(China University of Mining and Technology, Xuzhou, Jiangsu 22 1008)
About the author: Telly, born in 1957, male, doctor, professor, coalfield and coalbed methane geology, Qin Yong @ cumt.edu.cn.
Fund Projects: Supported by the National 973 Plan (2002CB2 1 1704) and the National Natural Science Foundation (40572095).
Based on CNKI China periodical full-text database, the distribution characteristics of coalbed methane papers in China are systematically retrieved and counted. On this basis, the relationship between the distribution of coalbed methane papers and the characteristics of industrial development in China is analyzed, and the demand trend of industrial development for science and technology is discussed. The results show that the distribution of papers in 1999 and 2002 respectively shows that the development of coalbed methane industry in China has gone through three historical stages, and the characteristics of scientific and technological demand in each stage are reflected in the distribution characteristics of papers. Therefore, the author thinks that the evaluation of coalbed methane resources and its methods are still the subject of future research, and further deepening the theory and methods of geological selection will help to improve the success rate of selection, and the adaptability of development technology is one of the important directions to be discussed in the future. We should pay enough attention to the research on the productivity, recovery ratio and its influencing factors of coalbed methane wells, and it is possible to fully explore the deep coalbed methane resources and development potential, and expand the new field of coalbed methane development in China. The research and development of environmental protection, high value-added conversion and utilization and miniaturized storage and transportation technology will help promote the healthy development of coalbed methane industry in China.
Keywords coalbed methane; Paper industry; develop
Present situation and industrial development of coalbed methane publishing in China
Qin Yong
(China University of Mining and Technology, Xuzhou 22 1008)
This paper systematically collected and analyzed the papers on coalbed methane published by China from China CNKI China Journal Full-text Database (CJFD)1994 to 2005. Based on data or information, this paper analyzes the correlation between the distribution of papers and the development of coalbed methane industry in China, and discusses the industry's demand for future science and technology. The results show that the three stages of the development of coalbed methane industry in China and the scientific and technological demand of each stage are shown through the distribution of papers, with 1999 and 2002 as the boundaries respectively. It is further pointed out that the evaluation and methodology of coalbed methane resources should be one of the topics to be studied in the future, and the in-depth study on the theory and method of optimization target will help to improve the reliability of coalbed methane optimization target. The adaptability of mining technology to coalbed methane geological conditions should be one of the research focuses, and the research on the productivity and recovery rate of coalbed methane wells should be paid attention to. Exploring the deep coalbed methane resources and development potential in an all-round way will help to open up new fields of coalbed methane industry, and the technological progress of coalbed methane environmental protection, high value-added utilization and miniaturized storage and transportation equipment will help to promote the benign development of the industry.
Keywords: coalbed methane; Paper; Happen; Industry; develop
Under the background of modern science and technology, the development of emerging industries is closely related to academic and technical research in this field. In other words, the distribution of foundation, application foundation and technical research papers in an industry field contains rich information about the development process of the industry, which can predict the development trend of the industry to some extent. The coalbed methane industry in China is currently in the start-up stage of commercial production [1]. Analyzing the output characteristics of coalbed methane papers and their relationship with industrial development will help to review the development history of coalbed methane industry in China and look forward to its development trend. Therefore, the author systematically searched the papers on coalbed methane in 1994-2005 by using the full-text database of China periodicals of China CNKI. On this basis, the distribution characteristics of coalbed methane papers in China in time and research direction are analyzed, and the main scientific and technological problems needing attention in industrial development are discussed.
1 CNKI overall distribution of coalbed methane papers
The results of system retrieval show that CNKI China periodical full-text database contains 1994-2005 CBM papers, with an average of 122 articles per year.
Through the analysis of the retrieval results (figure 1), we get the following general understanding:
First, China's coalbed methane papers have increased year after year, but the growth rate in different historical stages is obviously different. This feature is consistent with the difficult exploration process of China's coalbed methane industry, reflecting that the industry has experienced a phased development process from its inception to the present industrialization.
