WorldWideScience

Sample records for biogenic coalbed methane

  1. Enhancement of Biogenic Coalbed Methane Production and Back Injection of Coalbed Methane Co-Produced Water

    Energy Technology Data Exchange (ETDEWEB)

    Song Jin

    2007-05-31

    Biogenic methane is a common constituent in deep subsurface environments such as coalbeds and oil shale beds. Coalbed methane (CBM) makes significant contributions to world natural gas industry and CBM production continues to increase. With increasing CBM production, the production of CBM co-produced water increases, which is an environmental concern. This study investigated the feasibility in re-using CBM co-produced water and other high sodic/saline water to enhance biogenic methane production from coal and other unconventional sources, such as oil shale. Microcosms were established with the selected carbon sources which included coal, oil shale, lignite, peat, and diesel-contaminated soil. Each microcosm contained either CBM coproduced water or groundwater with various enhancement and inhibitor combinations. Results indicated that the addition of nutrients and nutrients with additional carbon can enhance biogenic methane production from coal and oil shale. Methane production from oil shale was much greater than that from coal, which is possibly due to the greater amount of available Dissolved Organic Carbon (DOC) from oil shale. Inconclusive results were observed from the other sources since the incubation period was too low. WRI is continuing studies with biogenic methane production from oil shale.

  2. Utilization of coalbed methane

    Energy Technology Data Exchange (ETDEWEB)

    Gustavson, J.B. [Gustavson Associates Inc., Boulder, CO (United States)

    1996-02-01

    Substantial progress has been made in capturing coalbed methane (CBM gas), which constitutes a valuable source of clean burning energy. It is of importance to study the various potential uses of coalbed methane and to understand the various technologies required, as well as their economics and any institutional constraints. In industrialised countries, the uses of coalbed methane are almost solely dependent on microeconomics; coalbed methane must compete for a market against natural gas and other energy sources - and frequently, coalbed methane is not competitive against other energy sources. In developing countries, on the other hand, particularly where other sources of energy are in short supply, coalbed methane economics yield positive results. Here, constraints to development of CBM utilization are mainly lack of technology and investment capital. Sociological aspects such as attitude and cultural habits, may also have a strong negative influence. This paper outlines the economics of coalbed methane utilization, particularly its competition with natural gas, and touches upon the many different uses to which coalbed methane may be applied. 24 refs., 4 figs.

  3. Re-assessing H and C Isotope Signatures of Biogenic Methane in Coalbeds and Shales: Metabolic Pathways and Alternative Influences

    Science.gov (United States)

    Vinson, D. S.; McIntosh, J. C.; Blair, N. E.; Martini, A. M.

    2013-12-01

    Hydrogen and carbon isotopes of microbial methane have long been applied to distinguish metabolic pathways of methanogenesis (utilization of acetate vs. H2+CO2 by methanogens). However, application of isotopic tools in hydrocarbon and biodegradation systems requires improved understanding of what is actually recorded by C and H isotopes of biogenic methane. Unlike culture studies where the fractionation factors of methanogenic pathways have been defined, field-collected gas or water samples represent net apparent isotope signatures influenced by a variety of overlapping water-rock-microbial interaction processes. Understanding these processes is important for modeling subsurface carbon cycling and biostimulation efforts for enhanced microbial gas production. Briefly, trends are apparent from a re-analysis of recently published water and gas isotope data from biogenic coalbed methane and shale gas systems: (1) δ13C-CH4 and the relationship between δ13C-CH4 and δ13C-CO2 (α13CCO2-CH4=(δ13C-CO2 + 1000)/(δ13C-CH4 +1000)), can also record the competition between methanogenesis and non-methanogenic processes (e.g. sulfate reduction), rather than simply recording the pathways of methanogenesis itself; and (2) Interpretation of δ2H-CH4 and δ2H-H2O can be inconsistent with δ13C-based fingerprinting techniques and indeed could be highly influenced by isotope exchange between water and methane precursors. This study provides an alternative approach for interpreting δ13C in shallow biogenic gas which considers that Corg may be consumed by competing, highly-fractionating and less-fractionating processes (e.g. methanogenesis and sulfate reduction, respectively). Whereas variation in apparent α13CCO2-CH4 could be inferred to indicate variation of metabolic pathways (that is, acetate fermentation vs. CO2 reduction) in some coalbed methane systems such as the Powder River Basin, the influx of sulfate relative to the overall Corg biodegradation rate could also be an

  4. Coalbed methane reservoir boundaries and sealing mechanism

    Institute of Scientific and Technical Information of China (English)

    SU Xianbo; LIN Xiaoying; LIU Shaobo; SONG Yan

    2005-01-01

    It is important to investigate the coalbed methane reservoir boundaries for the classification, exploration, and development of the coalbed methane reservoir.Based on the investigation of the typical coalbed methane reservoirs in the world, the boundaries can be divided into four types: hydrodynamic boundary, air altered boundary,permeability boundary, and fault boundary. Hydrodynamic and air altered boundaries are ubiquitous boundaries for every coalbed methane reservoir. The four types of the fault sealing mechanism in the petroleum geological investigation (diagen- esis, clay smear, juxtaposition and cataclasis) are applied to the fault boundary of the coalbed methane reservoir. The sealing mechanism of the open fault boundary is the same with that of the hydrodynamic sealing boundary.The sealing mechanism of the permeability boundary is firstly classified into capillary pressure sealing and hydrocarbon concentration sealing. There are different controlling boundaries in coalbed methane reservoirs that are in different geological backgrounds. Therefore, the coalbed methane reservoir is diversiform.

  5. China Accelerates Development of Coalbed Methane Industry

    Institute of Scientific and Technical Information of China (English)

    Wang Shenyan

    1997-01-01

    @@ Coalbed methane is a kind of natural gas self-accumulated in coalbed and adjacent strata. It was usually regarded hazardous in coal mine production and drained with an aim of coal mine safe production in the past time. Many countries have re-cently attached great importance to the development of coalbed methane since the United States developed the technique of extraction of coalbed methane through drilling a hole from the surface in the 1980s. It has rapidly become a new industrial sector, which provides both clean gas energy for residential and industrial purposes and raw material for chemical products such as fertilizer,carbon black and methanol.

  6. The Classification and Model of Coalbed Methane Reservoirs

    Institute of Scientific and Technical Information of China (English)

    SU Xianbo; LIN Xiaoying; SONG Yah; ZHAO Mengjun

    2004-01-01

    Coalbed methane has been explored in many basins worldwide for 30 years, and has been developed commercially in some of the basins. Many researchers have described the characteristics of coalbed methane geology and technology systematically. According to these investigations, a coalbed methane reservoir can be defined: "a coal seam that contains some coalbed methane and is isolated from other fluid units is called a coalbed methane reservoir".On the basis of anatomizafion, analysis, and comparison of the typical coalbed methane reservoirs, coalbed methane reservoirs can be divided into two classes: the hydrodynamic sealing coalbed methane reservoirs and the self-sealing coalbed methane reservoirs. The former can be further divided into two sub-classes: the hydrodynamic capping coalbed methane reservoirs, which can be divided into five types and the hydrodynamic driving coalbed methane reservoirs,which can be divided into three types. The latter can be divided into three types. Currently, hydrodynamic sealing reservoirs are the main target for coalbed methane exploration and development; self-sealing reservoirs are unsuitable for coalbed methane exploration and development, but they are closely related with coal mine gas hazards. Finally, a model for hydrodynamic sealing coalbed methane reservoirs is established.

  7. Developments of coalbed methane development in the U.S.

    Institute of Scientific and Technical Information of China (English)

    渠祁; 赵俊; 郭华

    2001-01-01

    After decades of development and technology advancement, coalbed methane has become an important source for U.S. energy consumption. Especial in recent year, U.S. coalbed methane production continues its healthy growth rate of about 10% per year. The paper takes emphasis on the technology developments and the engineering approaches of coalbed methane in the U.S.

  8. Developments of coalbed methane development in the U.S.

    Institute of Scientific and Technical Information of China (English)

    QU Qi; ZHAO Jun; GUO Hua

    2001-01-01

    After decades of development and technology advancem ent, coalbed methane has become an important source for U.S. energy consumption . Especial in recent year, U.S. coalbed methane production continues its health y growth rate of about 10% per year. The paper takes emphasis on the technology developments and the engineering approaches of coalbed methane in the U.S.

  9. Methane desorption from a coal-bed

    Energy Technology Data Exchange (ETDEWEB)

    A.D. Alexeev; E.P. Feldman; T.A. Vasilenko [National Academy of Sciences of Ukraine, Donetsk (Ukraine). Donetsk Institute for Physics of Mining Processes

    2007-11-15

    We study the desorption of methane from a coal-bed. A model taking into account both methane diffusion in coal-blocks and its filtration through the system of open pores and cracks is developed. Methane pressure in the coal-bed is found for an arbitrary instant of time. Dependency of the rate of methane release upon the block size, open and closed porosity, viscosity, solubility, bed pressure and temperature is established. We derive the effective coefficient of diffusion of methane in blocks containing closed pores filled with gaseous methane. It is shown that at a hindered diffusion methane is distinctly divided into the 'quick' and the 'slow' one. 25 refs., 5 figs.

  10. Geological and geochemical characteristics of the secondary biogenic gas in coalbed gases, Huainan coalfield

    Energy Technology Data Exchange (ETDEWEB)

    Xiaojun, Zhang; Zhenglin, Cao; Mingxin, Tao; Wanchun, Wang; Jinlong, Ma

    2010-09-15

    The research results show that the compositions of coalbed gases in Huainan coalfield have high content methane, low content heavy hydrocarbons and carbon dioxide, and special dry gas. The evolution coal is at the stage of generation of thermogenic gases, but the d13C1 values within the range of biogenic gas (d13C1 values from -56.7{per_thousand} to -67.9{per_thousand}). The d13C2 value of coalbed gases in Huainan coalfield shows not only the features of the thermogenic ethane, but also the mixed features of the biogenic methane and thermogenic ethane. In geological characteristics, Huainan coalfield has favorable conditions of generation of secondary biogenic gas.

  11. Influence of overpressure on coalbed methane reservoir in south Qinshui basin

    Institute of Scientific and Technical Information of China (English)

    LIU Shaobo; SONG Yan; ZHAO Menjun

    2005-01-01

    In theory, from the high temperature and pressure during the coal generating gas to the present low temperature and pressure of coalbed methane reservoir, the accumulation of coalbed methane was from oversaturated to undersaturated. The gas content of the coalbed methane reservoir in the south Qinshui basin was 12-35.7 m3/t. According to the isotherm and measured gas content of No. 3 coal,the adsorbed gas content in some wells was highly saturated and oversaturated, which was hard to theoretically understand. In addition, there were no thermogenic and biogenic gases at the late stage in the south Qinshui basin. This article proposed that the overpressure was the main reason for the present high saturation of the coalbed methane reservoir. In early Cretaceous, the coalbed methane reservoir was characterized by overpressure and high saturation caused by gas generation from coal measure source rocks. In late Cretaceous, the coalbed methane reservoir was rapidly uplifted,and with the temperature and pressure decreasing, the pressure condition of adsorbed gas changed from overpressure to normal-under pressure, which resulted in the high saturation and gas content in the present coalbed methane reservoir.

  12. 基于本源菌的褐煤生物气生成过程与可能途径%Processes and Possible Pathways of Biogenic Coalbed Methane Generation From Lignites Based on Parent Methanogen

    Institute of Scientific and Technical Information of China (English)

    王爱宽; 秦勇; 兰凤娟

    2012-01-01

    Using the parent anaerobic methanogen flora enriched from lignites in the Zhaotong basin, Yunnan, a simulation experiment was carried out in order to analyze the process and possible approach of the biogenic coalbed gas (CBG) generation. Results showed that the process of the biogenic CBG generation in a period of 130 days underwent at least two gas generation peaks with the higher gas generation rate at the first peak than that at the secondary peak. Gas produced during the first peak came mainly from the huminite group and the biodegradation of the inertinite and liptinite groups was strengthened relatively during the secondary peak. Plots of the carbon isotopic composition to the hydrogen isotopic composition of the simulated methane indicated a major approach of the acetate fermentation by which the biogenic methane was generated. During the stimulation process, the methane concentration raised with the drop of the carbon dioxide concentration. Carbon isotopic composition of the methane tended to become lighter and the hydrogen isotope composition to become heavier in the late period of the simulation process. These data indicate the carbon dioxide-reduction of the partial methane generated in the late period of the stimulation.%利用富集培养得到的本源产甲烷菌群对云南昭通褐煤样品进行生物气模拟实验,分析了褐煤生物气生成过程与可能途径.结果显示,为期130 d的褐煤生物气生成过程至少经历了两个产气高峰,第一高峰产气率高于第二高峰.本文认为第一高峰期间生气母质主要为褐煤中的腐殖组分,第二高峰期间类脂组和惰质组的微生物降解程度相对增强.甲烷碳氢同位素组成显示,模拟生物气主要通过乙酸发酵途径生成.模拟过程中,甲烷浓度和二氧化碳浓度具有相互消长的变化趋势,甲烷碳同位素组成在模拟后期有变轻趋势,氢同位素则趋于变重,表明模拟过程后期生成的部分甲烷具有二氧化碳还原成因.

  13. Biogenic Methane from Coal: The Oxidation Factor

    Science.gov (United States)

    Gallagher, L. K.; Glossner, A. W.; Landkamer, L.; Figueroa, L. A.; Mandernack, K. W.; Munakata Marr, J.

    2011-12-01

    Vast reserves of coal represent an untapped resource that can be used to produce methane gas, a cleaner energy alternative compared to standard fossil fuels. Microorganisms have demonstrated the ability to utilize coal as a carbon source, producing biogenic methane. With increasing demand for cleaner energy resources, understanding and enhancing biogenic methane production has become an area of active research. The conversion of coal to methane by microorganisms has been demonstrated experimentally by a number of research groups, but the state of the coal used as a substrate has not always been reported and may impact biogenic methane production. Microcosm experiments were designed in order to assess how the oxidation state of coal might influence methane production (e.g. as in a dewatered coal-bed natural gas system). Oxidized and un-oxidized coal samples from the Powder River Basin were incubated in microcosms inoculated with an enrichment culture that was derived from coal. Microcosms were characterized by headspace gas analysis, organic acid production, functional gene abundance (qPCR), and pyrosequencing of the 16S rRNA gene. Although the microbial consortium demonstrated the ability to utilize both oxidized and un-oxidized coal as a sole carbon source to generate methane, it was produced in higher quantities from the un-oxidized coal. This microbial community was dominated by Methanobacteriaceae (45%), epsilon-Proteobacteria (32%) and delta-Proteobacteria (13%). The results of this study provide a basis to develop strategies to enhance biogenic methane production from coal, as well as demonstrate the need for careful substrate preparation for inter-study comparisons.

  14. Chemical and stable isotopic evidence for water/rock interaction and biogenic origin of coalbed methane, Fort Union Formation, Powder River Basin, Wyoming and Montana U.S.A

    Science.gov (United States)

    Rice, C.A.; Flores, R.M.; Stricker, G.D.; Ellis, M.S.

    2008-01-01

    Significant amounts (> 36??million m3/day) of coalbed methane (CBM) are currently being extracted from coal beds in the Paleocene Fort Union Formation of the Powder River Basin of Wyoming and Montana. Information on processes that generate methane in these coalbed reservoirs is important for developing methods that will stimulate additional production. The chemical and isotopic compositions of gas and ground water from CBM wells throughout the basin reflect generation processes as well as those that affect water/rock interaction. Our study included analyses of water samples collected from 228 CBM wells. Major cations and anions were measured for all samples, ??DH2O and ??18OH2O were measured for 199 of the samples, and ??DCH4 of gas co-produced with water was measured for 100 of the samples. Results show that (1) water from Fort Union Formation coal beds is exclusively Na-HCO3-type water with low dissolved SO4 content (median < 1??mg/L) and little or no dissolved oxygen (< 0.15??mg/L), whereas shallow groundwater (depth generally < 120??m) is a mixed Ca-Mg-Na-SO4-HCO3 type; (2) water/rock interactions, such as cation exchange on clay minerals and precipitation/dissolution of CaCO3 and SO4 minerals, account for the accumulation of dissolved Na and depletion of Ca and Mg; (3) bacterially-mediated oxidation-reduction reactions account for high HCO3 (270-3310??mg/L) and low SO4 (median < 0.15??mg/L) values; (4) fractionation between ??DCH4 (- 283 to - 328 per mil) and ??DH2O (- 121 to - 167 per mil) indicates that the production of methane is primarily by biogenic CO2 reduction; and (5) values of ??DH2O and ??18OH2O (- 16 to - 22 per mil) have a wide range of values and plot near or above the global meteoric water line, indicating that the original meteoric water has been influenced by methanogenesis and by being mixed with surface and shallow groundwater.

  15. Achievements of China's Coal-bed Methane Exploration and Development

    Institute of Scientific and Technical Information of China (English)

    Zhao Qingbo; Tian Wenguang

    2008-01-01

    @@ Status quo of China's coal-bed methane exploration and development China's coal-bed methane resources China is abundant in coal-bed methane. The new round of resource assessment indicates that 119 potential coal-bed methane targets with burial depth of 2000m and area of 41.5×104km2 are distributed in more than 45 coal-bearing basins. The total resources of coal-bed methane is almost equivalent to that of conventional gas, ranking the third in the world. Among the basins, there are 8 has a coverage of more than 1×1012m3, they are Yili, Tuha,Ordos, Dianqiangui, Juggar, Hailaer, Erlian, and Qinshui.

  16. FEASIBILITY ANALYSIS OF SAFETY SIMULTANEOUS EXTRACTION OF COAL AND COALBED METHANE

    Institute of Scientific and Technical Information of China (English)

    Li Shugang

    2000-01-01

    Coalbed methane is of great value to extract and utilize in China, but the result of such research is not satisfied yet today.The paper analyzed the storage characteristics of coalbed methane, and then studied the behavior of coalbed methane using the key stratum theory of strata control.According to the features related to coalbed methane accumulations and delivery, the technique for safely simultaneous extraction of coal and coalbed methane is proposed, and benefit analysis is made too.

  17. Biogeochemistry of microbial coal-bed methane

    Science.gov (United States)

    Strc, D.; Mastalerz, Maria; Dawson, K.; MacAlady, J.; Callaghan, A.V.; Wawrik, B.; Turich, C.; Ashby, M.

    2011-01-01

    Microbial methane accumulations have been discovered in multiple coal-bearing basins over the past two decades. Such discoveries were originally based on unique biogenic signatures in the stable isotopic composition of methane and carbon dioxide. Basins with microbial methane contain either low-maturity coals with predominantly microbial methane gas or uplifted coals containing older, thermogenic gas mixed with more recently produced microbial methane. Recent advances in genomics have allowed further evaluation of the source of microbial methane, through the use of high-throughput phylogenetic sequencing and fluorescent in situ hybridization, to describe the diversity and abundance of bacteria and methanogenic archaea in these subsurface formations. However, the anaerobic metabolism of the bacteria breaking coal down to methanogenic substrates, the likely rate-limiting step in biogenic gas production, is not fully understood. Coal molecules are more recalcitrant to biodegradation with increasing thermal maturity, and progress has been made in identifying some of the enzymes involved in the anaerobic degradation of these recalcitrant organic molecules using metagenomic studies and culture enrichments. In recent years, researchers have attempted lab and subsurface stimulation of the naturally slow process of methanogenic degradation of coal. Copyright ?? 2011 by Annual Reviews. All rights reserved.

  18. Raton basin coalbed methane production picking up in Colorado

    Science.gov (United States)

    Hemborg, H. Thomas

    1996-01-01

    Coalbed methane production in the Raton basin of south-central Colorado and northeast New Mexico has gone over pilot testing and entered the development stage which is expected to last several years. The development work is restricted to roughly a 25 mile by 15 mile wide `fairway' centered about 20 miles west of Trinidad, Colorado. At last count, 85 wells were producing nearly 17.5 MMcfd of coalbed methane from the basin's Raton and Vermejo formation coals.

  19. Coalbed methane: Clean energy for the world

    Science.gov (United States)

    Ahmed, A.-J.; Johnston, S.; Boyer, C.; Lambert, S.W.; Bustos, O.A.; Pashin, J.C.; Wray, A.

    2009-01-01

    Coalbed methane (CBM) has the potential to emerge as a significant clean energy resource. It also has the potential to replace other diminishing hydrocarbon reserves. The latest developments in technologies and methodologies are playing a key role in harnessing this unconventional resource. Some of these developments include adaptations of existing technologies used in conventional oil and gas generations, while others include new applications designed specifically to address coal's unique properties. Completion techniques have been developed that cause less damage to the production mechanisms of coal seams, such as those occurring during cementing operations. Stimulation fluids have also been engineered specifically to enhance CBM production. Deep coal deposits that remain inaccessible by conventional mining operations offer CBM development opportunities.

  20. Water produced with coal-bed methane

    Science.gov (United States)

    ,

    2000-01-01

    Natural gas produced from coal beds (coal-bed methane, CBM) accounts for about 7.5 percent of the total natural gas production in the United States. Along with this gas, water is also brought to the surface. The amount of water produced from most CBM wells is relatively high compared to conventional natural gas wells because coal beds contain many fractures and pores that can contain and transmit large volumes of water. In some areas, coal beds may function as regional or local aquifers and important sources for ground water. The water in coal beds contributes to pressure in the reservoir that keeps methane gas adsorbed to the surface of the coal. This water must be removed by pumping in order to lower the pressure in the reservoir and stimulate desorption of methane from the coal (fi g. 1). Over time, volumes of pumped water typically decrease and the production of gas increases as coal beds near the well bore are dewatered.

  1. Exploiting coalbed methane and protecting the global environment

    Energy Technology Data Exchange (ETDEWEB)

    Yuheng, Gao

    1996-12-31

    The global climate change caused by greenhouse gases (GHGs) emission has received wide attention from all countries in the world. Global environmental protection as a common problem has confronted the human being. As a main component of coalbed methane, methane is an important factor influencing the production safety of coal mine and threatens the lives of miners. The recent research on environment science shows that methane is a very harmful GHG. Although methane gas has very little proportion in the GHGs emission and its stayed period is also very short, it has very obvious impact on the climate change. From the estimation, methane emission in the coal-mining process is only 10% of the total emission from human`s activities. As a clean energy, Methane has mature recovery technique before, during and after the process of mining. Thus, coalbed methane is the sole GHG generated in the human`s activities and being possible to be reclaimed and utilized. Compared with the global greenhouse effect of other GHGs emission abatement, coalbed methane emission abatement can be done in very low cost with many other benefits: (1) to protect global environment; (2) to improve obviously the safety of coal mine; and (3) to obtain a new kind of clean energy. Coal is the main energy in China, and coalbed contains very rich methane. According to the exploration result in recent years, about 30000{approximately}35000 billion m{sup 2} methane is contained in the coalbed below 2000 m in depth. China has formed a good development base in the field of reclamation and utilization of coalbed methane. The author hopes that wider international technical exchange and cooperation in the field will be carried out.

  2. Resources Conditions of Coalbed Methane Districts in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The China National Administration of Coal Geology accomplished an assessment of coalbed methane resources of China in 1988. The total amount of coalbed methane resources in China is 14336.944 billion m3,occurring in recoverable coal seams and beneath weathering zones,with coalbed methane content equal to or higher than 4 m3 per ton and buried depths smaller than 2000 m,among which there are 967.51 billion m3 of predicted reserves and 13369.434 billion m3 of future reserves. The resources in coal reservoirs with methane content of more than 8 m3 per ton are 12444.087 billion m3,and those with methane content between 4 to 8 m3 per ton are 1892.856 billion m3. There are 35 districts in which the resources abundance is higher than 150 million m3/km2,49 districts with the abundance between 50 million and 150 million m3/km2,and 31 districts with the abundance less than 50 million m3/km2. There is 9256.078 billion m3 of methane occurring in coal seams with buried depths less than 1500 m,and 5080.866 billion m3 in coal seams with buried depths between 1500 and 2000 m. There are 28 large-scale districts in which coalbed methane resources are more than 100 billions m3,28 medium-scale districts with coalbed methane resources between 20 billion and 100 billion m3 and 59 small-scale districts with resources amount less than 20 billion m3. The Jincheng area is one of the most favourable districts for coalbed methane resources in China.

  3. China's Development of Coalbed Methane Attracting World Attention

    Institute of Scientific and Technical Information of China (English)

    WANG Keyu

    1996-01-01

    @@ The worldwide environmental issue has been increasingly centered on the global warming climate because the ozone layer is devastated by emissions of carbon dioxide and other pollutants. Methane is the main element of the coalbed methane discharged in the process of coal exploitation. Methane is a high-effective and clean energy though the greenhouse effect of methane is 20 times larger than that of carbon dioxide.

  4. STUDY ON TRANSPORTATION NUMERICAL SIMULATION OF COALBED METHANE RESERVOIR

    Institute of Scientific and Technical Information of China (English)

    Ren Dong-mei; Zhang Lie-hui; Zhu Shui-qiao

    2003-01-01

    Coalbed methane is an unconventional gas resource and its special storage and migration laws need a series of evaluations and predictions. By analyzing the flowing characteristics of coalbed methane reservoir and using the known results for the dynamic prediction of natural gas reservoir, a three-dimensional mathematical model for the two-phase flow in coalbed methane reservoir was established. In this model the Langmuir isothermal adsorption law, the first Fick law and the second Fick law were applied to consider the absorption and diffusion of coalbed methane. The governing equations were discretized in a finite-difference form, and a full-implicit simulator (CBM-GW3D) for three-dimensional two-phase flow was developed. The field data of coalbed methane wells located at Liupanshui, Guizhou was used to verify the reliability of this model. This paper also presented the result of the sensitivity analysis for some factors. And this result proved the reliability and validity of this model.

  5. Geological and hydrological factors affecting coalbed methane producibility in the San Juan, Greater Green River and Piceance Basins

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A.R.; Kaise, W.R.; Tyler, R.; Hamilton, D.S.; Finley, R.J. [University of Texas at Austin, Austin, TX (United States). Bureau of Economic Geology

    1996-01-01

    In the traditional view, coalbed methane resources were generated in situ during coalification and stored primarily in micro-pores on the coal matrix`s large internal surface area by sorption. Net coal thickness and coal rank are assumed to be the dominant factors for determining areas of exceptionally high coalbed methane producibility. However, new insights based on research performed in the San Juan, Greater Green River, and Piceance Basins indicate that this traditional view is oversimplified because it fails to recognize the need for additional sources of gas beyond that generated initially during coalification to achieve unusually high gas contents. Migrated conventionally and hydrodynamically trapped gases, in-situ generated secondary biogenic gases, and solution gases are required to achieve high gas contents or fully gas-saturated coals. This paper summarises research on the geological and hydrological controls that are critical to coalbed methane producibility by contrasting the prolific San Juan and marginally-producing Greater Green River and Piceance Basins in the Rocky Mountain Foreland. These basins have different geologic and hydrologic attributes critical to coalbed methane producibility and are thought to be end-members of a coalbed methane producibility continuum. 7 refs., 7 figs.

  6. San Juan Basin, USA; coalbed methane development and production

    Energy Technology Data Exchange (ETDEWEB)

    Gluskoter, H. [US Geological Survey, Reston, VA (USA)

    2002-07-01

    Twenty one slides/overheads outline the talk on production of coalbed methane from sedimentary basins in the USA. Figures are given for production and reserves for the year 2000. The San Juan basin's geologic structure, containing resources of the Cretaceous coal age, primarily in the Fruitland Formation, is described. 4 refs.

  7. CNPC Develops Effective Coal-bed Methane Techniques

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    The technology for recovery of coal-bed methane developed by China National Petroleum Corporation (CNPC), which is the parent company of PetroChina, will help the nation lower reliance on overseas companies and better position itself to produce that resource at a low cost. Trapped in coal deposits, the special type of methane is one among several types of high-energy unconventional gases that are expected to become important sources of the country's energy.

  8. Noble gas tracing of groundwater/coalbed methane interaction in the San Juan Basin, USA

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z.; Ballentine, C.J.; Kipfer, R.; Schoell, M.; Thibodeaux, S. [ETH, Zurich (Switzerland). Inst. of Isotope Geology & Mineral Resources

    2005-12-01

    The San Juan Basin natural gas field, located in northwestern New Mexico and southwestern Colorado in the USA, is a case-type coalbed methane system. Groundwater is thought to play a key role in both biogenic methane generation and the CO{sub 2} sequestration potential of coalbed systems. We show here how noble gases can be used to construct a physical model that describes the interaction between the groundwater system and the produced gas. The results conclusively show that the volume of groundwater seen by coal does not play a role in determining the volume of methane produced by secondary biodegradation of these coalbeds. There is no requirement of continuous groundwater flow for renewing the microbes or nutrient components. Strong mass related isotopic fractionation of {sup 20}Ne/{sup 22}NE and {sup 38}Ar/{sup 36} isotopic ratios was also seen. This can be explained by a noble gas concentration gradient in the groundwater during gas production, which causes diffusive partial re-equilibration of the noble gas isotopes. It is important for the study of other systems in which extensive groundwater degassing may have occurred to recognize that severe isotopic fractionation of air-derived noble gases can occur when such concentration gradients are established during gas production. Excess air-derived Xe and Kr in our samples are shown to be related to the diluting coalbed methane and can only be accounted for if Xe and Kr are preferentially and volumetrically trapped within the coal matrix and released during biodegradation to form CH{sub 4}.

  9. Western Canadian coalbed methane gas activity chart 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    This geological map of major coal-bearing formations in western Canada identifies various coal basins in British Columbia, Alberta, and Saskatchewan along with their associated coal rank and land area. The map identifies coalbed methane projects underway as well as coalbed methane pilot projects in the Western Canada Sedimentary Basin (WCSB), and provides estimates for coal resources in-place (in billion tons), and coalbed gas-in-place (in trillion cubic feet). The ages of the coal-bearing formations range from Tertiary, Lower Cretaceous, Upper Cretaceous, and Upper Cretaceous-Tertiary. The major regions in British Columbia include the Insular coal fields, the Intermontane belt coal fields, the Northeast foothills and plains, and Southeast foothills. The following Calgary-based companies placed their advertisements on the map with highlights of the services they provide relating to coalbed methane development: Schlumberger, Sanjel, Fekete Associates, GrenCo Industries, Weatherford Underbalanced Systems, Weatherford Artificial Lift Systems, Toromont Process Systems, Pinnacle Technology, Enerflex, Sproule, Trident Exploration Corp., Perspective Consultants Inc., Halliburton Energy Services, Computer Modeling Group, Kudu Industries Inc., and CalFrac Well Services. Advertisement from Edmonton-based C-Fer Technologies, and the Toronto-based Canadian Institute Energy Group were also included on the map. 1 fig.

