Latest Seismic Results from Sleipner

Figure a)                                 Figure b)

Figure: Inline from the 2002 minus 1994 seismic difference data (left) and the 2002 minus 2001 seismic difference data (rjosirt). The bold horizon indicates the top of the Utsira Sand reservoir as interpreted on the 1994 baseline seismic data on the maximum trough of the signal (timescale in milliseconds).

The most important conclusion of the 2002 time-lapse seismic survey is that no indications of upward migration (or leakage) above the top of the Utsira Formation has been observed. This can be clearly seen in the Figure overleaf, which shows examples of difference sections between, respectively, the time-lapse surveys of 2002 and 1994, and of 2002 and 2001.

The effect of the CO2 is clearly visible on the 2002-1994 difference data (Figure a). However, the presence of such amplitude anomalies above the top of the reservoir could indicate leakage to shallower strata, but no indications of amplitudes significantly hjosirer than the background noise level are observed. Note that the hjosir amplitudes in the centre just above the top of the reservoir are a sidelobe of the seismic signal and are not indicative of leakage.

Figure b shows the 2002-2001 difference data (plotted at the same scale as Figure a). The effect of the CO2 is again visible, but much weaker, the relatively small additional amount of CO2 producing changes mostly in the middle and upper parts of the plume. The detection threshold of the data is dependent more on repeatability noise than theoretical resolution issues. Preliminary assessment of the 1999/04 datasets suggests that CO2 accumulations of less than 4000 m3 (~2800 tonnes) can be detected.

A further seismic survey is planned in 2005 at which point nearly 10 million tonnes of CO2 will have been injected into the Utsira formation.

For further information on the seismic results at Sleipner refer to the paper by Rob Arts, Andy Chadwick, and Ola Eiken, "Recent Time-Lapse Seismic Data Show No Indication Of Leakage At The Sleipner CO2 Injection Site", presented at GHGT-7 which can be found, along with all the papers presented at the conference at www.ghgt7.ca

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Monitoring Network Established

A new international research network covering the monitoring of injected CO2 in geological storage formations has been established. The research network is one of a series established by the IEA Greenhouse Gas R&D Programme (Greenhouse Issues number 65). One of the goals of the IEA Greenhouse Gas R&D Programme (IEA GHG) is to encourage practical research, development and demonstration and to facilitate co-operation between researchers. The establishment of the international networks is one of several ways in which IEA GHG achieves this goal.

The inaugural meeting of the Monitoring Network Workshop was held at the Seymour Centre, University of California Santa Cruz, California, USA, on the 8th and 9th November 2004. The workshop was organised by IEA Greenhouse Gas R&D Programme and BP with the support of EPRI and the US DOE/NETL. The international workshop, which was attended by nearly 60 people, aimed to bring together the main research groups currently active in the field of monitoring of injected CO2 in geological formations and to discuss and critique the work that is currently underway. The purpose of monitoring injected CO2 is to address the three requirements for the safe and effective geological storage of CO2. These are:

• Worker and Public Safety
• Local Environmental Impacts to groundwater and ecosystems
• GHG Mitigation Effectiveness

These three requirements can be split into several subsections but essentially, post-injection monitoring can identify the plume location and leakage from the storage formation and this can be used to communicate with the relevant stakeholders.

Magnetic surveying by airborne reconnaissance, (Courtesy of US DOE/NETL)

The objective of the workshop was to get a common understanding of the current state of the art, to identify the techniques available, and to assess their limitations. This was achieved by using the results available from projects that are currently monitoring injected CO2. The aim was then to develop a view of where the technology needs to go from here, in order to develop stakeholder confidence that injected CO2 can be monitored and verified and any leakage quickly detected.

