As Maersk Oil’s Culzean development starts to take shape, Tim Skelton looks at the technological highlights that will make this high-pressure, high-temperature (HPHT) mega-project one of the most advanced set-ups in the North Sea region.
Discovered in 2008, Culzean is the largest gas field to be developed in UK waters since Marathon Oil’s East Brae field got the go-ahead in 1990. Located around 240 km off the coast of Aberdeen, the US$4.5 billion development was approved by the UK Oil and Gas Authority in August 2015, and is estimated to contain recoverable resources of between 250 and 300 million barrels of oil equivalent.
Production is due to start up at Culzean in 2019, and is predicted to continue for at least 13 years. When it reaches peak output in around 2020 or 2021 it could be producing enough gas to cover 5% of all the UK’s demand, with forecast plateau production put at 60,000 to 90,000 barrels of oil equivalent per day. Maersk Oil UK operates the field with a 49.99% stake, alongside its project partners BP (as Britoil, (32%)) and JX Nippon (18.01%).
The project reached a key milestone at the end of last month when offshore engineers Sembcorp Marine handed over the high-spec jack-up Maersk Highlander rig to Maersk Drilling. Singapore-based Sembcorp had originally begun building the new rig for Hercules Offshore at its Jurong Shipyard, but Maersk later acquired it in a deal worth US$190 million.
Based on the Friede & Goldman JU 2000E design, the Maersk Highlander is a heavy-duty offshore drilling unit that will be well suited for the harsh operating conditions that come as standard in the North Sea. It can operate in water depths up to 120 metres, and drill down more than 9,000 metres. Other main characteristics include a 2 million pound (900 tonne) drilling tensile capacity, and a 28,000 kip (12,700 tonne) preload capacity for the legs.
What really sets the rig apart, however, are high-tech communication facilities that are designed help it run more efficiently with a minimum staff. This in turn will reduce operational costs at a time of low oil prices when margins are being squeezed.
One major incentive for basing more staff onshore and fewer offshore is reducing the number of helicopter flights needed to ferry workers to and from the rig. This will not only mitigate safety risks – helicopter transportation is often regarded as the single riskiest piece in the North Sea oil and gas jigsaw – but will also bring significant cost savings of its own.
Maersk said fully automating Culzean would not be practical, however. “Because of the nature of dry tree high-pressure, high-temperature (HPHT) developments, [full automation] would come with a number of unique challenges, and regular human intervention is required in a number of areas, especially later in well life,” project director Martin Urquhart said. “As such, we have embraced technology that ensures we instead minimise the number of people offshore. This will allow positions that would traditionally have been on the platform to be onshore, working in a real-time collaborative environment.”
According to Maersk’s estimates, offshore operators spend up to 30% of their time looking through worksheets, specs and procedures in order to find the data required to perform each task. The company believes that introducing better data management to make this information available instantly will significantly cut down on this “lost time.”
The key is to use an already widely available technology. Radio Frequency Identification (RFID) tags will be attached to all critical equipment on the platform. When scanned using a regular handheld device such as an iPad or a tablet, the tags will provide the operator with access to all the relevant information associated with that piece of equipment, from manufacturing data and certificates to drawings and maintenance history – even a video simulation showing maintenance and operations activities. Routine maintenance work can be carried out by staff running through a checklist on their tablet, and completing the required procedures as and when prompted.
The platform will also be linked to the mainland via a high-capacity broadband connection, which the company said would enable faster and better decision-making. “The volume of data our smart platform will generate demands a subsea fibre-optic cable, which allows for instant distribution of critical data. It will mean we can benefit from [both] our own and key equipment vendor’s global expertise without the need for these experts to be physically offshore,” Urquhart said.
Thanks to this high-speed communications network, any areas of non-compliance can be flagged up instantly and synchronised with a master data set onshore, and automatic notifications can be sent to the relevant operations support and management teams, both onshore and on the platform. When any piece of equipment encounters a problem, one of the platform workers simply has to take a photo of it with their tablet. At a stroke the onshore maintenance team can then retrieve the entire history of the problem part, find out where and when it was made, and learn what previous maintenance has been carried out on it.
For more complex issues, a permanent video conference link will allow onshore and offshore teams to talk to each other face-to-face whenever needed. The onshore experts can then assess the best course of action more quickly, and can discuss this with both the equipment manufacturer and the offshore team. Any required actions can then be assigned a priority level depending on how critical the equipment is, and closure will be tracked using conventional reporting dashboards.
“The aim is to tie everything together,” said Culzean’s Engineering Manager, Stuart McAuley. “One of the biggest challenges offshore today is that you spend a lot of time finding the right data. What we plan for Culzean is that if something breaks or a valve needs replacing, you will have instant access to the data required whether you are on the worksite, office or the other side of the world.”
Not only can these technological tweaks allow more positions to be based onshore, but routine maintenance and the ordering of spare parts can also be planned far more effectively. As a result, Maersk hopes to improve efficiency by 20% in man-hour terms compared to other comparable developments. Cost-wise, it is looking to save more than US$10 million per year.
“The full potential is still being mapped out, but in terms of managing quality – just in terms of being absolutely certain that the critical component being ordered is exactly what you need every single time – that alone is going to reduce unplanned downtime and that means better production efficiency over the coming decades,” McAuley concluded. “And that cash flow really adds up.”