Renewable energy will play a key role in the unstoppable energy transition, but natural gas, which is also a low-carbon energy source, is undoubtedly one of the feasible directions.

The "Proposal of the Central Committee of the Communist Party of China on Formulating the Thirteenth Five-Year Plan for National Economic and Social Development" released at the beginning of the month clearly stated that "promoting low-carbon circular development and actively developing natural gas, coalbed methane and shale gas". Du Xiangwan, chairman of the National Climate Expert Committee and academician of the Chinese Academy of Engineering, also pointed out earlier at the 2015 International Energy Reform Forum that my country should increase the proportion of natural gas in the primary energy structure, including unconventional natural gas such as shale gas and coalbed methane. Like conventional natural gas, it is a relatively clean fossil energy.

Statistics show that my country is rich in unconventional natural gas resources such as coalbed methane and shale gas. The total resources are 5 times that of conventional natural gas resources. The development and utilization of coalbed methane can achieve "two birds with one stone", while increasing the supply of clean energy. , and can effectively prevent the "first killer" that threatens the safety of miners - coal mine gas accident. However, in recent years, the production and utilization of coalbed methane has not reached the predetermined target. At the "15th International Coalbed Methane and Shale Gas Symposium" held on November 12, He Youguo, President of the Information Research Institute of the State Administration of Work Safety, pointed out that in today's increasingly tight energy supply, coalbed methane and shale gas The vigorous development of such unconventional natural gas will provide a reliable energy guarantee for the sustainable development of China's economy.

"Zero Exceeding Limit" Forces Strict Implementation

The development and utilization of coalbed methane is an important measure to turn waste into treasure and harm into profit.

This year, the State Administration of Work Safety issued the "Ten Regulations on Strengthening the Prevention and Control of Coal Mine Gas", and for the first time proposed the target management of zero gas over-limits and the requirement that outburst mines should be drained first and then constructed. measures to promote coal mine gas extraction and utilization.

"Strengthening coalbed methane extraction is the most important measure to prevent coal mine gas accidents." Huang Shengchu, director of the Research Center of the State Administration of Work Safety, pointed out. The state has always adhered to the principle of coal mine gas extraction first and then mining, and promoted the integration of coal mining and gas extraction. CBM and coal mine gas extraction have been developed from underground extraction to surface and underground comprehensive development, and ground multi-branch plume has been developed from surface fracturing single well extraction. shape well.

From 2005 to 2014, my country's gas extraction volume increased from 2.2 billion cubic meters to 13.3 billion cubic meters. With the increase in coalbed methane extraction, the country's coal mine gas accidents were significantly reduced. According to statistics, in 2014, there were 47 gas accidents in my country, resulting in 266 deaths, 1,905 fewer than in 2005. The latest data also shows that from January to September this year, the number of gas accidents and the number of deaths decreased by 33.3% and 53.8% year-on-year respectively; there were 3 major accidents this year, a year-on-year decrease of 57.1%.

However, the total amount of gas accidents is still relatively large and has not been effectively curbed. Zheng Xingzhou, Inspector of the Science and Technology Equipment Department of the State Coal Mine Safety Supervision Bureau, said: "Many factors restricting gas prevention and control have not been fundamentally improved, especially the continuous decline of the coal economic situation has brought new pressure on the safety production situation, requiring relevant workers to work harder on coal seams. Drainage and gas accident prevention.”

Zheng Xingzhou believes that with the continuous improvement of national environmental protection and safety standards and the development and improvement of surface coalbed methane development technology, it is an inevitable requirement for China's economic and social development that outburst mines and high-gas mines be pumped first and then built. Great potential and demand.

Low utilization rate of coal mine gas

Due to the high cost of CBM and the chaotic management of mining rights, the current development of CBM in my country is relatively slow.

According to the statistics of Zhang Suian of the CBM Research Center of China University of Petroleum, my country needs 450 million yuan to build 100 million cubic meters of coalbed methane production capacity, while conventional gas only needs about 100 million yuan. Therefore, some people in the industry pointed out that the recent drop in oil prices and the serious losses of coal enterprises will inevitably increase the investment pressure of enterprises on coalbed methane projects.