  10. Determination of coalbed methane potential and gas adsorption capacity in Western Kentucky coals

    Science.gov (United States)

    Mardon, S.M.; Takacs, K.G.; Hower, J.C.; Eble, C.F.; Mastalerz, Maria

    2006-01-01

    The Illinois Basin has not been developed for Coalbed Methane (CBM) production. It is imperative to determine both gas content and other parameters for the Kentucky portion of the Illinois Basin if exploration is to progress and production is to occur in this area. This research is part of a larger project being conducted by the Kentucky Geological Survey to evaluate the CBM production of Pennsylvanian-age western Kentucky coals in Ohio, Webster, and Union counties using methane adsorption isotherms, direct gas desorption measurements, and chemical analyses of coal and gas. This research will investigate relationships between CBM potential and petrographic, surface area, pore size, and gas adsorption isotherm analyses of the coals. Maceral and reflectance analyses are being conducted at the Center for Applied Energy Research. At the Indiana Geological Survey, the surface area and pore size of the coals will be analyzed using a Micrometrics ASAP 2020, and the CO2 isotherm analyses will be conducted using a volumetric adsorption apparatus in a water temperature bath. The aforementioned analyses will be used to determine site specific correlations for the Kentucky part of the Illinois Basin. The data collected will be compared with previous work in the Illinois Basin and will be correlated with data and structural features in the basin. Gas composition and carbon and hydrogen isotopic data suggest mostly thermogenic origin of coalbed gas in coals from Webster and Union Counties, Kentucky, in contrast to the dominantly biogenic character of coalbed gas in Ohio County, Kentucky.

  11. Coalbed methane/natural gas coal chart

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2005-10-01

    This map of coal and coalbed gas in Alberta also listed Canadian coal and coalbed gas resources by region, basin or coalfield; major coal-bearing formations or groups; coal rank; estimated in-place coal resources per billion tons; and estimated coalbed gas in-place resources. The major coalfields of British Columbia were shown to be grouped into Rocky Mountains, Insular and Intermontane coalfields. The insular belt includes the coalfields and deposits on Vancouver Island and small deposits on the Queen Charlotte Islands. Saskatchewan resources were also presented, along with resource potential in the east coast of Canada, the Alberta plains, the Upper and Lower Cretaceous regions and the Alberta foothills. A stratigraphic chart of coal bearing formations in the Western Canada Sedimentary Basin was presented, as well as a schematic cross-section showing major coal zones in Alberta. An inset map of North American coal basins was also provided. The following advertisers listed their services: Schlumberger, Weatherford, Kudu Industries Inc., Calfrac Well Services, Ferus Gas Industries Trust, Baker Hughes, MGV Energy Inc., Pembina Controls Inc., R and M Energy Systems Inc., Trident Exploration Corp., Enviro Noise Control, Toromont Energy Systems, Canyon Technical Services, Sproule, Enerflex, Computer Modelling Group Ltd., Norwest Corp., Fekete, Wellco Energy Services, Sanjel, Smithbits, Colt Engineering, Perspective Consultants Inc. and Concept Compression Corp.

  12. An evaluation of pretreatment agents for the stimulation of secondary biogenic coalbed natural gas

    Science.gov (United States)

    Huang, Zaixing

    Coalbed methane is considered to be an underexploited source of clean energy and, with the realization of its biogenic nature, it has attracted increasing interest in recent decades. Most of the published studies on biogenic coal bed natural gas (CBNG) have focused either on biostimulation (the addition of nutrients to stimulate the native microbial populations) or bioaugmentation (the addition of both nutrients and non-native microbial consortia of microorganisms). Although these approaches have shown promise, they are predicated on the assumption that the coal seam is nutrient-limited or that the existing microbial communities are not optimized to convert coal to natural gas. The premise of this research is that the organic matter present within the coal matrix is, for the most part, environmentally inert and not readily available to the microorganisms living within the coal seam. The goal of this research has been to focus on treatments that will increase the solubility, and hence the bioavailability, of coal to the indigenous microbial community. Initially, treatment agents representing acids, bases and oxidants were selected to evaluate the potential for the in situ solubilization and depolymerization of subbituminous coal. The bioavailability of the coal-derived constituents was then evaluated aerobically using biometer assays and anaerobic bioassays. The experiments have shown that the acid (nitric acid) and base (sodium hydroxide) treatments are more efficient than the oxidants (potassium permanganate and catalyzed hydrogen peroxide) with respect to total organic carbon (TOC). The carbon contained in the solubilized/depolymerized product of nitric acid treatments accounted for approximately 14% of the carbon from the Powder River Basin (PRB) coal evaluated in the study; however, the biometer assays revealed that the bioavailability of the solubilized/depolymerized products was not directly correlated to the amount of dissolved organic carbon (TOC). The

  13. A Comprehensive Model for Evaluating Coalbed Methane Reservoirs in China

    Institute of Scientific and Technical Information of China (English)

    YAO Yanbin; LIU Dameng; TANG Dazhen; HUANG Wenhui; TANG Shuheng; CHE Yao

    2008-01-01

    Coalbed methane reservoir (CBMR) evaluation is important for choosing the prospective target area for coalbed methane exploration and production. This study aims at identifying the characteristic parameters and methods to evaluate CBMR. Based on the geological surveys, laboratory measurements and field works, a four-level analytic hierarchy process (AHP) model for CBMR evaluation is proposed. In this model, different weights are prioritized and assigned on the basis of three main criteria (including reservoir physical property, storage capacity and geological characteristics), 15 sub-criteria, and 18 technical alternatives; the later of which are discussed in detail. The model was applied to evaluate the CBMR of the Permo-Carboniferous coals in the Qinshui Basin, North China. This GIS-based fuzzy AHP comprehensive model can be used for the evaluation of CBMR of medium-high rank (mean maximum vitrinite reflectance >0.5%) coal districts in China.

  14. Displacement desorption test of coalbed methane and its mechanism exploring

    Institute of Scientific and Technical Information of China (English)

    ZHANG Suian; HUO Yongzhong; YE Jianping; TANG Shuheng; MA Dongmin

    2005-01-01

    Through the test of CH4 displaced by CO2 using the coal sample as the adsorbent, this paper has found the coalbed methane (CBM) displacement desorption phenomenon under the natural conditions and CBM mining conditions. With the help of the adsorption theory of the modern physical chemistry and interfacial chemistry, the CBM competitive adsorption and displacement desorption mechanism are intensively discussed, and a new path for studying the CBM desorption mechanism in the CBM exploitation process is explored.

  15. Water Management Strategies for Improved Coalbed Methane Production in the Black Warrior Basin

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, Jack; McIntyre-Redden, Marcella; Mann, Steven; Merkel, David

    2013-10-31

    The modern coalbed methane industry was born in the Black Warrior Basin of Alabama and has to date produced more than 2.6 trillion cubic feet of gas and 1.6 billion barrels of water. The coalbed gas industry in this area is dependent on instream disposal of co-produced water, which ranges from nearly potable sodium-bicarbonate water to hypersaline sodium-chloride water. This study employed diverse analytical methods to characterize water chemistry in light of the regional geologic framework and to evaluate the full range of water management options for the Black Warrior coalbed methane industry. Results reveal strong interrelationships among regional geology, water chemistry, and gas chemistry. Coalbed methane is produced from multiple coal seams in Pennsylvanian-age strata of the Pottsville Coal Interval, in which water chemistry is influenced by a structurally controlled meteoric recharge area along the southeastern margin of the basin. The most important constituents of concern in the produced water include chlorides, ammonia compounds, and organic substances. Regional mapping and statistical analysis indicate that the concentrations of most ionic compounds, metallic substances, and nonmetallic substances correlate with total dissolved solids and chlorides. Gas is effectively produced at pipeline quality, and the only significant impurity is N{sub 2}. Geochemical analysis indicates that the gas is of mixed thermogenic-biogenic origin. Stable isotopic analysis of produced gas and calcite vein fills indicates that widespread late-stage microbial methanogenesis occurred primarily along a CO{sub 2} reduction metabolic pathway. Organic compounds in the produced water appear to have helped sustain microbial communities. Ammonia and ammonium levels increase with total dissolved solids content and appear to have played a role in late-stage microbial methanogenesis and the generation of N{sub 2}. Gas production tends to decline exponentially, whereas water production

  16. Coalbed methane resources of the Appalachian Basin, eastern USA

    Science.gov (United States)

    Milici, Robert C.; Hatch, Joseph R.; Pawlewicz, Mark J.

    2010-01-01

    In 2002, the U.S. Geological Survey (USGS) assessed the technically recoverable, undiscovered coalbed-gas resources in the Appalachian basin and Black Warrior basin Assessment Provinces as about 15.5 trillion cubic feet. Although these resources are almost equally divided between the two areas, most of the production occurs within relatively small areas within these Provinces, where local geological and geochemical attributes have resulted in the generation and retention of large amounts of methane within the coal beds and have enhanced the producibility of the gas from the coal. In the Appalachian basin, coalbed methane (CBM) tests are commonly commercial where the cumulative coal thickness completed in wells is greater than three meters (10 ft), the depth of burial of the coal beds is greater than 100 m (350 ft), and the coal is in the thermogenic gas window. In addition to the ubiquitous cleating within the coal beds, commercial production may be enhanced by secondary fracture porosity related to supplemental fracture systems within the coal beds. In order to release the methane from microporus coal matrix, most wells are dewatered prior to commercial production of gas. Two Total Petroleum Systems (TPS) were defined by the USGS during the assessment: the Pottsville Coal-bed gas TPS in Alabama, and the Carboniferous Coal-bed Gas TPS in Pennsylvania, Ohio, West Virginia, eastern Kentucky, Virginia, Tennessee, and Alabama. These were divided into seven assessment units, of which three had sufficient data to be assessed. Production rates are higher in most horizontal wells drilled into relatively thick coal beds, than in vertical wells; recovery per unit area is greater, and potential adverse environmental impact is decreased.

  17. GEOLOGIC SCREENING CRITERIA FOR SEQUESTRATION OF CO2 IN COAL: QUANTIFYING POTENTIAL OF THE BLACK WARRIOR COALBED METHANE FAIRWAY, ALABAMA

    Energy Technology Data Exchange (ETDEWEB)

    Jack C. Pashin; Richard E. Carroll; Richard H. Groshong, Jr.; Dorothy E. Raymond; Marcella McIntyre; J. Wayne Payton

    2003-01-01

    reactivity of supercritical CO{sub 2} in coal-bearing strata is unknown, and potential exists for supercritical conditions to develop below a depth of 2,480 feet following abandonment of the coalbed methane fields. High-pressure adsorption isotherms confirm that coal sorbs approximately twice as much CO{sub 2} as CH{sub 4} and approximately four times as much CO{sub 2} as N{sub 2}. Analysis of isotherm data reveals that the sorption performance of each gas can vary by a factor of two depending on rank and ash content. Gas content data exhibit extreme vertical and lateral variability that is the product of a complex burial history involving an early phase of thermogenic gas generation and an ongoing stage of late biogenic gas generation. Production characteristics of coalbed methane wells are helpful for identifying areas that are candidates for carbon sequestration and enhanced coalbed methane recovery. Many geologic and engineering factors, including well construction, well spacing, and regional structure influence well performance. Close fault spacing limits areas where five-spot patterns may be developed for enhanced gas recovery, but large structural panels lacking normal faults are in several gas fields and can be given priority as areas to demonstrate and commercialize carbon sequestration technology in coalbed methane reservoirs.

  18. Riemann problem for one-dimensional binary gas enhanced coalbed methane process

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    With an extended Langmuir isotherm, a Riemann problem for one-dimensional binary gas enhanced coalbed methane (ECBM) process is investigated. A new analytical solution to the Riemann problem, based on the method of characteristics, is developed by introducing a gas selectivity ratio representing the gas relative sorption affinity. The influence of gas selectivity ratio on the enhanced coalbed methane processes is identified.

  19. The pore-fracture system properties of coalbed methane reservoirs in the Panguan Syncline, Guizhou, China

    Directory of Open Access Journals (Sweden)

    Song Li

    2012-11-01

    Full Text Available The Panguan Syncline contains abundant coal resources, which may be a potential source of coalbed methane. In order to evaluate the coalbed methane production potential in this area, we investigated the pore-fracture system of coalbed methane reservoirs, and analyzed the gas sorption and seepage capacities by using various analytical methods, including scanning electron microscopy (SEM, optical microscopy, mercury-injection test, low-temperature N2 isotherm adsorption/desorption analyses, low-field nuclear magnetic resonance and methane isothermal adsorption measurements. The results show that the samples of the coal reservoirs in the Panguan Syncline have moderate gas sorption capacity. However, the coals in the study area have favorable seepage capacities, and are conductive for the coalbed methane production. The physical properties of the coalbed methane reservoirs in the Panguan Syncline are generally controlled by coal metamorphism: the low rank coal usually has low methane sorption capacity and its pore and microfractures are poorly developed; while the medium rank coal has better methane sorption capacity, and its seepage pores and microfractures are well developed, which are sufficient for the coalbed methane’s gathering and exploration. Therefore, the medium rank coals in the Panguan Syncline are the most prospective targets for the coalbed methane exploration and production.

  20. Developmental geology of coalbed methane from shallow to deep in Rocky Mountain basins and in Cook Inlet-Matanuska Basin, Alaska, USA and Canada

    Science.gov (United States)

    Johnson, R.C.; Flores, R.M.

    1998-01-01

    The Rocky Mountain basins of western North America contain vast deposits of coal of Cretaceous through early Tertiary age. Coalbed methane is produced in Rocky Mountain basins at depths ranging from 45 m (150 ft) to 1981 m (6500 ft) from coal of lignite to low-volatile bituminous rank. Although some production has been established in almost all Rocky Mountain basins, commercial production occurs in only a few. despite more than two decades of exploration for coalbed methane in the Rocky Mountain region, it is still difficult to predict production characteristics of coalbed methane wells prior to drilling. Commonly cited problems include low permeabilities, high water production, and coals that are significantly undersaturated with respect to methane. Sources of coalbed gases can be early biogenic, formed during the early stages of coalification, thermogenic, formed during the main stages of coalification, or late stage biogenic, formed as a result of the reintroduction of methane-gnerating bacteria by groundwater after uplift and erosion. Examples of all three types of coalbed gases, and combinations of more than one type, can be found in the Rocky Mountain region. Coals in the Rocky Mountain region achieved their present ranks largely as a result of burial beneath sediments that accumulated during the Laramide orogeny (Late Cretaceous through the end of the eocene) or shortly after. Thermal events since the end of the orogeny have also locally elevated coal ranks. Coal beds in the upper part of high-volatile A bituminous rank or greater commonly occur within much more extensive basin-centered gas deposits which cover large areas of the deeper parts of most Rocky Mountain basins. Within these basin-centered deposits all lithologies, including coals, sandstones, and shales, are gas saturated, and very little water is produced. The interbedded coals and carbonaceous shales are probably the source of much of this gas. Basin-centered gas deposits become overpressured

  1. Effects of structural deformation on formation of coalbed methane reservoirs in Huaibei coalfield, China

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Bo; Qu, Zhenghui; Li, Ming [School of Resources and Earth Science, China University of Mining and Technology, Xuzhou 221116 (China); Key Laboratory of CBM Resource and Reservoir-generating Process, China Ministry of Education, Xuzhou 221116 (China); Wang, Geoff G.X. [School of Chemical Engineering, The University of Queensland, QLD 4072 (Australia)

    2010-06-01

    Tectonically deformed coal is defined as coal formed by superimposed reformations from tectonic stress. The Huaibei coalfield is typically composed of various tectonically deformed coals containing rich coalbed methane resources. However, the occurrence of coal seam in this area is complicated largely by the structural deformation, which has not yet been evaluated systematically for exploration and exploitation of coalbed methane. In this study, tectonism in Huaibei coalfield is discussed by combining systematic analyses on the occurrence of coal seams and the formation of coalbed methane reservoirs. The study shows that, with structural deformation in the study area, the coal seams in Huaibei coalfield are distributed in north-south tectonic blocks and east-west tectonic zones. North tectonic block of Huaibei coalfield is not favourable for exploitation of coalbed methane because of low gas content or disadvantageous structural conditions. Within the south tectonic block, the east Suzhou syncline contains high gas content but coal permeability is very low. This area is generally not suitable for exploitation of coalbed methane and is a dangerous mining area due to gas outburst because of the widely developed mylonitic coals. South Suzhou and Nanping synclines in the middle part of the south tectonic block are exposed to relatively weak structural deformations. These synclines contain coals with high gas content and moderate permeability, which are beneficial for exploration and exploitation of coalbed methane. Linhuan mining area in the south tectonic block is generally not suitable for exploitation of coalbed methane, mainly because of well developed normal faults and interlayer slip structure, and presence of mylonitic coal, resulting in low gas content and poor structural conditions for mining coalbed methane. In contrast, Guoyang mining area in the west part of the south tectonic block, where tectonically deformed coal was generally underdeveloped, is a

  2. Coal geological factors for the storage of gas and coalbed methane resources evaluation research in Liupanshui

    Institute of Scientific and Technical Information of China (English)

    ZHANG Qing-long; WU Cai-fang

    2011-01-01

    The geological characteristics of coalbed methane from the research carried out in Liupanshui is based on analysis of faults,folds,roof and floor lithology,and depth of coal seam gas content,combined with the assessment of CBM resources calculated through buried depth scope,average coal seam thickness,and gas content,organized by the Ministry of Land and Resources in 2006,which launched the “national new round of coalbed methane re-sources evaluation” project to evaluate the coalbed methane resources in the standard category and divided coal-bed methane resources into Ⅰ,Ⅱ and Ⅲ Category of three resources categories.With this method on the other syncline to resources assessment,the area below 1 000 m is named as Ⅰ Category resources.And with the depth increasing,resources level decreases.

  3. Coalbed methane produced water in China: status and environmental issues.

    Science.gov (United States)

    Meng, Yanjun; Tang, Dazhen; Xu, Hao; Li, Yong; Gao, Lijun

    2014-01-01

    As one of the unconventional natural gas family members, coalbed methane (CBM) receives great attention throughout the world. The major associated problem of CBM production is the management of produced water. In the USA, Canada, and Australia, much research has been done on the effects and management of coalbed methane produced water (CMPW). However, in China, the environmental effects of CMPW were overlooked. The quantity and the quality of CMPW both vary enormously between coal basins or stratigraphic units in China. The unit produced water volume of CBM wells in China ranges from 10 to 271,280 L/well/day, and the concentration of total dissolved solids (TDS) ranges from 691 to 93,898 mg/L. Most pH values of CMPW are more than 7.0, showing the alkaline feature, and the Na-HCO3 and Na-HCO3-Cl are typical types of CMPW in China. Treatment and utilization of CMPW in China lag far behind the USA and Australia, and CMPW is mainly managed by surface impoundments and evaporation. Currently, the core environmental issues associated with CMPW in China are that the potential environmental problems of CMPW have not been given enough attention, and relevant regulations as well as environmental impact assessment (EIA) guidelines for CMPW are still lacking. Other potential issues in China includes (1) water quality monitoring issues for CMPW with special components in special areas, (2) groundwater level decline issues associated with the dewatering process, and (3) potential environmental issues of groundwater pollution associated with hydraulic fracturing.

  4. Alaska coal geology, resources, and coalbed methane potential

    Science.gov (United States)

    Flores, Romeo M.; Stricker, Gary D.; Kinney, Scott A.

    2004-01-01

    Estimated Alaska coal resources are largely in Cretaceous and Tertiary rocks distributed in three major provinces. Northern Alaska-Slope, Central Alaska-Nenana, and Southern Alaska-Cook Inlet. Cretaceous resources, predominantly bituminous coal and lignite, are in the Northern Alaska-Slope coal province. Most of the Tertiary resources, mainly lignite to subbituminous coal with minor amounts of bituminous and semianthracite coals, are in the other two provinces. The combined measured, indicated, inferred, and hypothetical coal resources in the three areas are estimated to be 5,526 billion short tons (5,012 billion metric tons), which constitutes about 87 percent of Alaska's coal and surpasses the total coal resources of the conterminous United States by 40 percent. Coal mining has been intermittent in the Central Alaskan-Nenana and Southern Alaska-Cook Inlet coal provinces, with only a small fraction of the identified coal resource having been produced from some dozen underground and strip mines in these two provinces. Alaskan coal resources have a lower sulfur content (averaging 0.3 percent) than most coals in the conterminous United States are within or below the minimum sulfur value mandated by the 1990 Clean Air Act amendments. The identified resources are near existing and planned infrastructure to promote development, transportation, and marketing of this low-sulfur coal. The relatively short distances to countries in the west Pacific Rim make them more exportable to these countries than to the lower 48 States of the United States. Another untapped but potential resource of large magnitude is coalbed methane, which has been estimated to total 1,000 trillion cubic feet (28 trillion cubic meters) by T.N. Smith 1995, Coalbed methane potential for Alaska and drilling results for the upper Cook Inlet Basin: Intergas, May 15 - 19, 1995, Tuscaloosa, University of Alabama, p. 1 - 21.

  5. Coal-bed methane water effects on dill and essential oils

    Science.gov (United States)

    Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic way of methane extraction. The water that is pumped out is known as coal-bed methane water (CBMW), which is high in sodium and other salts. In past 25 years, th...

  6. Assessment of coalbed methane utilization - economic efficiency for Kuznetsk coal basin in Russia

    Energy Technology Data Exchange (ETDEWEB)

    Tailakov, O.V.; Abramov, I.L.; Panchisheva, T.A.; Sinelnikova, A.V. [Institute of Coal and Coal Chemistry SB RAS (Russian Federation). Coalbed Methane Center

    1998-07-01

    The Kuznetsk Coal Basin has unique coalbed methane resources. The region has well developed industries which require low cost energy supplies. Methane may be employed as an important fuel source to meet energy demands. Methane utilisation economic efficiency is estimated by applying a computerised model. Six major production associations of Kuzbass are reviewed and appropriate coalbed methane utilisation options are defined for them. Results obtained will contribute to the compilation of business plans for projects to be implemented at two Kuzbass mines. 3 refs., 4 figs., tabs

  7. Sorption of methane and CO2 for enhanced coalbed methane recovery and carbon dioxide seauestration

    Institute of Scientific and Technical Information of China (English)

    Basanta Kumar Prusty

    2008-01-01

    Sequestration of CO2 in deep and unmineable coal seams is one of the attractive alternatives to reduce its atmospheric concentration. Injection of CO2 in coal seams may help in enhancing the recovery of coalbed methane. An experimental study has been carried out using coal samples from three different coal seams, to evaluate the enhanced gas recovery and sequestration potential of these coals. The coals were first saturated with methane and then by depressurization some of the adsorbed methane was desorbed. After partial desorption, CO2 was injected into the coals and subsequently they were depressurized again. Desorption of methane after the injections was studied, to investigate the ability of CO2 to displace and enhance the recovery of methane from the coals. The coals exhibited varying behavior of adsorption of CO2 and release of methane. For one coal, the release of methane was enhanced by injection of CO2, suggesting preferential adsorption of CO2 and desorption of methane. For the other two coals, CO2 injection did not produce incremental methane initially, as there was initial resistance to methane release. However with continued CO2 injection, most of the remaining methane was produced. The study suggested that preferential sorption behavior of coal and enhanced gas recovery pattern could not be generalized for all coals.

  8. Evaluation of gas content of coalbed methane reservoirs with the aid of geophysical logging technology

    Energy Technology Data Exchange (ETDEWEB)

    Xuehai Fu; Yong Qin; Geoff G.X. Wang; Victor Rudolph [China University of Mining and Technology, Xuzhou (China). School of Mineral Resources and Geosciences

    2009-11-15

    The geophysical logging technology has been employed in connection with field and laboratory tests for coal reservoir evaluation in Huainan and Huaibei coalfields, China. The relationships between coalbed gas content of coal reservoir and characteristics of geophysical logs have been investigated by means of the combined analyses of experimental and geophysical logging data. Coalbed gas content of drilling core samples from coal seams was determined experimentally. The results, together with the log data obtained from geophysical logging technology, have been analyzed by using geological statistics, permitting correlation of the coalbed gas content to the log responses. The correlation developed in this study provides better understanding of the coal reservoir for coalbed methane exploration in given coalfields by an improved prediction of the coalbed gas content. 30 refs., 6 figs., 4 tabs.

  9. Thermogenic and secondary biogenic gases, San Juan Basin, Colorado and New Mexico - Implications for coalbed gas producibility

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A.R.; Kaiser, W.R. (Univ. of Texas, Austin, TX (United States)); Ayers, W.B. Jr. (Taurus Exploration, Inc., Birmingham, AL (United States))

    1994-08-01

    The objectives of this paper are to (1) describe the types and the major components of coalbed gases, (2) evaluate the variability of Fruitland coalbed gas composition across the basin, (3) assess factors affecting coalbed gas origin and composition, (4) determine the timing and extent of gas migration and entrapment, and (5) suggest application of these results to coalbed gas producibility. Data from more than 750 Fruitland coalbed gas wells were used to make gas-composition maps and to evaluate factors controlling gas origin. The gas data were divided into overpressured, underpressured, and transitional categories based on regional pressure regime. Also, [delta][sup 13]C isotopic values from 41 methane, 7 ethane and propane, 13 carbon dioxide, and 10 formation-water bicarbonate samples were evaluated to interpret gas origin. The data suggests that only 25-50% of the gas produced in the high-productivity fairway was generated in situ during coalification. 82 refs., 14 figs., 3 tabs.

  10. Distribution and fractionation mechanism of stable carbon isotope of coalbed methane

    Institute of Scientific and Technical Information of China (English)

    QIN Shengfei; TANG Xiuyi; SONG Yan; WANG Hongyan

    2006-01-01

    The stable carbon isotope values of coalbed methane range widely,and also are generally lighter than that of gases in normal coal-formed gas fields with similar coal rank.There exists strong carbon isotope fractionation in coalbed methane and it makes the carbon isotope value lighter.The correlation between the carbon isotope value and Ro in coalbed methane is less obvious.The coaly source rock maturity cannot be judged by coalbed methane carbon isotope value.The carbon isotopes of coalbed methane become lighter in much different degree due to the hydrodynamics.The stronger the hydrodynamics is,the lighter the CBM carbon isotopic value becomes.Many previous investigations indicated that the desorption-diffusion effects make the carbon isotope value of coalbed methane lighter.However,the explanation has encountered many problems.The authors of this article suggest that the flowing groundwater dissolution to free methane in coal seams and the free methane exchange with absorbed one is the carbon isotope fractionation mechanism in coalbed methane.The flowing groundwater in coal can easily take more 13CH4 away from free gas and comparatively leave more 12CH4.This will make 12CH4 density in free gas comparatively higher than that in absorbed gas.The remaining 12CH4 in free gas then exchanges with the adsorbed methane in coal matrix.Some absorbed 13CH4 can be replaced and become free gas.Some free 12CH4 can be absorbed again into coal matrix and become absorbed gas.Part of the newly replaced 13CH4 in free gas will also be taken away by water,leaving preferentially more 12CH4.The remaining 12CH4 in free gas will exchange again with adsorbed methane in the coal matrix.These processes occur all the time.Through accumulative effect,the 12CH4 will be greatly concentrated in coal.Thus,the stable carbon isotope of coalbed methane becomes dramatically lighter.Through simulation experiment on water-dissolved methane,it had been proved that the flowing water could fractionate the

  11. A Comprehensive Appraisal on the Characteristics of Coal-Bed Methane Reservoir in Turpan-Hami Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The rich coal-bed methane resources in the Turpan-Hami Basin are mainly located in the Shisanjianfang, Hami, Shanshan, Sha'erhu, Kekeya, Kerjian, Aidinghu inclines and the Dananhu coal-bed methane reservoirs.The bigger coal-bed reservoirs are sitting at a depth of less than 1500 m.The coalbed methane generation, storage and confining conditions of the Turpan-Hami basin can be indicated by eight key parameters.They are coal-bed thickness, coal rank, missing period, permeability, Langmuir volume, rock covering ability, structural confinement and hydrodynamic sealing environment.These parameters constitute a comprehensive appraisal index system of the coal-bed methane reservoir characteristics of the Turpan-Hami basin.In these parameters, the missing period of coal-bed methane is indicated by a stratum missing intensity factor.It reflects the relative exposure period of coal series.The results of a fuzzy comprehensive judgment showed that the Shisanjianfang coal-bed methane reservoir has the best prospects for exploitation and the Sha'erhu, Shanshan, Hami coal-bed methane reservoirs are next in line.

  12. Results from Coalbed Methane Drilling in Winn Parish, Louisiana

    Science.gov (United States)

    Hackley, Paul C.; Warwick, Peter D.; Breland, F. Clayton; Richard, Troy E.; Ross, Kirk

    2007-01-01

    A coalbed methane (CBM) well in Winn Parish, Louisiana, named CZ Fee A No. 114, was drilled by Vintage Petroleum, Inc., in January 2004. The CZ Fee A No. 114 CBM well was drilled to a total depth of 3,114 ft and perforated at 2,730-2,734 ft in a Wilcox Group (Paleocene-Eocene) coal bed. Analytical data from the drilling project have been released by Vintage Petroleum, Inc., and by the current well operator, Hilcorp Energy Corporation (see Appendix) to the Louisiana Geological Survey (LGS) and the U.S. Geological Survey (USGS) for publication. General information about the CZ Fee A No. 114 CBM well is compiled in Table 1, and analytical data from the well are included in following sections. The CZ Fee A No. 114 well is located in eastern Winn Parish, approximately 30 mi east of where Wilcox Group strata crop out on the Sabine Uplift (fig. 1). In the CZ Fee A No. 114 well, lower Wilcox Paleocene coal beds targeted for CBM production occur at depths of 2,600-3,000 ft (fig. 2). Average monthly gas production for the reporting period August 1, 2004, through May 1, 2005, was 450 thousand cubic feet (Mcf) (Louisiana Department of Natural Resources, 2005).

  13. Coal-bed methane in Alberta : ownership and incidental production

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, A.

    2006-04-05

    Some of the challenges facing the emerging coal-bed methane (CBM) industry in Alberta include concerns regarding water protection, compression noise, well spacing and fracturing issues. One of the most fundamental questions regarding CBM is who in fact owns the resource and what rules oversee its production. The characteristics, development potential and origins of split title ownership of CBM in North America were examined in this paper. The history of freehold and Crown-owned land and the law regarding ownership and incidental production of petroleum, natural gas and bitumen in split-title situations were reviewed. The legal status of CBM in other jurisdictions was also examined. The issues of ownership and incidental production in Alberta were also discussed. The basic common law ownership principles regarding mineral ownership were applied to the characteristics of CBM in situ to conclude its possible owner in Alberta. The extension of established incidental mineral production principles to CBM were examined in the context of its characteristics. The official governmental position on CBM issues and the prospect of future legislative intervention were identified and the implications for industry and resource companies were also presented. The paper presented several recommendations including that Alberta should legislate to eliminate any right of recovery for historical or current venting of CBM during coal mining in order to remove a cloud of uncertainty over the industry. refs.

  14. British Columbia's new coalbed methane royalty regime

    Energy Technology Data Exchange (ETDEWEB)

    Molinski, D. [British Columbia Ministry of Energy and Mines, Victoria, BC (Canada). Energy and Minerals Div.

