_­Chingiz Cherniyazdanov, Deputy Chairman of the Management Board for business development, Kazakh Institute of Oil and Gas

Aidos Temirkhassov, Director of the Upstream projects Department, Kazakh Institute of Oil and Gas

Alexander Logvinenko, 1st category Development Engineer, Kazakh Institute of Oil and Gas

Coalbed methane is a hydrocarbon, the main component of natural gas. Coalbed methane is contained in coal beds. It is formed as a result of biochemical and physical processes during the transformation of plant material into coal. It is the cause of explosions in coal mines, which in certain conditions lead to disasters.

The developed earth depths and promising coal basins concentrate a significant part of the world's coal resources, as well as their complementary rock -methane, the scale of which is commensurate with the gas resources of traditional deposits of the world. In this regard, such basins should be considered as methane coal basins, subject to complex phased development, with advanced large-scale production of methane.

CBM (coalbed methane) is a cost-effective and expedient alternative type of energy. This type of energy is justified not only from an economic point of view, but, first of all, ensures the safety of life and environmental stabilization.

Coal beds are considered collectors and a significant source of methane because they store six to seven times more methane than conventional gas collectors do. CBM is found in three different forms: free gas, dissolved gas in bound coal water, and absorbed gas on the solid surface of coal. Despite the huge number of CBMs; it has features that distinguish it from other traditional oil and gas formations. This is due to the low porosity and permeability of coal beds.

Methane is the cleanest source of energy, does not contain harmful impurities, such as nitrogen and sulfur compounds. For example, every year the coal mines of the Karaganda region emit more than 300 million cubic meters of methane into the atmosphere. According to the data of the coal department of "ArcelorMittal Temirtau" JSC, only 17 million cubic meters were disposed annually in 2015-2020.

Degassing of coal deposits will significantly reduce the number of accidents at mines and emissions of harmful substances into the atmosphere. The production of CBM is economically feasible to solve the problems of local gas supply, the construction of power plants to provide electricity, switch motor vehicles / special equipment from diesel to gas engine fuel.

GLOBAL EXPERIENCE OF CBM MINING

As follows from the BP statistical report (Fig. 1), the ten leading countries account for 91% of the world's proven coal reserves (the CIS countries - Russia, Ukraine and Kazakhstan - collectively control 27%). At the same time, practical experience should be taken into account, which indicates that the largest amount of gas is contained in semi-bituminous and bituminous coal. According to the International Energy Agency (IEA), the global production of CBM can reach 200 billion cubic meters by 2035. In the future, by 2050, the volume may reach 1 trillion cubic meters/ year or 30-40% of the world's natural gas production. At the same time, methane reserves in North America amount to 85 trillion cubic meters, in the CIS countries - 112 trillion cubic meters, in China - 34 trillion cubic meters, and in the countries of the Pacific region - 13 trillion cubic meters. At the meeting of the US-Russian Working Group on Cooperation in the Field of energy, more detailed forecast estimates of CBM reserves were given. In 2005, "Gazprom promgaz" JSC gave its estimate of resources in Russia, the volume of which amounted to 49 trillion cubic meters. According to various estimates, the total reserves of CBM in Kazakhstan amount to - 1.1-1.7 trillion cubic meters.

Based on these figures, we can conclude that there is a significant potential for such projects in the CIS.

USA

Commercial mining of CBM was first carried out in the USA in the 1980s. Currently, the United States is a world leader in the exploration and production of unconventional hydrocarbons, including CBM. The development of the industry caused the introduction of strict regulations to ensure industrial and environmental safety of coal mining operations, as well as the effective introduction of new technologies in degassing coal beds. In addition, in order to attract investment in the exploration and production of CBM, a system of tax preferences was approved. Following the United States, countries such as Canada, the United Kingdom, China and India.

People’s Republic of China

In order to develop research in the field of exploration and production of CBM, the Chinese Government organized the China United Coalbed Methane National Engineering Research Center Co., Ltd with state oil and gas corporations as shareholders: Petro China, Sinopec and the Chinese Geological University.

In order to ensure the optimization of the cost of production and sale of CBM, legislative consolidation of tax preferences for settlements of companies investing in exploration and production of CBM has been adopted.

Also, the national operator Petro China Coalbed Methane Company Limited (hereinafter - PetroChina CBM), which is a subsidiary of the largest multinational oil and gas corporation of China Petro China, has been created to develop the exploration and production industry of the CBM.

