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Risk assessment focused on flow lines Draft of the long-awaited risk report suggests flow line spills are the largest, most common and most harmful on the North Slope Eric Lidji For Petroleum News
Rather than overhaul the entire oversight system of petroleum infrastructure, the State of Alaska should institute “incremental improvements” to prevent future spills, according to a draft of a long awaited risk assessment of North Slope oil and gas infrastructure.
The draft document from the Department of Environment Conservation has not yet been released publically, but was obtained by the Alaska Dispatch and posted on its website.
According to the draft, the study didn’t uncover a major increase in spills over the past 15 years, despite two high profile spills, and “the data does not indicate that the petroleum infrastructure is nearing its ‘end of life.’” However, “While there is no significant change in spill trends there is evidence to suggest that some spills may be linked to the age of the infrastructure which warrants increased vigilance, corrective actions and oversight.”
The draft focuses on flow lines and well lines, saying the frequency and severity of spills on those ancillary pipelines is greater than on the larger oil transmission pipelines. The report makes several broad suggestions for reducing spills on these smaller pipelines.
Flow line spills more common The DEC used the SPILLS database, a 20-year record of spills across the state, for a variety of liquids and even for small amounts, to look for trends, and found “no significant trends in the frequency of loss-of-integrity spills” but “some evidence that the frequency of large spills (over 1,000 gallons) trends upward over the study period.”
The study found that spills on small pipelines are more common than on larger pipelines.
Facility oil pipelines, like well lines, averaged 16.5 spills per year, compared to 4.9 flow line spills per year and 0.6 oil transmission pipeline spills per year, according to the draft.
Flow lines carry oil, natural gas and water from well sites to processing facilities. Flow lines account for the majority of the pipelines on the North Slope, more than 800 miles.
The spills larger than 1,000 gallons came equally from facility lines and flow lines. Most of the largest spills, those larger than 10,000 gallons, came from flow lines and were typically more harmful to the environment than facility line spills, which mostly fall on gravel. Flow line spills were also more likely to shut down production than other spills.
The draft study found that corrosion was the most common cause of flow line spills, followed by valve-seal failures. Valve-seal failures were the most common cause of oil transmission line spills, although corrosion caused the largest of those spills.
The study found that age increased the probably of infrastructure failure.
DEC could change oversight Because the frequency, size and impact of spills trends unfavorably toward flow lines, the draft report proposes five actions for the DEC focused on those smaller pipelines.
Those include:
• Augmenting existing state regulations for flow lines to “improve oil pollution prevention requirements and enhance DEC’s capability to enforce existing performance standards for flow lines at production facilities.”
• Sponsoring a conference on leak detection technologies with the goal of finding small leaks to avoid large spills. That effort could lead to new construction standards.
• Setting benchmarks for decreasing the frequency and size of spills and publishing annual reports to measure actual spill information against those expectations.
• Standardizing how the state reports the causes of spills to “identify ‘leading indicators’ — indicators that can be detected before a spill occurs — and to make future adjustments in industry practices and agency oversight to better prevent spills.”
• Working with the Department of Law “to examine the penalty structure for spills to see if statutes need updating and bolstering.”
Project in works since 2007 The results of the draft study might surprise some who remember a pair of high profile oil spills at BP-operated facilities on the North Slope in 2006, both caused by corrosion.
Those spills led to the creation of the study, in fact.
In 2007, then-Gov. Sarah Palin created the Petroleum Systems Integrity Office, repealing an agency created by her predecessor, and launched the risk assessment. Palin envisioned the project as a comprehensive overview of all oil and gas infrastructure on the North Slope, in Cook Inlet and in Valdez, as well as the 800-mile trans-Alaska oil pipeline.
That effort met obstacles though, chief among those being that the companies that owned the infrastructure did not want to hand over certain information crucial for the project.
Following a negative review from the National Academy of Sciences, the DEC narrowed the project scope earlier this year to look only at the causes of North Slope oil spills.
There is no public timetable for the release of the final report.
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