    2002-07-01

    The British Columbia Ministry of Energy and Mines is promoting the development of the coalbed methane (CBM) industry in the province in order to make CBM a viable and competitive investment option for industry. It is establishing a regulatory and fiscal regime for CBM development. Issues of concern regarding CBM development include water production, gas production rates, well numbers, and marginal economics. The features of the CBM royalty regime include a new producer cost of service allowance, the creation of a CBM royalty tax bank to collect excess PCOS allowances, and a royalty tax credit for wells drilled by the end of February, 2004. The marginal well adjustment factor threshold has been raised from 180 mcf per day to 600 mcf per day for CBM only. It was noted that royalties will probably not be payable for several years following the first commercial well because royalties are very depending on capital and operating costs, local infrastructure and price. Royalty regimes cannot save CBM from low gas prices, poor resources or economics. 2 figs.

  15. Hydrodynamics of coalbed methane reservoirs in the Black Warrior Basin: Key to understanding reservoir performance and environmental issues

    Science.gov (United States)

    Pashin, J.C.

    2007-01-01

    The Black Warrior Basin of the southeastern United States hosts one of the world's most prolific and long-lived coalbed methane plays, and the wealth of experience in this basin provides insight into the relationships among basin hydrology, production performance, and environmental issues. Along the southeast margin of the basin, meteoric recharge of reservoir coal beds exposed in an upturned fold limb exerts a strong control on water chemistry, reservoir pressure, and production performance. Fresh-water plumes containing Na-HCO3 waters with low TDS content extend from the structurally upturned basin margin into the interior of the basin. Northwest of the plumes, coal beds contain Na-Cl waters with moderate to high-TDS content. Carbon isotope data from produced gas and mineral cements suggest that the fresh-water plumes have been the site of significant bacterial activity and that the coalbed methane reservoirs contain a mixture of thermogenic and late-stage biogenic gases. Water produced from the fresh-water plumes may be disposed safely at the surface, whereas underground injection has been used locally to dispose of highly saline water. Wells in areas that had normal hydrostatic reservoir pressure prior to development tend to produce large volumes of water and may take up to 4 a to reach peak gas production. In contrast, wells drilled in naturally underpressured areas distal to the fresh-water plumes typically produce little water and achieve peak gas rates during the first year of production. Environmental debate has focused largely on issues associated with hydrologic communication between deep reservoir coal beds and shallow aquifers. In the coalbed methane fields of the Black Warrior Basin, a broad range of geologic evidence suggests that flow is effectively confined within coal and that the thick intervals of marine shale separating coal zones limit cross-formational flow. ?? 2007 Elsevier Ltd. All rights reserved.

  16. Cleats and their relation to geologic lineaments and coalbed methane potential in Pennsylvanian coals in Indiana

    Energy Technology Data Exchange (ETDEWEB)

    Solano-Acosta, Wilfrido [Indiana Geological Survey, Indiana University, Bloomington, Indiana (United States); Department of Geological Sciences, Indiana University, Bloomington, Indiana (United States); Mastalerz, Maria [Indiana Geological Survey, Indiana University, Bloomington, Indiana (United States); Schimmelmann, Arndt [Department of Geological Sciences, Indiana University, Bloomington, Indiana (United States)

    2007-11-22

    Cleats and fractures in Pennsylvanian coals in southwestern Indiana were described, statistically analyzed, and subsequently interpreted in terms of their origin, relation to geologic lineaments, and significance for coal permeability and coalbed gas generation and storage. These cleats can be interpreted as the result of superimposed endogenic and exogenic processes. Endogenic processes are associated with coalification (i.e., matrix dehydration and shrinkage), while exogenic processes are mainly associated with larger-scale phenomena, such as tectonic stress. At least two distinct generations of cleats were identified on the basis of field reconnaissance and microscopic study: a first generation of cleats that developed early on during coalification and a second generation that cuts through the previous one at an angle that mimics the orientation of the present-day stress field. The observed parallelism between early-formed cleats and mapped lineaments suggests a well-established tectonic control during early cleat formation. Authigenic minerals filling early cleats represent the vestiges of once open hydrologic regimes. The second generation of cleats is characterized by less prominent features (i.e., smaller apertures) with a much less pronounced occurrence of authigenic mineralization. Our findings suggest a multistage development of cleats that resulted from tectonic stress regimes that changed orientation during coalification and basin evolution. The coals studied are characterized by a macrocleat distribution similar to that of well-developed coalbed methane basins (e.g., Black Warrior Basin, Alabama). Scatter plots and regression analyses of meso- and microcleats reveal a power-law distribution between spacing and cleat aperture. The same distribution was observed for fractures at microscopic scale. Our observations suggest that microcleats enhance permeability by providing additional paths for migration of gas out of the coal matrix, in addition to

  17. The coalbed methane production potential method for optimization of wells location selection

    Institute of Scientific and Technical Information of China (English)

    Feng-Ke DOU; Yong-Shang KANG; Shao-Feng QIN; De-Lei MAO; Jun HAN

    2013-01-01

    A gas production potential method for optimization of gas wellsite locations selection is proposed in terms of the coalbed gas resources volume and the recoverability.The method uses the actual data about reservoirs in a coalbed gas field in central China to optimize wellsite locations in the studied area in combination with the dynamic data about actual production in the coalbed gas field,selects a favorable subarea for gas wells deployment.The method is established based on the basic properties of coal reservoirs,in combination with the coalbed thickness and the gas content to make an analysis of the gas storage potential of a coal reservoir,as well as resources volume and the permeability of a coal reservoir.This method can be popularized for optimization of wellsite locations in other methane gas development areas or blocks.

  18. Something old, something new .... recent coalbed methane exploration in the Gunnedah Basin

    Energy Technology Data Exchange (ETDEWEB)

    Bunny, M.R.; Weber, C.R. [Earth Resources Aust Pty Ltd., St Leonards, NSW (Australia)

    1996-08-01

    Describes recent coalbed methane (CBM) exploration in the Gunnedah Basin, NSW (Australia). Covers data obtained from previous coal surveys (e.g. coal rank and permeability), initial CBM assessment wells, and magnetics, structure and stress and radiometrics data from an airborne survey. It is concluded that the possibilities for commercial CBM in the Gunnedah basin are excellent. 4 refs., 1 fig.

  19. Sage-Grouse and Coal-Bed Methane: Can They Coexist within the Powder River Basin?

    Science.gov (United States)

    Duncan, Michael B.

    2010-01-01

    Concerns are growing regarding the availability of sustainable energy sources due to a rapidly growing human population and a better understanding of climate change. In recent years, the United States has focused much attention on developing domestic energy sources, which include coal-bed methane (CBM). There are vast deposits of the natural gas…

  20. Experimental study of enhancing coalbed methane recovery by carbon dioxide injection driving methane

    Institute of Scientific and Technical Information of China (English)

    LUO Dao-cheng; LIU Jun-feng

    2010-01-01

    In order to enhance coalbed methane recovery, taking a self-developed largecale simulation system for the platform, a modeling experiment of driving CH4 by CO2 gas injection was studied. The results of experiment indicates that there is a significant lag effect of adsorption and desorption on gas, the gas pressure is changed more rapidly in the process of carbon dioxide adsorption of coal than methane adsorption of coal; After the injection of carbon dioxide, compare with methane single desorption. In an early stage,speed and amount of methane single desorption are greater than the speed and amount of displacement desorption, the speed and amount of displacement desorption became greater. In the process of replacement, CH4 concentration constantly declined, while CO2concentration constantly rose. In the process of CO2 gas injection, the temperature of coal have been significantly increased, it is more beneficial to make CH4 gas molecules become free from the adsorbed state when temperature is increased. Under the pressure step-down at the same rate, using the method of CO2 driving CH4, compared with the method of conventional pressure step-down, the desorption rate of CH4 in coal can be raised about 2.13 times, at the same time, a lot of greenhouse gas CO2 will also be buried in the ground, there is a very significant environmental benefit.

  1. The enrichment characteristics and geological controlling factors of coalbed methane occurrence in Laochang area, Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    WU Cai-fang; CHEN Zhao-ying; WANG Cong; JIANG Wei

    2012-01-01

    The enriched characters of methane content in the main coal seam of Yunnan's Laochang coal mine was analyzed through combined with the geologic conditions of the research area:structure type,hydrogeology condition,coal reservoir's macerals,ash,water content,and so on.The geology factors of controlling gas in Laochang coal mine were illustrated; and the different geology models of controlling gas of geologic condition coupling were posed.Research shows that,in the region,the methane contents of the main coal seams decrease gradually from middle to all around it; the northeast and southeast is higher than the west.In the local area,the methane content of anticline axis is higher,and the gas content is reduced to both wings and plunging crown.On macroscopic view,the distribution of methane content in coal-beds was controlled by structural type.On microscopic view,the methane content in coal-beds is mainly involved in coal reservoir's macerals,ash content,and water content.The enriched characters of CBM in the research area are mainly the result of structure-hydrogeology-petrophysics coupling controls of CBM.On the basis of above analysis,according to the distribution character of methane content in coalbeds,the research area was divided into low gas area,middle gas area,and high gas area.

  2. Numerical simulation of coal-bed methane transfer with finite element method

    Institute of Scientific and Technical Information of China (English)

    DAI Li-qiang(代立强); LIU Bao-yu(刘宝玉)

    2003-01-01

    The mathematical model and the numerical simulation for the transfer of coal-bed methane were established based on the combination of the porous flow theory and elastic-plastic mechanics theory and the numerical solution was given, together with the consideration of the fluid-solid interaction between the coal-bed gas and coal framework. Then the dispersion for the equation of gas porous flow and coal seam distortion was carried out and the functional analysis equation was obtained. Finally, the coupling solution was educed and calculated by finite element method(FEM) on a model example.

  3. Coal-Bed Methane Resource of Mesozoic Basins in Jiamusi Landmass

    Institute of Scientific and Technical Information of China (English)

    Cao Chengrun; Wu Wei; Zheng Qingdao

    2002-01-01

    As a new-replacement of energy resource, coal bed methane is the important gas resource with great strategic significance. There are several number of Mesozoic coal-bearing basins in Jiamusi landmass, eastern Heilongjiang Province. Theresult of the resource assessment revealed that the total resource less than 1 500 m,s depth in the area is about 2 100×108m3. It shows that Jiamusi landmass has great potential of coal-bed gas and is one of the most prospecting districts for developing coal-bed gas in CBM-province Northeast China.

  4. Exploitation technology of pressure relief coalbed methane in vertical surface wells in the Huainan coal mining area

    Institute of Scientific and Technical Information of China (English)

    HAN Jia-zhang; SANG Shu-xun; CHENG Zhi-zhong; HUANG Hua-zhou

    2009-01-01

    Exploitation technology of pressure relief coalbed methane in vertical surface wells is a new method for exploration of gas and coalbed methane exploitation in mining areas with high concentrations of gas, where tectonic coal developed. Studies on vertical surface well technology in the Huainan Coal Mining area play a role in demonstration in the use of clean, new energy re-sources, preventing and reducing coal mine gas accidents and protecting the environment. Based on the practice of gas drainage engineering of pressure relief coalbed methane in vertical surface wells and combined with relative geological and exploration en-gineering theories, the design principles of design and structure of wells of pressure relief coaibed methane in vertical surface wells are studied. The effects of extraction and their causes are discussed and the impact of geological conditions on gas production of the vertical surface wells are analyzed. The results indicate that in mining areas with high concentrations of gas, where tectonic coal developed, a success rate of pressure relief coalbed methane in surface vertical well is high and single well production usually great. But deformation due to coal exploitation could damage boreholes and cause breaks in the connection between aquifers and bore-holes, which could induce a decrease, even a complete halt in gas production of a single well. The design of well site location and wellbore configuration are the key for technology. The development of the geological conditions for coalbed methane have a sig-nificant effect on gas production of coalbed methane wells.

  5. Method for Determining the Coalbed Methane Content with Determination the Uncertainty of Measurements

    Science.gov (United States)

    Szlązak, Nikodem; Korzec, Marek

    2016-06-01

    Methane has a bad influence on safety in underground mines as it is emitted to the air during mining works. Appropriate identification of methane hazard is essential to determining methane hazard prevention methods, ventilation systems and methane drainage systems. Methane hazard is identified while roadways are driven and boreholes are drilled. Coalbed methane content is one of the parameters which is used to assess this threat. This is a requirement according to the Decree of the Minister of Economy dated 28 June 2002 on work safety and hygiene, operation and special firefighting protection in underground mines. For this purpose a new method for determining coalbed methane content in underground coal mines has been developed. This method consists of two stages - collecting samples in a mine and testing the sample in the laboratory. The stage of determining methane content in a coal sample in a laboratory is essential. This article presents the estimation of measurement uncertainty of determining methane content in a coal sample according to this methodology.

  6. The characteristic curve of methane adsorbed on coal and its role in the coalbed methane storage research

    Institute of Scientific and Technical Information of China (English)

    CUI Yongjun; LI Yuhui; ZHANG Qun; JIANG Wenping

    2005-01-01

    Based on the adsorption potential theory, this paper processes and analyzes the isothermal adsorption data at different temperatures of four coal samples with different ranks. The research results indicate that the adsorption characteristic curve of methane adsorbed on the coal sample is a single curve, and the mathematical expression of the methane adsorption capacity, temperature and pressure is achieved from the characteristic curve. According to the calculating routine and method presented, the adsorption capacity at other equilibrium conditions can be calculated from the adsorption data of one temperature. The results of this paper are a significant contribution to the research on the storage mechanism of the coalbed methane.

  7. Analytical solution of coal-bed methane migration with slippage effects in hvpotonic reservoir

    Institute of Scientific and Technical Information of China (English)

    XIAO Xiao-chun; PAN Yi-shan; YU Li-yan; JIANG Chun-yu

    2011-01-01

    Using theoretical analysis, the single-phase gas seepage mathematical model influenced by slippage effects was established. The results show that the pressure of producing wells attenuates more violently than the wells without slippage effects. The decay rate of reservoir pressure is more violent as the Klinkenberg factor increases. The gas prediction output gradually increases as the Klinenberg factor increases when considering gas slippage effects. Through specific examples, analyzed the law of stope pore pressure and gas output forecast changing in a hypotonic reservoir with slippage effects. The results have great theoretical significance in the study of the law of coal-bed methane migration in hypotonic reservoirs and for the exploitation of coal-bed methane.

  8. GEOLOGIC SCREENING CRITERIA FOR SEQUESTRATION OF CO2 IN COAL: QUANTIFYING POTENTIAL OF THE BLACK WARRIOR COALBED METHANE FAIRWAY, ALABAMA

    Energy Technology Data Exchange (ETDEWEB)

    Jack C. Pashin; Richard E. Carroll; Richard H. Groshong Jr.; Dorothy E. Raymond; Marcella McIntyre; J. Wayne Payton

    2004-01-01

    Sequestration of CO{sub 2} in coal has potential benefits for reducing greenhouse gas emissions from the highly industrialized Carboniferous coal basins of North America and Europe and for enhancing coalbed methane recovery. Hence, enhanced coalbed methane recovery operations provide a basis for a market-based environmental solution in which the cost of sequestration is offset by the production and sale of natural gas. The Black Warrior foreland basin of west-central Alabama contains the only mature coalbed methane production fairway in eastern North America, and data from this basin provide an excellent basis for quantifying the carbon sequestration potential of coal and for identifying the geologic screening criteria required to select sites for the demonstration and commercialization of carbon sequestration technology. Coalbed methane reservoirs in the upper Pottsville Formation of the Black Warrior basin are extremely heterogeneous, and this heterogeneity must be considered to screen areas for the application of CO{sub 2} sequestration and enhanced coalbed methane recovery technology. Major screening factors include stratigraphy, geologic structure, geothermics, hydrogeology, coal quality, sorption capacity, technology, and infrastructure. Applying the screening model to the Black Warrior basin indicates that geologic structure, water chemistry, and the distribution of coal mines and reserves are the principal determinants of where CO{sub 2} can be sequestered. By comparison, coal thickness, temperature-pressure conditions, and coal quality are the key determinants of sequestration capacity and unswept coalbed methane resources. Results of this investigation indicate that the potential for CO{sub 2} sequestration and enhanced coalbed methane recovery in the Black Warrior basin is substantial and can result in significant reduction of greenhouse gas emissions while increasing natural gas reserves. Coal-fired power plants serving the Black Warrior basin in

  9. Analytical results from samples collected during coal-bed methane exploration drilling in Caldwell Parish, Louisiana

    Science.gov (United States)

    Warwick, Peter D.; Breland, F. Clayton; Hackley, Paul C.; Dulong, Frank T.; Nichols, Douglas J.; Karlsen, Alexander W.; Bustin, R. Marc; Barker, Charles E.; Willett, Jason C.; Trippi, Michael H.

    2006-01-01

    In 2001, and 2002, the U.S. Geological Survey (USGS) and the Louisiana Geological Survey (LGS), through a Cooperative Research and Development Agreement (CRADA) with Devon SFS Operating, Inc. (Devon), participated in an exploratory drilling and coring program for coal-bed methane in north-central Louisiana. The USGS and LGS collected 25 coal core and cuttings samples from two coal-bed methane test wells that were drilled in west-central Caldwell Parish, Louisiana. The purpose of this report is to provide the results of the analytical program conducted on the USGS/LGS samples. The data generated from this project are summarized in various topical sections that include: 1. molecular and isotopic data from coal gas samples; 2. results of low-temperature ashing and X-ray analysis; 3. palynological data; 4. down-hole temperature data; 5. detailed core descriptions and selected core photographs; 6. coal physical and chemical analytical data; 7. coal gas desorption results; 8. methane and carbon dioxide coal sorption data; 9. coal petrographic results; and 10. geophysical logs.

  10. Biogenic methane potential of marine sediments. Application of chemical thermodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Arning, E.T.; Schulz, H.M. [Helmholtz Centre Potsdam GFZ, Potsdam (Germany); Berk, W. van [Technical Univ. of Clausthal (Germany). Dept. of Hydrogeology

    2013-08-01

    Accumulations of biogenic methane-dominated gas are widespread and occur in a variety of depositional settings and rock types. However, the potential of biogenic methane remains underexplored. This is mainly due to the fact that quantitative assessments applying numerical modeling techniques for exploration purposes are generally lacking to date. Biogenic methane formation starts in relatively shallow marine sediments below the sulfate reduction zone. When sulfate is exhausted, methanogenesis via the CO{sub 2} reduction pathway is often the dominant biogenic methane formation process in marine sediments (Claypool and Kaplan, 1974). The process can be simplified by the reaction: 2CH{sub 2}O + Ca{sup 2+} + H{sub 2}O {yields} CH{sub 4} + CaCO{sub 3} + 2H{sup +}. The products of early diagenetic reactions initiate coupled equilibrium reactions that induce a new state of chemical equilibrium among minerals, pore water and gas. The driving force of the complex biogeochemical reactions in sedimentary environments during early diagenesis is the irreversible redox-conversion of organic matter. Early diagenetic formation of biogenic methane shortly after deposition ('early diagenesis') was retraced using PHREEQC computer code that is applied to calculate homogenous and heterogeneous mass-action equations in combination with one-dimensional diffusion driven transport (Parkhurst and Appelo, 1999). Our modeling approach incorporates interdependent diagenetic reactions evolving into a diffusive multi-component and multiphase system by means of thermodynamic equilibrium calculations of species distribution (Arning et al., 2011, 2012, 2013). Reaction kinetics of organic carbon conversion is integrated into the set of equilibrium reactions by defining type and amount of converted organic matter in a certain time step. It is the aim (1) to calculate quantitatively thermodynamic equilibrium conditions (composition of pore water, mineral phase and gas phase assemblage) in

  11. Optimization of enhanced coal-bed methane recovery using numerical simulation

    Science.gov (United States)

    Perera, M. S. A.; Ranjith, P. G.; Ranathunga, A. S.; Koay, A. Y. J.; Zhao, J.; Choi, S. K.

    2015-02-01

    Although the enhanced coal-bed methane (ECBM) recovery process is one of the potential coal bed methane production enhancement techniques, the effectiveness of the process is greatly dependent on the seam and the injecting gas properties. This study has therefore aimed to obtain a comprehensive knowledge of all possible major ECBM process-enhancing techniques by developing a novel 3D numerical model by considering a typical coal seam using the COMET 3 reservoir simulator. Interestingly, according to the results of the model, the generally accepted concept that there is greater CBM (coal-bed methane) production enhancement from CO2 injection, compared to the traditional water removal technique, is true only for high CO2 injection pressures. Generally, the ECBM process can be accelerated by using increased CO2 injection pressures and reduced temperatures, which are mainly related to the coal seam pore space expansion and reduced CO2 adsorption capacity, respectively. The model shows the negative influences of increased coal seam depth and moisture content on ECBM process optimization due to the reduced pore space under these conditions. However, the injection pressure plays a dominant role in the process optimization. Although the addition of a small amount of N2 into the injecting CO2 can greatly enhance the methane production process, the safe N2 percentage in the injection gas should be carefully predetermined as it causes early breakthroughs in CO2 and N2 in the methane production well. An increased number of production wells may not have a significant influence on long-term CH4 production (50 years for the selected coal seam), although it significantly enhances short-term CH4 production (10 years for the selected coal seam). Interestingly, increasing the number of injection and production wells may have a negative influence on CBM production due to the coincidence of pressure contours created by each well and the mixing of injected CO2 with CH4.

  12. Source and Cycling of Trace Metals and Nutrients in a Microbial Coalbed Methane System

    Science.gov (United States)

    Earll, M. M.; Barnhart, E. P.; Ritter, D.; Vinson, D. S.; Orem, W. H.; Vengosh, A.; McIntosh, J. C.

    2015-12-01

    The source and cycling of trace metals and nutrients in coalbed methane (CBM) systems are controlled by both geochemical processes, such as dissolution or precipitation, and biological mediation by microbial communities. CBM production by the microbes is influenced by trace metals and macronutrients such as nitrogen (N) and phosphate (P). Previous studies have shown the importance of these nutrients to both enhance and inhibit methane production; however, it's not clear whether they are sourced from coal via in-situ biodegradation of organic matter or transported into the seams with groundwater recharge. To address this knowledge gap, trace metal and nutrient geochemistry and the organic content of solid coal and associated groundwater will be investigated across a hydrologic gradient in CBM wells in the Powder River Basin, MT. Sequential dissolution experiments (chemical extraction of organic and inorganic constituents) using 8 core samples of coal and sandstone will provide insight into the presence of trace metals and nutrients in coalbeds, the associated minerals present, and their mobilization. If significant concentrations of N, P, and trace metals are present in core samples, in-situ sourcing of nutrients by microbes is highly probable. The biogeochemical evolution of groundwater, as it relates to trace metal and nutrient cycling by microbial consortia, will be investigated by targeting core-associated coal seams from shallow wells in recharge areas to depths of at least 165 m and across a 28 m vertical profile that include overburden, coal, and underburden. If microbial-limiting trace metals and nutrients are transported into coal seams with groundwater recharge, we would expect to see higher concentrations of trace metals and nutrients in recharge areas compared to deeper coalbeds. The results of this study will provide novel understanding of where trace metals and nutrients are sourced and how they are cycled in CBM systems.

  13. The Republic of the Philippines coalbed methane assessment: based on seventeen high pressure methane adsorption isotherms

    Science.gov (United States)

    Flores, Romeo M.; Stricker, Gary D.; Papasin, Ramon F.; Pendon, Ronaldo R.; del Rosario, Rogelio A.; Malapitan, Ruel T.; Pastor, Michael S.; Altomea, Elmer A.; Cuaresma, Federico; Malapitan, Armando S.; Mortos, Benjamin R.; Tilos, Elizabeth N.

    2006-01-01

    Introduction: The Republic of the Philippines has some 19 coal districts that contain coal deposits ranging from Eocene to Pleistocene in age. These coal districts include: (1) Catanduanes (Eocene); (2) Cebu, Zamboanga Sibuguey, Bukidnon, Maguindanao, Sarangani, and Surigao (Oligocene to Miocene); (3) Batan Island, Masbate, Semirara (including Mindoro), and Quezon-Polilio (lower-upper Miocene); (4) Davao, Negros, and Sorsogon (middle-upper Miocene); (5) Cotabato (lower Miocene-lower Pliocene), Cagayan-Isabella, and Quirino (upper Miocene-Pliocene); (6) Sultan Kudarat (upper Miocene-Pleistocene); and (7) Samar-Leyte (lower Pliocene-Pleistocene). In general, coal rank is directly related to the age of the deposits - for example, the Eocene coal is semi-anthracite and the Pliocene-Pleistocene coal is lignite. Total coal resources in these 19 coal districts, which are compiled by the Geothermal and Coal Resources Development Division (GCRDD) of the Department of Energy of the Philippines, are estimated at a minimum of 2,268.4 million metric tonnes (MMT) (approximately 2.3 billion metric tones). The largest resource (550 MMT) is the subbituminous coal in the Semirara (including Mindoro) coal district, and the smallest (0.7 MMT) is the lignite-subbituminous coal in the Quirino coal district. The combined lignite and subbituminous coal resources, using the classification by GCRDD and including Semirara and Surigao coal districts, are about 1,899.2 MMT, which make up about 84 percent of the total coal resources of the Philippines. The remaining resources are composed of bituminous and semi-anthracite coal. The subbituminous coal of Semirara Island in the Mindoro- Semirara coal district (fig. 2) is known to contain coalbed methane (CBM), with the coal being comparable in gas content and adsorption isotherms to the coal of the Paleocene Fort Union Formation in the Powder River Basin in Wyoming, USA (Flores and others, 2005). As a consequence, the presence of CBM in the

  14. Method for predicting economic peak yield for a single well of coalbed methane

    Institute of Scientific and Technical Information of China (English)

    YANG Shen; KANG Yong-shang; ZHAO Qun; WANG Hong-yan; LI Jing-ming

    2008-01-01

    The development of coalbed methane (CBM) in China poses great difficulties because of high investments, low production and high risks. So a study of the economic effect of a single well at its preliminary stage is helpful for commercial exploitation of CBM. Affected by wellbore flow pressure, initial reservoir pressure, relative permeability, Langmuir pressure and other factors,the trend of declining production of a single CBM well agrees, by and large, with a hyperbolic pattern of decline. Based on Arps'sequation, nearly 200 wells production with different peak yields and initial rates of were simulated. Given the present cost of drilling, gas production and engineering on the ground, the gross investment for the development of a single coalbed methane well was estimated for the Fanzhuang block in central China. Considering the current industrial policies for CBM, we established an economic assessment model and analyzed economic peaks. The results show the economic benefits with or without government subsidies at different peak yields of a single CBM well. The results of the evaluation can be directly applied in the Fanzhuang block. The evaluation method, formulated in our study, can be used to other areas with similar conditions.

  15. Reconstruction of a Nearly Complete Pseudomonas Draft Genome Sequence from a Coalbed Methane-Produced Water Metagenome

    Science.gov (United States)

    2016-01-01

    The draft genome sequence of Pseudomonas stutzeri strain K35 was separated from a metagenome derived from a produced water microbial community of a coalbed methane well. The genome encodes a complete nitrogen fixation pathway and the upper and lower naphthalene degradation pathways.

  16. CBM in 3-D: coalbed methane multicomponent 3-D reservoir characterisation study, Cedar Hill Field, San Juan Basin, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Davis, T.; Shuck, E.; Benson, R. [Colorado School of Mines, Golden, CO (United States). Dept. of Geophysics

    1995-10-01

    The article explains how 3-D multicomponent seismic surveys could substantially improve the production and development of fractured coalbed methane reservoirs. The technique has been used by Northern Geophysical for the detection of geological faults and zones of enhanced fracture permeability proximal to the fault in the western side of the Cedar Hill field in San Juan Basin, NM, USA. 3 figs.

  17. Reconstruction of a Nearly Complete Pseudomonas Draft Genome Sequence from a Coalbed Methane-Produced Water Metagenome

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Daniel E. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Gulliver, Djuna [AECOM Technology Corporation, Pittsburgh, PA (United States)

    2016-10-06

    The draft genome sequence ofPseudomonas stutzeristrain K35 was separated from a metagenome derived from a produced water microbial community of a coalbed methane well. The genome encodes a complete nitrogen fixation pathway and the upper and lower naphthalene degradation pathways.

  18. Research progress in studies on the coalbed gas geochemistry

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The current situation of geochemical studies on coalbed gas is reviewed in this paper. Generally, coalbed gas is compositionally dominated by methane with δ13C1 values ranging approximately from - 80‰ to - 10‰. However, few isotopic studies have been carried out on other components of coalbed gas except for hydrogen and carbon dioxide, whose δDCH4 values available for utilization vary from - 333‰ to - 117‰, and δ13CCO2 values from -29.4‰ to + 18.6‰. Two major types of coalbed gas, thermogenic gas and secondary biogenic gas, have been identified, and there are also some other classification criteria. Compared with conventional natural gases,coalbed gas has a wide distribution range of δ13C1 andδ13CCO2 values, especially possessing some extremely heavy values. Current problems that remain unsolved in the coalbed gas geochemistry include the variation mechanism, controlling factors and application of carbon and hydrogen isotopes of methane, the relation between the values of δ13C1 and Ro, the systematic classification scheme and criterion of genetic types, and the application of the coalbed gas geochemistry in evaluating target districts of the coalbed gas exploration.

  19. AVO analysis and modeling applied to fracture detection in coalbed methane reservoirs, Cedar Hill Field, San Juan basin, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, A.C.B. [Petrobras, Rio de Janeiro (Brazil); Davis, T.L.; Anderson, J.E.; Benson, R.D. [Colorado School of Mines, Golden, CO (United States)

    1994-12-31

    The Cedar Hill Field in the San Juan Basin, New Mexico, produces methane from fractured coalbed of the Fruitland Formation. The presence of fracturing is critical to methane production due to the absence of matrix permeability in the coals. To help characterize this coalbed reservoir a three-dimensional, multicomponent seismic survey was acquired in this field. Prestack P-wave amplitude data are used to delineate zones of larger Poisson`s ratio contrasts (or higher crack densities) in coalbed methane reservoir, while source-receiver azimuth sorting is used to detect preferential directions of azimuthal anisotropy. Two modeling techniques (using ray tracing and reflectivity methods) predict the effects of fractured coal-seam zones on non-normal P-wave reflectivity. Synthetic CMP gathers are generated for a horizontally layered earth model, which uses elastic parameters derived from sonic and density log measurements. Fracture density variations in the coalbeds are simulated by anisotropic modeling. The large acoustic impedance contrasts associated with the sandstone/coal interfaces dominate the P-wave reflectivity response. They far outweigh the effects of contrasts in anisotropy parameters, for the computed models. Seismic AVO analysis of nine macrobins obtained from the 3-D volume confirms model predictions. Areas with large AVO productions identify coal zones with large Poisson`s ratio contrast, therefore high fracture density.

  20. Biodegradation of sedimentary organic matter associated with coalbed methane in the Powder River and San Juan Basins, U.S.A.