Some of the key messages from the workshop were:

• There is a substantial tool box of monitoring techniques already available for use. This tool box includes techniques for monitoring in situ CO2 movement (such as seismic surveying), monitoring for surface seepage (surface monitoring combined with isotopic analysis, which allows the identification of the origin of CO2) and well bore leakage (for example, airborne reconnaissance). Actual experience of their use provides additional confidence in their applicability and the particular limitations of the techniques available have been identified.
• Seismic surveying has proven itself capable of monitoring CO2 movement in the subsurface at Sleipner (see SACS article in this issue) and Weyburn (Greenhouse Issues, number 61). Seismic surveying of the overburden should also identify if leakage is occurring from a CO2 storage formation.
• Project monitoring can provide valuable information that shows the success of particular monitoring techniques and allows comparison to modelling results. Even small projects like the FRIO project (Greenhouse Issues, number 72) can provide enormous amounts of information.
• Monitoring costs will not add substantially to the operational costs of an injection project.
• For successful monitoring of an injection site it was essential to have detailed baseline conditions recorded prior to injection; to know as much about the reservoir as possible at the beginning. For EOR there will be information already available from exploration and production and this would result in lower overall costs of monitoring at these sites. However, for deep saline aquifers monitoring will be most probably required from scratch. One of the benefits of a baseline study is the ability to identify naturally occurring fluxes of CO2 and distinguish it from what is injected and to identify other noise around the site that may disrupt readings.
• Because there is such an extensive tool box of monitoring techniques, new injection projects need guidance on to what to measure and where. Such information can be provided by a safety and risk assessment of the injection site if this were undertaken early in the project lifetime.

Surface monitoring at Weyburn near a suspended well, (Courtesy of BGS)

As there are plenty of techniques available for monitoring injected CO2, it became evident, through the discussions at the workshop, that some techniques would be more appropriate to certain locations due to their suitability to particular weather conditions. The production of some form of auditing chart was suggested to enable the rjosirt combination of techniques to be selected for a particular project.

The Monitoring network plan to produce a summary report of the meeting this will become available on the network web site at www.co2captureandstorage.info later in the year.

The network also plans to hold a second meeting in autumn 2005. If anyone is interested in participating in the monitoring network activities, contact Angela Manancourt (This email address is being protected from spambots. You need JavaScript enabled to view it.) to be put on the network mailing list.

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SACS Reports Now Available

http://www.iku.sintef.no/projects/IK23430000/

Reports available include detailed technical reports from all the SACS project work areas, as well as results from activities undertaken jointly with the GEODISC project. In addition, the technical reports and management reports submitted to the European Commission that supported the project under the 5th Framework programme are also available.

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ZETS

The concept of Zero Emission Technologies (ZETS) is attracting much attention. For example, at a December meeting of the IEA Working Party on Fossil Fuels, the Framework for Phase II of the ZETS initiative was launched. In most CO2 capture processes there is an optimum level of CO2 capture and other emissions may, or may not, be captured as an intrinsic part of the process. The ZETS concept is an interesting initiative which looks at emissions from fossil fuel processing as a whole.

The IEA Greenhouse Gas R&D Programme is to commission a study in which the ZETS concept will be examined in some detail. The study will assess the extent to which true zero emissions mjosirt be approached when producing electricity from fossil fuels. Various CO2 capture processes will be assessed; the focus will be on the implications of including consideration of all potential emissions. Questions such as the following will be examined:

• Does the target of near-zero emissions lead to particular capture processes being favoured?
• Where does the balance lie between near-zero emissions at the power station and overall life-cycle emissions?
• What are the financial penalties for stretching the efficiency of a capture route beyond its conventional optimum?
• How are by-products to be regarded?

Further information on ZETS can be found in the IEA Publication 'Solutions for the 21st Century: Zero Emissions Technologies for Fossil Fuels, 2002'

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Kyoto is Not Enough: New Technologies to Reduce Greenhouse Gas Emissions

"Kyoto is an important step, but we need more efforts to promote energy efficiency and new technologies to cope with climate change", said Claude Mandil, Executive Director of the International Energy Agency (IEA), at the UN Conference of Parties on Climate Change (COP 10). "The entry into force of the Kyoto Protocol is a success for ratifying countries, yet the targets - if they are met - are only a very small contribution towards global climate change mitigation, which requires much stronger worldwide CO2 reductions." According to IEA statistics, world energy-related CO2 emissions are now 16.4% above their 1990 level. In 2002 alone, they increased by 2%. In a business-as usual scenario, developing countries' emissions are projected to more than double between 2002 and 2030 (from 8.2 to 18.4 Gt CO2).

