Access to eco-friendly energy, improvement of the environmental situation in Kazakhstan, need to increase energy security and to ensure the safety of coal extraction require the development and use of efficient technologies. All the above mentioned range of problems can be solved by an extraction of coalbed methane, which is currently being emitted in large quantities into the environment.
Estimated reserves of coalbed methane in Kazakhstan amount to more than 3 trillion m3 and an annual production of 3-4 billion m3 will allow to supply all the needs of Kazakhstan in gas for at least 50 years. This can contribute to the development of a new energy industry.
The coal deposits of Kazakhstan are carbon-gaseous, because coal contains quantity of methane comparable with natural gas. According to various sources, the Karaganda coal basin contains from 1.0 to 4.0 trillion. m3 gas at a depth of 1800 meters. Every year in underground coal seams 500 mln. m3 of gas is extracted by means of degassing and ventilation. In this case about 15% of the total emission of methane is used as a fuel for mine boilers.
Methane is 20-40 times more effective than other gases, it absorbs infrared solar radiation. Coal bed methane is one of the most important non-conventional energy resources and now has to be considered as a very important component of fuel and energy resources. Furthermore, coal methane is a valuable source for the chemical industry in the production of methanol, ammonia, acetylene, protein mass and other products.
Over the past two decades in many mining countries of the world, a lot of efforts are taken to develop the vast resources of methane in coal deposits. On one hand, production of methane in the tunnels of active mines is considered as a source of affordable and cheaper gas fuel, on the other hand, it is concidered as a way to reduce the gas content and outburst of coal seams in order to create safe working conditions.
The problem of degasification of mine tunnels has always been among the priorities that require an immediate solution. Accidental releases of methane provoking people’s deaths, disasters and financial losses represent the cause of 90-93% of accidents that occurred in the coal mines of countries of the Commonwealth of Independent States in the past 5 years. The Institutionalization of large-scale production of coalbed methane will significantly reduce the risk of explosion of methane-air mixtures when developing new mines and the use of the produced gas for power plants in mines will increase the profitability of coal mining.
One ton of coal can generate up to 15-20 m3 of methane, that is 60-70% of its natural content in the coal layers. Kazakhstan is ranked as the ninth largest coal reserve in the world. However the country is lacking advanced technologies adapted to the conditions of Kazakh deposits and allowing the industrial production of methane. In fact, only now is this work launched in a systematic and pragmatic way.
The Institute for the study of complex mineral resources (IPKON) works at the creation of a non-traditional downhole geotechnology of extraction and processing of hydrocarbon resources contained in the coal-bearing strata (industrial production of coal bed methane). The Institute aims to create technologies for the extraction of methane from coal seams using the latest achievements of applied sciences. The current project is carried out on the Taldykuduk site in the Karaganda coal basin. Geological exploration of bedding conditions of coal seams and stratigraphic test drilling are carried out. The aim of IPKON is to create an experimental-industrial complex for the extraction of coal bed methane on the Taldykuduksk site, which will serve as a starting point for the commercial production of methane. Resources of methane in the Taldykuduk plot contain 28 billion m3. For comparison, the demand for gas in Karaganda region is from 1 to 1.5 billion m3 a year. Thus, just the Taldykuduk region can provide gas for more than 20 years.
Technologies of vertical drilling with the simultaneous drilling of the well across several coal seams were used for the first time in Kazakhstan. This allows to significantly increase the total capacity and the output of coal methane. Also for the first time in the country, a directional well was drilled in the coal seam at a distance of 400 m. The development of these wells continues, but already the results point to the great potential of the job.
The coalbed gas concentration ranges from 5 to 20 m3 / t in the optimal depth range (150 – 500 m). This is a very good indicator. Modern geophysical and geological research methods and advanced drilling equipment are used.
Furthermore, a technology of electro-magnetic resonance GEO-EMR (non-destructive geophysical survey) is used on the Taldykuduk site. GEO-EMR allows to determine the characteristics of the occurrence of coal seams and the presence of methane, carbon dioxide and water. This low-cost technology of geological research is carried out at the Earth’s surface without drilling.
Further studies will contribute to the development of effective methane production technology of coal seams adapted to the conditions of Kazakhstan coal deposits.