    Energy Technology Data Exchange (ETDEWEB)

    Formolo, Michael; Petsch, Steven [Department of Geosciences, University of Massachusetts, Amherst, MA, 01003-9297 (United States); Martini, Anna [Department of Geology, Amherst College, Amherst, MA, 01002 (United States)

    2008-10-02

    The Powder River Basin and San Juan Basin, U.S.A., are two of the most productive coalbed methane reserves in the world. Of particular interest is the microbial biodegradation of coal beds associated with this natural gas production. Biogenic methane production is indicated as a significant component to the total gas resources in the San Juan Basin, and as the nearly sole source for the shallow coals of the Powder River Basin. Molecular and isotopic signatures indicate a microbial origin for the gas. Geochemical characteristics of formation waters, such as elevated alkalinity and {sup 13}C-enriched dissolved inorganic carbon (DIC), further support extensive microbial degradation of coal organic matter associated with methanogenesis. Extractable organic matter isolated from coals in both basins point to patterns of hydrocarbon biodegradation in coals restricted to specific depths. To some extent, biodegradation patterns are similar to those observed in methanogenic, biodegraded black shales of the mid-continent of the United States. Specifically, both coals and shales exhibit near-quantitative removal of straight-chain and acyclic isoprenoid hydrocarbons. However, loss of aromatic hydrocarbons in the coals proceeds prior to the extensive removal of the saturated hydrocarbons, in contrast to what is conventionally observed in biodegraded petroleum systems or in black shales. In addition, previous thermal maturation histories in both the Fruitland and Fort Union coalbed methane systems have little impact on more recent hydrocarbon biodegradation. Instead, localized hydrologic conditions and subsurface geology likely play important roles in controlling the extents of biodegradation and methanogenesis. These results suggest that biodegradation of hydrocarbons coupled with methanogenesis may develop regardless of organic matter source across a range of inherited thermal maturities. (author)

  1. Evaluation of the seismic reflection method as a monitoring tool during primary and enhanced coalbed methane production

    Science.gov (United States)

    Lespinasse Fung, Diane Jael

    In this thesis I present an evaluation of the seismic reflection method as a monitoring tool during coalbed methane (CBM) production and enhanced coalbed methane (ECBM) production by CO2 injection. This evaluation is based on a workflow previously developed for monitoring CO2 storage in the Big George coalbeds in the Powder River Basin. I study the changes in seismic and the AVO response associated with coalbeds during primary production using a data set from the Mannville coals, which represent one of the most important CBM resources in the Province of Alberta. Using published data, I perform a single well flow simulation to make an assessment of its production forecast in a 10 year period. The flow simulation provides information on methane saturation and reservoir pressure during production, while the changes in porosity and permeability due to depletion are estimated according to the Palmer and Mansoori permeability model. Using well log data of the Corbett Field and the results of the flow simulation, I complete a Gassmann fluid substitution to replace brine by a mixture of brine and methane in the pore space and estimate the variations in Vp, Vs and density due to changes in fluid saturation. I evaluate offset dependent synthetic seismograms before and after fluid substitution, and I use different coalbed thicknesses to establish resolution limits. To observe significant changes in the character and phase of the wavelet due to the replacement of brine by methane I find that coalbed thickness must be at least 10 m, also in terms of AVO I observe that there is a decrease in amplitude with offset caused by the presence of methane in the pore space. Using the same methodology and production data from the Fruitland Coals Fairway in the North of the San Juan Basin U.S.A, which is considered the most productive CBM reservoir in the world, I evaluate Elastic Impedance (EI) and Elastic Impedance Coefficient (EC) response during ECBM by CO2 injection. In this case, I

  2. Influence of liquid water on coalbed methane adsorption: An experimental research on coal reservoirs in the south of Qinshui Basin

    Institute of Scientific and Technical Information of China (English)

    SANG Shuxun; ZHU Yanming; ZHANG Jing; ZHANG Xiaodong; ZHANG Shiyin

    2005-01-01

    Using Isothermal Adsorption/Desorption System Model IS-100 and Electrohydraulic Servo Rock System Model MTS815 as the main apparatuses and collecting samples from the major coal reservoirs in the south of Qinshui Basin, a hot point region of coalbed methane exploration, the paper carries out systematical comparisons of the isothermal adsorption experimental data for injection water coal sampies, equilibrium moisture samples and dry coal samples,probes and establishes an experimental method of injection water coal sample preparation and isothermal experiment to simulate real reservoir conditions, and then summaries the experimental regulations and discusses the mechanism of liquid water influencing coal methane adsorption. Results of the experiment indicate that: The Langmuir volume of injection water coal samples is notably larger than that of equilibrium moisture samples, as well as larger than or equivalent to that of dry coal samples; the Langmuir pressure of injection water coal samples is the highest, the next is equilibrium moisture samples, while the dry samples is the lowest, of which the experimental results of injection water samples to simulate real reservoir conditions are more close to the fact.Under the conditions of in-position reservoirs, liquid water in coals has evident influence on methane adsorption ability of coal matrix, which can increase the adsorbability of coal and make the adsorption regulation fit to Langmuir model better.Its major reason is the increase of wetting coal matrix adsorbability. The above experimental results overthrow the conventional cognition that liquid water has no influence on coalbed methane adsorption, which may lead to an improvement of the coalbed methane isothermal adsorption experimental method and of the reliability of coalbed methane resource evaluation and prediction.

  3. Coalbed methane : Canadian potential : is it analogous to the U.S.

    Energy Technology Data Exchange (ETDEWEB)

    Gatens, M. [MGV Energy Inc., Calgary, AB (Canada)

    2003-07-01

    A historical review of coalbed methane (CBM) evolution in North America was presented with reference to development in Canada and recent advances in technology. The Canadian CBM resource is estimated at several hundred Tcf. It was noted that the characteristics of CBM development in Canada are unique. The issues faced in Canadian CBM basins are different from those in the United States. Non-technical issues, such as CBM ownership and environmental concerns in the United States are having a growing impact on the pace of Canadian CBM development. For example, the problem of handling produced water in the Powder River Basin is inhibiting Canadian CBM development. However, the author pointed out that there is no produced water in Canadian CBM development. The author emphasized that stakeholders should be educated in Canadian CBM facts to ensure that CBM development in Canada proceeds responsibly, without confusion of U.S. issues that are non-issues in Canada.

  4. Numerical Simulation of CO2 Flooding of Coalbed Methane Considering the Fluid-Solid Coupling Effect.

    Directory of Open Access Journals (Sweden)

    Jianjun Liu

    Full Text Available CO2 flooding of coalbed methane (CO2-ECBM not only stores CO2 underground and reduces greenhouse gas emissions but also enhances the gas production ratio. This coupled process involves multi-phase fluid flow and coal-rock deformation, as well as processes such as competitive gas adsorption and diffusion from the coal matrix into fractures. A dual-porosity medium that consists of a matrix and fractures was built to simulate the flooding process, and a mathematical model was used to consider the competitive adsorption, diffusion and seepage processes and the interaction between flow and deformation. Due to the effects of the initial pressure and the differences in pressure variation during the production process, permeability changes caused by matrix shrinkage were spatially variable in the reservoir. The maximum value of permeability appeared near the production well, and the degree of rebound decreased with increasing distance from the production well.

  5. Gas productivity related to cleat volumes derived from focused resistivity tools in coalbed methane (CBM) fields

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Y.H.; Peeters, M.; Cloud, T.A.; Van Kirk, C.W. [Kerr McGee Rocky Mountain Corporation, Denver, CO (United States)

    2006-06-15

    Cleats are critical for coal-bed methane (CBM) production, but operators usually lack a viable method to determine productivity except for costly well tests. Wireline logs, run over the CBM deposits of the Drunkards Wash Unit located in the Uinta Basin of Utah, were used to develop a new method to relate productivity to the cleat volume. The latter is derived from a focused resistivity log and the wellbore-fluid resistivity. Induction tools are unsuitable for this method, because they are dominated by borehole effects in high resistivity coals and low resistivity mud. Moreover, they read too deep to be significantly affected by the substitution of formation fluid by borehole fluid in the cleats on which the method is based. The method was demonstrated by relating cleat volume to CBM gas productivity in 24 wells, an exercise that clearly separated good from poor producers.

  6. Monte-Carlo Method for Coalbed Methane Resource Assessment in Key Coal Mining Areas of China

    Institute of Scientific and Technical Information of China (English)

    Yang Yongguo; Chen Yuhua; Qin Yong; Cheng Qiuming

    2008-01-01

    Monte-Carlo method is used for estimating coalbed methane (CBM) resources in key coal mining areas of China. Monte-Carlo method is shown to be superior to the traditional volumetric method with constant parameters in the calculation of CBM resources. The focus of the article is to introduce the main algorithm and the realization of functions estimated by Monte-Carlo method, including selection of parameters, determination of distribution function, generation of pseudo-random numbers, and evaluation of the parameters corresponding to pseudo-random numbers. A specified software on the basis of Monte-Carlo method is developed using Visual C++ for the assessment of the CBM resources. A case study shows that calculation results using Monte-Carlo method have smaller error range in comparison with those using volumetric method.

  7. Analysis for pressure transient of coalbed methane reservoir based on Laplace transform finite difference method

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2015-09-01

    Full Text Available Based on fractal geometry, fractal medium of coalbed methane mathematical model is established by Langmuir isotherm adsorption formula, Fick's diffusion law, Laplace transform formula, considering the well bore storage effect and skin effect. The Laplace transform finite difference method is used to solve the mathematical model. With Stehfest numerical inversion, the distribution of dimensionless well bore flowing pressure and its derivative was obtained in real space. According to compare with the results from the analytical method, the result from Laplace transform finite difference method turns out to be accurate. The influence factors are analyzed, including fractal dimension, fractal index, skin factor, well bore storage coefficient, energy storage ratio, interporosity flow coefficient and the adsorption factor. The calculating error of Laplace transform difference method is small. Laplace transform difference method has advantages in well-test application since any moment simulation does not rely on other moment results and space grid.

  8. Geothermal field and its relation with coalbed methane distribution of the Qinshui Basin

    Institute of Scientific and Technical Information of China (English)

    SUN Zhanxue; ZHANG Wen; HU Baoqun; LI Wenjuan; PAN Tianyou

    2005-01-01

    The average geothermal gradient in the Qinshui Basin, Shanxi Province, North China, estimated from temperature logging data of 20 boreholes is 28.2±1.03℃/km.The thermal conductivities of 39 rock samples are measured and 20 heat flow values are obtained. The estimated heat flow ranges from 44.75 mW/m2 to 101.81 mW/m2, with a mean of 62.69±15.20 mW/m2. The thermal history reconstruction from the inversion of vitrinite data, using Thermodel for Windows 2004, reveals that the average paleo-heat flow at the time of maximum burial in late Jurassic to early Cretaceous is 158.41 mW/m2 for the north part, 119.57mW/m2 for the central part and 169.43 mW/m2 for the south part of the basin respectively. The reconstruction of the buried history of the strata indicates that the age for the end of sedimentation and the beginning of erosion for the basin is 108-156 Ma, and that the eroded thickness of the strata is 2603 m in the north, 2291 m in the central, and 2528.9 m in the south of the basin respectively. The "higher in the north and the south, lower in the central" distribution pattern of the paleo-heat flow coincides with the distribution of the coal-bed methane spatially and temporally, which shows that the coal-bed methane is controlled by the paleo-geotemperature field in the basin.

  9. Coal-Bed Methane Water Effects on Dill and Its Essential Oils.

    Science.gov (United States)

    Poudyal, Shital; Zheljazkov, Valtcho D; Cantrell, Charles L; Kelleners, Thijs

    2016-03-01

    Pumping water from coal seams decreases the pressure in the seam and in turn releases trapped methane; this is the most common and economic method of methane extraction. The water that is pumped out is known as "coal-bed methane water" (CBMW), which is high in sodium and other salts. In the past 25 yr, the United States has seen a 16-fold increase in the production of coal bed methane gas, and trillions of cubic meters are yet to be extracted. There is no sustainable disposal method for CBMW, and there are very few studies investigating the effects of this water on plants and their secondary metabolites and on soil properties. This study was conducted to determine the effects of CBMW on soil chemical properties and on the biomass and essential oil yield and composition of dill ( L.). This crop was grown in a greenhouse and was subjected to different levels of CBMW treatment: tap water only; 25% CBMW, 75% tap water; 50% CBMW, 50% tap water; 75% CBMW, 25% tap water; and 100% CBMW. The major dill oil constituents, limonene and α-phellandrene, were not affected by the treatments; however, the concentration of dill ether increased with increasing CBMW levels, whereas the concentration of carvone decreased. In soil, sodium level significantly increased with increasing level of treatment, but pH and cation exchange capacity were not much affected. Coal bed methane water could be used for irrigation of dill for one growing season, but longer-term studies may be needed to clarify the long-term effects on soil and plant.

  10. Application of Seismic Anisotropy Caused by Fissures in Coal Seams to the Detection of Coal-bed Methane Reservoirs

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Coal-bed methane is accumulated in micro-fissures and cracks in coal seams. The coal seam is the source terrace and reservoir bed of the coal-bed methane (Qian et al., 1996). Anisotropy of coal seams is caused by the existence of fissures. Based on the theory of S wave splitting: an S wave will be divided into two S waves with nearly orthogonal polarization directions when passing through anisotropic media, i.e. the fast S wave with its direction of propagation parallel to that of the fissure and slow S wave with the direction of propagation perpendicular to that of the fissure.This paper gives the results of laboratory research and field test on the S wave splitting caused by coal-seam fissures. The results show that it is feasible to detect fissures in coal seams by applying the converted S wave and finally gives the development zone and development direction of these fissures.

  11. Drilling and Testing the DOI041A Coalbed Methane Well, Fort Yukon, Alaska

    Science.gov (United States)

    Clark, Arthur; Barker, Charles E.; Weeks, Edwin P.

    2009-01-01

    The need for affordable energy sources is acute in rural communities of Alaska where costly diesel fuel must be delivered by barge or plane for power generation. Additionally, the transport, transfer, and storage of fuel pose great difficulty in these regions. Although small-scale energy development in remote Arctic locations presents unique challenges, identifying and developing economic, local sources of energy remains a high priority for state and local government. Many areas in rural Alaska contain widespread coal resources that may contain significant amounts of coalbed methane (CBM) that, when extracted, could be used for power generation. However, in many of these areas, little is known concerning the properties that control CBM occurrence and production, including coal bed geometry, coalbed gas content and saturation, reservoir permeability and pressure, and water chemistry. Therefore, drilling and testing to collect these data are required to accurately assess the viability of CBM as a potential energy source in most locations. In 2004, the U.S. Geological Survey (USGS) and Bureau of Land Management (BLM), in cooperation with the U.S. Department of Energy (DOE), the Alaska Department of Geological and Geophysical Surveys (DGGS), the University of Alaska Fairbanks (UAF), the Doyon Native Corporation, and the village of Fort Yukon, organized and funded the drilling of a well at Fort Yukon, Alaska to test coal beds for CBM developmental potential. Fort Yukon is a town of about 600 people and is composed mostly of Gwich'in Athabascan Native Americans. It is located near the center of the Yukon Flats Basin, approximately 145 mi northeast of Fairbanks.

  12. Drainage feature about coalbed methane wells in different hydrogeological conditions in Fanzhuaug area

    Institute of Scientific and Technical Information of China (English)

    NI Xiao-ming; LIN Ran; WANG Yan-bin

    2012-01-01

    It is aa important guarantee to enhance the production of coalbed methane (CBM) and reduce the project investment by finding out the drainage feature about CBM wells in different hydrogeological conditions.Based on the CBM exploration and development data on the Fanzhuang block in southeast Qinshui Basin and combined with the seepage principle and lithology on the roof and the bottom coalbed,the mathematical model of integrated permeability was established.By permeability experiments of the different lithologies on the roof and the floor within the 20 m range combined with the log curves,the integrated permeability of different lithological combinations were obtained.The starting pressure gradient and permeability of the roof and the floor for different lithologies was tested by "differential pressure-flow method".The relationships between the starting pressure gradient and the integrated permeability were obtained.The critical distance of limestone water penetrating into coal reservoirs was calculated.According to the drainage feature of CBM wells combined with the drainage data of some CBM wells,the results show that,when limestone water can penetrate into coal reservoirs,the daily water production is high and the daily gas production is low although there is no gas at the beginning of the drainage process,the CBM wells stop discharging water within 6 months after the gas began to come out,and the gas production is steadily improved.When limestone water can not penetrate into coal reservoirs,the daily water production is low and the daily gas production is high at the beginning of the drainage process,and it almost stops discharging water after some time when the gas come out,the daily gas production increases,and the cumulative water production is much lower.

  13. Multi-Layer Superposed Coalbed Methane System in Southern Qinshui Basin, Shanxi Province, China

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhang; Yong Qin; Xuehai Fu; Zhaobiao Yang; Chen Guo

    2015-01-01

    Multi-coalbed developed in Carboniferous–Permian coal-bearing strata of southern Qinshui Basin, and different coal-bearing segments have different coalbed methane (CBM) reservoiring characteristics. Analysis of previous studies suggests that the essence of an unattached CBM system is to possess a unified fluid pressure system, which includes four key elements, namely, gas-bearing coal-rock mass, formation fluid, independent hydrodynamic system and capping layer condition. Based on the exploration and exploitation data of CBM, it is discovered that the gas content of coal seams in southern Qinshui Basin presents a change rule of non-monotonic function with the seam dipping, and a turning point of the change appears nearby coal seam No. 9, and coal seams of the upper and the lower belong to different CBM systems respectively; well test reservoir pressure shows that the gradient of coal seam No. 15 of the Taiyuan Formation is significantly higher than that of coal seam No. 3 of the Shanxi Formation; the equivalent reservoir pressure gradient of coal seam No. 15 “jumps” obviously compared with the reservoir pressure gradient of coal seam No. 3 in the same vertical well, that is, the relation between reservoir pressure and burial depth takes on a characteristic of nonlinearity; mean-while, the vertical hydraulic connection among the aquifers of Shanxi Formation and Taiyuan Forma-tion is weak, constituting several relatively independent fluid pressure systems. The characteristics dis-cussed above reveal that the main coal seams of southern Qinshui Basin respectively belong to relatively independent CBM systems, the formation of which are jointly controlled by sedimentary, hydrogeolog-ical and structural conditions.

  14. Assessment of Surface Water Contamination from Coalbed Methane Fracturing-Derived Volatile Contaminants in Sullivan County, Indiana, USA.

    Science.gov (United States)

    Meszaros, Nicholas; Subedi, Bikram; Stamets, Tristan; Shifa, Naima

    2017-07-14

    There is a growing concern over the contamination of surface water and the associated environmental and public health consequences from the recent proliferation of hydraulic fracturing in the USA. Petroleum hydrocarbon-derived contaminants of concern [benzene, toluene, ethylbenzene, and xylenes (BTEX)] and various dissolved cations and anions were spatially determined in surface waters around 15 coalbed methane fracking wells in Sullivan County, IN, USA. At least one BTEX compound was detected in 69% of sampling sites (n = 13) and 23% of sampling sites were found to be contaminated with all of the BTEX compounds. Toluene was the most common BTEX compound detected across all sampling sites, both upstream and downstream from coalbed methane fracking wells. The average concentration of toluene at a reservoir and its outlet nearby the fracking wells was ~2× higher than other downstream sites. However, one of the upstream sites was found to be contaminated with BTEX at similar concentrations as in a reservoir site nearby the fracking well. Calcium (~60 ppm) and sulfates (~175 ppm) were the dominant cations and anions, respectively, in surface water around the fracking sites. This study represents the first report of BTEX contamination in surface water from coalbed methane hydraulic fracturing wells.

  15. Seismic attribute-based characterization of coalbed methane reservoirs: An example from the Fruitland Formation, San Juan basin, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Marroquin, I.D.; Hart, B.S. [McGill University, Montreal, PQ (Canada)

    2004-11-01

    The Fruitland Formation of the San Juan basin is the largest producer of coalbed methane in the world. Production patterns vary from one well to another throughout the basin, reflecting factors such as coal thickness and fracture and cleat density. In this study, we integrated conventional P-wave three-dimensional (3-D) seismic and well data to investigate geological controls on production from a thick, continuous coal seam in the lower part of the Fruitland Formation. Our objective was to show the potential of using 3-D seismic data to predict coal thickness, as well as the distribution and orientation of subtle structures that may be associated with enhanced permeability zones. To do this, we first derived a seismic attribute-based model that predicts coal thickness. We then used curvature attributes derived from seismic horizons to detect subtle structural features that might be associated with zones of enhanced permeability. Production data show that the best producing wells are associated with seismically definable structural features and thick coal. Although other factors (e.g., completion practices and coal type) affect coalbed methane production, our results suggest that conventional 3-D seismic data, integrated with wire-line logs and production data, are useful for characterizing coalbed methane reservoirs.

  16. Integrated exploration strategy for locating areas capable of high gas rate cavity completion in coalbed methane reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Klawitter, A.L.; Hoak, T.E.; Decker, A.D.

    1995-10-01

    In 1993, the San Juan Basin accounted for approximately 605 Bcf of the 740 Bcf of all coalbed gas produced in the United States. The San Juan {open_quotes}cavitation fairway{close_quotes} in which production occurs in open-hole cavity completions, is responsible for over 60% of all U.S. coalbed methane production. Perhaps most striking is the fact that over 17,000 wells had penetrated the Fruitland formation in the San Juan Basin prior to recognition of the coalbed methan potential. To understand the dynamic cavity fairway reservoir in the San Juan Basin, an exploration rationale for coalbed methan was developed that permits a sequential reduction in total basin exploration area based on four primary exploration criteria. One of the most significant criterion is the existence of thick, thermally mature, friable coals. A second criterion is the existence of fully gas-charged coals. Evaluation of this criterion requires reservoir geochemical data to delineate zones of meteoric influx where breaching has occurred. A third criterion is the presence of adequate reservoir permeability. Natural fracturing in coals is due to cleating and tectonic processes. Because of the general relationship between coal cleating and coal rank, coal cleating intensity can be estimated by analysis of regional coal rank maps. The final criterion is determining whether natural fractures are open or closed. To make this determination, remote sensing imagery interpretation is supported by ancillary data compiled from regional tectonic studies. Application of these four criteria to the San Juan Basin in a heuristic, stepwise process resulted in an overall 94% reduction in total basin exploration area. Application of the first criterion reduced the total basin exploration area by 80%. Application of the second criterion further winnows this area by an addition 9%. Application of the third criterion reduces the exploration area to 6% of the total original exploration area.

  17. The central and northern Appalachian Basin-a frontier region for coalbed methane development

    Science.gov (United States)

    Lyons, P.C.

    1998-01-01

    The Appalachian basin is the world's second largest coalbed-methane (CBM) producing basin. It has nearly 4000 wells with 1996 annual production at 147.8 billion cubic feet (Bcf). Cumulative CBM production is close to 0.9 trillion cubic feet (Tcf). The Black Warrior Basin of Alabama in the southern Appalachian basin (including a very minor amount from the Cahaba coal field) accounts for about 75% of this annual production and about 75% of the wells, and the remainder comes from the central and northern Appalachian basin. The Southwest Virginia coal field accounts for about 95% of the production from the central and northern parts of the Appalachian basin. Production data and trends imply that several of the Appalachian basin states, except for Alabama and Virginia, are in their infancy with respect to CBM development. Total in-place CBM resources in the central and northern Appalachian basin have been variously estimated at 66 to 76 trillion cubic feet (Tcf), of which an estimated 14.55 Tcf (~ 20%) is technically recoverable according to a 1995 U.S. Geological Survey assessment. For comparison in the Black Warrior basin of the 20 Tcf in-place CBM resources, 2.30 Tcf (~ 12%) is technically recoverable. Because close to 0.9 Tcf of CBM has already been produced from the Black Warrior basin and the proved reserves are about 0.8 Tcf for 1996 [Energy Information Administration (EIA), 1997]. U.S. Crude Oil, Natural Gas, and Natural Gas Liquids Reserves, 1996 Annual Report. U.S. Department of Energy DOE/EIA-0216(96), 145 pp.], these data imply that the central and northern Appalachian basin could become increasingly important in the Appalachian basin CBM picture as CBM resources are depleted in the southern Appalachian basin (Black Warrior Basin and Cahaba Coal Field). CBM development in the Appalachian states could decrease the eastern U.S.A.'s dependence on coal for electricity. CBM is expected to provide over the next few decades a virtually untapped source of

  18. Coalbed Methane-bearing Characteristics and Reservoir Physical Properties of Principal Target Areas in North China

    Institute of Scientific and Technical Information of China (English)

    TANG Shuheng; SUN Shenglin; HAO Duohu; TANG Dazhen

    2004-01-01

    The coalbed methane (CBM) resources in North China amounts up to 60% of total resources in China.North China is the most important CBM accumulation area in China, The coal beds of the Upper Paleozoic Taiyuan and Shanxi formations have a stable distribution. The coal reservoir of target areas such as Jincheng, Yanquan-Shouyang,Hancheng, Liulin, etc. have good CBM-bearing characteristics, high permeability and appropriate reservoir pressure, and these areas are the preferred target areas of CBM developing in China. The coal reservoirs of Wupu, Sanjiaobei, Lu'an,Xinmi, Anyang-Hebi, Jiaozuo, Xinggong and Huainan also have as good CBM-bearing characteristics, but the physical properties of coal reservoirs vary observably. So, further work should be taken to search for districts with high pressure,high permeability and good CBM-bearing characteristics. Crustal stresses have severe influence on the permeability of coal reservoirs in North China. From west to east, the crustal stress gradient increases, while the coal reservoirs permeability decreases.

  19. Coalbed Methane Production System Simulation and Deliverability Forecasting: Coupled Surface Network/Wellbore/Reservoir Calculation

    Directory of Open Access Journals (Sweden)

    Jun Zhou

    2017-01-01

    Full Text Available As an unconventional energy, coalbed methane (CBM mainly exists in coal bed with adsorption, whose productivity is different from conventional gas reservoir. This paper explains the wellbore pressure drop, surface pipeline network simulation, and reservoir calculation model of CBM. A coupled surface/wellbore/reservoir calculation architecture was presented, to coordinate the gas production in each calculation period until the balance of surface/wellbore/reservoir. This coupled calculation method was applied to a CBM field for predicting production. The daily gas production increased year by year at the first time and then decreased gradually after several years, while the daily water production was reduced all the time with the successive decline of the formation pressure. The production of gas and water in each well is almost the same when the structure is a star. When system structure is a dendritic surface system, the daily gas production ranked highest at the well which is the nearest to the surface system collection point and lowest at the well which is the farthest to the surface system collection point. This coupled calculation method could be used to predict the water production, gas production, and formation pressure of a CBM field during a period of time.

  20. A multi-scale model for CO2 sequestration enhanced coalbed methane recovery

    Institute of Scientific and Technical Information of China (English)

    G.X.WANG; X.R.WEI; V.RUDOLPH; C.T.WEI; Y.QIN

    2009-01-01

    This paper presents a multi-scale model to simulate the multicomponent gas diffusion and flow in bulk coals for CO2 sequestration enhanced coalbed methane recovery. The model is developed based on a bi-dispersed structure model by assuming that coal con-sists of microporous micro-particles, meso/macro-pores and open microfractures. The bi-disperse diffusion theory and the Maxwell-Stefan approach were incorporated in the model, providing an improved simulation of the CH4-CO2/CH4-N2 counter diffusion dynamics. In the model,the counter diffusion process is numerically coupled with the flow of the mixture gases occurring within macro-pores or fractures in coal so as to account for the interaction between diffusion and flow in gas transport through coals.The model was validated by both experimental data from literature and our CO2 flush tests, and shows an excellent agreement with the experiments. The results reveal that the gas diffusivities, in particular the micro-pore diffusivities are strongly concentration-dependent.

  1. ANOMALY IDENTIFICATION FROM SUPER-LOW FREQUENCY ELECTROMAGNETIC DATA FOR THE COALBED METHANE DETECTION

    Directory of Open Access Journals (Sweden)

    S. S. Zhao

    2016-06-01

    Full Text Available Natural source Super Low Frequency(SLF electromagnetic prospecting methods have become an increasingly promising way in the resource detection. The capacity estimation of the reservoirs is of great importance to evaluate their exploitation potency. In this paper, we built a signal-estimate model for SLF electromagnetic signal and processed the monitored data with adaptive filter. The non-normal distribution test showed that the distribution of the signal was obviously different from Gaussian probability distribution, and Class B instantaneous amplitude probability model can well describe the statistical properties of SLF electromagnetic data. The Class B model parameter estimation is very complicated because its kernel function is confluent hypergeometric function. The parameters of the model were estimated based on property spectral function using Least Square Gradient Method(LSGM. The simulation of this estimation method was carried out, and the results of simulation demonstrated that the LGSM estimation method can reflect important information of the Class B signal model, of which the Gaussian component was considered to be the systematic noise and random noise, and the Intermediate Event Component was considered to be the background ground and human activity noise. Then the observation data was processed using adaptive noise cancellation filter. With the noise components subtracted out adaptively, the remaining part is the signal of interest, i.e., the anomaly information. It was considered to be relevant to the reservoir position of the coalbed methane stratum.

  2. Discrete Fracture Modeling of 3D Heterogeneous Enhanced Coalbed Methane Recovery with Prismatic Meshing

    Directory of Open Access Journals (Sweden)

    Yongbin Zhang

    2015-06-01

    Full Text Available In this study, a 3D multicomponent multiphase simulator with a new fracture characterization technique is developed to simulate the enhanced recovery of coalbed methane. In this new model, the diffusion source from the matrix is calculated using the traditional dual-continuum approach, while in the Darcy flow scale, the Discrete Fracture Model (DFM is introduced to explicitly represent the flow interaction between cleats and large-scale fractures. For this purpose, a general formulation is proposed to model the multicomponent multiphase flow through the fractured coal media. The S&D model and a revised P&M model are incorporated to represent the geomechanical effects. Then a finite volume based discretization and solution strategies are constructed to solve the general ECBM equations. The prismatic meshing algorism is used to construct the grids for 3D reservoirs with complex fracture geometry. The simulator is validated with a benchmark case in which the results show close agreement with GEM. Finally, simulation of a synthetic heterogeneous 3D coal reservoir modified from a published literature is performed to evaluate the production performance and the effects of injected gas composition, well pattern and gas buoyancy.

  3. Well production challenges and solutions in a mature, very low-pressure coalbed methane reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Okotie, V.U.; Moore, R.L. [BP, Houston, TX (United States)

    2010-07-01

    Coalbed methane (CBM) had been produced in the regions of southwestern Colorado and northwestern New Mexico for the past 30 years. Parts of the field are now at a mature stage of reservoir pressure depletion. Well production operations in the high permeability fairway are challenged by low reservoir pressure, heavy coal fines production, artificial lift challenges, and the presence of paraffin, inorganic scale, and corrosion. In this study, history matching reservoir simulations were used to determine the causes of production inefficiencies. Field observations and operating guidelines were discussed and successful well intervention histories were presented. An analysis of the simulations indicated that shift in permeability trends were primarily caused by changes in the mechanical properties of the coal. Excess volumes of coal fines have caused wells in the region to require more frequent cleanouts, and the presence of paraffin deposits has restricted fluid flow. Corrosion in the fairway was attributed to a high percentage of carbon dioxide (CO{sub 2}) in gas streams. Effective wellbore cleanout and pumping systems have been developed to address issues related to coal failure. 14 refs., 15 figs.

