Cleaning technique makes platforms safer

April 28, 2011
Fire deluge remediation technology designed for North Sea platforms could have strong potential in the Gulf of Mexico, according to Paradigm Flow Solutions Ltd (PFSL).

Offshore staff

HOUSTON -- Fire deluge remediation technology designed for North Sea platforms could have strong potential in the Gulf of Mexico, according to Paradigm Flow Solutions Ltd (PFSL).

The Aberdeen-based company created its Deluge Preservation service last year, in response to concerns over asset integrity on older North Sea installations. These were heightened by the repercussions of last year’s Macondo incident in the Gulf.

In many of the UK’s first-generation platforms, corrosion scale and debris has built up in the water deluge systems designed to provide active fire protection, rendering them potentially ineffective. According to PFSL’s Managing Director Rob Bain: “Historically, the main options have been to use a chemical cleaning treatment to remove the corrosion and scale, or use high-pressure retrojetting systems. Both can be highly damaging to thin-walled pipework. The alternative is full replacement of the pipework, which can entail a prolonged shutdown and high cost.

“We felt something else could be provided to restore these systems to their required conditions, without having to take them off-line in the process.”

PFSL decided to adapt a bespoke rotary power brushing technique that it had previously applied in topsides drains and utility systems.

“Having proved the concept,” Bain says, “we approached several UK operators and got positive responses. We were invited to go offshore to perform trials late last year, on 25-30 year-old, first-generation platforms. We found that a lot of the deposits in the pipework had remained, after other contractors had tried their cleaning methods. This was all successfully removed by PFSL systems with the latest works showing an improvement of deluge flow from 11 liters/minute, meter² to 75 liters/minute, meter² .

“Typically, UK North Sea operators must perform annual tests to demonstrate that performance standards are being achieved. Some operators now have to do this every two to four weeks, continually flushing debris out, but without addressing the root cause of the problem.”

PFSL’s technique involves use of brushes ranging in diameter from 0.5-in, to 6-in. (1.3-15.2-cm), depending on the diameter of the pipes. The brushes are driven by a small rotating motor with flexible shaft, powered by air and water. They are designed to navigate through small bore pipework, acute bends, and restricted access areas to target blocked areas.

Debris is flushed out and captured for analysis and subsequent disposal, and the pipework is then treated with a bespoke, non-toxic corrosion and scale inhibitor to prevent any further build-up post-cleaning.

“We can do this three to five times quicker than conventional techniques, and without taking the system offline,” Bain says. PFSL also provides internal video inspections via a boroscope before and after cleaning, along with deluge testing results, to demonstrate that the blockages have been cleared.

PFSL’s biggest client in the UK sector is a major operator of mature fields and is now looking to implement the process on all the old platforms it has acquired from previous operators. PFSL feels the technique could also be valid in the GoM, where Bureau of Ocean Energy Management, Regulation, and Enforcement is expected to introduce prescriptive legislation on offshore safety, which should include fire deluge systems.

04/28/2011