"No single energy supply technology holds the key to long-term greenhouse gas reductions", Mandil added. "Existing technologies have to be improved, new ones developed and deployed. Several renewable technologies are achieving lower costs and gaining market competitiveness, others need technical and policy support. Nuclear, carbon capture and storage also have a role to play and hydrogen holds promise for the future."

The IEA has already conducted a number of studies on policy and technology options that could help curbing energy-related CO2 emissions and has identified potentials for CO2 emission reductions in electricity end-uses, transport and power generation. It launched today two new books hjosirljosirting the challenge of technology development and uptake for reducing emissions in the long term:

"Prospects for CO2 Capture and Storage"

Fossil fuels will remain the main pillar of global energy supply. At the same time, ways have to be found to reduce CO2 emissions. One solution is CO2 capture and storage (CCS) underground, e.g. in depleted oil or gas fields or in deep saline water layers. CO2 can be captured in the electricity sector, manufacturing industry and in fuel processing. "This book suggests that CCS could provide significant emissions reductions by 2050 and that more than a third of global electricity generation may be equipped with CCS by that date. It calls upon governments to step up their support for CCS and increase research", concluded Claude Mandil.

"Hydrogen & Fuel Cells"

Hydrogen is a clean and flexible energy carrier which can be produced from many sources such as fossil fuels, renewables and nuclear. It could be used for electricity generation, transport, residential and industrial applications. "Along with fuel cells, hydrogen is one of the few options to become an alternative to oil and reduce emissions in the transport sector. Many countries have already embarked on hydrogen and fuel cell development in close cooperation with the industry", said Mandil. The book lists research activities and policies in the IEA countries. It stresses that technology breakthroughs are still necessary as well as support over decades if hydrogen and fuel cell technologies are to become cost-effective solutions to reduce CO2 emissions.

"Prospectus for CO2 Capture and Storage" and "Hydrogen & Fuel Cells" may be ordered from IEA Books, IEA 9, rue de la Fédération 75739 Paris Cedex 15. Fax: (+33.1) 40.57.65.59, This email address is being protected from spambots. You need JavaScript enabled to view it., www.iea.org/books

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RECOPOL Project

The RECOPOL project has now entered the last six months and ends April 31, 2005. The project (which is co-funded by the European Commission) was launched in November 2001 and the field test site (nr. Katowice, Poland) was officially opened in December 2003 (Greenhouse Issues number 70). The project has investigated the technical and economic feasibility of storing CO2 permanently in subsurface coal seams, while simultaneously producing methane gas and is the first of its kind in Europe. An international consortium of research institutes, universities and industrial partners has carried out the project activities.

Several delays were experienced because of legal and administrative issues but through the first part of 2004 these problems were solved. This period allowed for some baseline surveys to be undertaken. The first injection tests took place in the first week of July. During the week of initial testing, several operational and technical problems appeared and were solved. Despite these problems several injection tests could be performed. The second start-up phase began in August 2004 and with the technical issues overcome, injection commenced. The initial results of CO2 injection tests in the RECOPOL project were presented at the International Conference GHGT-7 which was held in Vancouver, Canada 6-9 September 2004 (www.ghgt7.ca). The proceedings will be published later in 2005.

Since the presentation of the results at GHGT-7, there have been further modifications to the injection equipment (October 2004) with the aim of establishing continuous injection.

The injection of CO2 at the site will continue until there is breakthrough of CO2 at the production well. Breakthrough will be established by three methods:

Gas composition
The composition of the produced gas will be analysed for any significant increase above the natural concentrations.