  4. Structure of the western Cumberland Basin : implications for coalbed-methane exploration

    Energy Technology Data Exchange (ETDEWEB)

    Waldron, J.W.F. [Alberta Univ., Edmonton, AB (Canada). Dept. of Earth and Atmospheric Sciences; Rygel, M.C. [Nebraska-Lincoln Univ., Lincoln, NE (United States). Dept. of Geosciences

    2006-07-01

    The Athol Syncline is a prominent structure in the western Cumberland Basin of Nova Scotia. The basin contains a Carboniferous succession and is currently a target for exploration for coalbed methane. Subsidence and tectonism in the Cumberland Basin were partly controlled by differential flow of Windsor Group evaporites. The Joggins Formation in the Athol Syncline is famous for preserved upright fossil trees. New seismic profiles reveal that the Athol Syncline has potential traps for conventional hydrocarbons where thick fluvial sand units rest against salt walls at the margins of minibasins. The Cumberland Group is thin and lacks significant coals. A basinwide comparison showed that salt withdrawal at depth was responsible for much of the subsidence responsible for the preservation of the coal-bearing Joggins Formation. Contouring of reflections in the seismic profiles provided better definition of the subsurface geometries and potential extent of coal-bearing units in the Athol syncline. The subsurface geometries revealed some new exploration targets for this and similar depocentres in the Maritimes Basin. Coal distribution was found to be influenced by both tectonism and differential withdrawal of evaporites.

  5. CO2 Sequestration in Coalbed Methane Reservoirs: Experimental Studies and Computer Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Muhammad Sahimi; Theodore T. Tsotsis

    2002-12-15

    One of the approaches suggested for sequestering CO{sub 2} is by injecting it in coalbed methane (CBM) reservoirs. Despite its potential importance for CO{sub 2} sequestration, to our knowledge, CO{sub 2} injection in CBM reservoirs for the purpose of sequestration has not been widely studied. Furthermore, a key element missing in most of the existing studies is the comprehensive characterization of the CBM reservoir structure. CBM reservoirs are complex porous media, since in addition to their primary pore structure, generated during coal formation, they also contain a variety of fractures, which may potentially play a key role in CO{sub 2} sequestration, as they generally provide high permeability flow paths for both CO{sub 2} and CH{sub 4}. In this report we present an overview of our ongoing experimental and modeling efforts, which aim to investigate the injection, adsorption and sequestration of CO{sub 2} in CBM reservoirs, the enhanced CH{sub 4} production that results, as well as the main factors that affect the overall operation. We describe the various experimental techniques that we utilize, and discuss their range of application and the value of the data generated. We conclude with a brief overview of our modeling efforts aiming to close the knowledge gap and fill the need in this area.

  6. Coalbed Methane Extraction and Soil Suitability Concerns in the Powder River Basin, Montana and Wyoming

    Science.gov (United States)

    ,

    2006-01-01

    The Powder River Basin is located in northeastern Wyoming and southeastern Montana. It is an area of approximately 55,000 square kilometers. Extraction of methane gas from the coal seams that underlie the Powder River Basin began in Wyoming in the late 1980s and in Montana in the late 1990s. About 100-200 barrels of co-produced water per day are being extracted from each active well in the Powder River Basin, which comes to over 1.5 million barrels of water per day for all the active coalbed methane wells in the Basin. Lab testing indicates that Powder River Basin co-produced water is potable but is high in sodium and other salts, especially in the western and northern parts of the Powder River Basin. Common water management strategies include discharge of co-produced water into drainages, stock ponds, evaporation ponds, or infiltration ponds; treatment to remove sodium; or application of the water directly on the land surface via irrigation equipment or atomizers. Problems may arise because much of the Powder River Basin contains soils with high amounts of swelling clays. As part of the USGS Rocky Mountain Geographic Science Center's hyperspectral research program, researchers are investigating whether hyperspectral remote sensing data can be beneficial in locating areas of swelling clays. Using detailed hyperspectral data collected over parts of the Powder River Basin and applying our knowledge of how the clays of interest reflect energy, we will attempt to identify and map areas of swelling clays. If successful, such information will be useful to resource and land managers.

  7. Powder River Basin Coalbed Methane Development and Produced Water Management Study

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Resources International

    2002-11-30

    Coalbed methane resources throughout the entire Powder River Basin were reviewed in this analysis. The study was conducted at the township level, and as with all assessments conducted at such a broad level, readers must recognize and understand the limitations and appropriate use of the results. Raw and derived data provided in this report will not generally apply to any specific location. The coal geology in the basin is complex, which makes correlation with individual seams difficult at times. Although more than 12,000 wells have been drilled to date, large areas of the Powder River Basin remain relatively undeveloped. The lack of data obviously introduces uncertainty and increases variability. Proxies and analogs were used in the analysis out of necessity, though these were always based on sound reasoning. Future development in the basin will make new data and interpretations available, which will lead to a more complete description of the coals and their fluid flow properties, and refined estimates of natural gas and water production rates and cumulative recoveries. Throughout the course of the study, critical data assumptions and relationships regarding gas content, methane adsorption isotherms, and reservoir pressure were the topics of much discussion with reviewers. A summary of these discussion topics is provided as an appendix. Water influx was not modeled although it is acknowledged that this phenomenon may occur in some settings. As with any resource assessment, technical and economic results are the product of the assumptions and methodology used. In this study, key assumptions as well as cost and price data, and economic parameters are presented to fully inform readers. Note that many quantities shown in various tables have been subject to rounding; therefore, aggregation of basic and intermediate quantities may differ from the values shown.

  8. Biogenic origin of coalbed gas in the northern Gulf of Mexico Coastal Plain, U.S.A.

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, Peter D.; Hackley, Paul C. [U.S. Geological Survey, 956 National Center, Reston, VA 20192 (United States); Breland, F. Clayton Jr. [Louisiana Department of Natural Resources, 617 North 3rd Street, Baton Rouge, LA 70802 (United States)

    2008-10-02

    New coal-gas exploration and production in northern Louisiana and south-central Mississippi, Gulf of Mexico Basin, is focused on the Wilcox Group (Paleocene-Eocene), where the depth to targeted subbituminous C to high volatile C bituminous coal beds ranges from 300 to 1680 m, and individual coal beds have a maximum thickness of about 6 m. Total gas content (generally excluding residual gas) of the coal beds ranges from less than 0.37 cm{sup 3}/g (as-analyzed or raw basis; 1.2 cm{sup 3}/g, dry, ash free basis, daf) at depths less than 400 m, to greater than 7.3 cm{sup 3}/g (as-analyzed basis; 8.76 cm{sup 3}/g, daf) in deeper (> 1,500 m) parts of the basin. About 20 Wilcox coal-gas wells in northern Louisiana produce from 200 to 6485 m{sup 3} of gas/day and cumulative gas production from these wells is approximately 25 million m{sup 3} (as of December, 2006). U.S. Geological Survey assessment of undiscovered, technically recoverable gas resources in the Gulf of Mexico Coastal Plain, including northern and south-central Mississippi, indicates that coal beds of the Wilcox Group contain an estimated mean total 109.3 million m{sup 3} (3.86 trillion ft{sup 3}) of producible natural gas. To determine the origin of the Wilcox Group coal gases in northern Louisiana, samples of gas, water, and oil were collected from Wilcox coal and sandstone reservoirs and from under- and overlying Late Cretaceous and Eocene carbonate and sandstone reservoirs. Isotopic data from Wilcox coal-gas samples have an average {delta}{sup 13}C{sub CH4} value of - 62.6 permille VPDB (relative to Vienna Peedee Belemnite) and an average {delta}D{sub CH4} value of - 199.9 permille VSMOW (relative to Vienna Standard Mean Ocean Water). Values of {delta}{sup 13}C{sub CO2} range from - 25.4 to 3.42 permille VPDB. Produced Wilcox saline water collected from oil, conventional gas, and coalbed gas wells have {delta}D{sub H2O} values that range from - 27.3 to - 18.0 permille VSMOW. These data suggest that the

  9. Enhanced microbial coalbed methane generation: A review of research, commercial activity, and remaining challenges

    Science.gov (United States)

    Ritter, Daniel J.; Vinson, David S.; Barnhart, Elliott P.; Akob, Denise M.; Fields, Matthew W.; Cunningham, Al B.; Orem, William H.; McIntosh, Jennifer C.

    2015-01-01

    Coalbed methane (CBM) makes up a significant portion of the world’s natural gas resources. The discovery that approximately 20% of natural gas is microbial in origin has led to interest in microbially enhanced CBM (MECoM), which involves stimulating microorganisms to produce additional CBM from existing production wells. This paper reviews current laboratory and field research on understanding processes and reservoir conditions which are essential for microbial CBM generation, the progress of efforts to stimulate microbial methane generation in coal beds, and key remaining knowledge gaps. Research has been primarily focused on identifying microbial communities present in areas of CBM generation and attempting to determine their function, in-situ reservoir conditions that are most favorable for microbial CBM generation, and geochemical indicators of metabolic pathways of methanogenesis (i.e., acetoclastic or hydrogenotrophic methanogenesis). Meanwhile, researchers at universities, government agencies, and companies have focused on four primary MECoM strategies: 1) microbial stimulation (i.e., addition of nutrients to stimulate native microbes); 2) microbial augmentation (i.e., addition of microbes not native to or abundant in the reservoir of interest); 3) physically increasing microbial access to coal and distribution of amendments; and 4) chemically increasing the bioavailability of coal organics. Most companies interested in MECoM have pursued microbial stimulation: Luca Technologies, Inc., successfully completed a pilot scale field test of their stimulation strategy, while two others, Ciris Energy and Next Fuel, Inc., have undertaken smaller scale field tests. Several key knowledge gaps remain that need to be addressed before MECoM strategies can be implemented commercially. Little is known about the bacterial community responsible for coal biodegradation and how these microorganisms may be stimulated to enhance microbial methanogenesis. In addition, research

  10. Numerical Simulation of Unsteady-State Flow in Dual Porous Coalbed Methane Horizontal Wells with Complex Boundary Conditions

    Directory of Open Access Journals (Sweden)

    Cheng-yong Li

    2015-01-01

    Full Text Available The bottom-hole pressure response which can reflect the gas flow characteristics is important to study. A mathematical model for description of gas from porous coalbed methane (CBM reservoirs with complex boundary conditions flowing into horizontal wells has been developed. Meanwhile, basic solution of boundary elements has been acquired by combination of Lord Kelvin point source solution, the integral of Bessel function, and Poisson superimpose formula for CBM horizontal wells with complex boundary conditions. Using this model, type curves of dimensionless pressure and pressure derivative are obtained, and flow characteristics of horizontal wells in complex boundary reservoirs and relevant factors are accordingly analyzed.

  11. Feasibility of CO2 Sequestration with Simultaneous Enhanced Coalbed Methane Recovery in the Powder River Basin, Wyoming

    Science.gov (United States)

    Ross, H. E.; Zoback, M. D.

    2005-12-01

    CO2 sequestration in geological formations has been proposed as a means to reduce greenhouse gas concentrations in the atmosphere. Coal is an attractive geologic environment for CO2 sequestration because CO2 is retained in the coal as an adsorbed phase and the cost of sequestration can be offset by enhanced coalbed methane recovery. Using reservoir simulations of sub-bituminous coal in the Powder River Basin, Wyoming, we examined the feasibility of injecting and sequestering CO2 in this basin, particularly looking at whether hydraulically fracturing the coal would help increase CO2 injectivity. Our 3D model was built in an area where the least principal stress is equal to the overburden stress, resulting in horizontal hydraulic fractures, and gamma ray logs from coalbed methane wells were used to determine the depth and thickness of the coal. These wells produce from the Big George coal, which is approximately 20 m thick in this area, with a depth to the top of 310-360 m. Geostatistical techniques were employed to populate the coal matrix and cleats with permeability and porosity data taken from published reports. We conducted enhanced coalbed methane simulations using a commercial enhanced coalbed methane simulator. Our base case involved one injection well and one production well (1/4 of a 5-spot pattern). We then added a hydraulic fracture at the base of the injector and closed the rest of the well off. All our simulations were run with and without coal matrix shrinkage and swelling. The natural fracture system of the coal is the main pathway for gas migration. We found that gravity and buoyancy were the major driving forces behind gas flow within the coal, which reduced gas sweep efficiency and sequestration. Gravity caused the gas to migrate upwards at first and then along the top of the coal. The presence of the hydraulic fracture assisted in greater penetration of gas into the base of the reservoir, creating a more uniform vertical sweep as gas rose to the

  12. Treatment of Simulated Coalbed Methane Produced Water Using Direct Contact Membrane Distillation

    Directory of Open Access Journals (Sweden)

    Dong-Wan Cho

    2016-05-01

    Full Text Available Expolitation of coalbed methane (CBM involves production of a massive amount saline water that needs to be properly managed for environmental protection. In this study, direct contact membrane distillation (DCMD was utilized for treatment of CBM-produced water to remove saline components in the water. Simulated CBM waters containing varying concentrations of NaCl (1, 20, and 500 mM and NaHCO3 (1 and 25 mM were used as feed solutions under two transmembrane temperatures (Δ40 and 60 °C. In short-term distillation (~360 min, DCMD systems showed good performance with nearly 100% removal of salts for all solutes concentrations at both temperatures. The permeate flux increased with the feed temperature, but at a given temperature, it remained fairly stable throughout the whole operation. A gradual decline in permeate flux was observed at Δ60 °C at high NaHCO3 concentration (25 mM. In long-term distillation (5400 min, the presence of 25 mM NaHCO3 further decreased the flux to 25%–35% of the initial value toward the end of the operation, likely due to membrane fouling by deposition of Ca-carbonate minerals on the pore openings. Furthermore, pore wetting by the scalants occurred at the end of the experiment, and it increased the distillate conducitivity to 110 µS·cm−1. The precipitates formed on the surface were dominantly CaCO3 crystals, identified as aragonite.

  13. Coalbed methane : How much ? At what cost? the U.S. experience

    Energy Technology Data Exchange (ETDEWEB)

    Kuuskraa, V. [Advanced Resources International Inc., Houston, TX (United States)

    2003-07-01

    A historical review of coalbed methane (CBM) development in the United States was presented with particular reference to the Powder River Basin (PRB) and what can be learned from the successes and failures of CBM development. When CBM was first introduced in the early 1980s, some energy analysts referred to it as moonbeam gas, but it has quickly become a mainstay of U.S. natural gas supply. The technical feasibility of producing gas from coals was first demonstrated in pilot wells at the Oak Grove Mine in the Warrior Basin, and at an isolated Cahn well in the San Juan Basin. Technical setbacks of improperly drilled and completed CBM wells in the same basins, however, nearly destroyed CBM development. Today, CBM extends to various basins including Central Appalachia, the Powder River Basin, the Raton Basin, and the Uinta Basin. CBM currently accounts for approximately 1.6 Tcf (8 per cent) of annual production and 17.5 Tcf (10 per cent) of proven reserves. Experience from these basins has shown that: low cost completions and efficient operations can counter low productivity of coals; low rank, thick coals can be very profitable; every coal basin requires unique adaptation of lessons learned elsewhere; and, well performance can be enhanced with technology and insights. The Powder River Basin alone now provides over 1 Bcfd of new natural gas supply. The size of the gas resource in PRB was examined. It was emphasized that advances in technology should be utilized to make this resource more accessible and economic with less environmental impact. 25 figs.

  14. Three-dimensional audio-magnetotelluric sounding in monitoring coalbed methane reservoirs

    Science.gov (United States)

    Wang, Nan; Zhao, Shanshan; Hui, Jian; Qin, Qiming

    2017-03-01

    Audio-magnetotelluric (AMT) sounding is widely employed in rapid resistivity delineation of objective geometry in near surface exploration. According to reservoir patterns and electrical parameters obtained in Qinshui Basin, China, two-dimensional and three-dimensional synthetic "objective anomaly" models were designed and inverted with the availability of a modular system for electromagnetic inversion (ModEM). The results revealed that 3-D full impedance inversion yielded the subsurface models closest to synthetic models. One or more conductive targets were correctly recovered. Therefore, conductive aquifers in the study area, including hydrous coalbed methane (CBM) reservoirs, were suggested to be the interpretation signs for reservoir characterization. With the aim of dynamic monitoring of CBM reservoirs, the AMT surveys in continuous years (June 2013-May 2015) were carried out. 3-D inversion results demonstrated that conductive anomalies accumulated around the producing reservoirs at the corresponding depths if CBM reservoirs were in high water production rates. In contrast, smaller conductive anomalies were generally identical with rapid gas production or stopping production of reservoirs. These analyses were in accordance with actual production history of CBM wells. The dynamic traces of conductive anomalies revealed that reservoir water migrated deep or converged in axial parts and wings of folds, which contributed significantly to formations of CBM traps. Then the well spacing scenario was also evaluated based on the dynamic production analysis. Wells distributed near closed faults or flat folds, rather than open faults, had CBM production potential to ascertain stable gas production. Therefore, three-dimensional AMT sounding becomes an attractive option with the ability of dynamic monitoring of CBM reservoirs, and lays a solid foundation of quantitative evaluation of reservoir parameters.

  15. Coalbed methane-produced water quality and its management options in Raniganj Basin, West Bengal, India

    Science.gov (United States)

    Mendhe, Vinod Atmaram; Mishra, Subhashree; Varma, Atul Kumar; Singh, Awanindra Pratap

    2015-09-01

    Coalbed methane (CBM) recovery is associated with production of large quantity of groundwater. The coal seams are depressurized by pumping of water for regular and consistent gas production. Usually, CBM operators need to pump >10 m3 of water per day from one well, which depends on the aquifer characteristics, drainage and recharge pattern. In India, 32 CBM blocks have been awarded for exploration and production, out of which six blocks are commercially producing methane gas at 0.5 million metric standard cubic feet per day. Large amount of water is being produced from CBM producing blocks, but no specific information or data are available for geochemical properties of CBM-produced water and its suitable disposal or utilization options for better management. CBM operators are in infancy and searching for the suitable solutions for optimal management of produced water. CBM- and mine-produced water needs to be handled considering its physical and geochemical assessment, because it may have environmental as well as long-term impact on aquifer. Investigations were carried out to evaluate geochemical and hydrogeological conditions of CBM blocks in Raniganj Basin. Totally, 15 water samples from CBM well head and nine water samples from mine disposal head were collected from Raniganj Basin. The chemical signature of produced water reveals high sodium and bicarbonate concentrations with low calcium and magnesium, and very low sulphate in CBM water. It is comprehend that CBM water is mainly of Na-HCO3 type and coal mine water is of Ca-Mg-SO4 and HCO3-Cl-SO4 type. The comparative studies are also carried out for CBM- and mine-produced water considering the geochemical properties, aquifer type, depth of occurrence and lithological formations. Suitable options like impounding, reverse osmosis, irrigation and industrial use after prerequisite treatments are suggested. However, use of this huge volume of CBM- and mine-produced water for irrigation or other beneficial purposes

  16. Coalbed methane-produced water quality and its management options in Raniganj Basin, West Bengal, India

    Science.gov (United States)

    Mendhe, Vinod Atmaram; Mishra, Subhashree; Varma, Atul Kumar; Singh, Awanindra Pratap

    2017-06-01

    Coalbed methane (CBM) recovery is associated with production of large quantity of groundwater. The coal seams are depressurized by pumping of water for regular and consistent gas production. Usually, CBM operators need to pump >10 m3 of water per day from one well, which depends on the aquifer characteristics, drainage and recharge pattern. In India, 32 CBM blocks have been awarded for exploration and production, out of which six blocks are commercially producing methane gas at 0.5 million metric standard cubic feet per day. Large amount of water is being produced from CBM producing blocks, but no specific information or data are available for geochemical properties of CBM-produced water and its suitable disposal or utilization options for better management. CBM operators are in infancy and searching for the suitable solutions for optimal management of produced water. CBM- and mine-produced water needs to be handled considering its physical and geochemical assessment, because it may have environmental as well as long-term impact on aquifer. Investigations were carried out to evaluate geochemical and hydrogeological conditions of CBM blocks in Raniganj Basin. Totally, 15 water samples from CBM well head and nine water samples from mine disposal head were collected from Raniganj Basin. The chemical signature of produced water reveals high sodium and bicarbonate concentrations with low calcium and magnesium, and very low sulphate in CBM water. It is comprehend that CBM water is mainly of Na-HCO3 type and coal mine water is of Ca-Mg-SO4 and HCO3-Cl-SO4 type. The comparative studies are also carried out for CBM- and mine-produced water considering the geochemical properties, aquifer type, depth of occurrence and lithological formations. Suitable options like impounding, reverse osmosis, irrigation and industrial use after prerequisite treatments are suggested. However, use of this huge volume of CBM- and mine-produced water for irrigation or other beneficial purposes

  17. 煤层气综合利用趋势研究%Study on Comprehensive Utilization Trend of Coal-bed Methane

    Institute of Scientific and Technical Information of China (English)

    姚成林

    2016-01-01

    China is rich in coal-bed methane resources, but its utilization rate is less than 20%. To counter to this problem, research was carried out on its utilization and it was found out that on one hand, the lower gas extraction rate and gas extraction concentration were disadvantageous for the utilization of the coal-bed methane, and on other hand, the utilization technology and methods were single. By improving the extraction rate and extraction concentration of coal-bed methane and comprehensively utilizing the coal-bed methane in different concentration such as for civil use, electricity generation, the production of compressed methane and the utilization of ventilation air methane, the high efficient utilization of coal-bed methane resource can be realized and its pollution to the atmospheric environment can be relieved.%我国煤层气资源丰富,但利用率不足20%,针对这一情况,通过研究发现其原因在于:一方面我国煤层透气性差,抽采率及抽采浓度低,不利于煤层气利用;另一方面我国煤层气利用技术和途径单一。提高煤层气抽采率和抽采浓度,并采用包括民用、发电、浓缩和通风煤层气利用等各种技术手段,综合利用不同浓度的煤层气,可实现煤层气资源的高效利用,并缓解对环境的排放压力。

  18. Biogenic origin of coalbed gas in the northern Gulf of Mexico Coastal Plain, U.S.A

    Science.gov (United States)

    Warwick, P.D.; Breland, F.C.; Hackley, P.C.

    2008-01-01

    New coal-gas exploration and production in northern Louisiana and south-central Mississippi, Gulf of Mexico Basin, is focused on the Wilcox Group (Paleocene-Eocene), where the depth to targeted subbituminous C to high volatile C bituminous coal beds ranges from 300 to 1680??m, and individual coal beds have a maximum thickness of about 6??m. Total gas content (generally excluding residual gas) of the coal beds ranges from less than 0.37??cm3/g (as-analyzed or raw basis; 1.2??cm3/g, dry, ash free basis, daf) at depths less than 400??m, to greater than 7.3??cm3/g (as-analyzed basis; 8.76??cm3/g, daf) in deeper (> 1,500??m) parts of the basin. About 20 Wilcox coal-gas wells in northern Louisiana produce from 200 to 6485??m3 of gas/day and cumulative gas production from these wells is approximately 25??million m3 (as of December, 2006). U.S. Geological Survey assessment of undiscovered, technically recoverable gas resources in the Gulf of Mexico Coastal Plain, including northern and south-central Mississippi, indicates that coal beds of the Wilcox Group contain an estimated mean total 109.3??million m3 (3.86??trillion ft3) of producible natural gas. To determine the origin of the Wilcox Group coal gases in northern Louisiana, samples of gas, water, and oil were collected from Wilcox coal and sandstone reservoirs and from under- and overlying Late Cretaceous and Eocene carbonate and sandstone reservoirs. Isotopic data from Wilcox coal-gas samples have an average ??13CCH4 value of - 62.6??? VPDB (relative to Vienna Peedee Belemnite) and an average ??DCH4 value of - 199.9??? VSMOW (relative to Vienna Standard Mean Ocean Water). Values of ??13CCO2 range from - 25.4 to 3.42??? VPDB. Produced Wilcox saline water collected from oil, conventional gas, and coalbed gas wells have ??DH2O values that range from - 27.3 to - 18.0??? VSMOW. These data suggest that the coal gases primarily are generated in saline formation water by bacterial reduction of CO2. Shallow (hydrocarbons from

  19. Accumulation of coal-bed methane in the south-west part of the Upper Silesian Coal Basin (southern Poland)

    Energy Technology Data Exchange (ETDEWEB)

    Kedzior, Slawomir [University of Silesia, Faculty of Earth Science, Bedzinska 60, 41-200 Sosnowiec (Poland)

    2009-10-01

    The archives of the Polish Geological Institute house a wealth of coal-bed methane (CBM) data from surface boreholes and excavations in coal from the deposits of the Upper Silesian Coal Basin (USCB). These data support a model for the origin of substantial methane accumulations in the south-west part of the basin that reflects the interplay of the factors controlling methane sorption capacity and those controlling methane content. The factors controlling the sorption capacity of coal include coal rank, temperature, pressure, moisture content and maceral composition. Methane-content controls include lithology, stratigraphy, tectonics, hydrogeology and mining activity. The nature of the coal-bearing Carboniferous horizons, the sorption/desorption properties of the coals, the disposition of faults and folds, the topography of the Carboniferous palaeosurface and the presence of an impermeable Miocene cover were key controls. The methane accumulated in coal seams and in their host rocks in settings comparable with those in which petroleum and gas deposits are trapped. (author)

  20. Current status and technical challenges of CO2 storage in coal seams and enhanced coalbed methane recovery:an overview

    Institute of Scientific and Technical Information of China (English)

    Xiaochun Li; Zhi-ming Fang

    2014-01-01

    In the past two decades, research on CO2 storage in coal seams and simultaneously enhanced coalbed methane recovery (ECBM) has attracted a lot of attention due to its win–win effect between greenhouse gas (CO2) emission reduction and coalbed methane recovery enhancement. This paper presents an overview on the current status of research on CO2-ECBM in the past two decades, which involves CO2 storage capacity evaluations, laboratory investigations, mod-elings and pilot tests. The current status shows that we have made great progress in the ECBM technology study, especially in the understanding of the ECBM mechanisms. However, there still have many technical challenges, such as the definition of unmineable coal seams for CO2 storage capacity evaluation and storage site characterization, methods for CO2 injec-tivity enhancement, etc. The low injectivity of coal seams and injectivity loss with CO2 injection are the major technique challenges of ECBM. We also search several ways to promote the advancement of ECBM technology in the present stage, such as integrating ECBM with hydraulic fracturing, using a gas mixture instead of pure CO2 for injection into coal seams and the application of ECBM to underground coal mines.

  1. Bioassay for estimating the biogenic methane-generating potential of coal samples

    Science.gov (United States)

    Jones, E.J.P.; Voytek, M.A.; Warwick, P.D.; Corum, M.D.; Cohn, A.; Bunnell, J.E.; Clark, A.C.; Orem, W.H.

    2008-01-01

    Generation of secondary biogenic methane in coal beds is likely controlled by a combination of factors such as the bioavailability of coal carbon, the presence of a microbial community to convert coal carbon to methane, and an environment supporting microbial growth and methanogenesis. A set of treatments and controls was developed to bioassay the bioavailability of coal for conversion to methane under defined laboratory conditions. Treatments included adding a well-characterized consortium of bacteria and methanogens (enriched from modern wetland sediments) and providing conditions to support endemic microbial activity. The contribution of desorbed methane in the bioassays was determined in treatments with bromoethane sulfonic acid, an inhibitor of microbial methanogenesis. The bioassay compared 16 subbituminous coal samples collected from beds in Texas (TX), Wyoming (WY), and Alaska (AK), and two bituminous coal samples from Pennsylvania (PA). New biogenic methane was observed in several samples of subbituminous coal with the microbial consortium added, but endemic activity was less commonly observed. The highest methane generation [80????mol methane/g coal (56??scf/ton or 1.75??cm3/g)] was from a south TX coal sample that was collected from a non-gas-producing well. Subbituminous coals from the Powder River Basin, WY and North Slope Borough, AK contained more sorbed (original) methane than the TX coal sample and generated 0-23????mol/g (up to 16??scf/ton or 0.5??cm3/g) new biogenic methane in the bioassay. Standard indicators of thermal maturity such as burial depth, nitrogen content, and calorific value did not explain differences in biogenic methane among subbituminous coal samples. No original methane was observed in two bituminous samples from PA, nor was any new methane generated in bioassays of these samples. The bioassay offers a new tool for assessing the potential of coal for biogenic methane generation, and provides a platform for studying the

  2. An overview of research progress of adsorption and desorption of coal-Bed methane%煤层气吸附解吸研究进展综述

    Institute of Scientific and Technical Information of China (English)

    常广涛; 王一帆; 董特特

    2015-01-01

    对于煤层气吸附、解吸特征及机理的研究,是揭示煤层气成藏机理及高效开发煤层气的基础。通过对国内外文献资料的调研,详细论述了煤层气吸附解吸的机理和过程,介绍了影响煤层气吸附与解吸的因素以及各种煤层气吸附的数学模型,提出了煤层气吸附与解吸研究中存在的问题,进而为煤层气藏的高效、合理开发奠定理论基础。%The characteristics and mechanism research of coal-bed methane adsorption and desorption is the foundation of efficient development of coal-bed methane. The mechanism and process of adsorption and desorption of coal-bed methane are discussed in detail. The mathematical model and influencing factors as well as problems among the research are given. These can help to provide a theoretical foundation for the efficient,rational exploitation of coal-bed methane.

  3. Chemical and stable isotopic composition of water and gas in the Fort Union Formation of the Powder River Basin, Wyoming and Montana: Evidence for water/rock interaction and the biogenic origin of coalbed natural gas

    Science.gov (United States)

    Rice, Cynthia A.; Flores, Romeo M.; Stricker, Gary D.; Ellis, Margaret S.

    2008-01-01

    Significant amounts (> 36 million m3/day) of coalbed methane (CBM) are currently being extracted from coal beds in the Paleocene Fort Union Formation of the Powder River Basin of Wyoming and Montana. Information on processes that generate methane in these coalbed reservoirs is important for developing methods that will stimulate additional production. The chemical and isotopic compositions of gas and ground water from CBM wells throughout the basin reflect generation processes as well as those that affect water/rock interaction. Our study included analyses of water samples collected from 228 CBM wells. Major cations and anions were measured for all samples, δDH2O and δ18OH2O were measured for 199 of the samples, and δDCH4 of gas co-produced with water was measured for 100 of the samples. Results show that (1) water from Fort Union Formation coal beds is exclusively Na–HCO3-type water with low dissolved SO4 content (median < 1 mg/L) and little or no dissolved oxygen (< 0.15 mg/L), whereas shallow groundwater (depth generally < 120 m) is a mixed Ca–Mg–Na–SO4–HCO3 type; (2) water/rock interactions, such as cation exchange on clay minerals and precipitation/dissolution of CaCO3 and SO4 minerals, account for the accumulation of dissolved Na and depletion of Ca and Mg; (3) bacterially-mediated oxidation–reduction reactions account for high HCO3 (270–3310 mg/L) and low SO4 (median < 0.15 mg/L) values; (4) fractionation between δDCH4 (− 283 to − 328 per mil) and δDH2O (− 121 to − 167 per mil) indicates that the production of methane is primarily by biogenic CO2 reduction; and (5) values of δDH2O and δ18OH2O (− 16 to − 22 per mil) have a wide range of values and plot near or above the global meteoric water line, indicating that the original meteoric water has been influenced by methanogenesis and by being mixed with surface and shallow groundwater.