Secondly, the distribution characteristics of different types of papers reveal the stage characteristics of China's coalbed methane industry at present. In the total number of papers, geology and exploration papers account for 54.33%, development technology papers account for 14.88%, utilization and storage papers account for 6.42%, economics and policy papers account for 4.03%, and environmental protection papers account for 1.30%. The distribution characteristics of geological exploration papers mainly reflect that China's coalbed methane industry is in the initial stage of development.
Thirdly, the time distribution of various papers fluctuates regularly, which is a concentrated reflection of the different demand for science and technology in different stages of industrial development.
Figure 1 CNKI China periodical full-text database CBM paper categories and annual distribution
It is worth noting that during the period of 1994-2005, the number of CNKI coalbed methane papers increased by 12.80 times, with an average annual growth rate of about 106%. Further analysis shows that the number of papers has increased nonlinearly in three stages, which indicates that the development of China's coalbed methane industry has gone through three stages so far (Figure 2). Among them: 447 papers in the first stage, with an average annual output of about 75 papers; 390 articles in the second stage, with an average annual output of 130 articles; There are 628 papers in the third stage, with an average annual output of about 209. At the same time, the growth and decline of various papers at different stages are highly corresponding to the different needs of geological research, exploration evaluation and development test at each stage.
Fig. 2 Time series distribution of total papers in China HowNet and development stage of coalbed methane industry in China.
Distribution of Two CNKI Papers and Development Stages of Coalbed Methane Industry in China
2. 1 stage 1: evidence-natural gas-exploration stage
This stage can be traced back to the first half of 1980s and ended in 1999, which lasted for four "five-year" plans. During this period, the number of coalbed methane papers increased from 20 in 1994 to 129 in 1999, with a linear growth in time series, with a total growth rate of 54.5%, an average annual growth rate of about 9 1%, and the number of authors and units increased significantly (Figure/kloc-)
Judging from the distribution of papers, geological and exploration papers occupy an absolute advantage, accounting for 60% of the total number of papers at this stage, with an average of about 45 papers per year; Development technology papers are less than 8%, with an average of about 6 papers per year; The proportion of papers in utilization, storage and transportation, economy and policy, environmental protection and other categories is very low, with an average of about 2 papers per year (Figure 1, Figure 2). This distribution is a typical feature of the early development of coalbed methane industry in various countries, that is, scientific research and production focus on finding "evidence", framing resources, selecting regions and verifying targets.
In the papers on geology and exploration (Figure 3), most of them reported the research results of coalbed methane resource evaluation and geological selection (42%, with an average of about 19) and reservoir physical properties and adsorption (34%, with an average of about 15), which reflected the characteristics of accumulating data and exploring experience. There are only two papers on the conditions and process of reservoir formation, and there are 1 paper on the recoverability of coalbed methane. This research has not been paid attention to, which shows that the lack of basic research has led to the blindness of coalbed methane geological selection and natural gas exploration, which is also an important reason for the low success rate of coalbed methane geological selection in China at this stage [3].
At this stage, the development of technical papers is mostly the digestion and application of foreign technology. Among them, papers on drilling, well testing and completion account for a large proportion (35%, with an average of about 6 papers), drainage and stimulation measures have been given due attention (24%, with an average of about 4 papers), and desorption-diffusion-seepage, the basis of coalbed methane exploitation, has been paid attention to (6%, with an average of about 1 paper), but the research results of coalbed methane well productivity and recovery have been reported.
Fig. 3 Distribution of papers in different research directions of coalbed methane geology and exploration in China Zhiwang
Fig. 4 Distribution of papers in different research directions of CBM development technology in China Knowledge Network.
