Researchers' Proposals


Express of Interest

Framework 6 Express of Interest

Coalbed methane LOWPERM-CBM

Express of Interest

Coalbed Methane Production from Low Permeability Coal Seams

LOWPERM-CBM

Integrated Project



Coalbed Methane (CBM)


During coalification large quantities of methane rich gas are generated and stored within the coal on its internal surfaces. The in-situ coal has extremely large internal surface area; it can store high volumes of gas. The gas may be a source of serious mine hazards, methane outbursts and can also be valuable source of energy, if exploitable.

The gas either migrates into secondary sandstone reservoirs, or remains trapped in the coal seams. The huge Groningen gas-field of The Netherlands is derived from coal seams. If the gas remains trapped in the coal, special production technologies can be applied for its extraction. A group of these technologies is already well established and is in commercial operation. About 7,5 % of the present US natural gas production comes from CBM resources (USGS 2002). The diagram below indicates the character of the presently used technology in the US.



Low permeability coal seams


The European hard coal occurrences have also large potential as source of CBM. However most of these deposits suffered strong tectonic deformation, which have resulted in the reduction of permeability of the coal. These low permeability coal seams have no developed production technology at the moment, thus they are not commercially extractable. Such occurrences exist in several countries, among others in Hungary and Poland.


According to results of research on laboratory scale (Toth et al 1999), there are relatively simple technical solutions to overcome this problem. The studied methods involve three main steps:


- Detailed geological and structural reconstruction of the coalfield

Detailed structural analzsis is necessary to choose the optimal points of the coalfield to position CBM exploration/production drillholes.

- Breaking the internal structure of coal (and liberate the methane) with special fracfluids

Hydraulic fracturing, and other methods to emhamce CBM gas release of the coal.

- Ensure sufficient permeability by mining methods to permit migration of the gas Drilling the coalfield with closely spaced special oriented boreholes


The Hungarian hard coal occurrence – Mecsek Coalfields – offers excellent test site for demonstration of the technologies. The coal production from this coalfield was stopped in 2000. The coalfield contains an estimated 117 Bn cu.m of methane-rich gas (96 % methane content). Tests with established CBM extraction technologies were not successful. The amount of natural gas equals to the total known sandstone-reservoir gas resources of Hungary. At an assumed 20% recovery rate the gas production from this coalfield would cover 3,5 years of the total national consumption. The unsuccessful tests to implement the traditional CBM extraction method in the early 1990s provided a great number of technical data for the later successful laboratory programme.

Environmental aspects


The draining of methane from abandoned coalfields and its use to produce energy stops uncontrolled methane emission from the natural and manmade conducts to the atmosphere. Using the methane in power plants means converting methane to carbon dioxide. The conversion reduces the greenhouse effect resulted from the otherwise released methane.


The CBM production from coalfields in the case of low permeability coals needs additional energy input to mobilize the methane rich gas. One of the possible energy input methods is injection of CO2 into the coal seam. This gas is preferably absorbed on the internal surfaces of coal, thus expelling and mobilizing the methane. This behavior of the carbon dioxide was recognized and used for tests of possible sequestration of this "greenhouse" gas in the coal seams. The method is already used during the enhanced oil recovery (EOR) production in depleted oil fields. Tests are being carried out for the application of the method in connection with CBM production. In case if the CBM gas is used as fuel for thermal power plants, methane is converted into CO2 during the process. This gas could be injected back into the coal seam, thus enhancing methane recovery, and realizing a near-zero emission energy production process. Such a possibility was highlighted by Pashin et al (2000) for the CBM production fields in the USA, Alabama basin.



European position


One of the leading countries in the research and commercial application of CBM energy is Germany, where this resource was qualified as renewable resource. The first CBM fired power plant started in 1952. The largest operation is in Lünen, with 931 kW plant capacity. Several coalfields in the Ruhr and Sahr basins are now tested. In France the Methamine project works since 1990, producing 1,470 million cu.m gas since its start, and used as natural gas. In the UK two sites operate since 1999, and opportunities sought by several companies. Poland and the Czech republic are two leading Eastern European players in hard coal mining, with parallel high potential for CBM production. Poland developed a CBM plant at the Wesola mine in Myslowice.

A test field is planned for development in Bulgaria.




