Scale Plus coming second. The combination worked almost as well as the neat Triple7 Eco-Scale Plus which is surprising as the other two products in the mix had very poor results. Likely the good result of the combination is only on account of the inclusion of the Triple7 Eco-Scale Plus in the mix.

The below photo shows the original pipework re-emerging from under the scale on the Triple7 Eco-Scale Plus and on the combination mix.

Client Conclusion

For use in the rigs lines for the treatment of scale build up. “Product 1” and “Product 2” are a waste of money and existing stocks should be used up if nothing else is available. No future orders should be made. The product “Triple7 Eco-Scale Plus” performs markedly better and is environmentally friendly as well and should be the only product we use for the foreseeable future, as the above tests show it significantly outperforms the others.