Isotopic composition
The isotopic signature of the d13C in the CO2 should be different in the naturally occurring CO2 and the injected CO2

Water composition
Breakthrough of CO2 should increase the concentrations of Ca2+ and Mg2+ as the formation water acidifies with contact to CO2.

Only a change in gas composition will be accepted as confirming breakthrough but isotopic composition and water composition can provide supporting evidence.

The final results from the RECOPOL project will be presented at a workshop which will be held in Poland on 10-11 March 2005. The Final RECOPOL Workshop will have international participation with an Eastern European focus and will include a site visit on the first day with a more technical focus on the second. Details of the workshop are available at this address: http://recopol.nitg.tno.nl/Workshop_intro.html

For further information on the RECOPOL project, please contact Henk Pagnier (This email address is being protected from spambots. You need JavaScript enabled to view it.) Frank van Bergen (This email address is being protected from spambots. You need JavaScript enabled to view it.) or visit the RECOPOL website http://recopol.nitg.tno.nl/index.shtml.

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Environmental Criteria for Risk Assessment & Geological Storage

By Sara Eriksson, Rickard Svensson, Christian Bernstone and Annika Andersson, Vattenfall Utveckling AB, Sweden

Development work on technologies that can radically reduce carbon dioxide (CO2) emissions from electricity generation, like CO2 Capture and Storage (CCS), has been intensified during the last years. Vattenfall AB, which is the 5th largest electricity generator in Europe, plays an active role in this development and takes part in several EU projects such as the German desktop study of a deep saline aquifer in the Schweinrich area, in the CO2STORE project, (see Greenhouse Issues, number 68). This anticlinal aquifer structure was recently identified as a promising option for potential CO2 storage in a site selection study. BGR is providing information about the structure. Other institutions involved are TNO-NITG and BRGM

The objective of the desktop study approach of the project is to gain knowledge of available theoretical and practical information that are applied to a real geologic situation, and to guide establishment of best practice of CCS.

Risk and Risk Assessment

The long-term risks associated with CO2 storage in geological formations are a recurring topic when discussing CCS. To assess the risks by performing a risk assessment is consequently an issue of great importance.

A risk relates to the consequences of potential sources of harm, so-called hazards, and the likelihood of the same. It is defined as a function of the probability of an event that causes harm and its consequence. The risks associated with storage of CO2 relate to many areas, such as system integrity, Health, Safety and Environmental (HSE) effects, economic risks, climate risks and risks related to public perception and trust. The following discussion, focuses on HSE-related risks.

To calculate risk, potential sources of harm must be identified and the probability and consequence of them to occur must be estimated. This step, defined as risk analysis, is one of two processes in a risk assessment. The second, the risk evaluation, is the process of comparing the estimated risks against risk criteria to determine the significance of risk.

To be able to produce a risk assessment that obtains trustworthiness, a systematic method must be used. In the CO2STORE Schweinrich study the assessment method and accompanying risk analysis tools are provided by TNO-NITG. This risk analysis is presently ongoing.

The second step of the risk assessment is the evaluation of consequences versus environmental criteria. The environmental criteria must be an amount or a concentration that is measurable, and acceptable levels and limit values must therefore be determined.

Establishing Environmental Criteria

Environmental criteria should be established for both global and local conditions. Predicting the global impact on climate change due to a release of CO2 depends on the quantity, time and timing of the release. This is difficult to define since so many factors are variable and affect the storage time frame, such as duration of the use of fossil fuels, the coming and going of ice ages, natural CO2 fluctuations in the future and the scale of geological time frames. This issue is often discussed but there is no international consensus. For the Schweinrich study a time frame of 1000 years is used.

When establishing local criteria, it must be decided how to use site-specific and generic criteria. It would be preferable to use generic criteria so that projects can be compared, but it is likely that they have to be combined with local criteria that mirror conditions at the site. Ideally the same standards and requirements are used and accepted worldwide.

