Prospects for CBM production in Russia
Prospective coal basins and those under development contain a significant part of global coal resources accompanied by methane. Coalbed methane resources are commensurate with the world’s conventional gas resources. Methane concentration in the mixture of coalbed natural gases reaches 80 to 98 per cent.
Scientifically proven assessment of the coal-bearing formations’ role as the major sources of methane accumulation in the Earth’s crust opens up new wide horizons in building up the resources of hydrocarbon gases. Methane, being a most hazardous by-product of coal, is becoming a valuable natural resource to be produced from coal mines as an independent commercial product or as a by-product, in the process of comprehensive phased development of gas-bearing coal fields.
Peculiarities of coalbed methane (CBM) development
There are two essentially different ways of CBM recovery: from coal mines (existing mine take areas) and from CBM wells.
CBM recovery from coal mines is an integral part of the deep mining technique – degassing. When produced from coal mines, the amount of CBM is small and is mainly used for technological purposes of coal producers immediately in the coal production area.
CBM wells ensure commercial production of methane, which, in this case, is regarded not as a by-product of coal, but as an independent mineral resource. Commercial development of CBM is associated with specific technologies of gas recovery intensification (the most common options are hydraulic fracturing, air or air-to-air mixture injection into a well, electrothermal bed stimulation).
It should be noted that not every type of coal is suitable for methane production. Thus, long-flaming brown coal fields are featured with low methane content. Anthracite coal is characterized with high gas content; however, it cannot be recovered due to high density and very low permeability of the deposit. The coals that fall somewhere in between the brown coals and the anthracite coals are attributable to the most favorable ones for methane production. This kind of coal is deposited in Kuzbass, where Gazprom is fully engaged in the innovative project for coalbed methane production according to Russian President’s instructions.
Russian forecasted CBM resources
Forecasted methane resources of the major coal basins in Russia are estimated to contain 83.7 trillion cubic meters making up approximately one-third of the country’s forecasted natural gas resources. Kuzbass is distinguished from the rest of Russia’s coal basins and may reasonably be considered as the world’s largest among the explored CBM basins. The basin’s forecasted methane resources are estimated at over 13 trillion cubic meters.
These estimates are given for the coal and methane resources deposited at a depth of 1,800–2,000 meters. Deeper coal deposits of the basin keep the immense amount of methane estimated at 20 trillion cubic meters that seems to be sufficient in the long run. The resource base of Kuzbass ensures large-scale production of methane (beyond the mine fields) as a separate mineral resource.
International practice of CBM production
The necessity, possibility and feasibility of large-scale commercial CBM production is confirmed with the practice of CBM fields development in the USA, the world’s leader in terms of the ‘new gas industry’ advancement. CBM is also commercially produced in Australia, Canada and China.
Current status of CBM production in Russia
Until recently, CBM was extracted in Russia as a by-product from the existing mine take areas only through the mine degassing systems incorporating the wells drilled from surface. In the recent years, these systems have yielded some 0.5 billion cubic meters of methane per annum in the Pechorsky and Kuznetsky basins.
In 2003 Gazprom launched a project to estimate the possibility of commercial CBM production in Kuzbass. Gazprom Dobycha Kuznetsk is the license owner entitled to prospect, explore, and produce CBM within the Southern Kuzbass group of coal fields.
Annual CBM production in Kuzbass will be 4 billion cubic meters at the plateau period and 18 to 21 billion cubic meters in the long run.
At Taldinskoye field in Kuzbass
In 2005 a test site was established at the Taldinskoye field to develop the CBM production technology. Gazprom Promgaz researchers elaborated the CBM production technology there. 31 international and Russian patents were received across the entire process cycle from CBM exploration to utilization. Moreover, two-thirds of the equipment items used during the pilot project execution were made in Russia.
Between 2008 and 2009 eight wells were drilled in the eastern part of the Taldinskoye field. In 2010 pilot operation of the exploratory wells was launched and the produced gas was supplied to gas filling stations. The pilot operation resulted in obtaining the parameters required to make CBM reserves commercial as well as in approbating the well completion, gas extraction and treatment technologies needed for top-priority areas and prospects development in Kuzbass.
Exploratory well at Taldinskoye field
On February 12, 2010 Gazprom launched Russia’s first CBM production facility at the Taldinskoye field.
Dmitry Medvedev orders to launch CBM production facility at Taldinskoye field
In 2011 the CBM development operations continued. The daily gas production from the Taldinskaya area totaled 20 thousand cubic meters.
At present, Gazprom is performing geological exploration at the Naryksko-Ostashkinskaya area of the Southern Kuzbass group of fields.
In December 2010 and February 2011 two CBM-fired reciprocating-engine power plants were commissioned at the Taldinskoye field. The power plants made it possible to supply electricity to the Taldinsky coal strip mine substation, the Zhernovskaya 1 and Zhernovskaya 3 mines under construction as well as provide electricity to gas facilities of the Taldinskoye field and the Naryksko-Ostashkinskaya area.
Gas-fired reciprocating-engine power plant at Taldinskoye field
In February 2012 the Central Commission for Hydrocarbon Fields Development under the Federal Subsurface Use Agency approved the Development Plan worked out by Gazprom Promgaz for the pilot commercial development of the southeastern part of the Taldinskoye coalbed methane field. It is the first draft document for CBM field development in Russia. The Plan specifies a system for commercial field development based on exploration and test operation data.
CBM production profile in Kuzbass top-priority areas, billion cubic meters per annum
The Plan was elaborated due to estimation of methane reserves as an independent mineral resource and its inclusion into the Russian Classified Index of Natural Resources and Underground Waters. Pre-development and construction works for 14 production wells are currently in progress at the Taldinskoye field.
New kind of natural resource
In order to raise the investment attractiveness of the CBM projects featured by high capital intensity, the regulatory framework has to be improved. In May 2010 Gazprom submitted proposals to the Russian Federation Government on the measures to boost CBM production. The top-priority measure was to categorize CBM as a new kind of natural resource through adding the ‘Natural Gas (Methane) from Coal Beds’ entry in the Russian Classified Index of Natural Resources and Underground Waters.
Tax incentives in the form of a zero tax rate for this mineral resource production could become the next stage of the regulatory framework improvement and the basic means of state support.
The measures proposed by Gazprom will give an impetus to CBM production development in Russia, considerably expand the feedstock base of the national gas industry and significantly increase the operational safety in coal mines through lowering CBM emissions.
In November 2011 coalbed methane was categorized as an independent mineral resource and included into the Russian Classified Index of Natural Resources and Underground Waters.
Objective reasons for CBM production in Russia
Favorable geological features and CBM occurrence in Russia create reasonable preconditions for launching, primarily in Kuzbass, and subsequently in other coal basins, large-scale production of methane as a separate natural resource.
The necessity of setting up CBM production facilities in Kuzbass is explained by the following factors:
- availability of large-scale CBM deposits in Russia;
- availability of state-of-the-art technologies for commercial CBM production that have been widely used internationally in the recent years;
- Russia’s sci-tech potential and capability to coordinate and perform scientific research on the matter.
Among Russia’s regions insufficiently supplied with gas fuel, a number of coal producing regions could fully satisfy their gas demand owing to large-scale CBM production. In addition, gas production and utilization will improve the environmental situation in the coal-mining regions, reduce the gas explosion hazard associated with coal production from future mines and create new jobs at gas production and processing facilities.