ISO SIM rules to combine stronger data handling with regional risk analysis

The new ISO 19901-9 - Structural Integrity Management guidelines will define regional weather risks alongside stricter data analysis to improve risk-based approaches, Pat O’Connor, Chair of the ISO Committee, said.

Some of the world’s best oil and gas engineers are about to complete two-and-a-half years work on International Standard ISO 19901-9 - SIM, the new global standard for Structural Integrity Management (SIM).

The new guidelines, expected to be completed in the coming months, will introduce more detailed requirements over how firms structure their organisations to manage the SIM process throughout the life of the platform, O’Connor told Upstream Intelligence.

These requirements will lead to better data control and a more risk-based approach to integrity management, he said.

ISO 19901-9 will set out the requirements regarding hazards such as metocean storms, hurricanes, seismic events or vessel impact, and will be specific as to whether the platform is manned or unmanned for these events. The criteria will use the surviving the event return period as opposed to a reserve strength ratio, as this factors in variations in the metocean hazard curves and wave-in-deck loadings for different regions.

“The approach we’ve taken is to prescribe universal minimum requirements that must be met by the owners and operators of fixed offshore platforms. The intention is that they may be made more rigorous by regional annexes that take into account considerations such as whether an area suffers from specific hazards such as hurricanes or seismic activity, and whether local calibration studies have been completed,” O’Connor said.

The aim is to improve the way regulations treat an existing platform in order to preserve the structural integrity of the jacket structure and the topsides of fixed and floating systems. In addition to structure-critical components such as the jacket, it will cover safety-critical attachments, such as risers and riser guards, and operation-critical connections, such as caissons. It also addresses the fabric maintenance of topsides, which includes handrails, gratings and equipment supports.

The ISO 19901-9 requirements will be aligned, and eventually merged, with the American Petroleum Institute’s recommended practice, as contained in API RP 2SIM.

Controlling risk

A key innovation in the new Standard is the addition of a management framework requirement.

Operators and suppliers will have to demonstrate their organizations can maintain the SIM process for the life of the platform, and employees have the competencies to carry it out.

“This means that companies will have to show that they have their data and analysis under control,” O’Connor said.

This will allow the firm to adopt a risk-based approach, which leads to a more focused and efficient use of resources. If the firms cannot meet this requirement, they will default to the minimum code requirements for inspection intervals and scopes of work.

ISO 19901-9 sets out four key process areas for SIM: data, evaluation, strategy and program.

“Data collection has historically been a problem. In the North Sea (and other regions) operators have typically delegated this task to diving companies for jackets and other service companies for topsides. These companies compile huge databases, which may be lost if they go bust, or charged for if the service company decides that it is an asset that can be monetized,” O’Connor said.

Data could be collected through monitoring the integrity of a platform, and this can be sent over the internet for engineer review, “so that you know immediately whether you have an issue,” he said.

Another key area of advice is in appropriate analysis.

“In many cases, contractors believe they have reliability numbers that have been established over the years and they use them to decide whether there are problems – and they can be well wide of the mark. So, care should be taken with how and when detailed analyses are used and when reliance should be based on them,” O’Connor said.

Simple analysis methods can be used for most structures, leaving detailed analyses for special cases which can be used to calibrate or tweak the simpler methods.

“Best estimates for material, soils, loadings and resistance should always be used in assessing the overall performance of a complex jacket,” O’Connor said.

Reliability will not be a requirement in the ISO 19901-9 guidelines, but some advice will be included in the informative section to show how it could be used.

The SIM strategy should be defined by the operator and should take into account the results of analyses, informed by the engineer’s knowledge of the history of the platform, as well as the available data from the original design, fabrication and inspections, and the modes of structural failures, he said.

Early use

As well as the four step SIM process in the operational phase, SIM should be taken into account during design, and in fact many owners are now doing this.

“A good start is to produce an initial database, with drawings, summary criteria and summary analyses results, all kept in a secure and easy-to-access place,” O’Connor said.

Simple algorithms can also be used to batch-assess large numbers of platforms.

“I’ve used simple tools since the eighties and nineties to assess the relative (and sometimes the specific) risks faced by 300 or 400 platforms at a time. For example, you can compile a screening list organised by priority by looking at four or five factors, such as year of construction, water depth, number of legs and method of bracing. In fact, in many instances the likelihood of failure can be estimated (fairly accurately) and if you add the manning status and equipment on the platform, the overall risk can be shown as a matrix.”

Supporting investment

At a time of tighter budgets, the clear guidelines set out in the new ISO code will allow operators’ structural integrity engineers to better communicate SIM requirements to the rest of the company.

“Although the industry’s understanding of structural management has improved over the years, it is still the case that those responsible for it have more of a voice if they can quote the occasional standard or regulation to support their recommendations and assigned budgets,” O’Connor said.

For projects in the North Sea, which is self-regulating, firms must commit to spending on activities that don’t increase revenue, while in the Gulf of Mexico regulators urge strict compliance with prescriptive standards which “tend to regulate the worst companies and punish the good ones,” he said.

O’Connor believes the improved SIM process implementation and data evaluation provided by the new ISO standard, will help lead to more effective and focused programs that “keep the platform fit for service for as long as it is required by operations.”