Production indicators for the production of CBM PetroChina CBM:

-         Proven reserves: 386 billion cubic meters;

-         CBM production volume: 1.4 billion cubic meters/year;

-         Methane content of coal: from 10 to 30 cubic meters/ton.

One of the features of CBM production is a relatively long (1-3 years) period of water extraction (pumping water from coal beds in order to reduce pressure), followed by full-fledged methane production. Fig. 3 shows that only in the second year after drilling the well, the production of CBM reaches the planned level.

COALBED METHANE EXTRACTION TECHNOLOGIES

There are two fundamentally different ways of CBM production: mine (Coal Mine Methane), obtained as a result of underground degassing of coal mines, and borehole (Coal Bed Methane), obtained by drilling wells and using CBM intensification technology. On a global scale, coal methane has been used as an alternative energy source for several decades, turning from a problem related to the safety of miners into a valuable, high-quality and environmentally valuable energy carrier.

The essence of all CBM production technologies is the preliminary drilling of wells before the development of coal seams. As a result, the level of methane content decreases, which leads to a significant reduction in the risk of accidents. However, until the early 1970s, despite numerous studies and experiments, this method of removing methane was considered ineffective, and therefore was not widely used. This is due to the fact that the methane extraction process itself is more like oil extraction: it is necessary to use pumps to pump water out of formations. As a result, the pressure in the layers decreases, which leads to the release of gas from the pores of coal. A typical scheme for the extraction of CBM using hydraulic fracturing is shown in Fig. 4.

RELEVANCE OF EXPLORATION AND PRODUCTION OF CBM IN KAZAKHSTAN

For the maximum possible and effective use of natural gas, the Government of the Republic of Kazakhstan considers CBM as an alternative and promising type of blue fuel in the concept of development of the gas sector until 2030.

The specific volume of natural gas in the energy balance of the world may be about 30% by 2030. In this regard, interest in non-traditional energy sources has been constantly increasing lately. If the trend to reduce the production of more affordable gas is continued; this will lead to transformation.

To date, residents of ten regions of the Republic of Kazakhstan have access to commercial gas, while commercial gas is supplied to a number of gasified regions only in regional centers and relatively large cities.

The long-term experience of coal mining in the mines of the Karaganda basin confirms the high explosiveness of coal beds due to the high methane content in coal beds, leading to numerous victims and destruction.

The oil and gas industry deals with exploration, production and processing of CBM; as a rule, coal-mining companies in the Karaganda region do not have the necessary technologies and qualified personnel for the development of such projects.

Currently, industrial and commercial mining of CBM is carried out in limited quantities, degassing is only the preparation of coal beds.

The analysis of international experience clearly demonstrates that the key factor in the development of CBM mining projects is combining efforts of research organizations and industry companies with the provision of state support in the form of tax preferences and simplification of procedures in the field of subsoil use.

“KING" JSC

The concept of development of the gas sector of the Republic of Kazakhstan until 2030 defines the vision and main approaches to the phased reform and integrated development of the gas sector of the Republic of Kazakhstan provides for the existing Kazakhstan's significant potential in terms of exploration and production of CBM, in addition to traditional gas resources. In pursuance of the updated Action Plan for the implementation of the instructions of the President of the Republic of Kazakhstan N. A. Nazarbayev on organization of CBM exploration and mining» approved in September 2016 by the Ministry of Energy of the Republic of Kazakhstan, "Kazakh Institute of Oil and Gas" JSC carries out work on geological exploration of the CBM within the framework of the innovative investment project "Extraction of methane from coal beds of the Karaganda coal basin".

"KING" JSC acted as a partner of "ArcelorMittal Temirtau" JSC in the implementation of an investment project for the extraction and processing of CBM. As of 2021, reserves are being determined, meetings are being held with leading domestic and international scientists and service companies dealing with the exploration and production of CBM, with modern technologies and experience in the exploration and production of coalbed methane. "KING" JSC offers projects in two directions: utilization of CBM by creating a GTPP (gas turbine power plant) with a capacity of up to 300 MW, utilization of CBM due to the construction of a plant for the production of gas chemistry (LNG, GTL and other products of gas chemical production). At the same time, "ArcelorMittal Temirtau" JSC plans to achieve a target of 1.5 billion cubic meters of CBM/year by 2027.

The development of the methane-coal deposit provides for the construction of more than 1,000 wells, 26 of them will be built as part of geological exploration in 2022-2024. Investments in the project amount to more than US$100 million. The enterprise will reach the design capacity of 100 thousand tons of liquefied natural gas in 2025. All projects are planned to be implemented by attracting private investment.