Need and relevance


The proposed research contributes to the objectives set in the EU Council decision COM(2002)43 final, Annex I: 1.1.6.1. Sustainable energy systems

- aims to develop untapped energy resources in EU countries

- decreases the dependence on imported fuels

Since the preliminary field tests and laboratory investigations have already supplied data and concepts to a possibly viable technological solution, it is considered, that the project could be realized in short to medium time span.

It needs European mobilization and resources, since conventional (and commercially viable) technologies are inefficient to extract these resources, in the frame of this project the several parallel and partial research efforts could be focussed and integrated into one powerful concentrated project. Similarly, the combined size of necessary funds and time possibly exceeds the capacity limits of a mining company or national mining bureau.



Scale of ambition and critical mass


The development of coalbed methane resources has strategic importance to Europe, since conventional hydrocarbon mineral fuel resources are gradually depleting. In Europe, with the closure of coalmines, a large number of coalfields still store this source of energy, which may become commercially viable if adequate production technology can be developed.


The research is timely since the number of active coal-fired thermal power plants is gradually reduced, the environmental permits of these plants expire, and they are replaced by gas-fired systems, thus increasing the market demand towards the natural gas.


The European research community has both the critical mass and the excellence to achieve significant results on this field. There were strong research efforts to solve the permeability problems of these coal deposits, and make the methane occurrences economic to extract their gas content. Such advanced research was carried out in different major European research centers, with the following examples from Central Eastern Europe:


Name of research center

Country

Special field of interest

References

University of Miskolc

Hungary

Gas adsorption, mining operations and methane hazards, Mecsek coal field geology

J Toth

Z Nemedi-Varga

Hungarian Geological Survey

Hungary

Resource estimation, economic evaluation of CBM Mecsek

B Fodor

University of Leoben

Austria

Pannonian Basin CBM

R Sachsenhofer

Naftaplin

Croatia

Drava basin CBM

V. Steinbauer

University of Mining and Metallurgy Krakow

Poland

Coalbed gas origin of Silesian and Lublin Basins

M J Kotarba

Institute for Rock Mechanics, Academy of Science,

Poland

Gas adsorption



Integration of the project

The basic research would be directly coupled to technological development and later the demonstration stage. The Hungarian consortium, which is ready to prepare a project proposal consists of university researchers, mineral exploration company, and thermal power plant, located on the demonstration site, which would be the end user of the CBM to be produced from the Mecsek coal-fields. The following parties have indicated interest to participate in the Hungarian segment of the project:


Name of the participant

Activity and experience

Role in the project

University of Miskolc

Basic research

- geology, chemistry and kinetics of the Mecsek CBM

Training of technical personnel

Initiator

Basic research

Coordination

Training

Rotaqua KFT

Drilling company, SME, based in the Mecsek area, experience in specialized drilling

Drilling, field tests

Geonardo KFT

Environmental R+D company, SME, partner in several ongoing EU projects and proposals on this field

Link to FP5 and other R+D projects, project organization and management assistance

Pannon Power RT

Mecsek Thermal Power Plant,

at present coal-fired TPP, which needs to convert its operation to use of natural gas

End-user, technological tests and operation with CBM, sequestration of carbon dioxide


Similar teams are planned to be organized in other EU research centers and demonstration sites.



Project objectives - summary


The main objectives of the proposal are

- To provide viable methods of increasing permeability of the coalbeds

Repeated energy impacts should be initiated, in combination with introduction of hydraulic fracturation

- To work out proper drilling methods to tap the resource.

This includes applying oriented drilling, and application of advanced techniques used in oil-gas industry

- To test different driving energy sources to expel the methane from the coal seams.



References


Landis, E.R., Rohrbacher T.J., Barker C.E., Fodor B., Gombar G. (2002): Coalbed gas in the Mecsek basin, Hungary (in press).


Pashin J.C., Groshong H.R. Jr., Carrol, R.E. (2000): Enhanced coalbed methane recovery through the sequestration of carbon dioxide: potential for market based environmental solution for the Black Warrior Basin, Alabama. Environmental Geology.


USGS (2000): Fact Sheet FS-123-00. www.usgs.gov


Tóth J., Lakatos J., Lakatos-Szabó J (1999): A Possibility to Produce Methane from Low Permeability Coal Seams. in: Lakatos I. (ed): Challenges of an Interdisciplinary Science – Akadémiai Kiadó, Budapest. pp. 265-274.