The above characteristics reveal that the research at this stage is aimed at the initial process of coalbed methane industry in China, which is characterized by finding evidence in coalbed methane geological research, finding gas in exploration and groping in development test. On the whole, it tries to solve the geological problems of coalbed methane in China by introducing and digesting relevant foreign theories and technologies, accumulates rich information on the basic geological conditions of coalbed methane, and obtains a basic understanding of coalbed methane resources and their distribution laws in China. The characteristics of coal reservoir is the core problem of coalbed methane geology, which has always been concerned by people. The development technology suitable for the geological characteristics of coalbed methane in China has been tested and explored, and the national or regional development strategy of coalbed methane industry has begun to be considered regionally.
2.2 The second stage: exploration-investigation-hesitation stage.
This period lasted for three years, starting in 2000 and ending in 2002. At present, the number of papers on coalbed methane is stable at about 130 per year, and the average number of papers is 73% higher than that in the first stage, but the composition of papers has changed obviously (Figure 1).
In terms of paper categories, there are 209 papers on geology and exploration, accounting for 54% of the total papers in this stage. The average number of papers (about 70) has increased significantly compared with the first stage, but the number of papers has decreased significantly from 1999 to 200 1, and there is a trend of increasing again in the later stage. The number of papers on development technology has greatly increased, accounting for 10 percentage point higher than that in the first stage; The research on economy and policy, utilization, storage and transportation has attracted more attention, and the proportion of papers has increased by 5-6 percentage points (Figure 1, Figure 2).
Compared with the first stage, the number and proportion of research results on coal reservoir physical properties and adsorbability in geological and exploration papers in this stage increased significantly (105, 50%), which constituted the research theme; Although resource evaluation and geological selection still get more attention, the proportion is obviously reduced (29%); The ratio of accumulation conditions to papers processed is basically unchanged (65,438+00%), but the average number of papers (7) has obviously increased (Figure 3). It shows that the conventional evaluation and selection methods tend to be mature at this stage, and the research attention turns to the deep-seated control mechanism problems such as coal reservoir characteristics and reservoir-forming effect closely related to mining geological conditions.
As far as development technology is concerned, there are 17 articles on drilling, completion and well testing, with an average of about 8 articles per year, which is greatly improved compared with the first stage, but the proportion (25%) of the total papers in this stage has decreased; There are 18 papers on drainage and production increase measures, and the proportion (27%) has increased; There are 1 1 papers on productivity and oil recovery, and the proportion has increased from zero to about 16%; Desorption-seepage-diffusion papers 14, accounting for 2 1% of the total papers at this stage, and the proportion has obviously increased (Figure 4). The research on drainage measures, productivity and recovery ratio has been strengthened, and the research on mining foundation and application foundation has been attached great importance, and the research focus has shifted to the downstream of development technology. This is an effort to solve the bottleneck problem in the development of coalbed methane industry in China, and it is also one of the signs that the industry is gradually maturing.
This stage: in addition to further expanding the exploration constituency and continuing natural gas exploration; More efforts should be focused on the areas with certain exploration projects in the first stage, so as to further narrow the exploration target area and provide a more reliable basis for the development of experiments; At the same time, although drainage experiments have been carried out in nearly 20 areas, most of them have not achieved ideal results, which has led to the development of experiments and the impact on industry confidence. However, during this period, the basic and technical research of coalbed methane development has made great progress, especially in the aspects of mining methods and stimulation measures, desorption and diffusion seepage mechanism of coalbed methane, productivity and recovery analysis, which laid an important technical foundation for the arrival of China's coalbed methane industrialization era.
The distribution characteristics of the above papers show that the development process of coalbed methane industry in China has entered a new stage, and the demand for science and technology has changed greatly, which is manifested in the geological exploration of coalbed methane, the general survey in exploration and the undetermined development experiment. On the whole, it is in the stage of "labor pains" to promote the arrival of the era of coalbed methane industrialization in China.
2.3 Stage III: Procurement-Detailed Investigation-Commercial Stage
Since 2003, the development of coalbed methane industry in China has entered a new historical period, that is, the stage of commercial production. Its main signs are: the geological research of coalbed methane enters the source, the exploration practice enters the detailed investigation, and the development enters the commercial production. The embryonic form of coalbed methane industry in China has been formed, and it shows a rapid development momentum. These signs are reflected in the number and structure of coalbed methane papers.
