Building the skills to tackle complex engineering problems
Helen Li, Wells Engineering Lead
The Bass Strait, which separates Victoria and Tasmania, is home to some of Australia's oldest oil and gas -producing facilities.
In 1965, Esso and BHP Billiton drilled Australia's first offshore well in the strait, which now contains 21 offshore platforms and installations operated by ExxonMobil Australia on behalf of the Gippsland Basin Joint Venture.
With some of these oil and gas fields now reaching end of life, ExxonMobil is working through the complex process of safely decommissioning the facilities.
This decommissioning process entails removal of all structures, equipment and property no longer used, unless it is demonstrated that an equal or better environmental outcome is achieved from something other than complete removal.
“Considering it took half a century to put the infrastructure in place, removing it in the span of a few years will be quite an undertaking,” said Helen Li, an engineering lead in ExxonMobil’s wells team.
There are over 400 wells in the Bass Strait, and roughly half of them will require “plug and abandonment”, or P&A – the industry term for decommissioning, in the short term. Li’s team manages a few rigs with several wells and platforms assigned to them.
“Managing a rig is like managing a project,” she said. “There’s a number of engineers working in our team and we custom design the right P&A strategy for every single well.”
Once oil extraction has come to an end, the principle of abandoning a well is to ensure sufficient equipment is removed and the natural seal is restored as much as possible through the creation of a “rock-to-rock barrier”.
This entails consultation with geologists and reservoir engineers to ensure cement is pumped into targeted locations to restore the geological seal, along with engaging service providers to secure the right equipment and materials.
One of the challenging aspects of P&A work, however, is recovering materials that have been under the seabed for decades, some at a depth of over 3,000 metres.
“We need to ensure they are properly cleaned, and they are safely transported on shore to be disposed of.”
ExxonMobil is setting a precedent, not only in Australia, but globally, with some of the technologies and workflow used to abandon wells.
"We are one of the first to undertake such large-scale abandonment activities in offshore Australia,” added Li.
The benefits of credentialing
In 2012, Li achieved a Mechanical Engineering Charter through Engineers Australia (EA) in partnership with ExxonMobil.
Going through the process helped her realise she wanted to hone her skills in the design and verification aspects of mechanical engineering.
Being a chartered engineer opened doors for Li, who had the opportunity to work overseas for ExxonMobil in a Middle Eastern joint venture.
“Once I got my credential, I was then able to continue building on my skills,” said Li. “After 10 years of skill accumulation, I was able to take on bigger and bigger projects.”
When Li was first credentialed, there weren't many areas of practice in which to become a chartered engineer. This year, when ExxonMobil rolled out a new credentialing system in partnership with EA, opening up credentialing opportunities for engineers across the business, the pool widened.
"EA looked through my experience, skills, and the projects I worked on,” Li said. “In addition to my initial Mechanical Engineering Charter, I was given Petroleum Engineering and Engineering Management charters.”
All three credentials align with Li’s decommissioning responsibilities in the Bass Strait.
“The credentialing process gave me an opportunity to look through the definitions of these different areas of practice and fill any gaps in my skills,” she said. “It's a good check point, 10 years on, to see if I’m still on the right track.”
As a well P&A lead, Li manages a team of engineers and technicians from very different backgrounds.
The communication skills she learnt and revised through her Engineering Management Charter have helped her effectively lead the team
“The range of the skills and backgrounds in this team is a lot wider than I’m used to,” she said. “Communicating with different people, gauging how they would respond, or using different techniques to engage them are skills I’ve needed to demonstrate in this role.”
Alan Black, Senior Engineering Advisor
ExxonMobil’s Longford Gas Plant, situated in South Gippsland, plays a vital role in south east Australia’s supply of essential energy.
Along with the four plants, there are two pipelines running 187 kilometres from Longford to Long Island Point carrying gas liquids for further processing and distribution.
In a year beset by the war in Ukraine, a colder-than usual winter, coal plant outages, and intermittent renewable power generation, demand for gas-fired power in Australia’s south-east has skyrocketed.
“With all of ExxonMobil’s Gippsland gas being sold to the Australian domestic market,it was crucial for ExxonMobil to optimise production across its facilities and pipelines this year,” said Senior Engineering Advisor Alan Black, who is in charge of reviewing the technical aspects of any changes that are made.
Key optimisation strategies included updates to ExxonMobil’s pipeline set up and reconfiguring the plants, which saw an increase in production by 11% and allowed the team to deliver the highest annual gas production from the Gippsland Basin in the past five years.
“In gas processing we are adjusting the temperature of the fluids to get the separation into the right product streams. By carefully monitoring the process we can optimise the temperatures thereby minimising overall energy requirements,” he said.
“This also goes to monitoring the number of heaters and other equipment running, especially as demand changes, to ensure we are operating with the optimum set-up.”
At a plant level, daily coordination meetings allow the engineering, operations and maintenance groups to analyse the past day from both a safety and production perspective, and plan ahead for the next.
“We anticipate things including the weather forecast and how much gas demand there's likely to be,” said Black.
For a wider production outlook, meetings between the onshore plants and the offshore production platforms in the Bass Strait are held to discuss which platforms should produce certain amounts of gas to meet demand in the most efficient way.
“Then there's separate engineering team reviews, where we talk about what modifications we can make that would allow us to bring more gas in,” said Black.
A skills refresh
With 20 years’ experience in the oil and gas industry, Black was chartered 15 ago years with the Institute of Chemical Engineers. However, he took the opportunity to undergo the credentialing process with EA a few months ago.
Going through the process again tested his knowledge on ethical issues, laws and the wider expectations of a professional engineer, which was particularly helpful through the optimisation process.
“For example, if an engineer is proposing a change to a plan and I'm reviewing it, I have the responsibility to consider whether it could have any unintended consequences or impacts, and if all the right people have been consulted on the change.”
When ExxonMobil first flagged its new credentialing partnership with EA, Black was immediately on board.
“It’s been a successful program, as I know quite a few people who have gone through the process at the same time as myself,” he said.
While there are several detailed competency systems within ExxonMobil that ensure skill development for different engineering disciplines, Black thinks external accreditation is equally important.
“When we look at project and asset support teams, it’s helpful to highlight where the competencies are and whether people are credentialed in those areas,” he said.
“On the flipside, as newer engineers come into the organisation, it's something they can aspire to and work towards.”