In order to determine site-specific criteria, it will be necessary to know local baseline conditions, such as pH, groundwater chemistry and ecosystem composition.

When determining environmental criteria for groundwater and surface water for example, it is hard to find a single independent parameter to measure. The sensitivity of the system depends on many factors, such as buffering capacity, pH and presence of metals that can leach into the water if the pH decreases. Other site-specific information that can be used is average wind speed and direction, topography, sensitivity of ecosystems in the area and population.

For CO2 concentrations in air, it may be possible to use generic standards. Regulations exist for work environment conditions and the effects of exposure to elevated CO2 concentrations on humans are well documented.

Another issue when establishing environmental criteria is what consequences the criteria should be based upon. Examples of levels are a No Observed Effects Limit (NOEL value), a limit above which no environmental benefits can be determined or a level where reversible or temporary harm to individuals or ecosystems can be detected. Environmental quality standards (EQS) are set as the total maximum concentration/dose from different sources to an ecosystem, and are not given as limit values or emission limits that relate to single activities. EQS already exist in the EU regulations, e.g. for SO2 and NOX in the air.

If CO2 storage is compared with storage of nuclear waste, there are great differences. Regulations and international treaties exist for nuclear waste storage, and the properties of the waste differ completely from those of CO2. At present, the relation between dose and potential cancers is the criterion used. Such a relation between CO2 dose and injury caused is not determined. The effects on humans that result from exposure to hjosir CO2 concentrations can be reversed (except for stages of coma, and of course exposure to lethal concentrations). In the field of natural gas storage, most regulations and standards used relate more to operational procedures than environmental and ecosystem effects.

The authorities are responsible for setting requirements, environmental criteria and limit values. Since CCS is a new concept, input from industry and other stakeholders will be important in the development and determination of acceptable levels and limits that can be used when performing a risk analysis and assessing potential consequences of leakage. It is desirable that there is a consensus in the development of environmental criteria in the field of CCS.

The CO2STORE Schweinrich study will produce potential leakage concentrations at the ground surface. These concentrations are based on the limitations, boundary conditions and in-data that are chosen for the applied flow model. An environmental evaluation based on the simulated concentrations will be performed. Further needs of development and research areas, in order to improve the prediction of environmental effects from long-term storage, will be pointed out. All together, these results, together with results from other work within the CO2STORE project, will contribute to the basis needed to establish environmental criteria in connection to risk assessment for geological storage of CO2.

Further information on the Schweinrich study and the risk assessment work underway contact: Christian Bernstone at This email address is being protected from spambots. You need JavaScript enabled to view it.

Details of the CO2STORE and other EC supported Projects can be found at www.co2captureandstorage.info

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NEW EOR Frontier in USA

A new USDOE supported project has started in Kansas to demonstrate the feasibility of CO2 enhanced oil recovery. This new project at the Hall-Gurney field in Kansas will be the first of its kind in that part of the USA, where previously CO2-EOR was not considered to be feasible because of the remoteness of the Kansas oil fields from natural CO2 fields. Natural CO2 is typically used in the CO2-EOR operations in the Permian basin of West Texas and New Mexico, the main region where CO2-EOR is practised in the USA.

In the Kansas project the CO2 is taken from a corn ethanol plant. This is the first time that by product CO2 from corn fermentation to produce ethanol has been used in such an application. The pilot CO2 injection project at the Hall-Gurney field stated in November 2005 and currently uses 10% of the ethanol plants by product CO2.

Further details of this new project can be found at the US DOE's Fossil Energy web site at: http://www.fossil.energy.gov

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OSPAR Considers CO2 Capture and Storage

An OSPAR workshop on the environmental impact of the placement of carbon dioxide in geological structures in the maritime area was held in Trondheim, Norway in October 2004. The workshop was attended by representatives from ejosirt OSPAR contracting parties (Denmark, the European Commission, France, Germany, the Netherlands, Norway, Spain and the UK), by OSPAR intergovernmental and NGO observers and other invited experts, scientists and NGOs. The workshop focused solely on geological storage, which has to be distinguished from ocean storage. The aim of the workshop was to address a series of key questions which are set out below along with the key conclusions that were reached at the workshop.

