BP calls in the experts

BP has retained three corrosion experts to evaluate and make recommendations for improving its corrosion management programme in Alaska. The three will independently review and make recommendations for improving the corrosion inspection, monitoring and prevention programme currently in place at Prudhoe Bay and other BP sites in Alaska.

The appointments were made public by Bob Malone, chairman and president, BP America, when appearing before the Subcommittee on Oversight and Investigations, Energy & Commerce Committee of the US House of Representatives. He apologised for the company's recent operating failures and said preventing environmental damage is an absolute priority.

BP is continuing its programme of ultrasonic inspections at Prudhoe Bay and has completed around one mile of pipeline in both the eastern and western operating areas. It says no integrity issues have been identified beyond those found in the initial pig run.

Insulation removal work in the western area was halted temporarily as over 100 workers completed enhanced training for asbestos handling and the company assessed how to handle the material safely. The insulation was applied when the line was originally installed in the late 1970s. Around three miles of insulation has been removed in the eastern area.

Daren Beaudo, spokesman for BP Exploration Alaska (BPXA), said in a written statement to PE that the company is working through a plan to complete pigging of the Prudhoe Bay Unit transit line.

"We've been in discussions with the DOT (US Department of Transportation) and it's clear that they think smart pigging every five years would be beneficial in helping us manage the lines. We are working to do this," he said.

According to Beaudo, the Lisburne line has been pigged and smart pigged and preliminary results confirm the line is fit for service. BP, he said, has also completed a segment in the eastern operating area and is committed to completing all pigging by the end of November.

Pigging is only one of the methods being used to inspect and maintain crude transit lines. "The inspection, maintenance and assurance programme over the years has incorporated combinations of state-of-the-art ultrasonic, radiographic, magnetic flux, guided wave and electromagnetic inspection techniques," Beaudo stated.

Where pipelines are above ground, they allow for direct inspection of pipeline sections where corrosion is most likely to occur. With buried pipelines, however, smart pigging is the only way to inspect for corrosion without unearthing the pipeline.

"Given the above ground accessibility of North Slope lines and the extensive inspection programme already in place, BPXA did not believe it necessary to smart pig every five years," Beaudo explained.

The company runs around 370 maintenance pigs per year on the North Slope at Prudhoe, either because of mechanical issues or because corrosion monitoring suggests it. The frequency of pigging depends upon many factors, including the build-up of sediments and other solids such as wax.

"Pigging frequency varies significantly on the North Slope and in the industry," said Beaudo. "For example, the Northstar oil pipeline is pigged every two weeks to prevent paraffin build-up. There's no cause- and-effect mechanism for the build- up of solids and corrosion.

"The unique role we believe solids played in the Oil Transit Line 2-1 leak was that it prevented the appropriate levels of corrosion inhibitor to effectively treat the pipe and kill bacterially-generated corrosion," he concluded.

Malone has added an additional $1 billion to the $6 billion already earmarked to upgrade safety at BP's US refineries and for integrity management in Alaska. The latter will account for a $550-million spend over the next two years.

BP expects delivery by the end of the year of the 16 miles of pipeline ordered from US mills to replace existing lines at Prudhoe Bay.



A case for traceability software ?



The Cadbury recall is likely to accelerate demand for traceability systems that support speedy identification of such problems and limit the potential fall-out if contaminated product does reach the market.

Even before the chocolate recall, UK food manufacturers were digesting new legislation brought in after the BSE scare, requiring them to be able to precisely trace the source of all ingredients.

There are currently very few software products on the market that offer such functionality, said Mike Croot, manager, production management group of UGS UK & Ireland, which supplies product lifecycle management systems.

"Traceabilty has always been seen as a slightly bigger project and not something that you do at SCADA-cost level," explained Croot, who believes that such software could have made a big difference to Cadbury both before and after the recall.

According to Croot, many companies still use paper-based systems to log the production flow, but few actually check this unless there is a problem. "By the time they get to that stage it is too late and the product is in boxes, shipped out the door and in the shops," he commented.

With the latest supervisory control products, real-time data can be brought into the system and measured against set standards to flash up when you are producing outside specification, Croot explained.

These systems, he said, now offer "something like a birth certificate for each product saying this product came from this line at such a time and was made with ingredient from these suppliers on this date; and this person authorised the change in the set by temperature and this person authorised change in the mix."

Moreover, he said, if there was a potential problem between points A and B you can identify which batches to recall from the barcode on the side of the box and track where the product has been shipped to.