Severe Scaling Removed from U-Tube Heat Exchangers

Throughput improves following in-situ heat exchanger cleaning

Summary

The ‘A’ platform, operating in the oil field off the coast of Qatar, was experiencing problems because of severe blockages inside two shell and tube crude oil heat exchangers particularly in the U-bend section. The severe scaling was affecting rig processes – and the quality of the crude oil exported from the platform.

Challenge

• The scaling and blockages were restricting the amount of heat put into the crude oil which helps reduce the water content.
• The less water in the oil, the better the crude quality.
• The right temperature also reduces the viscosity of the oil and improves platform efficiency by being able to process and pump the oil faster.
• Previous cleaning efforts by other contractors using conventional and even some quite-advanced methods had failed to clear either the straight legs or U sections.

Solution

• Tube Tech International used its MicroSafeflex lance supplied from their Wysperflex pump jetting system.
• Low volumes of sea water were fed to the pump, filtered then boosted to super-high pressures of over 40,000 psi.
• Tube Tech International’s specifically designed U bend MicroSafelex cleaning nozzle was able to pass around even the tightest radius bends to remove both blockages and scale as it went.
• The oil field was logistically a technically challenging operation and Tube Tech International’s project planners had to be sure every piece of equipment, including several alternatives tested to extreme at their works in order to execute the contract successfully, were on hand for the job.
• Tube Tech International proved that previous industry standards for cleaning such equipment with U bends were inadequate and, for the first time on this unit, Tube Tech gave not only the straight legs, but also the U sections a complete internal clean.
• For the client it resulted in:
• Higher thermal efficiency of the unit
• Crude being heated to elevated temperature to increase water removal
• Less water content therefore higher quality of crude from the platform
• Increased throughput and output
• Thorough clean of the U sections for the first time

Client Comment

The client’s Senior Process Engineer said: “Tube Tech International had been patiently waiting in the wings while we tried other high-tech and traditional options, both locally and globally, with limited success. The time came to try Tube Tech International, a company which is reputed to be a technical leader in their field by the likes of Shell, BP and Total. I confess to being pleasantly surprised when we witnessed not only the level of success the Tube Tech team achieved where others had failed but their professionalism, dedication and team work, not just from site personnel but from their HQ in England. Tube Tech were the only company we found that was willing to develop a brand new, dedicated solution to our problem with several back-ups in tow. In my opinion they definitely live up to their reputation as a world leader in their field of hi tech cleaning. The savings our Company has made have been substantial and therefore I have absolutely no hesitation in recommending this company to others.”

Tube Tech Comment

Scott Donson, Technical Sales Manager: “Logistically and technically this was a big and quite complex operation because we had to overcome several obstacles, not least limited access combined with removing extremely hard deposits from hairpin bends, on an oil rig in the middle of the ocean. The variety of equipment shipped to the Gulf assured us the greatest possible chance of success and was far more than other contractors had taken previously. We thoroughly tested our new technologies and equipment prior to shipping on mock tubes with blockages to the same dimensions as the clients crude heater to be certain our unique nozzle designs would negotiate the tightest of bends. Once our system was installed and we had demonstrated our ability to extract the tenacious blockages hiding around the bends, the client allowed us the time to achieve best overall cleanliness which was to ultimately benefit our client long term. Patience and dexterity of technology was the key on this occasion. Its lovely to see the upfront planning and hard work back at base paying off culminating in a successful operation and a really happy client.”

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