  4. Integrated petrophysical log evaluation for coalbed methane in the Hancheng area, China

    Science.gov (United States)

    Deng, Shaogui; Hu, Yunyun; Chen, Dong; Ma, Zhiqiang; Li, Hu

    2013-06-01

    In order to investigate coalbed physical parameters and gas bearing properties, based on coal core experiments, a nonlinear comprehensive model estimating coal properties and gas content is established. Three-dimensional numerical simulation of the dual laterolog response of a coalbed fracture is carried out, and a dual laterolog fast computation model for predicting fracture porosity is established. The results show that the study area mainly developed lean coal and meagre coal. The coalbed is rich in gas. Ash content, volatile dry ash-free basis, true density and fixed carbon show good correlation. The logging responses of the coalbed have distinct characteristics; however, the responses highly depend on coal composition and gas content. The simulated annealing differential evolution (SADE) neural network is adopted to predict coal composition and gas content. Numerical analysis of the dual laterolog responses of the coal fractures shows that as coal matrix resistivity increases, the dual laterolog apparent resistivity increases accordingly. For a coalbed with low-angle fractures, deep and shallow resistivity show little difference; however, for a coalbed with high-angle fractures, its dual laterolog shows an obvious positive difference. Fracture porosity and dual laterolog apparent conductivity presents a linear relationship. According to coal matrix resistivity distribution and fracture development, a fast computation model to predict fracture porosity is established based on the dual laterolog. Field data show that the predicted coal composition and gas content from the SADE algorithm agree with that of coal core analysis, and the calculated fracture porosity based on the dual laterolog matches the coal core's macroscopic description.

  5. Study on clean development of coalbed methane in China%我国煤层气清洁发展研究

    Institute of Scientific and Technical Information of China (English)

    苏钰杰; 徐凯

    2012-01-01

    Coalbed methane, with rich reserves m China, is a quality new energy of strategic significance. Hence, utilization of the gas in a scientific manner can effectively address the energy crisis problem. However, use of the gas cannot be said to be optimistic in China at present since a variety of problems surface. From the perspective of clean development mechanism, this paper explores the valuable experiences of other countries in coalbed methane development, in an attempt to find a roadmap on which China can overcome the dilemma in coalbed methane development and that is suitable for its own situations. It is expected to look for an effective point where the clean development mechanism is in conjunction with the coalbed methane, and come up with the measures for China's coalbed methane to step onto a benign path of scaled production.%煤层气是一种具有重要战略意义的优质新能源,在我国储量丰富.科学地利用煤层气将能有效解决能源危机问题,但是我国煤层气的利用状况不容乐观,存在着一系列问题,本文从清洁发展机制的角度出发,探讨国外煤层气发展的有益经验,试图寻找能使我国煤层气发展走出困境并适合国情的发展路径,期待能够发现清洁发展机制和煤层气发展的有效契合点,以期为我国煤层气步入规模化良性发展轨道出谋划策.

  6. Sources of biogenic methane to form marine gas hydrates: In situ production or upward migration?

    Energy Technology Data Exchange (ETDEWEB)

    Paull, C.K.; Ussler, W. III; Borowski, W.S.

    1993-09-01

    Potential sources of biogenic methane in the Carolina Continental Rise -- Blake Ridge sediments have been examined. Two models were used to estimate the potential for biogenic methane production: (1) construction of sedimentary organic carbon budgets, and (2) depth extrapolation of modern microbial production rates. While closed-system estimates predict some gas hydrate formation, it is unlikely that >3% of the sediment volume could be filled by hydrate from methane produced in situ. Formation of greater amounts requires migration of methane from the underlying continental rise sediment prism. Methane may be recycled from below the base of the gas hydrate stability zone by gas hydrate decomposition, upward migration of the methane gas, and recrystallization of gas hydrate within the overlying stability zone. Methane bubbles may also form in the sediment column below the depth of gas hydrate stability because the methane saturation concentration of the pore fluids decreases with increasing depth. Upward migration of methane bubbles from these deeper sediments can add methane to the hydrate stability zone. From these models it appears that recycling and upward migration of methane is essential in forming significant gas hydrate concentrations. In addition, the depth distribution profiles of methane hydrate will differ if the majority of the methane has migrated upward rather than having been produced in situ.

  7. Coalbed Methane Procduced Water Treatment Using Gas Hydrate Formation at the Wellhead

    Energy Technology Data Exchange (ETDEWEB)

    BC Technologies

    2009-12-30

    Water associated with coalbed methane (CBM) production is a significant and costly process waste stream, and economic treatment and/or disposal of this water is often the key to successful and profitable CBM development. In the past decade, advances have been made in the treatment of CBM produced water. However, produced water generally must be transported in some fashion to a centralized treatment and/or disposal facility. The cost of transporting this water, whether through the development of a water distribution system or by truck, is often greater than the cost of treatment or disposal. To address this economic issue, BC Technologies (BCT), in collaboration with Oak Ridge National Laboratory (ORNL) and International Petroleum Environmental Consortium (IPEC), proposed developing a mechanical unit that could be used to treat CBM produced water by forming gas hydrates at the wellhead. This process involves creating a gas hydrate, washing it and then disassociating hydrate into water and gas molecules. The application of this technology results in three process streams: purified water, brine, and gas. The purified water can be discharged or reused for a variety of beneficial purposes and the smaller brine can be disposed of using conventional strategies. The overall objectives of this research are to develop a new treatment method for produced water where it could be purified directly at the wellhead, to determine the effectiveness of hydrate formation for the treatment of produced water with proof of concept laboratory experiments, to design a prototype-scale injector and test it in the laboratory under realistic wellhead conditions, and to demonstrate the technology under field conditions. By treating the water on-site, producers could substantially reduce their surface handling costs and economically remove impurities to a quality that would support beneficial use. Batch bench-scale experiments of the hydrate formation process and research conducted at ORNL

  8. Discussion on Cascade Utilization Technology for Coal-bed Methane%煤层气梯级利用技术探讨

    Institute of Scientific and Technical Information of China (English)

    姚成林

    2016-01-01

    This paper described the present development and utilization situation of coal-bed methane both at home and abroad. To counter to the coal-bed methane of different concentrations, the paper analyzed the technologies suitable for its processing and utilization in order to improve its utilization rate and gain the maximum economic benefits. Based on the present technological level, it clarified the cascade processing and utilization technology, i. e. the coal-bed methane with the volume fraction more than 90% suited to directly purified and compressed into pipeline natural gas or purified into CNG / LNG; the coal-bed methane with the volume fraction from 30% to 90% suited to apply the purification technology ( the direct cryogenic liquefaction or pressure-swing adsorption) for CNG / LNG preparation;the coal-bed methane with the volume fraction from 8%to 30% suited to be used for low-concentration gas-fired power generation;and the coal-bed methane with the volume fraction from 1% to 8% can be mixed for regenerative oxidation utilization.%介绍了国内外煤层气开发与利用现状。针对不同浓度的煤层气,分析了其适宜的加工利用技术方式,以提高煤层气利用率及获得最大的经济效益。根据目前技术水平,阐明了煤层气梯级加工利用技术方式:甲烷体积分数在90%以上的煤层气适宜直接净化加压制成管道输送天然气或提纯制取CNG/LNG;甲烷体积分数为30%~90%的煤层气宜采用提纯技术(直接深冷液化或变压吸附)生产CNG/LNG;甲烷体积分数为8%~30%的煤层气宜采用低浓度瓦斯发电技术进行利用;甲烷体积分数为1%~8%的煤层气可经掺混后进行蓄热氧化利用。

  9. Classification of coalbed methane enrichment units in Qinshui basin%沁水盆地煤层气富集单元划分

    Institute of Scientific and Technical Information of China (English)

    徐刚; 李树刚; 丁洋

    2013-01-01

    The paper has studied tectonic dynamical conditions, thermal dynamical conditions and hydraulic condi-tions influencing coalbed methane enrichment in Qinshui basin. Coalbed methane enrichment units have been di-vided based on tectonic dynamical conditions in Qinshui basin and combined with thermal dynamical conditions and hydraulic conditions. The results show that there are four geological tectonic units and nine coalbed methane enrichment units in Qinshui basin, the two more favorable areas and three favorable areas of coalbed methane ex-ploitation have been affirmed by possible recovery assessment. Coalbed methane enrichment has resulted from combined action of tectonic dynamical conditions, thermal dynamical conditions and hydraulic conditions as well as time-space configuration, the reasonable combination of tectonic dynamical conditions, thermal dynamical con-ditions and hydraulic conditions could have formed the best zone for coalbed methane exploitation.%通过分析研究影响沁水盆地煤层气富集的构造动力条件、热动力条件和水动力条件,进而以沁水盆地形成的构造动力条件为基础,结合热动力条件和水动力条件,对沁水盆地煤层气富集单元进行划分。研究结果表明:沁水盆地可以划分为4个地质构造单元、9个煤层气富集区,并通过可采性评价,确定了2个煤层气开发有利区和3个较有利区;煤层气富集是构造动力条件、热动力条件和水动力条件综合作用以及时空匹配的结果,这3个条件的合理配置才能形成煤层气开发的有利区块。

  10. Geologic and hydrologic characterization of coalbed-methane reservoirs in the San Juan basin

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, W.R. (Univ. of Texas, Austin, TX (United States)); Ayers, W.B. Jr.

    1994-09-01

    Fruitland coals are best developed in the north-central part of the San Juan basin. Coal distribution is controlled by shoreline and fluvial depositional settings. Hydraulic gradient, pressure regime, and hydrochemistry reflect regional permeability contrasts. The most productive (>1 MMcf/D) coalbed wells occur along a structural hinge line in association with a regional permeability barrier (no-flow boundary) at the basin center.

  11. Coordination of coal and coal-bed methane development model%浅谈煤层气的开发利用现状及前景

    Institute of Scientific and Technical Information of China (English)

    白优

    2016-01-01

    After 10 years of coal-bed methane development,it has formed a relatively mature industry pattern.Through a series of technical problems to overcome,coal-bed methane industry has made significant progress in Jincheng,Shanxi and other places. CBM is a high-quality environment-friendly clean energy,its large-scale development and utilization prospects are very optimistic. In this paper,the use of the current situation and development of coalbed methane resources are described in detail,at the same time,the prospects for the development of coal-bed methane made a bold prediction.%我国煤层气经过10多年的发展,已经形成了比较成熟的产业化模式。通过对一系列技术难题的攻克,煤层气产业已经在山西晋城等地取得重要进展。煤层气是一种清洁优质的环保型能源,它的大规模开发利用前景十分乐观。本文对我国煤层气资源的开发和利用现状进行了详细介绍,同时,对煤层气发展的前景做了大胆的预测。

  12. U.S. Geological Survey and Bureau of Land Management Cooperative Coalbed Methane Project in the Powder River Basin, Wyoming

    Science.gov (United States)

    ,

    2006-01-01

    Introduction: Evidence that earthquakes threaten the Mississippi, Ohio, and Wabash River valleys of the Central United States abounds. In fact, several of the largest historical earthquakes to strike the continental United States occurred in the winter of 1811-1812 along the New Madrid seismic zone, which stretches from just west of Memphis, Tenn., into southern Illinois (fig. 1). Several times in the past century, moderate earthquakes have been widely felt in the Wabash Valley seismic zone along the southern border of Illinois and Indiana (fig. 1). Throughout the region, between 150 and 200 earthquakes are recorded annually by a network of monitoring instruments, although most are too small to be felt by people. Geologic evidence for prehistoric earthquakes throughout the region has been mounting since the late 1970s. But how significant is the threat? How likely are large earthquakes and, more importantly, what is the chance that the shaking they cause will be damaging?The Bureau of Land Management (BLM) Wyoming Reservoir Management Group and the U.S. Geological Survey (USGS) began a cooperative project in 1999 to collect technical and analytical data on coalbed methane (CBM) resources and quality of the water produced from coalbeds in the Wyoming part of the Powder River Basin. The agencies have complementary but divergent goals and these kinds of data are essential to accomplish their respective resource evaluation and management tasks. The project also addresses the general public need for information pertaining to Powder River Basin CBM resources and development. BLM needs, which relate primarily to the management of CBM resources, include improved gas content and gas in-place estimates for reservoir characterization and resource/reserve assessment, evaluation, and utilization. USGS goals include a basinwide assessment of CBM resources, an improved understanding of the nature and origin of coalbed gases and formation waters, and the development of predictive

  13. Drilling & completion techniques for coalbed methane wells in Jincheng Area,Shanxi,China%山西晋城地区煤层气钻井完井技术

    Institute of Scientific and Technical Information of China (English)

    田中岚

    2001-01-01

    通过对晋城地区所钻煤层气井的钻井完井技术总结,提出了适合该地区煤层气开发的钻井技术、完井技术、煤层保护技术、绳索取心技术、固井技术等。%It is introduced in the paper that a summary of drilling & completion techniques for coal-bed methane wells,which drilled in Jincheng area,Shanxi,China,1999.A set of techniques are suitable for coal-bed methane development are evaluated,such as drilling,completion,coal protection,wire line coring tools and coment.

  14. Discuss on Key Coalbed Methane Drainage Technology in Jiaoping Mining Area%焦坪矿区煤层气排采关键技术探讨

    Institute of Scientific and Technical Information of China (English)

    万志杰

    2012-01-01

    This paper aims to propose viewpoint concerning equipment selection and drainage technology for further coalbed methane development after Jurassic system coal seam of Jiaoping mining area to pro- vide references for coalbed methane development of Jiaoping mining area combining problems arising from on - site drainage management process of JPC-O1 well of Jiaoping mining area.%结合焦坪矿区JPC—01井现场排采管理过程中遇到的问题,对焦坪矿区侏罗系煤层以后开发煤层气的设备选型以及排采工艺提出相应的观点,为以后焦坪矿区开发煤层气提供参考。

  15. Effects of coal-bed methane discharge waters on the vegetation and soil ecosystem in Powder River Basin, Wyoming

    Science.gov (United States)

    Stearns, M.; Tindall, J.A.; Cronin, G.; Friedel, M.J.; Bergquist, E.

    2005-01-01

    Coal-bed methane (CBM) co-produced discharge waters in the Powder River Basin of Wyoming, resulting from extraction of methane from coal seams, have become a priority for chemical, hydrological and biological research during the last few years. Soil and vegetation samples were taken from affected and reference sites (upland elevations and wetted gully) in Juniper Draw to investigate the effects of CBM discharge waters on soil physical and chemical properties and on native and introduced vegetation density and diversity. Results indicate an increase of salinity and sodicity within local soil ecosystems at sites directly exposed to CBM discharge waters. Elevated concentrations of sodium in the soil are correlated with consistent exposure to CBM waters. Clay-loam soils in the study area have a much larger specific surface area than the sandy soils and facilitate a greater sodium adsorption. However, there was no significant relation between increasing water sodium adsorption ratio (SAR) values and increasing sediment SAR values downstream; however, soils exposed to the CBM water ranged from the moderate to severe SAR hazard index. Native vegetation species density was highest at the reference (upland and gully) and CBM affected upland sites. The affected gully had the greatest percent composition of introduced vegetation species. Salt-tolerant species had the greatest richness at the affected gully, implying a potential threat of invasion and competition to established native vegetation. These findings suggest that CBM waters could affect agricultural production operations and long-term water quality. ?? Springer 2005.

  16. Design of Oxidation Regenerator for Coal-bed Methane Desulfurization%煤层气脱硫氧化再生槽的设计

    Institute of Scientific and Technical Information of China (English)

    文娟

    2013-01-01

    Before the use of the coal-bed methane, H2 S content in it must be lowered down to the demand with the desulfurizing system. This paper described the oxidation regeneration method for coal-bed methane desulfurization, and expounded the principle and technological process of the presently-used PDS wet oxidation regeneration method for coal-bed methane desulfurization, discussed the influence of some factors such as the regenerating time, temperature and the alkalinity of desulfurizing solution on the oxidation regeneration method, and based on these conditions, the structure of the oxidation regenerator and the injector were designed.%煤层气在利用之前,需要通过脱硫系统将其中的H2 S脱除至要求浓度以下。介绍了煤层气脱硫氧化再生技术,阐述了目前常用的PDS法湿式脱硫氧化再生技术的原理和工艺过程;讨论了再生时间、温度、脱硫液碱度等因素对氧化再生工艺的影响,基于这些条件,对氧化再生槽的结构、喷射器进行了设计。

  17. Potential for CO2 sequestration and enhanced coalbed methane production in the Netherlands

    NARCIS (Netherlands)

    Hamelinck, C.N.; Schreurs, H.; Faaij, A.P.C.; Ruijg, G.J.; Jansen, Daan; Pagnier, H.; Bergen, F. van; Wolf, K.-H.; Barzandji, O.; Bruining, H.

    2006-01-01

    This study investigated the technical and economic feasibility of using CO2 for the enhanced production of coal bed methane (ECBM) in the Netherlands. This concept could lead to both CO2 storage by adsorbing CO2 in deep coal layers that are not suitable for mining, as well as production of methane.

  18. Potential for CO2 sequestration and enhanced coalbed methane production in the Netherlands

    NARCIS (Netherlands)

    Hamelinck, C.N.; Schreurs, H.; Faaij, A.P.C.; Ruijg, G.J.; Jansen, Daan; Pagnier, H.; Bergen, F. van; Wolf, K.-H.; Barzandji, O.; Bruining, H.

    2006-01-01

    This study investigated the technical and economic feasibility of using CO2 for the enhanced production of coal bed methane (ECBM) in the Netherlands. This concept could lead to both CO2 storage by adsorbing CO2 in deep coal layers that are not suitable for mining, as well as production of methane.

  19. The relative contribution of methanotrophs to microbial communities and carbon cycling in soil overlying a coal-bed methane seep.

    Science.gov (United States)

    Mills, Christopher T; Slater, Gregory F; Dias, Robert F; Carr, Stephanie A; Reddy, Christopher M; Schmidt, Raleigh; Mandernack, Kevin W

    2013-06-01

    Seepage of coal-bed methane (CBM) through soils is a potential source of atmospheric CH4 and also a likely source of ancient (i.e. (14) C-dead) carbon to soil microbial communities. Natural abundance (13) C and (14) C compositions of bacterial membrane phospholipid fatty acids (PLFAs) and soil gas CO2 and CH4 were used to assess the incorporation of CBM-derived carbon into methanotrophs and other members of the soil microbial community. Concentrations of type I and type II methanotroph PLFA biomarkers (16:1ω8c and 18:1ω8c, respectively) were elevated in CBM-impacted soils compared with a control site. Comparison of PLFA and 16s rDNA data suggested type I and II methanotroph populations were well estimated and overestimated by their PLFA biomarkers, respectively. The δ(13) C values of PLFAs common in type I and II methanotrophs were as negative as -67‰ and consistent with the assimilation of CBM. PLFAs more indicative of nonmethanotrophic bacteria had δ(13) C values that were intermediate indicating assimilation of both plant- and CBM-derived carbon. Δ(14) C values of select PLFAs (-351 to -936‰) indicated similar patterns of CBM assimilation by methanotrophs and nonmethanotrophs and were used to estimate that 35-91% of carbon assimilated by nonmethanotrophs was derived from CBM depending on time of sampling and soil depth.

  20. The relative contribution of methanotrophs to microbial communities and carbon cycling in soil overlying a coal-bed methane seep

    Science.gov (United States)

    Mills, Christopher T.; Slater, Gregory F.; Dias, Robert F.; Carr, Stephanie A.; Reddy, Christopher M.; Schmidt, Raleigh; Mandernack, Kevin W.

    2013-01-01

    Seepage of coal-bed methane (CBM) through soils is a potential source of atmospheric CH4 and also a likely source of ancient (i.e. 14C-dead) carbon to soil microbial communities. Natural abundance 13C and 14C compositions of bacterial membrane phospholipid fatty acids (PLFAs) and soil gas CO2 and CH4 were used to assess the incorporation of CBM-derived carbon into methanotrophs and other members of the soil microbial community. Concentrations of type I and type II methanotroph PLFA biomarkers (16:1ω8c and 18:1ω8c, respectively) were elevated in CBM-impacted soils compared with a control site. Comparison of PLFA and 16s rDNA data suggested type I and II methanotroph populations were well estimated and overestimated by their PLFA biomarkers, respectively. The δ13C values of PLFAs common in type I and II methanotrophs were as negative as −67‰ and consistent with the assimilation of CBM. PLFAs more indicative of nonmethanotrophic bacteria had δ13C values that were intermediate indicating assimilation of both plant- and CBM-derived carbon. Δ14C values of select PLFAs (−351 to −936‰) indicated similar patterns of CBM assimilation by methanotrophs and nonmethanotrophs and were used to estimate that 35–91% of carbon assimilated by nonmethanotrophs was derived from CBM depending on time of sampling and soil depth.

  1. Coal and Coalbed Methane Co-Extraction Technology Based on the Ground Movement in the Yangquan Coalfield, China

    Directory of Open Access Journals (Sweden)

    Guozhong Hu

    2015-07-01

    Full Text Available The Yangquan coalfield is one of the typical highly gassy mining areas in China. However, its coal seams are of lower permeability, which are not conductive to coalbed methane (CBM drainage. In this study, based on the theory of the ground movement, we analyzed the principle of coal and CBM coextraction in the Yangquan coalfield, and established the technology system of coal and CBM coextraction which was further implemented in the coal and CBM coextraction in the Yangquan coalfield. The coal and CBM coextraction technologies based on the “pressure-relief and permeability-increase” effect caused by the mining overburden movement can optimally ensure the safe and efficient mining and improve the gas drainage rate. A series of developed coal and CBM coextraction technologies for the Yangquan coalfield were mainly characterized by the high-level gas drainage roadway. This reached a maximum gas drainage amount of 270,000 m3/day for single drainage roadway and a pressure-relief gas drainage rate of >90%. Those technologies significantly improved the gas drainage effect safely and efficiently achieving the coal and CBM coextraction.

  2. Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

    Science.gov (United States)

    Bern, Carleton R.; Boehlke, Adam R.; Engle, Mark A.; Geboy, Nicholas J.; Schroeder, K.T.; Zupancic, J.W.

    2013-01-01

    Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (∼3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO4 salts more soluble than gypsum. Irrigation with high SAR (∼24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

  3. Shallow groundwater and soil chemistry response to 3 years of subsurface drip irrigation using coalbed-methane-produced water

    Energy Technology Data Exchange (ETDEWEB)

    Bern, C. R.; Boehlke, A. R.; Engle, M. A.; Geboy, N. J.; Schroeder, K. T.; Zupancic, J. W.

    2013-10-04

    Disposal of produced waters, pumped to the surface as part of coalbed methane (CBM) development, is a significant environmental issue in the Wyoming portion of the Powder River Basin, USA. High sodium adsorption ratios (SAR) of the waters could degrade agricultural land, especially if directly applied to the soil surface. One method of disposing of CBM water, while deriving beneficial use, is subsurface drip irrigation (SDI), where acidified CBM waters are applied to alfalfa fields year-round via tubing buried 0.92 m deep. Effects of the method were studied on an alluvial terrace with a relatively shallow depth to water table (~3 m). Excess irrigation water caused the water table to rise, even temporarily reaching the depth of drip tubing. The rise corresponded to increased salinity in some monitoring wells. Three factors appeared to drive increased groundwater salinity: (1) CBM solutes, concentrated by evapotranspiration; (2) gypsum dissolution, apparently enhanced by cation exchange; and (3) dissolution of native Na–Mg–SO{sub 4} salts more soluble than gypsum. Irrigation with high SAR (24) water has increased soil saturated paste SAR up to 15 near the drip tubing. Importantly though, little change in SAR has occurred at the surface.

  4. Sr isotope tracing of aquifer interactions in an area of accelerating coal-bed methane production, Powder River Basin, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Frost, C.D.; Pearson, B.N.; Ogle, K.M.; Heffern, E.L.; Lyman, R.M. [University of Wyoming, Laramie, WY (United States). Dept. of Geology & Geophysics

    2002-07-01

    Sr isotope data on groundwater samples from coal and overlying sandstone aquifers in the eastern Powder River Basin, Wyoming, demonstrate that the Sr isotope ratio effectively identifies groundwater from different aquifers where major ion geochemistry and 0 and H stable isotope data fail. Groundwaters from sandstone aquifers have a uniform Sr-87/Sr-86 ratio of 0.7126-0.7127. Waters from coal seams vary from Sr-87/Sr-86 ratio = 0.7127 near the recharge area to 0.7151 farther into the basin. The distinct Sr isotope signatures of sandstone and coal aquifers may reflect different sources of Sr in these two rock types: Sr in sandstones is held primarily in carbonate cement, whereas coals contain more radiogenic Sr in organic matter. The Sr isotope ratio is useful in identifying wells that contain mixed waters, whether due to well construction or to incomplete aquifer isolation. Measurement and continued monitoring of the Sr isotope ratio in groundwaters should provide a powerful tool for characterizing the impact of the burgeoning coal-bed methane industry on the hydrology of the Powder River Basin.

  5. Overcoming the challenges of gathering system requirements for coalbed methane production : a San Juan Basin case study

    Energy Technology Data Exchange (ETDEWEB)

    Midkiff, K. [Burlington Resources Canada Ltd., Calgary, AB (Canada)

    2002-07-01

    For the past 14 years, Burlington Resources has operated the Val Verde Gas Gathering and Treating System in the San Juan Basin of New Mexico and Colorado. It is a world-class CO{sub 2} removal and dehydration facility consisting of 8 individual treating trains. This paper described the company's experiences with material and equipment selection, pressure regimes, design objectives and other issues regarding CO{sub 2} production, including environmental challenges. The coalbed methane (CBM) production contained a substantial quantity of CO{sub 2} (10 per cent) and was not suitable for gathering and processing within the conventional infrastructure of the San Juan Basin. Val Verde gathers gas from 229 wellheads and 10 central delivery points. There are about 465 miles of pipeline in the area. Because of the depletion characteristics of CBM systems, most of the wells gathered by Val Verde currently use wellhead booster compression prior to entry into the system. The paper described the gathering and processing requirements for CBM, pressure regimes, the efficiency of modular design, CO{sub 2} management, and hydraulic modeling systems. A comparison of CBM systems to conventional gathering systems was also presented. 6 figs.

  6. THE APPLICATION OF SEISMIC FACIES TECHNOLOGY TO COAL-BED METHANE EXPLORATION%地震相技术在煤层气勘探中的应用

    Institute of Scientific and Technical Information of China (English)

    祁雪梅; 董守华

    2012-01-01

    在分析了采用地震相技术预测煤层气含量可行性的基础上,首先利用无监督向量量化网络对研究区地震资料进行了地震波形划分,然后在钻孔实测煤层气含量值的指导下,依赖地震波形特征反演与煤层气含量有关综合特征,完成了使用地震相分布图对勘探区煤层气含量的预测.预测结果与实测值相符,具有较高的预测分辨率,从而证明了该方法的有效性和实用性.%This paper analyzed the feasibility of applying seismic facies technology to forecasting coal-bed methane content. The authors first made seismic wave division in the study area by using unsupervised vector quantization network, and then completed coal-bed methane content prediction in the exploration area based on seismic facies under the guidance of the measured coal-bed methane values in drill holes and according to seismic wave characteristics. The results are consistent with the measured values and have relatively high prediction of resolution, suggesting that the application of seismic facies technology is an effective approach to predicting coal - bed methane content.

  7. The effect of coal-bed methane water on spearmint and peppermint.

    Science.gov (United States)

    Zheljazkov, Valtcho D; Cantrell, Charles L; Astatkie, Tess; Schlegel, Vicki; Jeliazkova, Ekaterina; Lowe, Derek

    2013-11-01

    Coal bed methane is extracted from underground coal seams that are flooded with water. To reduce the pressure and to release the methane, the water needs to be pumped out. The resulting waste water is known as coal bed methane water (CBMW). Major concerns with the use of CBMW are its high concentrations of S, Na, dissolved Ca, Mg, SO, and bicarbonate (HCO). Irrigation water is a scarce resource in most of the western states. The objective of this study was to evaluate the effect of various amounts of CBMW on the growth, essential oil content, composition, and antioxidant activity of spearmint ( L.) and peppermint ( L.) crops that were irrigated with the water. These two crops are grown in some western states and are potential specialty crops to Wyoming farmers. The irrigation treatments were 0% CBMW (tap water only), 25% CBMW (25% CBMW plus 75% tap water), 50% CBMW (50% CBMW and 50% tap water), 75% CBMW (75% CBMW plus 25% tap water), and 100% CBMW. Analyses of the data revealed that the CBMW treatments did not affect the antioxidant capacity of spearmint or peppermint oil (242 and 377 μmol L Trolox g, respectively) or their major oil constituents (carvone or menthol). Coal bed methane water at 100% increased total phenols and total flavonoids in spearmint but not in peppermint. Coal bed methane water also affected oil content in peppermint but not in spearmint. Spearmint and peppermint could be watered with CBMW at 50% without suppression of fresh herbage yields. However, CBMW at 75 and 100% reduced fresh herbage yields of both crops and oil yields of peppermint relative to the control.

  8. 燃气发电机组在低浓度煤层气综合开发中的应用%Application of Gas Genset in Comprehensive Development and exploitation of Low Concentration Coalbed Methane

    Institute of Scientific and Technical Information of China (English)

    张成江; 原义刚; 高山

    2015-01-01

    介绍了燃气发电机组在低浓度煤层气综合开发中的应用,为燃气发电机组在煤层气中的应用扩大了20个百分点,且有着极其重大的社会和经济效益。%This paper introduces gas genset in comprehensive development and exploitation of low concentration coalbed methane and 20 percent points that are increased in the gas genset application of coalbed methane, which has a significant benefit in society and economy.

  9. Origin of minerals in joint and cleat systems of the Pottsville Formation, Black Warrior basin, Alabama: Implications for coalbed methane generation and production

    Science.gov (United States)

    Pitman, J.K.; Pashin, J.C.; Hatch, J.R.; Goldhaber, M.B.

