Managing Risk Deep Beneath the Ocean

Article published in The Regulator | Issue 1: 2020

The safety of all offshore oil and gas operations relies on a central component: the continued integrity of boreholes drilled thousands of metres below the ocean floor. In the industry this is termed “well integrity” – with the aim of always maintaining control of wells and the fluids they contain.

According to NOPSEMA’s Well Integrity Manager, Mark Bourne, well integrity is the most important consideration in ensuring the health and safety of offshore workers and the responsible management of the environment.

“Our Well Integrity Team is fundamental to NOPSEMA’s core business. Our focus is on preventing an incident or emergency event through proactive risk management,” Mr Bourne said.

NOPSEMA’s Well Integrity Team comprises six internationally experienced experts trained in engineering, operations and geology. Their role is to assess and monitor the risk management plans of oil and gas companies to ensure that the drilling and maintenance of offshore wells is conducted with risks As Low As Reasonably Practicable – or risk “ALARP”. Risk ALARP means that there are no other practicable measures that can be used to further reduce the risks.

There are approximately 900 regulated wells in Commonwealth waters. Around two thirds are operational with the remainder shut-in or awaiting permanent abandonment.

“Production projects can run over 30-something years, and well integrity doesn’t stop when the well is plugged and abandoned. Industry needs to ensure that the well is designed to maintain well integrity forever."

A Well Operations Management Plan, or WOMP, is the corner-stone of the management of well integrity over the complete life-cycle. An oil company (i.e. a “titleholder”) proposing to undertake offshore drilling activities in Commonwealth waters must submit a WOMP to NOPSEMA for assessment and acceptance. The WOMP describes the characteristics of the well and the well activities to be undertaken, and must clearly demonstrate how the titleholder will reduce risks to ALARP.

“We’re talking about an 8 inch diameter borehole that reaches perhaps 4 km below the seabed: not something that can actually be seen. So it’s all about ensuring that the WOMP addresses all the potential well risks through effective management practices. Then, during operations, when we receive a notification of a well integrity incident, we need to look at that aspect of the WOMP to see what’s gone wrong, and that the corrective actions are adequately covered in the WOMP."

The Well Integrity Team reviews each WOMP for consistencies, anomalies and omissions throughout the well life cycle.

“A WOMP assessment usually takes a full month because we have to understand everything about the planned operations, the physical well and its intended use. It could be that the well is producing on a platform with 20 or 30 other wells that may be 25 years old and built to different standards, so there’s a lot to consider."

In addition to checking WOMPs against the requirements of relevant Commonwealth regulations, well integrity specialists conduct regular on-site inspections and undertake interviews with titleholders as part of an ongoing assessment process.

“Normal inspection procedure is to interview personnel, check documentation and observe operational procedures to make sure titleholders are acting in accordance with procedures and standards described in their accepted WOMP."

“Drilling rig operations are monitored by the titleholder in real time, 24/7. We review the daily drilling reports to get an understanding of the current well operations and how the risks are being managed."

“It’s all about uncertainties – what the titleholder does to manage the unexpected. Uncertainties could include finding that the subsurface pressures are higher or lower than expected, or that the geological formations are not as predicted. These uncertainties are managed by risk assessments and a management of change process within a defined operating envelope - an area we focus heavily on."

More than half of Australia’s offshore wells are more than 20 years old. NOPSEMA recognises the prevalence of aging assets and the importance of appropriate maintenance as key regulatory issues for the offshore oil and gas industry.

As part of its regulatory role, NOPSEMA may take enforcement action against a titleholder when risks are not being effectively managed. Although this may address the particular issue identified, the prevention of future events across industry is the goal.

In some cases a failure to maintain safe systems and facilities has resulted in significant financial loss through production shut-downs and repair costs. In a recent example, a titleholder implemented an extended shutdown of a facility in order to address integrity deficiencies and comply with NOPSEMA’s enforcement actions.

NOPSEMA regularly hosts forums and workshops for stakeholders to discuss opportunities for improvement such as well barriers, operational risk assessments, source control and the health and safety of offshore workers. Details of these events are readily available via the NOPSEMA website: www.nopsema.gov.au.