A sharp increase in incidents with the potential to develop into a major accident was registered at the land plants in 2020. In addition to two serious fires at Melkøya and Tjeldbergodden, a worrying rise was seen in the number of unignited hydrocarbon leaks.
“This trend gives grounds for concern,” says Anne Myhrvold, director general of the Petroleum Safety Authority Norway. “What’s needed here is an even more systematic and purposeful commitment.
“Managements and companies must get to grip to grips with this, show that they understand risk and demonstrate that they are handling it in a good way to prevent undesirable incidents.”
The RNNP findings nevertheless show that much is going the right way in Norway’s petroleum sector, with the number of incidents where a major accident potential was present down slightly offshore. Hydrocarbon leaks and well control incidents are both at a historic low.
At the same time, the overall indicator of near misses for a major accident on the Norwegian continental shelf (NCS) reveals a small rise – largely because of a noticeable increase in structural incidents, particularly on mobile facilities. Their big potential contributes to the indicator moving the wrong way.
“Although figures for the NCS are relatively stable, this isn’t good enough,” Myhrvold observes. “The goal must be a further reduction in the number of incidents.”
Results for maintenance management show that the amount of such work carried out on the NCS and at the land plants declined from 2019 to 2020. A lot of maintenance has not been implemented as planned.
The probable cause is the coronavirus epidemic, which has prompted the postponement of a number of turnarounds and delays to planned maintenance.
On the NCS, the companies appear to have prioritised maintenance of safety-critical equipment. At the land plants, however, the backlog of maintenance for HSE-critical equipment increased last year.
“Inadequate maintenance or failure to carry it out altogether is often a contributory factor for incidents and major accidents,” says Myhrvold. “So it’s important that the companies ensure these shortfalls don’t develop into a safety risk over time.”
Where barriers are concerned, she notes a worrying trend in test results for safety-critical valves on NCS facilities, and describes this as serious.
“We can’t accept weaknesses in the barriers which control inward and outward energy flows. Given the attention devoted by the industry in recent years to preventing major accidents, it should be possible to achieve greater improvements in this area.”
The main findings of RNNP 2020 in brief
Major accident risk on the NCS
Five unignited hydrocarbon leaks were registered in 2020, compared with six the year before. This is the lowest number so far recorded. While three leaks were above one kilogram per second (kg/s), seven years have passed since a leak last exceeded 10 kg/s.
Ten well control incidents occurred in 2020, all in the lowest risk category. Although their number was lower than in 2019, the frequency of such incidents normalised to the number of wells drilled was within the expected range.
Eleven incidents of damage to structures and maritime systems were registered in 2020, compared with five the year before.
The overall indicator, where all near-miss incidents are weighted against their inherent accident potential, showed an insignificant increase in 2020.
Major accident risk on land
Where the land plants are concerned, 17 near-miss incidents with an inherent major accident potential were reported in 2020 compared with eight the year before.
The plants experienced a worrying increase in unignited hydrocarbon leaks and two serious fires at Melkøya and Tjeldbergodden respectively. Both the latter are under investigation by the PSA, and will reports on them will be published on psa.no in due course.
Hours devoted to preventive and corrective maintenance on the permanent NCS facilities declined in 2020. Although the total backlog for preventive maintenance is low, it has shown a growing trend over the past three years and was at the 2013 level in 2020.
The backlog for HSE-critical preventive maintenance has remained roughly stable during this period, but the number of hours in total outstanding corrective maintenance increased substantially in 2020 compared with the year before.
A decline in hours devoted to maintenance also occurred at the land plants from 2019 to 2020. In particular, the amount of preventive maintenance carried out was significantly reduced compared with 2018-19.
Turnarounds also consumed considerably fewer hours compared with the year before. In addition, both overall outstanding and HSE-critical corrective maintenance increased from 2019.
The industry is making growing use of leading indicators, which say something about the robustness to withstand incidents. Barrier indicators are an example, and convey information about the ability of barriers to function when required.
These indicators still reveal big differences in level between facilities on the NCS. A positive trend can be seen over time for a number of the barriers subject to the industry’s self-defined requirements, but the level has been more or less stable in recent years.
Nevertheless, there appears to be an increase in errors with some barriers. Leak tests with riser valves, in particular, have shown a rising trend for faults in recent years. Results for a number of the safety-critical valve types are well over the industry norm.
Big variations in barrier indicators can be observed between the land plants. Collectively, the trend for these indicators has been stable or positive in recent years. The indicator for emergency shutdown valves is also above the industry requirement.
A total of 191 reportable personal injuries were registered on the NCS in 2020, down from 234 the year before. Twenty-five were classified as serious compared with 33 in 2019.
Nine incidents which satisfied the criteria for categorising as serious personal injury were reported at the land plants, compared with seven the year before.
The number of serious personal injuries per million working hours in 2020 declined for mobile facilities but increased on production facilities and at the land plants.