Could result in more oil
Used as an injection gas, CO2 could bring about a major increase in oil production from the Norwegian continental shelf.
This is shown by studies carried out by IKU Petroleum Research, which has made estimates of the potential of injecting CO2 into a specific Norwegian oil field. According to IKU´s calculations, CO2 injection would enable 63% of the oil in this field to be produced, while standard production methods based on water injection would allow 43% of the oil to be produced. These figures are based on laboratory tests and computer simulations of reservoirs that the institute has done for the Ministry of the Environment and the three Norwegian oil companies.
"We also carried out laboratory tests using oil from another Norwegian field, and this oil also turned out to have positive characteristics as far as CO2 injection is concerned. These fields were not selected on the basis of being particularly suitable for CO2 injection," points out Erik Lindeberg, senior scientist at IKU.
Problems remain
"There are still problems in injecting CO2 or other gases into reservoirs in order to enhance oil recovery. If the CO2 is already available, the major problem is to prevent gas breakthrough from taking place too early in the reservoir. In all gas injection projects, the gas has a tendency to "sneak past" the oil and flow through the production wells. This problem is well known in the USA, where operators have been injecting CO2 for many years, and it is still an important field of research. Solutions to this problem will have to be based on the characteristics of individual reservoirs. In our simulations of this particular field, we decided on a combination of two different methods", says Lindeberg.Taxes are the key
IKU has evaluated the economics of the investments that would be required to start CO2 injection in the light of the estimated gains in oil production. A possible gas-fuelled power station on the coast was used as one of a number of potential sources of CO2 in the analysis."According to this scenario, the investments would be too large to allow the project to stand on its own feet financially. Our calculations show that if a CO2 injection bonus at the same level as the current CO2 tax were introduced, the return on investments would be comparable to other investment possibilities on land and offshore", says Lindeberg.
"The EU Commission has proposed introducing a much lower CO2 tax than Norway´s, but even at that level our scenario would be interesting. If you bear in mind Europe´s large number of coal-fired power stations, our results should certainly be of interest", says Erik Lindeberg.