Innovative idea could expand
North Sea Winds Fuel Production
From his office in Aberdeen, Scotland, Allan MacAskill can monitor the weather in the Moray Firth from Web cams perched atop Talisman Energy’s two 87-meter tall wind turbines at the Beatrice Field.
MacAskill, a petroleum engineer by education and experience, is project director of Talisman’s Beatrice Wind Farm Demonstrator Project – the world’s first deepwater wind farm, located on the North Sea’s continental shelf some 25 kilometers off Scotland’s east coast.
Talisman will monitor the performance of its wind farm project during the next three to five years to determine whether to ramp up to a commercial-scale operation with as many as 200 turbines capable of producing 20 percent of Scotland’s energy needs.
Talisman purchased the Beatrice Field from BP in 1996, and immediately started cutting operating costs in this mature oilfield serviced by three offshore platforms: Alpha, Bravo and Charlie.
As oil production continued to decline – and as electricity costs increased per barrel – Talisman sought new and innovative cost savings.
In 2001, with oil prices trending upwards, Talisman decided against decommissioning the Beatrice Alpha platform; rather, it decided to redevelop the field and reuse the platform – as a hub for the wind farm.
Talisman’s intent? Breathe new economic life into the field and extract more reserves.
Their plan worked; the innovative use of wind energy is keeping Beatrice pumping around 1,800 barrels per day – and the sight of the twin turbines’ 61-meter long blades turning with the Alpha production platform in the background is for many an elegant juxtaposition of renewable energy enhancing the economics of a non-renewable and aging oilfield.
“We were able to think outside of the box, and extend the life of the Alpha platform,” MacAskill said.
“What we have is a unique set of infrastructure located just outside of territorial waters,” he added. “The platform infrastructure is the hub for a large-scale wind farm.”
Money Spent, Money Saved
The Beatrice Field is unique because it’s located very close to shore and it’s connected, via buried submarine cables, to the Scottish mainland and the national power grid. The same set of ideal circumstances doesn’t necessarily apply to other production platforms in the North Sea, according to MacAskill.
Discovered in 1976 by Mesa Petroleum Corp. – and named after AAPG member T. Boone Pickens’ wife – production from the field peaked at around 6,000 barrels per day in the mid-1980s. To date, Beatrice has produced more than 165 million barrels of 38 degree API oil out of an estimated 495 million barrels originally in place, from Middle and Lower Jurassic sandstone reservoirs.
Talisman installed the first five-megawatt (MW) turbine in August 2006, followed by the second 5MW turbine in July 2007. These machines, manufactured by REpower Systems AG of Germany, are the world’s largest offshore wind turbines.
This “21st century technology” is not cheap, MacAskill said – the project represents a capital expenditure of £45 million. While the price tag may seem high – about US $90 million invested to date in research, engineering, environmental evaluation, fabrication and installation – on a really windy day these two turbines can supply more than 80 percent of Beatrice’s daily power needs.
Averaged over the course of the year, these twin turbines generate about one-third of Beatrice’s daily electricity needs. Talisman estimated Beatrice’s electrical power needs for 2006 at £7.5 million – the turbines, engineered with a 20-year production life, therefore represent an excellent return on investment.
A new-comer to the wind energy business, Talisman entered a 50/50 joint venture with Scottish and Southern Energy (SSE), a large utility company with expertise in renewable energy. To offset capital expenditures and to minimize project risks at Beatrice, Talisman and SSE obtained grants from several strategic partners dedicated to increasing wind energy capacity in the North Sea:
- The European Union (EU) contributed six million euros.
- BERR, the Department for Business Enterprise and Regulatory Reform (formerly DTI, the Department of Trade and Industry) contributed £three million.
- The Scottish Executive (or the government of Scotland) contributed £three million.
First Time for Everything?
Talisman and SSE pioneered new engineering technologies – specialized cranes and vertical slings – for the onshore assembly of the world’s largest offshore wind turbines and blades.
Once fully assembled, the turbines and blades were picked up, transported to the site by specialized floating vessels and landed – all within a 24-hour timeframe.
Talisman was the first wind farm operator to use a jacket substructure for offshore wind turbines and the first to install a tower turbine and blades – in a single lift – from a floating vessel. Talisman dubbed this new technology, assembly and installation process “BOWTIS,” for the Beatrice Offshore Wind Technology Installation System.
For routine maintenance and in the event of catastrophic failure, the entire BOWTIS process is reversible.
