Platform

On 15 March, offshore experts gathered in London for the Oceanology International Conference (OI 2016). One of the topics on the agenda was ‘Oil & Gas: ‘What’s next for ageing offshore assets?’

With a maximum decommissioning spend forecast for 2017, the strand explored opportunities and technology requirements for what is likely to be a bow wave of activity around engineering skills, new technology, environmental surveys, logistical planning and purpose-built equipment.

Total forecast decommissioning expenditure from 2015 to 2024 stands at £16.9bn and over the next decade 79 oil and gas platforms are earmarked for removal from the UK Continental Shelf (UKCS).

"The majority of installations on the UKCS have exceeded their design life."

OI 2016 attendees also considered the counterpoint to decommissioning projects in the shape of asset life extension (ALE), including alternative uses for abandoned fields and structures. With the price of crude barely above $35 a barrel at the time of writing and E&P budgets stretched, ALE is now a keystone strategy for upstream operators struggling with over-supply and plunging revenues.

"The majority of installations on the UKCS have exceeded their design life," states Tom Milne, health and safety policy manager at industry body Oil & Gas UK. "Companies employ integrity management systems that keep them informed as to the asset condition, which helps to guide ALE.

"Extending the life of ageing offshore assets or determining that it is uneconomic to do so is down to each individual operator – and the low global oil price may very well affect those kinds of decisions. E&P companies may not want to drill new wells or they might decide to extend the life of certain fields. There is also the possibility that such decisions could bring forward cessation of production."

Ensuring integrity: guidance around ALE methodology and practice

ALE is not just related to platform structures, pipework and pressure vessels, but also encompasses control and instrumentation, IT and software, staff demographics, skills, training and competencies.

As equipment ages, increased challenges to maintaining integrity need to be managed, both as a result of cumulative degradation over time (such as corrosion, wear and fatigue), or where like-for- like replacements are no longer suitable due to obsolescence or changes in engineering standards.

"Oil & Gas UK has published risk-based guidance on the methodology and approach for safe ALE on installations, including the recent ‘Guidance on the management of ageing and life extension for UKCS oil and gas installations’," explains Milne. "It also provides advice for managing life extension for pipelines and risers, FPSOs, structures and electrical controlling instrumentation systems.

"If an operator is going to change the purpose of the asset – for example, to modify it for carbon capture and storage – the operator has to go through a management of change process.

Guidance produced by Oil & Gas UK could be used to help duty holders determine that the asset is fit for purpose before that happens so that changes can then be made to the safety case. A change of use would bring different hazards and would need to be managed in a different way. Companies would need to ensure that threat mechanisms are properly assessed and that the design of infrastructure such as pipelines, risers, wells and process systems is capable of change of usage."

The Oil & Gas UK Ageing and Life Extension Steering Group was established in 2012 to bring together industry, The Energy Institute and regulators, and provide a cohesive and collaborative approach to promoting and addressing ALE-related issues on the UKCS as they arose, as Milne explains.

"The Health and Safety Executive concluded its three-year KP4 inspection programme focused on the offshore industry’s management of ALE in December 2013," he says. "The industry’s focus and management of ALE has since continued with the development of three key pieces of guidance, and the recently published [document] ‘Ageing and life extension for subsea pipelines and risers’ in January 2016. "In addition, new technology is helping deliver more effective ways of undertaking inspection and integrity management. An example of this is the use of drones for inspection work," he adds.

Remote possibilities: innovations in inspection, acquisition and testing

Milne is referring to the increased use of remotely operated aerial vehicles (ROAVs) and unmanned aerial vehicles for live flare inspections, structural inspections of equipment such as drilling derricks, and internal tank inspections on operational vessels including bulk carriers and tankers.

Cyberhawk Innovations, a world leader in aerial inspection and survey using ROAVs, reported record growth in 2015 and completed its first ever ROAV internal tank inspection on an operational FPSO.

The oil price has forced the offshore industry to get creative when it comes to technology designed to streamline ALE projects, and visitors to OI 2016 were exposed to some of the latest innovations. As well as addressing challenges associated with ALE on the UKCS such as the CO2 storage capacity of the UK’s abandoned and depleting fields, speakers also highlighted advancements in the field including the retrofitting of real time impressed current cathodic protection and remote field appraisal testing. Other IT innovations include improved signal processing and data analytics, remote inspection methods, and technologies that provide integrity information from beneath insulation and coatings.

"By focusing on data acquisition from mobile platforms, Adus is able to capture laser data in inaccessible areas."

ADUS DeepOcean undertakes precision sonar and underwater laser surveys of aging subsea assets beyond the maximum depth of current oil and gas operations. By focusing on data acquisition from mobile platforms, ADUS is able to capture laser data in inaccessible areas and the 3D point cloud data acquired allows the regeneration of ‘as is’ plans and drawings of older seabed infrastructure.

Invaluable assets: training the next generation of ALE experts

During past boom times in the oil and gas industry, preserving assets beyond their operational life was largely seen as a side issue, but with prices depressed and marginal oil and gas fields tipping into terminal decline, ALE has been transformed from a niche concern into a key industry differentiator.

"As the UK offshore oil and gas industry seeks to maximise the economic recovery of hydrocarbon reserves -¬ and technology is developed to enable that objective – so many installations will remain in service beyond their originally planned operational life span," Milne concludes. "This inevitably presents challenges to the industry in managing the effects of ageing on assets, plant and equipment, to ensure that integrity can be maintained throughout the full asset life cycle."

With skills shortages and the effects of the great crew change beginning to be felt on the UKCS and beyond, Milne nevertheless remains sanguine about the level of expertise available in the ALE field.

"ALE is all about helping operators maximise the value and the economic life of their assets without compromising on safety, and universities and training providers are delivering in necessary fields like integrity and corrosion engineering," he says. "There doesn’t appear to be a shortage of new talent."