    2003-01-01

    Coalbed methane is produced from naturally fractured strata in the lower Pennsylvanian Pottsville Formation in the eastern part of the Black Warrior basin, Alabama. Major fracture systems include orthogonal fractures, which consist of systematic joints in siliciclastic strata and face cleats in coal that strike northeast throughout the basin. Calcite and minor amounts of pyrite commonly fill joints in sandstone and shale and, less commonly, cleats in coal. Joint-fill calcite postdates most pyrite and is a weakly ferroan, coarse-crystalline variety that formed during a period of uplift and erosion late in the burial history. Pyrite forms fine to coarse euhedral crystals that line joint walls or are complexly intergrown with calcite. Stable-isotope data reveal large variations in the carbon isotope composition of joint- and cleat-fill calcite (-10.3 to + 24.3??? Peedee belemnite [PDB]) but only a relatively narrow range in the oxygen-isotope composition of this calcite (-16.2 to -4.1 ??? PDB). Negative carbon values can be attributed to 13C-depleted CO2 derived from the oxidation of organic matter, and moderately to highly positive carbon values can be attributed to bacterial methanogenesis. Assuming crystallization temperatures of 20-50??C, most joint- and cleat-fill calcite precipitated from fluids with ??18O ratios ranging from about -11 to +2 ??? standard mean ocean water (SMOW). Uplift and unroofing since the Mesozoic led to meteoric recharge of Pottsville strata and development of freshwater plumes that were fed by meteoric recharge along the structurally upturned, southeastern margin of the basin. Influxes of fresh water into the basin via faults and coalbeds facilitated late-stage bacterial methanogenesis, which accounts for the high gas content in coal and the carbonate cementation of joints and cleats. Diagenetic and epigenetic minerals can affect the transmissivity and storage capacity of joints and cleats, and they appear to contribute significantly to

  10. Expansion and Enhacement of the Wyoming Coalbed Methane Clearinghouse Website to the Wyoming Energy Resources Information Clearinghouse.

    Energy Technology Data Exchange (ETDEWEB)

    Hulme, Diana [Univ. of Wyoming, Laramie, WY (United States); Hamerlinck, Jeffrey [Univ. of Wyoming, Laramie, WY (United States); Bergman, Harold [Univ. of Wyoming, Laramie, WY (United States); Oakleaf, Jim [Univ. of Wyoming, Laramie, WY (United States)

    2010-03-25

    Energy development is expanding across the United States, particularly in western states like Wyoming. Federal and state land management agencies, local governments, industry and non-governmental organizations have realized the need to access spatially-referenced data and other non-spatial information to determine the geographical extent and cumulative impacts of expanding energy development. The Wyoming Energy Resources Information Clearinghouse (WERIC) is a web-based portal which centralizes access to news, data, maps, reports and other information related to the development, management and conservation of Wyoming's diverse energy resources. WERIC was established in 2006 by the University of Wyoming's Ruckelshaus Institute of Environment and Natural Resources (ENR) and the Wyoming Geographic Information Science Center (WyGISC) with funding from the US Department of Energy (DOE) and the US Bureau of Land Management (BLM). The WERIC web portal originated in concept from a more specifically focused website, the Coalbed Methane (CBM) Clearinghouse. The CBM Clearinghouse effort focused only on coalbed methane production within the Powder River Basin of northeast Wyoming. The CBM Clearinghouse demonstrated a need to expand the effort statewide with a comprehensive energy focus, including fossil fuels and renewable and alternative energy resources produced and/or developed in Wyoming. WERIC serves spatial data to the greater Wyoming geospatial community through the Wyoming GeoLibrary, the WyGISC Data Server and the Wyoming Energy Map. These applications are critical components that support the Wyoming Energy Resources Information Clearinghouse (WERIC). The Wyoming GeoLibrary is a tool for searching and browsing a central repository for metadata. It provides the ability to publish and maintain metadata and geospatial data in a distributed environment. The WyGISC Data Server is an internet mapping application that provides traditional GIS mapping and analysis

  11. Depositional sequence stratigraphy and architecture of the cretaceous ferron sandstone: Implications for coal and coalbed methane resources - A field excursion

    Science.gov (United States)

    Garrison, J.R.; Van Den, Bergh; Barker, C.E.; Tabet, D.E.

    1997-01-01

    This Field Excursion will visit outcrops of the fluvial-deltaic Upper Cretaceous (Turonian) Ferron Sandstone Member of the Mancos Shale, known as the Last Chance delta or Upper Ferron Sandstone. This field guide and the field stops will outline the architecture and depositional sequence stratigraphy of the Upper Ferron Sandstone clastic wedge and explore the stratigraphic positions and compositions of major coal zones. The implications of the architecture and stratigraphy of the Ferron fluvial-deltaic complex for coal and coalbed methane resources will be discussed. Early works suggested that the southwesterly derived deltaic deposits of the the upper Ferron Sandstone clastic wedge were a Type-2 third-order depositional sequence, informally called the Ferron Sequence. These works suggested that the Ferron Sequence is separated by a type-2 sequence boundary from the underlying 3rd-order Hyatti Sequence, which has its sediment source from the northwest. Within the 3rd-order depositional sequence, the deltaic events of the Ferron clastic wedge, recognized as parasequence sets, appear to be stacked into progradational, aggradational, and retrogradational patterns reflecting a generally decreasing sediment supply during an overall slow sea-level rise. The architecture of both near-marine facies and non-marine fluvial facies exhibit well defined trends in response to this decrease in available sediment. Recent studies have concluded that, unless coincident with a depositional sequence boundary, regionally extensive coal zones occur at the tops of the parasequence sets within the Ferron clastic wedge. These coal zones consist of coal seams and their laterally equivalent fissile carbonaceous shales, mudstones, and siltstones, paleosols, and flood plain mudstones. Although the compositions of coal zones vary along depositional dip, the presence of these laterally extensive stratigraphic horizons, above parasequence sets, provides a means of correlating and defining the tops

  12. Commercialization of previously-wasted coal mine gob gas and coalbed methane

    Energy Technology Data Exchange (ETDEWEB)

    Sakashita, B.J. [Resource Enterprises, Inc., Salt Lake City, UT (United States); Deo, M.D. [Utah Univ., Salt Lake City, UT (United States). Dept. of Chemical and Fuels Engineering

    1993-12-31

    Enrichment of a gas stream with only one contaminant is a relatively simple process (depending on the contaminant) using available technology. Most of the gas separation technology developed to date addresses this problem. However, gob gas has a unique nature, consisting of five primary constituents, only one of which has any significant value. These constituents are: methane, nitrogen, oxygen, carbon dioxide and water vapor. Each of the four contaminants may be separated from the methane using existing technologies that have varying degrees of complexity and compatibility. However, the operating and cost effectiveness of the combined system is dependent on careful integration of the clean-up processes. In summary, the system design that is expected to be the most favorable from both technical and economic viewpoints is a facility consisting of (1) a PSA nitrogen rejection unit, (2) a catalytic combustion deoxygenation process, (3) an amine or membrane carbon dioxide removal system, and (4) a conventional dehydration unit, as depicted in Figure 1.

  13. Tracking solutes and water from subsurface drip irrigation application of coalbed methane-produced waters, Powder River Basin, Wyoming

    Science.gov (United States)

    Engle, M.A.; Bern, C.R.; Healy, R.W.; Sams, J.I.; Zupancic, J.W.; Schroeder, K.T.

    2011-01-01

    One method to beneficially use water produced from coalbed methane (CBM) extraction is subsurface drip irrigation (SDI) of croplands. In SDI systems, treated CBMwater (injectate) is supplied to the soil at depth, with the purpose of preventing the buildup of detrimental salts near the surface. The technology is expanding within the Powder River Basin, but little research has been published on its environmental impacts. This article reports on initial results from tracking water and solutes from the injected CBM-produced waters at an SDI system in Johnson County, Wyoming. In the first year of SDI operation, soil moisture significantly increased in the SDI areas, but well water levels increased only modestly, suggesting that most of the water added was stored in the vadose zone or lost to evapotranspiration. The injectate has lower concentrations of most inorganic constituents relative to ambient groundwater at the site but exhibits a high sodium adsorption ratio. Changes in groundwater chemistry during the same period of SDI operation were small; the increase in groundwater-specific conductance relative to pre-SDI conditions was observed in a single well. Conversely, groundwater samples collected beneath another SDI field showed decreased concentrations of several constituents since the SDI operation.Groundwater-specific conductance at the 12 other wells showed no significant changes. Major controls on and compositional variability of groundwater, surface water, and soil water chemistry are discussed in detail. Findings from this research provide an understanding of water and salt dynamics associated with SDI systems using CBM-produced water. Copyright ??2011. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  14. Controls on coalbed methane potential and gas sorption characteristics of high-volatile bituminous coals in Indiana

    Science.gov (United States)

    Solano-Acosta, Wilfrido

    The increasing demand for energy and a growing concern for global warming, owing in part to the steep rise in anthropogenic greenhouse gas emissions, have sparked worldwide interest in clean coal technologies. Although the energy potential of coal is large, there are many environmental concerns associated with its large-scale utilization. An alternative solution to increasing demand for energy is the recovery of coalbed methane (CBM), an efficient and clean fossil fuel associated with extensive coal deposits. CBM today represents nearly 10 percent of the energy consumed in the United States. From an environmental perspective, coal beds that are too deep or that contain low-quality coal are being investigated as potential sites for permanently sequestering carbon dioxide emissions (CO2 sequestration). Methane has been documented in coals of various ranks. The occurrence and distribution of economically recoverable quantities of CBM result from the interplay between stratigraphy, tectonics, and hydrology. This study evaluates geologic factors that control the occurrence of CBM in Indiana coals, ranging from large-scale processes (i.e., burial and fracturing) to molecular interactions between CBM and the physical structure of coal (i.e., gas adsorption). This study investigates the role of tectonics and burial in the formation of coal fracture sets (cleats) that are critical for CBM extraction. Based on field data, I investigate the role of fracturing with regard to gas occurrence and CBM producibility. The timing of cleat formation is evaluated via carbon and oxygen isotopic signatures of cleat-filling minerals. In addition to field-scale observations, this study includes an experimental component that, based on a multitude of laboratory data, constrains optimum conditions for coal-sample preservation prior to laboratory analyses for exploration. Chemical analyses, petrography, grain-size distributions, Fourier transform infra-red (FTIR) spectroscopy, pore

  15. 峰峰矿区地质特征及煤层气赋存%The geological characteristics and the coalbed methane accumulation in Fengfeng mine district

    Institute of Scientific and Technical Information of China (English)

    许建平; 袁莉

    2001-01-01

    鼓山背斜是峰峰矿区的主控构造。鼓山背斜以西,断层发育,煤层埋藏较浅,地下水补、径、排条件良好,造成煤层气的逸散,煤层含气量低;鼓山背斜以东,地形相对较低,煤层呈单斜构造向深部倾伏,地下水补、径、排条件较差,煤层气得以保存和富集。%Gushan anticline is the main controlling structure in Fengfeng mine district. In the western part of Gushan anticline, faults develops, coal seams bury in small depth, ground water is in good conditions of supply, flow and drainage. As a result, the coalbed methane scattered and the gas content in coal seams is very low. But in the eastern part, the topography is lower, coal seams are in singe inclination and incline toward depths, ground water is in worse conditions of supply, flow and drainage, the coalbed methane is well preserved and the gas content is high.

  16. Coal and coalbed-methane resources in the Appalachian and Black Warrior basins: maps showing the distribution of coal fields, coal beds, and coalbed-methane fields: Chapter D.1 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Trippi, Michael H.; Ruppert, Leslie F.; Milici, Robert C.; Kinney, Scott A.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The maps contained in this chapter show the locations of coal fields, coal beds assessed by the U.S. Geological Survey (USGS) in 2000, and coalbed-methane fields in the central and southern Appalachian basin study areas, which include the coal-producing parts of the Black Warrior basin. The maps were compiled and modified from a variety of sources such as Tully (1996), Northern and Central Appalachian Basin Coal Regions Assessment Team (2001), Hatch and others (2003), Milici (2004), and unpublished data from the State geological surveys of Pennsylvania, West Virginia, Virginia, and Alabama. The terms “coalbed methane” and “coal-bed gas” are used interchangeably in this report. All of the figures are located at the end of this report.

  17. 电絮凝处理煤层气产出水%Treatment of water produced with coal-bed methane by electrocoagulation

    Institute of Scientific and Technical Information of China (English)

    李向东; 冯启言; 宋均轲; 蔡娟

    2012-01-01

    Electrocoagulation was applied to water produced with coal-bed methane treatment.Comparing aluminum and iron electrodes,the former one was selected in the electrocoagulation experiments.The effect of the operational parameters such as inter-electrode,the pH value and current density was investigated.The results showed that the electrocoagulation was an effective water treatment technique for water produced with coal-bed methane.The optimum working pH was found to be in the neutral condition,allowing water produced with coal-bed methane to be treated directly without adding soluble salts to the water and changing the pH of the solution.The appropriate experimental conditions for water produced with coal-bed methane treatment by electrocoagulation are quantified.Electrode distance is 1 cm.The current intensity is 30 A/m2.The COD and SS reach 9.6 mg/L and 8.5 mg/L after 10 min reaction,of which the removal efficiencies are about 75.1% and 88.8%,respectively.The pH value of effluent is 7.8.The power requirement is 1.75 kWh/m3.Experimental investigations show that the electrocoagulation is an effective water treatment technique for water produced with coal-bed methane.%采用电絮凝法处理煤层气产出水,通过铁和铝2种电极材料的处理效果的比较,选择铝电极进行实验,研究了电极间距、原水pH值以及电流密度等因素对电絮凝处理效果的影响。实验结果表明,电絮凝法对煤层气产出水的化学需氧量(COD)和固体悬浮物(SS)具有良好的去除效果,原水pH接近中性时处理效果较好,电絮凝处理过程中不需添加可溶性盐和改变pH值。实验中确定的电絮凝处理条件为:电极间距1 cm,电流密度30 A/m2,反应10 min后,出水的COD、SS分别为9.6 mg/L和8.5 mg/L,去除率分别达到75.1%和88.8%,出水pH为7.8,电能消耗为1.75 kWh/m3。

  18. Physiology and Genetics of Biogenic Methane-Production from Acetate

    Energy Technology Data Exchange (ETDEWEB)

    Sowers, Kevin R

    2013-04-04

    Biomass conversion catalyzed by methanogenic consortia is a widely available, renewable resource for both energy production and waste treatment. The efficiency of this process is directly dependent upon the interaction of three metabolically distinct groups of microorganisms; the fermentative and acetogenic Bacteria and the methanogenic Archaea. One of the rate limiting steps in the degradation of soluble organic matter is the dismutation of acetate, a predominant intermediate in the process, which accounts for 70 % or more of the methane produced by the methanogens. Acetate utilization is controlled by regulation of expression of carbon monoxide dehydrogensase (COdh), which catalyzes the dismutation of acetate. However, physiological and molecular factors that control differential substrate utilization have not been identified in these Archaea. Our laboratory has identified sequence elements near the promoter of the gene (cdh) encoding for COdh and we have confirmed that these sequences have a role in the in vivo expression of cdh. The current proposal focuses on identifying the regulatory components that interact with DNA and RNA elements, and identifying the mechanisms used to control cdh expression. We will determine whether expression is controlled at the level of transcription or if it is mediated by coordinate interaction of transcription initiation with other processes such as transcription elongation rate and differential mRNA stability. Utilizing recently sequenced methanosarcinal genomes and a DNA microarray currently under development genes that encode regulatory proteins and transcription factors will be identified and function confirmed by gene disruption and subsequent screening on different substrates. Functional interactions will be determined in vivo by assaying the effects of gene dosage and site-directed mutagenesis of the regulatory gene on the expression of a cdh::lacZ operon fusion. Results of this study will reveal whether this critical

  19. On Coalbed Methane Industrial Components and Gas Content Calculation Model in Heshun Area%和顺地区煤层气工业组分与含气量计算研究

    Institute of Scientific and Technical Information of China (English)

    张作清

    2013-01-01

    以和顺地区煤层工业分析实验和现场煤层气含气量测试为基础,利用煤层灰分、固定碳、挥发分、水分等四元工业组分的内在关系,分别建立煤心密度与灰分的线性关系、灰分与挥发分的线性关系、灰分与固定碳的线性关系,得出和顺地区煤层四元工业组分的测井计算模型.经过扩径校正,对确定的深侧向电阻率、自然伽马、补偿密度、补偿声波时差等4条对含气量敏感的测井曲线进行单相关分析,引入复合参数P计算煤层气含量,显著提高了煤层气含量的计算精度,取得了预期的地质效果.%Based on the coalbed industrial composition analysis and coalbed methane field test of Heshun district, this paper builds new models of the coalbed four industrial composition with density log by means of their inner relationship. For improving coalbed gas content model, we first make correction on borehole enlargement, then build and analyze the relations among gas content and conventional logs such as density, neutron, gamma ray, and etc. Last, put forward a new combined model (composite parameter P) to calculate the coalbed methane content. This new model significantly improves coalbed methane content calculation accuracy, and achieves expected geological consistency.

  20. Leaky hydrocarbon wells are an unconsidered source for biogenic methane in the North Sea

    Science.gov (United States)

    Vielstädte, L.; Haeckel, M.; Karstens, J.; Linke, P.; Schmidt, M.; Steinle, L.; Wallmann, K. J. G.

    2016-12-01

    Shallow gas migration along hydrocarbon wells constitutes a potential methane emission pathway that currently is not recognized in any regulatory framework or greenhouse gas inventory. We conducted the first methane emission measurements at offshore abandoned wells in the Central North Sea (CNS) and found that considerable amounts of biogenic methane (i.e. δ13C 2,300) originating from shallow gas accumulations (water of the North Sea (11±6 kt yr-1), where it is expected to contribute to the export of methane into the North Atlantic Ocean. In the North Sea and in other hydrocarbon-prolific provinces of the world shallow gas pockets are frequently observed in the sedimentary overburden and aggregate leakages along the numerous wells drilled in those areas may be significant, particularly from infrastructure located in shallow coastal waters but also onshore, where gas is directly emitted into the atmosphere. Advanced knowledge of current methane emissions sources will aid in adapting the respective regulatory frameworks and will help to improve the monitoring of petroleum infrastructure.

  1. Investigation of Biogenic and Non-biogenic Methane Sources in Texas

    Science.gov (United States)

    Yang, S.; Talbot, R. W.; Liu, L.; Lan, X.

    2016-12-01

    Methane (CH4) is a potent greenhouse gas with its mixing ratio increasing in the global atmosphere. Texas is one of the significant areas where underestimation of CH4 emissions by the U.S. inventories are pronounced. This study focused on two areas of Texas: Houston, the energy capital of the world, and the Barnett Shale area which is one of the largest onshore natural gas fields in the United States. The investigation of background CH4 and the fingerprints of CH4 emissions are critical to understanding potential impacts of extensive nature gas operations in these two areas. One-year of stationary CH4 measurements were studied to deduce the regional background CH4 characteristics and to identify the principle CH4 sources in Houston. Key information concerning CH4 sources can be obtained through the stable carbon isotope δ13CH4 during two field campaigns using a state-of-the-art mobile laboratory. CH4 mixing ratio and δ13C in CH4 were sampled by two cavity ring-down spectrometers (CRDS), one of which is coupled to a custom air core 13C sampling device which can supply more than 600 measurements for each plume analysis. Here, we report results of the overall δ13CH4 values and CH4 emission signatures derived from thirty-three sources in the two studied areas, ranging from oil production and processing, waste managements and landfills, to livestock. δ13CH4 signatures of these sources vary from -76‰ to -23‰. Several repeated measurements were sampled to investigate the variability of source signatures. We investigated a case of unexpected massive CH4 leaking detected near the San Jacinto River Fleet site. At the regional scale, the comparison of background δ13CH4 signatures were conducted to obtain the difference of dominate CH4 sources in two study areas. At the local scale, the combination of tower and mobile lab measurements were used to estimate and characterize CH4 emissions in Houston. The results and findings can supply valuable references for the local

  2. Fermentation enhancement of methanogenic archaea consortia from an Illinois basin coalbed via DOL emulsion nutrition.

    Directory of Open Access Journals (Sweden)

    Dong Xiao

    Full Text Available Microbially enhanced coalbed methane technology must be used to increase the methane content in mining and generate secondary biogenic gas. In this technology, the metabolic processes of methanogenic consortia are the basis for the production of biomethane from some of the organic compounds in coal. Thus, culture nutrition plays an important role in remediating the nutritional deficiency of a coal seam. To enhance the methane production rates for microorganism consortia, different types of nutrition solutions were examined in this study. Emulsion nutrition solutions containing a novel nutritional supplement, called dystrophy optional modification latex, increased the methane yield for methanogenic consortia. This new nutritional supplement can help methanogenic consortia form an enhanced anaerobic environment, optimize the microbial balance in the consortia, and improve the methane biosynthesis rate.

  3. Fermentation enhancement of methanogenic archaea consortia from an Illinois basin coalbed via DOL emulsion nutrition.

    Science.gov (United States)

    Xiao, Dong; Peng, Su-Ping; Wang, En-Yuan

    2015-01-01

    Microbially enhanced coalbed methane technology must be used to increase the methane content in mining and generate secondary biogenic gas. In this technology, the metabolic processes of methanogenic consortia are the basis for the production of biomethane from some of the organic compounds in coal. Thus, culture nutrition plays an important role in remediating the nutritional deficiency of a coal seam. To enhance the methane production rates for microorganism consortia, different types of nutrition solutions were examined in this study. Emulsion nutrition solutions containing a novel nutritional supplement, called dystrophy optional modification latex, increased the methane yield for methanogenic consortia. This new nutritional supplement can help methanogenic consortia form an enhanced anaerobic environment, optimize the microbial balance in the consortia, and improve the methane biosynthesis rate.

  4. Deposition of Biogenic Iron Minerals in a Methane Oxidizing Microbial Mat

    Directory of Open Access Journals (Sweden)

    Christoph Wrede

    2013-01-01

    Full Text Available The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and iron sulfides, building up these chimneys. Iron sulfides are generated by the microbial reduction of oxidized sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic iron sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger iron sulfide mineral aggregates.

  5. Deposition of biogenic iron minerals in a methane oxidizing microbial mat.

    Science.gov (United States)

    Wrede, Christoph; Kokoschka, Sebastian; Dreier, Anne; Heller, Christina; Reitner, Joachim; Hoppert, Michael

    2013-01-01

    The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and iron sulfides, building up these chimneys. Iron sulfides are generated by the microbial reduction of oxidized sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic iron sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger iron sulfide mineral aggregates.

  6. Evaluation of optimized well location and geology characteristics of coal-bed methane in Shulan coalfield of Fraxinus mandshurica zone%舒兰煤田水曲柳区煤层气地质特征及优选井位评价

    Institute of Scientific and Technical Information of China (English)

    谢石; 谢颖; 于宁

    2015-01-01

    The coal-bed methane sources in Shulan coalfield of Fraxinus mandshurica zone are better. Ten billion cubic meters coal-bed methane is expected to be received. The content of coal-bed methane is higher in this district which is an ideal exploration and development area of coal-bed methane.%舒兰煤田水曲柳区煤层气资源条件较好,有望获得煤层气资源量约10亿立方米,同时该区具有煤层气含量较高,页岩层在煤系地层中较发育,是理想的煤层气勘探开发区.

  7. 含氧煤层气流量变化对液化工艺影响的模拟研究%Simulation Study on Influence of Flow Change of Oxygen-contained Coal-bed Methane upon Liquefaction Process

    Institute of Scientific and Technical Information of China (English)

    朱菁; 王长元; 张武; 任小坤

    2014-01-01

    In this paper, simulation calculation wad carried out on the liquefaction process of coal-bed methane by using HYSYS software and analysis was made on influence of the flow change of coal-bed methane upon the energy consumption of liquefaction and the recovery rate of methane. The results showed that the change range of the total liquefaction energy consumption was identical with that of coal-bed methane flow, of which the change range of the nitrogen compression energy consumption was greater than that of coal-bed methane flow and that of the MRC compression energy consumption was smaller than that of coal-bed methane;the flow change increased the liquefaction energy consumption of unit LNG product, but the flow decrease did not affect the recovery rate of coal-bed methane, and only the flow increase may reduce its recovery rate. In actual operation, it’ s better to make the cooling system having 5% margin so as to ensure the security and stability of the liquefaction process.%利用HYSYS软件对煤层气液化工艺进行模拟计算,分析了煤层气流量变化对液化能耗和CH4回收率的影响,结果表明:总液化能耗变化幅度与煤层气流量变化幅度一致,其中氮气压缩功耗变化幅度大于流量变化幅度,混合冷剂压缩功耗变化幅度小于流量变化幅度;煤层气流量变化会使LNG单位产品液化能耗增加,但流量减小不影响CH4回收率,只有流量增加会降低CH4回收率。在实际运行时,应使制冷系统提供的冷量留有5%的余量,以确保工艺过程的安全与稳定。

  8. Estimates for biogenic non-methane hydrocarbons and nitric oxide emissions in the Valley of Mexico

    Science.gov (United States)

    Velasco, Erik

    Biogenic non-methane hydrocarbons (NMHC), 2-methyl-3-buten-2-ol (methylbutenol or MBO) and nitrogen oxide (NO) emissions were estimated for the Valley of Mexico developing a spatially and temporally resolved emission inventory for air quality models. The modeling domain includes all the Metropolitan Mexico City Area, the surrounding forests and agriculture fields. The estimates were based on several sources of land use and land cover data and a biogenic emission model; the biomass density and tree characteristics were obtained from reforestation program data. The biogenic emissions depend also on climatic conditions, mainly temperature and solar radiation. The temperature was obtained from a statistical revision of the last 10 yr data reported by the Mexico City Automatic Atmospheric Monitoring Network, while the solar radiation data were obtained from measurements performed in a typical oak forest in the Valley and from sources of total solar radiation data for Mexico City. The results indicated that 7% of total hydrocarbon emissions in Mexico Valley are due to vegetation and NO emissions from soil contribute with 1% to the total NO x emissions.

  9. Assessment of the Environmental Impacts of Coalbed Methane Development in the Powder River Basin - Use of Coalbead Methane Produced Water for Cropland Irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Jeff Morris

    2009-01-30

    Water quality is a major concern with regard to development of coalbed methane (CBM) in the Powder River Basin, Wyoming. Large quantities of water are being produced and discharged as a by-product in the process of releasing natural gas from coal. Current practices of discharging large volumes of water into drainage channels or using it to irrigate cropland areas has the potential to elevate salinity and sodicity in soils. Elevated salinity affects the ability of plants to uptake water to facilitate biochemical processes such as photosynthesis and plant growth. Elevated sodicity in irrigation water adversely affects soil structure necessary for water infiltration, nutrient supply, and aeration. Salinity and sodicity concentrations are important in that a sodic soil can maintain its structure if the salinity level is maintained above the threshold electrolyte concentration. In this study, cropland soil and CBM water were treated with gypsum and sulfur. Changes in soil chemistry among different treatments were monitored using a split plot experiment. The CBM water used for irrigation had an EC of 1380 {micro}S cm{sup -1} and SAR of 24.3 mmol{sup 1/2} L{sup -1/2}. Baseline and post treatment soil samples were collected to a depth of 60 cm within each study plot, analyzed, and characterized for chemical parameters. Comparisons between Spring 2004 and Fall 2004 soil chemistry data after one irrigation season (using the equivalent of 1 month of irrigation water or {approx}12 inches) indicated that irrigating with Piney Creek water or a 50:50 blend of Piney Creek water and CBM water did not cause SAR values to increase. A combination of using a gypsum amendment to the soil along with a gypsum injection and sulfur burner treatment to the irrigation water resulted in the lowest SAR value in the first soil horizon among treatments irrigated solely with CBM produced water. The SAR value resulting from this combination treatment was 53% lower than using CBM water with no

  10. 企业人力资源管理效益提升研究%Research on Raising Efficiency of Human Resources Management in Coalbed Methane Enterprises

    Institute of Scientific and Technical Information of China (English)

    孙磊

    2015-01-01

    企业要加强人力资源效益体系建设,发挥人力资源管理的积极作用,为实施人力资源管理战略创造良好的环境;积极推进煤层气综合改革机制,为煤层气开发利用和人力资源管理制度创新提供重要的平台,实现人力资源的全方位管理。%The coalbed methane enterprise should strengthen the construction of human resource benefit system, exerting its positive effect, which will create a good environment for implementing its strategic management. CBM enterprises should promote actively the comprehensive reform mechanism, provide an important platform for human resources management system innovation, and realize the full range management of human resources management.

  11. Biogenic methane leakage on the Aquitaine Shelf: fluid system characterization from source to emission

    Science.gov (United States)

    Michel, Guillaume; Dupré, Stéphanie; Baltzer, Agnès; Imbert, Patrice; Ehrhold, Axel; Battani, Anne; Deville, Eric

    2017-04-01

    The recent discovery of biogenic methane emissions associated with methane-derived authigenic carbonate mounds along the Aquitaine Shelf edge offshore SW France (140 to 220 m water depth) questions about the initiation and temporal evolution of this fluid system (80 km N-S and 8 km E-W). Based on a multi-data study (including multibeam echosounder, subbottom profiler, single channel sparker seismic, 80 traces air gun seismic data and well cuttings and logs), different scenarii are proposed for the organic matter source levels and migration pathways of the methane. Several evidence of the presence of gas are observed on seismic data and interpreted to be linked to the biogenic system. Single channel sparker seismic lines exhibit an acoustic blanking (between 75-100 ms TWT below seafloor and the first multiple) below the present-day seepage area and westwards up to 8 km beyond the shelf-break. An air gun seismic line exhibits chaotic reflections along 8 km below the seepage area from the seabed down to 700 ms TWT below seafloor. Based on 1) the local geothermal gradient about 26 °C/km and 2) the window for microbial methanogenesis ranging from 4 to 56 °C, the estimation of the bottom limit for biogenic generation window is about 1.5 km below seafloor. Cuttings from 3 wells of the area within the methanogenesis window show average TOC (Total Organic Carbon) of 0.5 %; however, one well shows some coal levels with 30-35 % TOC in the Oligocene between 1490 and 1540 m below seafloor. Geochemical analysis on crushed cuttings evidenced heavy hydrocarbons up to mid-Paleogene, while shallower series did not evidence any. In the first scenario, we propose that methane is sourced from the Neogene prograding system. The 0.5% average TOC is sufficient to generate a large volume of methane over the thickness of this interval (up to 1 km at the shelf break area). In the second scenario, methane would be sourced from the Oligocene coals; however their spatial extension with regard

  12. Coalbed Reserves to be Exploited for New Energy

    Institute of Scientific and Technical Information of China (English)

    Du Ming

    1996-01-01

    @@ Approved by the State Council of China in March 1996,the China United Coalbed Methane Co., Ltd. (China CBM)was founded in Beijing, consisting of the Ministry of Coal Industry (MOCI), the Ministry of Geology and Mineral Resources (MGMR) and the China National Petroleum Corporation (CNPC). It marks the development of coalbed methane entering into a new stage in China.

