Returning greenhouse gases to the ground
Technion is part of the “MUSTANG” research project, funded by the EU and overseen by Upsala University of Sweden. The project includes a field trial of carbon dioxide injection into abandoned oil wells at Heletz
By Avi Belizovsky
Everyone senses global warming, which is a result of the increase in the concentration of greenhouse gases, at the top of which is carbon dioxide, methane and other gases. In many places in the world, following international agreements such as the Kyoto Protocol from about a decade ago, governments are limiting and setting caps on carbon dioxide emissions.
In general, the limiting system works like this: Any company that wishes to increase in any way whatsoever the amount of carbon it release to the atmosphere is required to pay a fine. These fines are earmarked for bodies developing clean energy. On the other hand, companies that produce petroleum or burn it to produce electricity can offset these taxes if they reduce their carbon emissions in other ways.
One way that companies such as the Norwegian company Statoil has been doing this for 16 years is by capturing carbon dioxide in the chimney, before it is emitted into the atmosphere, cooling it, turning it into a liquid and finally – injecting it back through wells into a depleted oil or gas reservoirs, so that the harmful gas can remain there forever and not contribute to global warming.
Nevertheless, the question arises as to who guarantees that the gas will not leak back into the atmosphere and consequently, nothing will have been gained. To answer this, a scientific and technological study by geologists who specialize in underground reservoirs and hydraulics (in our case, we are actually talking about liquid gas and not water, but some features are the same) was required. “MUSTANG” is an integrative project that began June 1, 2009 and is planned to run for four years with funding by the Seventh Framework Program of the European Commission (FP7).
"We expect to see how the carbon dioxide gas behaves in Israel’s geology.”
The “MUSTANG” consortium comprises 19 institutions among which are universities, research institutes and large companies from Sweden, England, Scotland, Spain, Romania, Germany, and Israel. The Israeli partners are the Technion, the Geophysics Institutes, Lapidot Ltd., and EWRE Ltd. The strategic objectives of the consortium are to develop guidelines, methods and tools to characterize deep brine-containing aquifers in which to store carbon dioxide for long periods of time. This new knowhow is to be based on firm scientific knowledge about the critical processes involved in such opertations.
The project aims to improve and develop design, monitoring and verification technologies so that they especially suit the sequestration of CO2 below ground, in order to reliably verify the physical and chemical properties of such sites, and facilitate short reaction times in revealing and monitoring CO2 plumes in subterranean reservoirs that were previously contained petroleum and gas or in reservoirs containing saline water. The research includes development of technologies that enable identification of leaks, should there be any, during the process of CO2injection and sequestration in the underground reservoir.
The second aim is to improve understanding of the relevant processes of CO2sequestration using theoretical research, lab experiments, research in nature and research using field trials such as the example of the gas injection to be done at Heletz. This project is being conducted in parallel to a similar project at Ketzin near Berlin.
Prof. Jacob Bear of the Faculty of Civil and Environmental Engineering at the Technion is the head of the research team charged with developing models that will facilitate design of the project for injecting the CO2 into deep geological saline layers. “These models will enable the design of injection projects under different condition, prediction of the dispersion of the CO2 in geological layers, geochemical processes and also the possibility that the gas will leak back up to above ground. This information is necessary for risk assessment, if any, and for decision making bodies. Also in Israel there is a need to get rid of the CO2 emissions from power stations and cement factories, which are the big producers of CO2. It is important that the knowledge created by this research, funded by the European Community, also interests bodies in Israel such as the Ministry of Environmental Protection, the Ministry of National Infrastructures, the Electric Company and others. In Europe and the U.S., there is a large volume of activities on the subject – research and applied. This is a huge industry that is going to grow and Israel must be a part of it.”
Sandip Sharma, a petroleum reservoir engineer, is the director of the CO2injection project in Hawaii as part of the CO2CRC organization (Australia): “The trial in Australia was a breakthrough in that through it we were able to understand legislative issues. It turned out that there were overlaps and contradictions between two laws and we needed to draw up new legislation focused on CO2 injection. In addition, in executing the actual project we had to negotiate with community members worried about, for example, leaks. Our project was in an agricultural area that produces milk and there was concern that a CO2 leak from the mine might in some way damage the milk or cheese being produced there. However, cooperation with the community is important because it is difficult to get anything without support.
“We also learned about technical problems and what happens to a gas plume that spreads through the reservoir. Because this field is still in its infancy, it is important to develop theoretical models and carry out measurements in real time in order to verify and calibrate them. Models are meant to provide a way for us to predict what will happen in another 100 and 200 years, and therefore, it is important that there be consistency between the monitoring results and the model – something that will provide assurance that the model accurately predicts the future.”
The company that is actually doing this in a number of petroleum and/or natural gas wells is Statoil of Norway. Tor Anders Thorpe is a senior engineer and has been in charge of CO2injection activities for about 16 years in the company’s well in the North Sea. He speaks of his experiences: “The more we operate the project, the more it approximates the normal operation of a petroleum and gas reservoir. Underground is always different than what you expect, but with our experience and the different ways, it can always be done safely. You must remember that we are injecting CO2beneath the surface and it is different than natural gas; however, it has many features that are similar to natural gas or water, for example, when it becomes a plume dispersing underground. In effect, we are talking about the same physical laws that operate when pumping petroleum but just in the opposite direction.
“We already have three sites to compare with each other – Sleipner, in the heart of the North Sea near the water border between Norway and Britain, In Salah, in the heart of the Sahara Desert in Algeria (together with BP and the Algerian oil company Sunatark), and in Snohvit, on the border with the Barnets Sea on the northwest shore of Norway. Whereas in Sleipner the petroleum well is shallow – just 800 m below the sea’s bottom and it has a swift current, in In Salah we are talking about a dry well, at a depth of 2,100 m, and because of this depth and the fact that the ground rose up from a deeper area because there was once a mountain here, the flow is very slow, and in Snohvit, at a depth of 2,600 m, of which 350 m is below the sea bottom, we can learn about three different geologic environments.
“We inject gas that is mostly (96%-98%) carbon dioxide, while the rest is methane. The gas is generated from natural gas that we pump and sell. Since this is a commercial well, we conduct the research alongside the commercial operations, something that is not always possible given that the production has first priority
“We have always been helped by international research partners, even before the MUSTANG project, for two reasons: first, it brings together experts from different backgrounds and when several experts from different disciplines are involved in solving the same problem, the chances are that the reliability of the results will increase. The second reason is to improve our reliability, and as is well known, the credibility of petroleum and gas companies when talking about environmental subjects is not of the best, and therefore, it is preferable to rely on outside experts and reach a consensus about the scientific interpretation of findings.
“The technology may be similar but the geology varies from place to place and consequently it is important for us to learn about more and more environments and this is the reason we joined this research in Ketzin in Germany and we are partners in the research in Heltz and expect to see how the carbon dioxide gas behaves in Israel’s geology.”
The 2010 Horton Medal, a prize awarded by the American Geophysical Union (AGU), was awarded to Prof. Jacob Bear of the Faculty of Civil and Environmental Engineering at the Technion, at a recent ceremony held in San Francisco, California. Prof. Bear was given the prestigious award for his achievements in the field of hydrology.
Prof. Bear was surprised by a cake and good wishes for his award during the opening event of the meeting of researchers participating in the MUSTANG project. The medal is awarded by the American Geophysical Union to one person at most per year for their extraordinary contribution to hydrology.
