If Statoil and Shell are able to realize their project for subsea CO2 capture for improved oil recovery, the Heidrun platform in the Norwegian Sea will need large-scale adaptation in order to utilize the new technology.
Subsea Capture of CO2 for Improved Oil Recovery
However, with maturing oilfields the challenge is to use the CO2 to produce more oil, and the key for this is improved oil recovery (IOR). When the conditions are right, the injection of CO2 into a petroleum reservoir results in improved cash flow as well as long-term storage of this greenhouse gas.
Although using CO2 for increasing oil recovery is a proven technology in 70 onshore fields in the United States, the technology is still in its infancy when it comes to offshore oil production. While Statoil is a world leader in storing CO2 for climate reasons, with respect to “utilizing CO2 for IOR, however, we are still learning,” says Statoil energy advisor Olav Kårstad, one of the main players in the company’s CO2 recovery project.
“The North Sea and even parts of the Norwegian Sea are regarded as potentially suitable targets, because numerous oil fields, gas processing sites and CO2 sources are relatively concentrated here when compared with other offshore regions around the world,” Kårstad says.
However, transportation of CO2 to the oil fields is a challenge, and Statoil is considering using conventional pipelines as well as specialized CO2 tankers similar to those used for transporting liquefied petroleum gas (LPG). In some cases ships might be the cheapest and most flexible solution, and the CO2 will be liquefied at -50 ºC in these tankers.
Even if the potential benefits can be substantial, Statoil has to consider the cost effectiveness involved in modifying platforms and infrastructure and the technical feasibility of using IOR technology in offshore oilfields.
Together with Shell, Statoil signed an agreement in March 2006 for studying to use CO2 from a gas-fired power station at Tjeldbergodden in mid-Norway for IOR at the Draugen and Heidrun oil and gas fields in the Norwegian Sea. The two companies have made it very clear that some form of risk sharing or support from the government is necessary in order to make this project go ahead.
Kårstad sees a large potential in this groundbreaking project and its environmental benefits, and he is confident the Norwegian government is warming up to such an idea. “This will be the world’s largest offshore project for the use of carbon dioxide for IOR,” he says. “We will be able to utilize and store approximately 2–2.5 million tonnes of CO2 annually in the Draugen field, and in time, in the Heidrun field.”
Starting out as a direct action protest group in 1986, the Oslo-based Bellona Foundation has developed into a multi-disciplinary international environmental NGO. Today Bellona is one of the world’s most recognized technology- and solution-oriented environmental champions, and has offices on two continents. Norwegian and international industries have developed strong partnerships with Bellona to develop their environmental strategies, and Bellona is helping to hold them accountable.
Carbon capture and storage (CCS) is an essential part of Bellona’s activities, and one of the organization’s leaders, Marius Holm, thinks it is important to look outside Norway’s borders to take advantage of the environmental gains.
“The CO2 value chain should be a European value chain. It can provide substantial CO2 reductions, and it is a major step towards zero emission fossil fuel. Furthermore, it can contribute to the competitiveness of European industry,” he says.
Vapour Recovery Specialists
Crude oil vapours could be a serious danger to the environment, and therefore Aker Kværner has invested substantial resources to minimize this problem. The company has signed a contract with Statoil to design and deliver the world’s largest system for capturing and recovering volatile organic compounds (VOC). The contract is worth NOK 115 million, and will be operational at the Mongstad refinery at the end of 2007 or beginning of 2008.
“Entering this agreement with Statoil for the supply of the world’s largest VOC recovery unit confirms Aker Kværner’s position as a world-class vendor of VOC recovery units,” says Morten Reimer Hansen, president of Aker Kværner Cool Sorption, which is the Aker Kværner company responsible for delivering the system.
|Aker Kværner Cool Sorption’s land-based gasoline VOC plant in French Guyana.
© Aker Kværner Cool Sorption
Oil Spill Detection Systems
Cleaning up oil spills is not only dependent on having the equipment to collect the oil; it also requires sophisticated systems to discover and monitor the oil. Miros is a small Norwegian company with only 30 employees, but it has a competence required by the global oil industry, and today it is a world leader in the field of wave monitoring utilizing radar and microwave technology.
“We are a leading producer of sensors and systems that monitor sea states, waves and sea current using the Doppler radar and microwave technology,” says Miros CEO Erik Sandsdalen, adding that the Oil Spill Detection (OSD) system has been under development since 2000, and that its remote monitoring technology has been installed on over 200 vessels, platforms and onshore sites worldwide.
Global giants like BP, Shell, Total E&P, ExxonMobil, ChevronTexaco and Statoil have invested enormous amounts and resources in oil spill security, and therefore they co-own NOFO – the Norwegian Clean Seas Association for Operating Companies. NOFO is an oil spill response organization operating on the Norwegian continental shelf, and Miros has developed the OSD system in close cooperation with NOFO in order to ensure that operational requirements are complied with. The flexibility of the system enables it to trace and recover oil in conditions of darkness and low visibility – thus the total effectiveness of a clean-up operation is considerably improved.
In May 2006, NOFO conducted a field trial of oil spill recovery off the west coast of Norway which included the assistance of four airplanes from four different countries, a helicopter carrying out air surveillance, and three vessels with the OSD system onboard. Sandsdalen was very pleased with the results.
“Residual oil from a previous recovery operation was discovered at late evening, and the same oil spill was detected by the OSD system on two vessels. Thus, a vessel was navigated with the assistance from the OSD radar system to collect the oil during the night, and one of the intentions of the OSD system was confirmed,” he said.
Cleaning of Formation Water
Increasing demands on the oil industry for cleaner production will prohibit the discharge of produced water. When exploiting oil, you will always have water, or what is called formation water. Two Norwegian companies have developed slightly different technologies to clean this formation water, but both are considered world leaders in the field.
ProPure and M-I Epcon are small companies using the latest technology to remove both dispersed oil and dissolved aromatic components from large volumes of produced water.
The amount of produced water worldwide is increasing every year, and there are a great number of mature fields at the Norwegian continental shelf. In some of these mature fields there could be as much as ten times as much water as oil. The treatment of produced water is necessary to both increase productivity and protect the environment.
“Our technology is a possible solution for both increasing oil production and meeting zero discharge goals,” says Torbjørn Juliussen, M-I Epcon’s marketing manager. “The Epcon CFU Technology has been tested and developed jointly with the oil companies, and today it is a proven technology in the treatment of produced water and one of the preferred choices of oil operators.”
Most recently, Epcon’s technology has been selected by Hydro to treat the produced water from the Troll B platform in the North Sea from August 2006.
Epcon’s competitor ProPure and its CTour produced water technology is staying with them every step of the way, however. “Our technology has been validated through a series of field tests, and full-scale installation at six different offshore production facilities in the North Sea. By 2007, two-thirds of the projected discharge of produced water on the Norwegian continental shelf will be treated by the CTour technology,” says Ove Hole, manager of ProPure’s water treatment business area.
ProPure’s CTour unit for the cleaning of produced water.
Havila Troll is a specialized vessel for emergency readiness on the Norwegian continental shelf; the ship carries out such tasks as human rescue, fire-fighting assistance, and collects oil in its own lenses and stores the oil in separate tanks of more than 1,000 m3. The ship was used during NOFO’s May 2006 oil spill field trial.