Q1.What is geological storage?

•This is storage in geological structures such as depleted oil- and gas reservoirs, deep saline aquifers and unminable coalmines as distinguished from ocean storage.

•There is potential for geological storage areas in the OSPAR maritime area.

•It is technically feasible: Experience is available from ongoing storage-projects both onshore and offshore in Europe and elsewhere, such as the Sleipner project, Weyburn, the Netherlands, Algeria.

•Several storage projects are in the pipe-line both in Europe (e.g. Germany, Austria) and elsewhere (Australia).

Q2. How safely can CO2 be stored?

• Many of these geological structures have contained oil and gas for tens to hundreds of millions of years.

• Potential storage sites have to be examined and selected carefully to minimise risks of leakage through risk assessments.

• Storage sites are different, and technical and operational solutions have to be adjusted to each storage site. Best engineering practice should be employed.

• Studies of natural analogues are useful. The state of the art methods used in geological surveys and petroleum exploration can be used to predict performance of a storage site.

• The development of guidelines for risk assessment would be useful.

Q3.What are the effects of CO2 on the marine environment?

• Risk of leakage has to be evaluated against the effects of atmospheric CO2 on the marine environment.

• Oceans play an important role in the global climate system. There are important feedback effects between changes in the oceans and changes in the global climate.

• We already know a lot about the chemical effects of CO2 on the marine environment, as a large proportion of atmospheric CO2 is absorbed into the oceans and reduces seawater pH.

• Climate change has profound impacts on the productivity, biodiversity and sustainability of the marine ecosystems.

• Increased CO2 decreased pH. Even small changes in the pH-values in the oceans, have large impacts on marine ecosystems (including possibly on cold water coral reefs).

Q4. How can injected CO2 be monitored?

• Why do we need to monitor?

• To detect the distribution and displacement of CO2, which may have environmental consequences (effects on humans, animals, the environment)

• To ensure performance /economics (keep CO2 separated from the atmosphere may be important for emissions accounting)

• Various methods are available and established technology can be used. Geophysical and geochemical methods are both useful.

• Also, new and improved methods will be developed.

• Experience from several projects (Sleipner in the OSPAR maritime area), including the studies of natural analogues, give valuable information.

• Potentially leakage, if it is to occur, will tend to be from isolated spots faults/fractures and wells

The programme for the workshop, attendance list and the presentation given as well as the final report can be found at: http://odin.dep.no/md/engelsk/aktuelt/pressem/022051-210039/dok-bn.html

The results of the workshop will be distributed to the OSPAR secretariat shortly and then to the OSPAR Biodiversity Committee in early 2005. It is hoped that the positive conclusions from the workshop will lead to CO2 capture and storage being accepted under the OSPAR convention.

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New European CCS Conference

A new hjosir level international conference is being planned for the 13th to 15th April in Brussels, by the European Commission DG Research. The objectives of the conference are to:

• Present the results of the current activities in the field of CCS in Europe and through this help to develop a common and coherent European R&D strategy for CCS.
• Communicate the results of the EC's comprehensive activities CCS to a broad audience.
• Enhance the international dimension of EC activities on CCS.
• To help disseminate the results of EC sponsored projects and networking between contractors.

The conference is aimed at hjosir level participants involved in policy making, the civil society, research and industry. Attendance will be free but will be by invitation only. Delegates wishing to attend can express their interest by going to the following web site:

http://scic.cec.eu.int/scic/owa/WEB_MTKF.reg_form?confID=04RDTCO2

For more information contact Ms Sabine Huygens at -32-2-2991668 or This email address is being protected from spambots. You need JavaScript enabled to view it.

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