During the three years from 2003 to 2005, the total number of CNKI papers on coalbed methane increased sharply, reaching 628, with an average of about 209 papers, which was 6 1% higher than that in the second stage and nearly half of the total papers in the first stage (Figure 1, Figure 2). The proportion of development technical papers has increased, the research on utilization, storage and transportation technology has been further paid attention to, the basic research has been significantly strengthened, and the research focus has been further shifted to the middle and lower reaches of coalbed methane industry, which is more suitable for the scientific and technological needs of commercial production stage.
Geological and exploration papers account for about 565,438+0% of the stage papers, and still account for a large proportion, which is an inevitable feature of the initial stage of China's coalbed methane industry. Among them, the physical properties and adsorption of coal reservoirs are still the focus of research, but the proportion of papers has dropped to about 39%; Resource evaluation and geological selection are still the scientific and technological needs of the industry, and the proportion of papers (27%) is basically the same as that of the previous stage; The research on reservoir-forming conditions and process has been highly concerned, and the proportion of papers has increased by about 9 percentage points compared with the previous stage (Figure 3).
At present, the proportion of development technical papers is 19%, which is slightly higher than the previous stage, indicating that the research on the midstream of coalbed methane industry in China has been further valued. Among them, the number of papers on drilling, completion and well testing (25 papers) is more than that in the first stage, but the proportion continues to decrease (about 21%); There were 34 papers on drainage and stimulation measures, the number increased significantly, and the proportion increased slightly (29%); There are 12 papers on productivity and oil recovery, and the number and proportion (about 10%) are obviously reduced compared with the previous stage; There are 25 articles on desorption-seepage-diffusion, the number of which is obviously increased, and the proportion is basically the same as that of the previous stage (Figure 4). The proportion of papers on drilling, completion and well testing is relatively reduced, the proportion of papers on drainage and stimulation measures is significantly increased, and the number of papers on desorption-seepage diffusion is significantly increased, especially in the development technology in 2005 (Figure 1, Figure 2), which shows that the commercial production and demonstration projects of coalbed methane in China have a strong demand for new technology development and related basic research.
At this stage, a batch of state-approved coalbed methane reserves were added, and the exploration of coalbed methane reservoir-forming conditions and mechanisms at the national level was fully launched, marking the shift of coalbed methane geological research in China from the stage of investigation of resources and basic geological conditions to the stage of "detailed investigation" of resources and the exploration process of reservoir-forming functions; A new breakthrough has been made in the exploration and development test of coalbed methane in large well pattern, and technologies such as horizontal pinnate wells and cluster wells have been initially applied in coalbed methane development. On-the-spot tests of new technologies to increase production, such as carbon dioxide injection, and the commercial production of coalbed methane in Jincheng area marked the transition of China's coalbed methane industry from development test stage to commercial production start-up stage.
Distribution characteristics of three CNKI papers and scientific and technological problems that should be paid attention to in industrial development
By further analyzing the distribution characteristics of C N KI papers, some problems are found, and solving these problems is the direction that China's coalbed methane industry needs to continue to develop.
First of all, the evaluation of coalbed methane resources has been a subject of research and discussion for more than 20 years. In particular, there are different opinions on the quantity and composition of coalbed methane resources in China and some regions, and the proportion of coalbed methane reserves approved by the state is extremely low. The reasons mainly lie in three aspects: first, the evaluation method lacks normative requirements; Second, there are still unresolved major basic problems in resource estimation; Third, the level of resource exploration and verification is very low. Therefore, the evaluation of coalbed methane resources and its methods will still be a subject that needs to be studied for a long time to come. It will be helpful to solve this problem to formulate normative documents on evaluation methods and requirements at the national level, strengthen basic research with adsorption mechanism as the core [3] and intensify exploration and development experiments.