This will restrict the development of coalbed methane, and it will be difficult to improve the utilization rate of coal mine gas, and it will even continue to decline. This means that my country, like other countries, will also face a period of low-speed development or even relative stagnation of CBM.

In order to speed up the cultivation and development of the coalbed methane industry and implement the requirements of the "Energy Development Strategic Action Plan (2014-2020)", in February this year, the National Energy Administration issued the "Coalbed Methane Exploration and Development Action Plan" to clarify the development of the "13th Five-Year Plan". Objectives, and put forward the main tasks and safeguard measures for the development of the coalbed methane industry. Encouraged by relevant policies, coalbed methane exploration has expanded from North China to Northwest and Southwest China, from high-rank coal to low-rank coal, and the Qinshui and Ordos Basins have entered commercial development.

The latest data shows that in the first half of 2015, the national coalbed methane extraction volume was 8.88 billion cubic meters, and the utilization volume was 4.13 billion cubic meters. Among them, the output of surface coalbed methane was 2.11 billion cubic meters, 47.8% of the annual target was achieved, and the utilization volume was 1.87 billion cubic meters; the underground coal mine gas extraction volume was 6.77 billion cubic meters, 50.2% of the annual target was achieved, and the utilization volume was 2.26 billion cubic meters. In addition, according to He Youguo, shale gas exploration and development technology and equipment have basically been localized, the cost of horizontal wells has been continuously reduced, and the construction period has been continuously shortened.

However, due to the low concentration of underground coalbed methane, its utilization is very difficult. According to statistics, in 2014, the utilization rate of coal mine gas was 4.53 billion cubic meters, and the utilization rate was 34.2%, and about 8.73 billion cubic meters of coal mine gas had not been utilized; in the first half of 2015, the coal mine gas utilization rate was 33.3%.

Huang Shengchu pointed out that under normal circumstances, the concentration of underground coalbed methane extraction should be higher than 30%, but the concentration of our large coalbed methane extraction is less than 20%.

Generally speaking, there are mainly two ways to improve the gas utilization rate of coal mines by increasing the concentration of gas extraction and strengthening the utilization of low-concentration gas.

New Approach: Gas Utilization in Abandoned Coal Mine

By the end of 2014, my country had accumulated 15,172 surface wells. With the adjustment of coal structure, closure and integration and the advancement of the battle against coal gas, a certain number of coal mines have been withdrawn from the market one after another. These abandoned and closed coal mines are rich in gas resources. In order to avoid wasting resources and become new disaster resources, gas development and utilization of abandoned coal mines will become a new way of gas extraction.

In the opinion of Dr. David Corridi, general manager of Cindyke Sustainable Resources in the UK, if the business model is feasible, the utilization of waste coal mine gas will be transformed from debt to positive assets, not only can clean energy be used, but also coal mining can be obtained. The additional value, the formation of mature extraction and utilization technology, can also solve the employment problem of miners after the coal mine is closed, and the profits are considerable.

"The utilization of waste coal mine gas in foreign countries has been commercialized, with mature technology and advanced management. The development and utilization of waste coal mine gas in my country has just started, and a series of technical specifications and technological processes such as project design, production operation, and pollution control are still immature, and it is necessary to further strengthen science and technology. Tackling key problems and researching resource assessment methods, utilization processes and safety guarantee measures suitable for my country's geological conditions." Liu Wenge, deputy director of the Information Research Institute of the State Administration of Work Safety, pointed out.

"The closed coal mines are mainly located in Shanxi, Hunan, Guizhou, Sichuan, Yunnan and other provinces, and are the next key provinces for the development of abandoned coal mine gas." Liu Wenge introduced.

The reporter learned that my country has completed a number of cooperation projects with the European Union, APEC, International Energy Agency, World Bank, Asian Development Bank, as well as government agencies and foreign companies in more than a dozen countries such as the United Kingdom, Australia and Japan. He has accumulated certain experience in gas development and utilization policy formulation, resource assessment and development of technical consulting services.

He Youguo pointed out that the next step will be to select the coal industry group to carry out a feasibility study on the development and utilization of waste coal mine gas, assist enterprises in the construction of demonstration projects, and promote the development of my country's waste coal mine gas industry.

                                                                                                                      Article source: National Energy Network