“Three years ago, people would have laughed at putting wind turbines in 50 meters of water, and assembling them onshore,” MacAskill said. “People mocked us for the distance of the project from shore.”
Water depths of 45 meters are deemed shallow for the oil industry, but such water depths are challenging for pioneering wind turbine technologies. Prior to the Beatrice project, the majority of offshore wind farms in the Europe were located in waters five to 15 meters deep.
MacAskill said there’s a 25- to 50-kilometer wide area on the continental shelf that’s now accessible for wind energy.
“By demonstrating that wind turbines can be installed in deep water,” he explained, “we’ve suddenly opened up vast areas of coastline offshore Europe.”
The Beatrice demonstrator project sprang out of DOWNVInD (Distant Offshore Windfarms with No Visual Impact in Deepwater), a pan-European initiative managed by Talisman and SSE for the commercialization of deepwater wind farms.
“Fundamentally, the closer you come to shore, the more pressure there is on the environment,” MacAskill said of near shore wind farm developments.
He described various and key stakeholders in the near shore area – fishing, leisure craft, tourism and shipping lanes all are occurring closer to the shore.
“At Beatrice, we’re operating way outside of peoples’ interests.”
Providing the Power
During the past decade many oil and gas companies have evolved into integrated energy companies, entering into the renewable energy fields of solar, wind, tidal and landfill gas. Other companies, including Alberta’s oil sands producers, are employing co-generation technology and the gasification of coke, bitumen and biomass to produce electricity, which commands a premium price in remote regions of Canada.
For the E&P sector, the electricity generation usually represents the single largest operating cost in remote locales, including the North Sea.
MacAskill described the offshore wind industry as “new, with no defined skill sets required to work in this energy sector.” Petroleum engineering skills, he said, formed an excellent basis for the wind farm project – project management, offshore experience, working with technology and the sanctioning of projects.
“However, this is a different industry,” he said. “It has wires and not pipes – and there are many new aspects we need to learn.”
MacAskill’s team has worked closely with project engineers from SSE, who provided Talisman with expertise in the power generation business.
“Part of the interest in undertaking this work is not only using and applying our own skills in new ways,” he said, “but learning new skills and working in an emerging area which crosses the boundaries between oil and gas technology and electricity generation.”
During the next three to five years, Talisman will monitor performance, economics and environmental issues associated with the Beatrice Wind Farm Demonstrator Project. And, while he’s checking the weather in the Moray Firth, MacAskill also can monitor the structural integrity of the machines.
The turbines are equipped with SCADA control systems, fiber optic cables and strain gauges that measure – from the tips of the blades to the length of the tower, down the jackets and all the way to the seabed – the machine’s structural performance. The turbines are operated from the Alpha platform, but with the platform’s consent, the manufacturer REpower can operate them from its headquarters in Germany.
If it makes economic sense, Talisman and SSE may construct a 1-gigawatt (GW) deepwater wind farm at Beatrice – that’s equivalent in size to 200 of the 5MW turbines.
Turbine technology, however, is rapidly evolving to “bigger is better,” and manufacturers already are designing 7MW turbines for the deepwater offshore environment. Beatrice’s 1GW offshore wind farm would provide enough “green” energy for 20 percent of Scotland’s needs.
In its efforts to diversify energy sources, the Scottish government has set aggressive targets for renewable energy – it aims to generate at least 50 percent of Scotland’s electricity from renewable sources by 2020.
“Scotland is rich in renewable energy resources as it is rich in fossil fuels,” a government spokesperson said. “Like oil and gas, renewable energy is going to make a huge impact on Scotland’s economy, and pioneering projects like this (Beatrice) are tremendously encouraging. Thanks to the trail blazed by this project, it is clear that offshore wind can go a long way to helping us realize our vision of becoming a renewable energy powerhouse of Europe.”
However, the economic viability of large-scale deepwater wind farms is questionable.
“Show me the money,” MacAskill said. “We need a commercial environment that enables us to scale up. We need to increase incentives for green energy, and we need to improve the technology, to reduce costs.”
Photos courtesy of Talisman Energy; EXPLORER graphic
Talisman Energy and partner Scottish and Southern Energy pioneered new technologies – specialized cranes and vertical slings – for the onshore assembly of the world’s largest offshore wind turbines and blades. Once fully assembled, the turbines and blades were picked up, transported to the Beatrice Field by specialized vessels and landed – all within a 24-hour timeframe.