Secondly, there are more than 50 coalbed methane geological constituencies involved in the literature, but at present there are no more than 5 constituencies with commercial development or visible prospects, and several rounds of exploration and development pilot projects have been carried out in some constituencies. There are many reasons for this situation, including the scientific and adaptive defects of selection theory and method, the limited development level and understanding of early exploration and development testing technology, and the lack of management experience of drilling/completion/drainage technology [3]. Therefore, it is possible to improve the success rate of coalbed methane geological selection in China on the basis of in-depth study of the theory and method of selection, data review and application of new technologies, and summing up the experience and lessons of development technology.
Thirdly, foreign traditional and advanced CBM development technologies are almost always cited in China, but in most cases the application results are not satisfactory. Facing up to this situation, it seems that we should consider the following three questions: first, are all advanced technologies suitable for the geological conditions of coalbed methane in specific constituencies in China? Second, is the development effect of traditional technology in a specific constituency not as good as that of advanced technology? Thirdly, what development technologies have China independently developed that are suitable for the geological conditions of coalbed methane in China? Of course, the answer to the first two questions isno. As for the latter question, the key technology of independent research and development has not been reported. The key to these three problems lies in the adaptability of various development technologies, which is also one of the important directions to be devoted to research in the future.
Fourthly, there are few reports on the research results of CBM well productivity, CBM recovery and its influencing factors, which are far from the technical requirements of CBM commercial production stage. The reason is that most of the previous practices in China are development experiments, and the demand for them is not great, and the accumulated data is very limited, which is difficult to meet the requirements of this study. However, at the present stage of commercial development and pursuit of economic benefits, sufficient attention should be paid to this research, including systematic tracking and analysis of drainage performance, comparative analysis of different coalbed methane geological conditions, deepening the study of coalbed methane desorption-seepage law and mechanism, and developing more scientific numerical simulation technology.
Fifth, the potential new field of deep coalbed methane development has not been paid enough attention, and the feasibility study results of deep resources and conventional oil and gas production are rarely reported. There are a large number of deep coalbed methane resources in China [4], and the coalbed methane in most large and medium-sized sedimentary basins is generated together with conventional oil and gas. Some previous studies have shown the possibility of deep coalbed methane and conventional oil and gas [5]. Therefore, a comprehensive study and discussion on the resource potential of deep coalbed methane from the aspects of resource potential, reservoir-forming process, geological selection and exploration and development experiments will help to expand the new horizons of coalbed methane development in China.
Sixth, we should pay attention to the environmental protection and the technical problems of utilization, storage and transportation of coalbed methane that may be caused by coalbed methane mining. Of the 1465 CNKI coalbed methane papers since 1994, only 19 papers are about environmental protection, almost all of which are philosophical discussions or foreign related technologies. Papers on utilization, storage and transportation are increasing year by year (figure 1), but most of them are about coal-bed methane power generation and pipe network transportation technology. This situation may affect the healthy development of coalbed methane industry in China. According to the geological and development characteristics of coalbed methane in China, it will be helpful to make up for the shortcomings of coalbed methane industry in China by carrying out environmental protection technology research or case analysis, developing coalbed methane conversion and utilization technology with higher added value and miniaturized utilization storage and transportation technology and device adapted to the distributed development characteristics of coalbed methane in mining areas.
refer to
television 2006. Situation and Challenges Faced by China CBM Industrialization (Ⅰ): Current Development Stage. Natural gas industry, 26 (1): 4 ~ 7.
[2] China periodical full-text database. http://2 1 1 . 70 . 2 15.35/kns 50/
[3] TV. 2006. Situation and Challenges Faced by China CBM Industrialization (Ⅱ): Key Scientific and Technological Issues. Natural gas industry, 26 (2): 6 ~ 10.
[4] television. 2006. Situation and Challenges Faced by China CBM Industrialization (III): Trends and Prospects. Natural gas industry, 26 (3): 1 ~ 5.
On TV, Song Quanyou, Fu. 2005. Discussion on the feasibility of coalbed methane and conventional oil and gas exploitation. Natural gas geoscience, 16 (4): 492 ~ 498.