  13. 气体钻井设备在新疆煤层气项目中的应用%Application of gas drilling equipment in Xinjiang coalbed methane project

    Institute of Scientific and Technical Information of China (English)

    孙立伟

    2011-01-01

    Most coalbed methane reservoirs are featured by low pressure, low permeability and low saturation, etc. Circulation loss is a frequent problem encountered in the process of coal seam drilling. On the other hand, conventional stimulation and blowdown recovery techniques are hard to work. Application of gas drilling equipment in Xinjiang coalbed methane project for aerated underbalanced drilling and methane displacement with nitrogen has shown very good effect in coping with circulation loss problem and improving coalbed methane recovery.%大多数煤层气藏具有低压、低渗、低饱和度等特点,这使得一方面在煤层钻井过程中容易出现井漏问题,另一方面使得常规增产改造和降压开发技术难于奏效.通过对气体钻井设备在新疆煤层气项目中充气欠平衡钻井和注氮驱替甲烷施工的分析,表明气体钻井设备对于解决地层漏失和提高煤层气的采收率具有很好的现场应用效果.

  14. Methylotrophic methanogenesis governs the biogenic coal bed methane formation in Eastern Ordos Basin, China.

    Science.gov (United States)

    Guo, Hongguang; Yu, Zhisheng; Liu, Ruyin; Zhang, Hongxun; Zhong, Qiding; Xiong, Zhenghe

    2012-12-01

    To identify themethanogenic pathways present in a deep coal bed methane (CBM) reservoir associated with Eastern Ordos Basin in China, a series of geochemical and microbiological studies was performed using gas and water samples produced from the Liulin CBM reservoir. The composition and stable isotopic ratios of CBM implied a mixed biogenic and thermogenic origin of the methane. Archaeal 16S rRNA gene analysis revealed the dominance of the methylotrophic methanogen Methanolobus in the water produced. The high potential of methane production by methylotrophic methanogens was found in the enrichments using the water samples amended with methanol and incubated at 25 and 35 °C. Methylotrophic methanogens were the dominant archaea in both enrichments as shown by polymerase chain reaction (PCR)–denaturing gradient gel electrophoresis (DGGE). Bacterial 16S rRNA gene analysis revealed that fermentative, sulfate-reducing, and nitrate-reducing bacteria inhabiting the water produced were a factor in coal biodegradation to fuel methanogens. These results suggested that past and ongoing biodegradation of coal by methylotrophic methanogens and syntrophic bacteria, as well as thermogenic CBM production, contributed to the Liulin CBM reserves associated with the Eastern Ordos Basin.

  15. Methodologies and results of the latest assessment of coalbed methane resources in China%新一轮全国煤层气资源评价方法与结果

    Institute of Scientific and Technical Information of China (English)

    刘成林; 朱杰; 车长波; 杨虎林; 樊明珠

    2009-01-01

    新一轮的全国煤层气资源评价是迄今为止评价规模最大、范围最广、资源系列最全的一次,其成果已经得到了广泛应用.为此,详细介绍了新一轮全国煤层气资源评价采用的方法,并与我国历次煤层气资源评价进行了对比.新一轮全国煤层气资源评价采用了以体积法为主的评价方法体系,以煤层含气量、可采系数、煤层气资源类别评价标准等为关键评价参数,系统评价了全国42个主要含煤层气盆地(群)、121个含气区带的煤层气资源.评价结果表明:全国埋深2 000 m以浅煤层气地质资源量为36.81×10~(12)m~3,可采资源量为10.87×10~(12)m~3;煤层气资源集中分布在鄂尔多斯、沁水、准噶尔等大型盆地,在层系,深度和地理环境的分布上具有很强的不均衡性,资源品质较好,以Ⅰ、Ⅱ类为主.%The latest nationwide assessment of coal-bed methane resources is the largest in size and the most complete in re-source series, and the assessment results have been widely applied. The methodologies are introduced in detail and compared with that applied in previous assessments of coal-bed methane resources in China. The latest round of coal-bed resources assess-ment used a method system dominated by volumetric method and various key evaluation parameters including coal-bed methane content, recovery factors, and standards for classification and evaluation of coal-bed methane. A total of 42 major basins (basin groups) containing coal-bed methane and 121 gas-bearing zones methane plays were systematically assessed. The results show that the original coal-bed methane in-place is 36.81 tcm in the coal layers with a burial depth of less than 2000 m, of which 10.87 tcm is ultimately recoverable. The coal-bed methane resources are concentrated in large basins such as Ordos, Qinshui and Junggar. Their distribution in layer series, depth and geographic environment is highly uneven. The resources volume is large and

  16. Comprehensive Log Evaluation for Coalbed Methane Reservoir in Eastern Block of Ordos Basin%鄂东气田煤层气储层测井综合评价方法研究

    Institute of Scientific and Technical Information of China (English)

    刘之的; 杨秀春; 陈彩红; 张继坤

    2013-01-01

    It has an important significance for coalbed methane exploration and development that accurately and comprehensively evaluating the coalbed methane reservoir with log data.In view of many parameters affecting the performance of coalbed methane reservoir,as well as geological features,physical properties and characteristics of the coal reservoir,six indexes are selected to reflect the CBM reservoir quality.They are coal petrography index,fracture growth index,fracture porosity index,permeability index,coalbed methane content index and effective thickness index.Due to the strong heterogeneity of coalbed methane reservoirs of gas field in eastern block of Ordos basin,the reservoir parameters are often random and fuzzy in the comprehensive evaluation of the coalbed methane reservoir,therefore we suggest a fuzzy comprehensive evaluation model.Using log data which have abundant geological information of coalbed methane reservoir and the laboratory analysis data of actual coal core,the fuzzy evaluation set is established to evaluate the coalbed methane reservoir,based on which the fuzzy comprehensive evaluation model is carried out for the work area.The comprehensive log evaluation result has a good consistency with laboratory test and analysis result.%影响煤层气储层性能的参数众多.从煤储层地质特征、物性特征和储集特征出发,优选出能够充分反映煤层气储层优质与否并且利用测井资料易于求取的6个指标:煤岩性质和结构、裂缝发育程度、裂缝孔隙度、渗透率、煤层气含量和有效厚度.针对鄂东气田煤层气储层非均质性强,煤层气储层综合评价中存在储层参数的随机性、模糊性等诸多问题,给出煤层气储层模糊综合评价模型.利用测井资料和实际煤岩心室内分析资料,构建用于煤层气储层测井综合评价的模糊评判集,并基于此模糊评判集,采用模糊综合评价模型对工区内重点井进行了模糊综合评判.该评

  17. Microbially-Enhanced Coal Bed Methane: Strategies for Increased Biogenic Production

    Science.gov (United States)

    Davis, K.; Barhart, E. P.; Schweitzer, H. D.; Cunningham, A. B.; Gerlach, R.; Hiebert, R.; Fields, M. W.

    2014-12-01

    Coal is the largest fossil fuel resource in the United States. Most of this coal is deep in the subsurface making it costly and potentially dangerous to extract. However, in many of these deep coal seams, methane, the main component of natural gas, has been discovered and successfully harvested. Coal bed methane (CBM) currently accounts for approximately 7.5% of the natural gas produced in the U.S. Combustion of natural gas produces substantially less CO2 and toxic emissions (e.g. heavy metals) than combustion of coal or oil thereby making it a cleaner energy source. In the large coal seams of the Powder River Basin (PRB) in southeast Montana and northeast Wyoming, CBM is produced almost entirely by biogenic processes. The in situ conversion of coal to CBM by the native microbial community is of particular interest for present and future natural gas sources as it provides the potential to harvest energy from coal seams with lesser environmental impacts than mining and burning coal. Research at Montana State University has shown the potential for enhancing the subsurface microbial processes that produce CBM. Long-term batch enrichments have investigated the methane enhancement potential of yeast extract as well as algal and cyanobacterial biomass additions with increased methane production observed with all three additions when compared to no addition. Future work includes quantification of CBM enhancement and normalization of additions. This presentation addresses the options thus far investigated for increasing CBM production and the next steps for developing the enhanced in situ conversion of coal to CBM.

  18. 采动影响下煤层气地面井的经济和安全效益分析%Analysis on Economic and Safety Benefits of Surface Coal-bed Methane Wells

    Institute of Scientific and Technical Information of China (English)

    焦海滨; 付军辉; 孙海涛

    2014-01-01

    This PaPer described the calculation method for the economic indicators such as the investment cost of the surface coal-bed methane wells( the wells under the mining influence),the sales revenues and so on,and analyzed the safety benefits of this Project. By taking Sihe Mine of Jincheng Anthracite Mining GrouP Co. ,Ltd. ,as an examPle,the PaPer gave a systematical analysis on the economic and safety benefits of the surface coal-bed methane wells under the mining influence,and the results showed that the direct annual economic return rate of the surface coal-bed methane wells under the mining influence can reach 3. 87% after gas extraction,and the indirect economic benefits and safety benefits after gas extraction were more substantial. The analysis results can Provide a basis for the coal-bed methane develoPment by surface wells.%介绍了采动影响下的煤层气地面井(采动影响井)投资成本、销售收入等经济指标的计算方法,并对该项目的安全效益进行了分析。以晋煤集团寺河矿为实例,对其采动影响井的经济效益、安全效益进行了系统分析,结果表明:采动影响井抽采后直接经济年收益率可达3.87%,且抽采后间接的经济、安全效益均较为可观。分析结果可为采动区地面井煤层气开发提供依据。

  19. The effect of coal bed dewatering and partial oxidation on biogenic methane potential

    Science.gov (United States)

    Jones, Elizabeth J.P.; Harris, Steve H.; Barnhart, Elliott P.; Orem, William H.; Clark, Arthur C.; Corum, Margo D.; Kirshtein, Julie D.; Varonka, Matthew S.; Voytek, Mary A.

    2013-01-01

    Coal formation dewatering at a site in the Powder River Basin was associated with enhanced potential for secondary biogenic methane determined by using a bioassay. We hypothesized that dewatering can stimulate microbial activity and increase the bioavailability of coal. We analyzed one dewatered and two water-saturated coals to examine possible ways in which dewatering influences coal bed natural gas biogenesis by looking at differences with respect to the native coal microbial community, coal-methane organic intermediates, and residual coal oxidation potential. Microbial biomass did not increase in response to dewatering. Small Subunit rRNA sequences retrieved from all coals sampled represented members from genera known to be aerobic, anaerobic and facultatively anaerobic. A Bray Curtis similarity analysis indicated that the microbial communities in water-saturated coals were more similar to each other than to the dewatered coal, suggesting an effect of dewatering. There was a higher incidence of long chain and volatile fatty acid intermediates in incubations of the dewatered coal compared to the water-saturated coals, and this could either be due to differences in microbial enzymatic activities or to chemical oxidation of the coal associated with O2 exposure. Dilute H2O2 treatment of two fractions of structural coal (kerogen and bitumen + kerogen) was used as a proxy for chemical oxidation by O2. The dewatered coal had a low residual oxidation potential compared to the water-saturated coals. Oxidation with 5% H2O2 did increase the bioavailability of structural coal, and the increase in residual oxidation potential in the water saturated coals was approximately equivalent to the higher methanogenic potential measured in the dewatered coal. Evidence from this study supports the idea that coal bed dewatering could stimulate biogenic methanogenesis through partial oxidation of the structural organics in coal once anaerobic conditions are restored.

  20. Organic geochemical investigation and coal-bed methane characteristics of the Guasare coals (Paso Diablo mine, western Venezuela)

    Science.gov (United States)

    Quintero, K.; Martinez, M.; Hackley, P.; Marquez, G.; Garban, G.; Esteves, I.; Escobar, M.

    2011-01-01

    The aim of this work was to carry out a geochemical study of channel samples collected from six coal beds in the Marcelina Formation (Zulia State, western Venezuela) and to determine experimentally the gas content of the coals from the Paso Diablo mine. Organic geochemical analyses by gas chromatography-mass spectrometry and isotopic analyses on-line in coalbed gas samples were performed. The results suggest that the Guasare coals were deposited in a continental environment under highly dysoxic and low salinity conditions. The non-detection of 18??(H)-oleanane does not preclude that the organic facies that gave rise to the coals were dominated by angiosperms. In addition, the presence of the sesquiterpenoid cadalene may indicate the subordinate contribution of gymnosperms (conifers) in the Paleocene Guasare mire. The average coalbed gas content obtained was 0.6 cm3/g. ??13C and D values indicate that thermogenic gas is prevalent in the studied coals. Copyright ?? Taylor & Francis Group, LLC.

  1. 43rd annual meeting of the Society of Coal Mining Engineers. Part 3. Coalbed methane activity in the U.S.A.; 1994 nendo (dai 43 kai) zenkoku tanko gijutsukai taikai koenshu. 3. Amerika no tanso gas kaihatsu genkyo ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Tamari, A. [Coal Mining Research Center, Tokyo (Japan)

    1994-09-20

    Hitherto, the coalbed methane gas gushing out accompanied by the coal mining is only emphasized as the obstacle on the viewpoint of safety of colliery in disregard of the fact that a part thereof has been gathered and used for a long time. However, in the overseas coal producing countries having rich coal resources, the evaluation on said coalbed methane as the clean and new energy has been raised in these years, and also from the stand of decreasing the release of methane which is one of the main reasons causing the warming of the earth the researches and the technical development are carried out for the active reclamation thereof. Especially, the coalbed methane activity in the United States shows a rapid growth as the important supplying resource of clean energy shouldering a general part of the natural gas resource in the future. In this paper, simultaneously with the description of the resource and production of coalbed methane the United States, the practical status of San Juan Basin and Black Warrior Basin as the representative coalfield is described. At last, the ventilation technique of coalbed methane in Jim Walter Resources Company are introduced. 3 refs., 12 figs., 1 tab.

  2. 煤层气分子成泡的微观过程研究%A Study on Micro Process of Coalbed Methane Molecules' Bubble Formation

    Institute of Scientific and Technical Information of China (English)

    张硕; 杨平

    2012-01-01

    The chemical theories are used to describe process of coalbed methane (CBM) molecules' dissolution and bubbles formation. Moreover,forces and works of bubbles formation are analyzed,combined with real situation of the field production practice, bubbles formation influence of temperature, overlying pressure,reservoir water salinity,pressure drop and pore medium size are discussed. It shows that methane molecules' bubbles formation in the water includes methane molecules four process of bubbles dissolved in water,local gathered nucleation,bubbles formation and bubble burst,the air bubble growth and stability. The smaller overlying pressure is, the larger pressure drop is, the easier methane molecules form stable bubbles,during early period of CBM development,low temperature and low salinity are benefical to bubble formation when methane molecules move with the diffusion way.%运用化学理论对煤层气分子(主要成分为甲烷)在地层水的溶解和成泡过程进行了描述,对成泡过程的受力与做功进行分析,并结合生产实际讨论了温度、生产压差、地层水矿化度、压力降和孔隙介质的大小对甲烷分子成泡规律的影响.研究表明:甲烷分子在水中成泡包括甲烷分子在水中的溶解、局部聚集成核、成泡与气泡的破裂和气泡的生长与稳定4个过程.上覆压力越小,开发的压力降越大越有利于甲烷分子脱附后形成稳定的气泡;在煤层气开发初期,甲烷以扩散方式运移,低温和低矿化度有利于气泡的生成.

  3. Coalbed-methane production in the Appalachian basin: Chapter G.2 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Milici, Robert C.; Polyak, Désirée E.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    Coalbed methane (CBM) occurs in coal beds of Mississippian and Pennsylvanian (Carboniferous) age in the northern, central, and southern Appalachian basin coal regions, which extend almost continuously from Pennsylvania southward to Alabama. Most commercial CBM production in the Appalachian basin is from three structural subbasins: (1) the Dunkard basin in Pennsylvania, Ohio, and northern West Virginia; (2) the Pocahontas basin in southern West Virginia, eastern Kentucky, and southwestern Virginia; and (3) part of the Black Warrior basin in Alabama. The cumulative CBM production in the Dunkard basin through 2005 was 17 billion cubic feet (BCF), the production in the Pocahontas basin through 2006 was 754 BCF, and the production in the part of the Black Warrior basin in Alabama through 2007 was 2.008 TCF. CBM development may be regarded as mature in Alabama, where annual production from 1998 through 2007 was relatively constant and ranged from 112 to 121 BCF. An opportunity still exists for additional growth in the Pocahontas basin. In 2005, annual CBM production in the Pocahontas basin in Virginia and West Virginia was 85 BCF. In addition, opportunities are emerging for producing the large, diffuse CBM resources in the Dunkard basin as additional wells are drilled and technology improves.

  4. Reasearch advances in coalbed methane (CBM) deoxygeneration by catalytic combustion%催化燃烧法用于煤层气脱氧的研究进展

    Institute of Scientific and Technical Information of China (English)

    袁善良; 薄其飞; 蒋毅

    2016-01-01

    对已报道的国内煤层气开采及脱氧的研究进展进行了综述,介绍了贵金属和非贵金属(过渡金属氧化物型、钙钛矿型等)两类催化剂催化燃烧甲烷在低浓度煤层气脱氧中的研究进展,并对两类催化剂脱氧机理进行了阐述,简要介绍了低浓度煤层气脱氧工艺改进,并在此基础上提出了煤层气脱氧中需要解决的问题和应用前景。%The domestic present situation of coalbed methane (CBM) exploitation and the recent advances in CBM deoxygeneration researches were introduced, including both noble metal and non-noble metal (transition metal oxides, perovskite, etc.) catalysts for low concentration CMM deoxygeneration by catalytic combustion, their reaction mechanisms and process improvement. Finally, the problems and prospects of CBM deoxygeneration were presented.

  5. 我国煤层气开采利用存在的问题及建议%The Problems that China Faces in Coal-Bed Methane Development and Utilization and Some Suggestions

    Institute of Scientific and Technical Information of China (English)

    靳贝贝

    2014-01-01

    我国煤层气开采利用现状不容乐观,存在扶持政策落实不到位、煤层气抽采难度增大、煤层气和煤炭矿业权制度不完善、煤层气利用受限制等问题。建议从以下几个方面促进我国煤层气开发利用的进程和产业化发展:(1)理顺煤、气资源开发主体;(2)增强经济政策的扶持力度;(3)加强理论研究和基础设施保障;(4)完善法律和标准体系建设。%The main problems that China faces in coal-bed methane development and utilization at present include the following:support policies to implement are not in place;it has become more dififcult in extracting coal bed gas;mining right system relating coal and coal-bed gas is imperfect;and the utilization of coal-bed gas is restricted. On account of this, this paper proposes some measures required for improving the process of coal-bed methane development and utilization, as well as industrial development. These measures lay emphasis on the following:straightening out the main body for coal gas resources development;increasing the support of economic policy;strengthening the theory study and infrastructure assurance;and developing laws and standard system construction.

  6. 3-D FRACTURE PROPAGATION SIMULATION AND PRODUCTION PREDICTION IN COALBED

    Institute of Scientific and Technical Information of China (English)

    郭大立; 纪禄军; 赵金洲; 刘慈群

    2001-01-01

    In accordance with the fracturing and producing mechanism in coalbed methane well, and combining the knowledge of fluid mechanics, linear elastic fracture mechanics,thermal transfer, computing mathematics and software engineering, the three-dimensional hydraulic fracture propagating and dynamical production predicting models for coalbed methane well is put forward. The fracture propagation model takes the variation of rock mechanical properties and in-situ stress distribution into consideration. The dynamic performance prediction model takes the gas production mechanism into consideration. With these models, a three-dimensional hydraulic fracturing optimum design software for coalbed methane well is developed, and its practicality and reliability have been proved by example computation.

  7. Separating methane emissions from biogenic sources and natural gas by vertical column enhancements of ammonia, ethane, and methane in the Colorado Front Range

    Science.gov (United States)

    Chiu, R.; Volkamer, R. M.; Blumenstock, T.; Hase, F.; Hannigan, J. W.; Kille, N.; Frey, M.; Kumar Sha, M.; Orphal, J.

    2015-12-01

    Methane sources in the Colorado Front Range include biogenic sources from cattle feedlots and natural gas operations. Although numerous studies have measured methane emissions, there remains significant uncertainty regarding the relative contributions of these various methane emission sources. Here we present data from a March 2015 field campaign that deployed two Bruker EM27 Sun Fourier Transform Spectrometers (FTS) and the University of Colorado Solar Occultation Flux (CU-SOF) FTS in Eaton, Colorado; the former were used to measure enhancements in the methane vertical column densities (VCD), while the latter was used to measure ethane and ammonia VCDs. A third EM27 FTS was deployed to a background site in Westminster, Colorado which was far removed from cattle and petroleum operations. Northerly winds make possible the determination of methane VCD column enhancement from Westminster to Eaton. All instruments were compared during several background days at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado. This presentation explores the potential of methane source attribution using ammonia as a tracer for feedlot emissions and ethane as a tracer for petroleum emissions.

  8. Distribution and geochemical characterization of coalbed gases at excavation fields at natural analogue site area Velenje Basin, Slovenia

    Science.gov (United States)

    Kanduč, Tjaša; Žigon, Stojan; Grassa, Fausto; Sedlar, Jerneja; Zadnik, Ivo; Zavšek, Simon

    2016-04-01

    Unconventional gas resources, including coal bed methane and shale gas, are a growing part of the global energy mix, which has changed the economic and strategic picture for gas consuming and producing countries, including the USA, China and Australia that, together are responsible for around half the currently recoverable unconventional gas resources. However, CBM production was often hindered by low permeability and mineralization in cleats and fractures, necessitating the development of cost effective horizontal drilling and completion techniques. Geochemical and isotopic monitoring of coalbed gases at excavation fields in Velenje Basin started in year 2000, with the aim to obtain better insights into the origin of coalbed gases. Results from active excavation fields in the mining areas Pesje and Preloge in the year period 2014-2015 are presented in this study. Composition and isotopic composition of coalbed gases were determined with mass - spectrometric methods. The chemical (methane, carbon dioxide, nitrogen) and isotopic composition of carbon in methane and carbon dioxide in the Velenje Basin vary and depend on the composition of the source of coalbed gas before excavation, advancement of the working face, depth of the longwall face, pre-mining activity and newly mined activity. The basic gas components determined in excavation fields are carbon dioxide and methane. Knowledge of the stable isotope geochemistry of coal bed and shale gas and the related production water is essential to determine not only gas origins but also the dominant methanogenic pathway in the case of microbial gas. Concentrations of methane at active excavation fields are changing from 1.8 to 63.9 %, concentrations of carbon dioxide are changing from 36.1 to 98.2% and CDMI (Carbon Dioxide Methane Index) index from 0.2 to 100 %. Isotopic composition of carbon dioxide is changing from -11.0 to -1.9‰ , isotopic composition of methane from -71.8 to -43.3‰ , isotopic composition of

  9. Effect of coal matrix swelling on enhanced coalbed methane production. A field and laboratory study. Geologica Ultraiectina (315)

    NARCIS (Netherlands)

    van Bergen, F.

    2009-01-01

    Carbon capture and storage (CCS) is considered a key technology to reduce worldwide emissions of carbon dioxide (CO2). One CCS option is to inject CO2 into subsurface coal beds. When combined with simultaneous, enhanced, production of methane naturally present in the coal, this process is referred t

  10. 3D Geological Modeling of CoalBed Methane (CBM) Resources in the Taldykuduk Block Karaganda Coal Basin, Kazakhstan

    Science.gov (United States)

    Sadykov, Raman; Kiponievich Ogay, Evgeniy; Royer, Jean-Jacques; Zhapbasbayev, Uzak; Panfilova, Irina

    2015-04-01

    Coal Bed Methane (CBM) is gas stored in coal layers. It can be extracted from wells after hydraulic fracturing and/or solvent injection, and secondary recovery techniques such as CO2 injection. Karaganda Basin is a very favorable candidate region to develop CBM production for the following reasons: (i) Huge gas potential; (ii) Available technologies for extracting and commercializing the gas produced by CBM methods; (iii) Experience in degassing during underground mining operations for safety reasons; (iv) Local needs in energy for producing electricity for the industrial and domestic market. The objectives of this work are to model the Taldykuduk block coal layers and their properties focusing on Coal Bed Methane production. It is motivated by the availability of large coal bed methane resources in Karaganda coal basin which includes 4 300 Bm3 equivalent 2 billion tons of coal (B = billion = 109) with gas content 15-25 m3/t of coal (for comparison San Juan basin (USA) has Methane (CH4) can be considered as an environmentally-friendly fuel compared to coal. Actually, the methane extracted during mining is released in the atmosphere, collecting it for recovering energy will reduce CO2 equivalent emissions by 36 Mt, good news regarding climate warming issues. The exploitation method will be based on a EOR technology consisting in injecting CO2 which replaces methane in pores because it has a higher adsorption capacity than CH4; exploiting CBM by CO2 injection provides thus a safe way to sequestrate CO2 in adsorbed form. The 3D geological model was built on Gocad/Skua using the following available data set: 926 wells and large area (7 x 12 km). No seismic data; coal type and chemical components (S, ash, …); unreliable available cross-section & maps due to old acquisition; quality mature coal; complex heterogeneous fractures network reported on geological cross sections; and utilization issues of the water extracted in the early stages of exploitation. The resulting

  11. Results of coalbed-methane drilling, Mylan Park, Monongalia County, West Virginia: Chapter G.3 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Ruppert, Leslie F.; Fedorko, Nick; Warwick, Peter D.; Grady, William C.; Britton, James Q.; Schuller, William A.; Crangle, Robert D.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The Department of Energy National Energy Technology Laboratory funded drilling of a borehole (39.64378°N., 80.04376°W.) to evaluate the potential for coalbed-methane and carbon-dioxide sequestration at Mylan Park, a public park in Monongalia County, W. Va. The total depth of the borehole was 2,525 feet (ft) and contained 1,483.41 ft of Pennsylvanian coal-bearing strata, 739.67 ft of Mississippian strata, and 301.93 ft of Devonian strata.

  12. Results of coalbed-methane drilling, Meadowfill Landfill, Harrison County, West Virginia: Chapter G.4 in Coal and petroleum resources in the Appalachian basin: distribution, geologic framework, and geochemical character

    Science.gov (United States)

    Ruppert, Leslie F.; Trippi, Michael H.; Fedorko, Nick; Grady, William C.; Eble, Cortland F.; Schuller, William A.; Ruppert, Leslie F.; Ryder, Robert T.

    2014-01-01

    The U.S. Environmental Protection Agency funded drilling of a borehole (39.33889°N., 80.26542°W.) to evaluate the potential of enhanced coalbed-methane production from unminable Pennsylvanian coal beds at the Meadowfill Landfill near Bridgeport, Harrison County, W. Va. The drilling commenced on June 17, 2004, and was completed on July 1, 2004. The total depth of the borehole was 1,081 feet (ft) and contained 1,053.95 ft of Pennsylvanian coal-bearing strata, and 27.05 ft of Mississippian strata.

  13. 关于煤层气、页岩气,谁应优先开发利用的讨论%Discussion of Giving Priority to Coal-bed Methane or Shale Gas Development

    Institute of Scientific and Technical Information of China (English)

    潘伟尔

    2012-01-01

    No matter how we evaluate the mission on the importance and emergency or feasibility of economic techniques, the top priority of development should be given to coal-bed methane as the unconventional natural gas at the moment in China.%无论从轻重缓急程度还是经济技术可行性分析看,我国非常规天然气开发利用的当务之急应是煤层气.

  14. Hydraulic fracturing and wellbore completion of coalbed methane wells in the Powder River Basin, Wyoming: Implications for water and gas production

    Energy Technology Data Exchange (ETDEWEB)

    Colmenares, L.B.; Zoback, M.D. [Stanford University, Stanford, CA (United States). Dept. of Geophysics

    2007-01-15

    Excessive water production (more than 7000 bbl/month per well) from many coalbed methane (CBM) wells in the Powder River Basin of Wyoming is also associated with significant delays in the time it takes for gas production to begin. Analysis of about 550 water-enhancement activities carried out during well completion demonstrates that such activities result in hydraulic fracturing of the coal. Water-enhancement activities, consists of pumping 60 bbl of water/min into the coal seam during approximately 15 min. This is done to clean the well-bore and to enhance CBM production. Hydraulic fracturing is of concern because vertical hydraulic fracture growth could extend into adjacent formations and potentially result in excess CBM water production and inefficient depressurization of coals. Analysis of the pressure-time records of the water-enhancement tests enabled us to determine the magnitude of the least principal stress (S{sub 3}) in the coal seams of 372 wells. These data reveal that because S{sub 3} switches between the minimum horizontal stress and the overburden at different locations, both vertical and horizontal hydraulic fracture growth is inferred to occur in the basin, depending on the exact location and coal layer. Relatively low water production is observed for wells with inferred horizontal fractures, whereas all of the wells associated with excessive water production are characterized by inferred vertical hydraulic fractures. The reason wells with exceptionally high water production show delays in gas production appears to be inefficient depressurization of the coal caused by water production from the formations outside the coal. To minimize CBM water production, we recommend that in areas of known vertical fracture propagation, the injection rate during the water-enhancement tests should be reduced to prevent the propagation of induced fractures into adjacent water-bearing formations.

  15. Research on sequence stratigraphy, hydrogeological units and commingled drainage associated with coalbed methane production: a case study in Zhuzang syncline of Guizhou province, China

    Science.gov (United States)

    Li, Xin; Fu, Xuehai; Ge, Yanyan; Chang, Xixi

    2016-12-01

    Exploitation of coalbed methane (CBM) involves groundwater extraction to depressurize coal reservoirs. This can involve groundwater extraction from multiple coal seams (commingled drainage). Interlayer interferences, caused by heterogeneity of hydrodynamic fields of the different coal gas reservoirs, can restrain CBM production. Understanding of the hydrogeological characteristics of each reservoir, inseparable from characteristics of the sequence stratigraphic framework, is critical for CBM exploration. Analysis of Zhuzang syncline in Guizhou province, China, found gas- and water-blocking strata near the maximum flooding surface in the upper part of each third-order stratigraphic sequence; thus, the hydrogeological units were divided vertically (SQ4, SQ3, SQ2 and SQ1) by the boundaries of the third-order sequence. The commingled-drainage CBM wells were analyzed by numerical simulation and Extenics theory, on the basis of characteristics of the hydrogeological units. Gas content, reservoir pressure and hydrodynamic parameters were found to vary between the hydrogeological units. The interlayer interference was not obvious where there was commingled drainage within single hydrogeological units with similar hydrodynamic force; this was validated by observing the consistent pressure decrease within each reservoir using historical matching. Since the source of drainage water varied from stratum SQ3 to SQ4 (containing lower hydrodynamic force compared to SQ3), it was obvious that groundwater extraction from SQ4 was restrained by SQ3, by showing obvious interlayer interference and restrained CBM production during commingled drainage across the different hydrogeological units. Reservoirs within each single hydrogeological unit tend to obtain higher CBM yield, thus take priority for commingled drainage.

  16. Effects of Adsorbed Gases on the Physical and Transport Properties of Low-Rank Coal, PRB, WY: Implications for Carbon Sequestration and Enhanced Coalbed Methane Recovery

    Science.gov (United States)

    Yang, Y.; Zoback, M. D.; Hagin, P. N.

    2010-12-01

    When CO2 is injected into unminable coalbeds, it has the potential to enhance the amount of methane production (ECBM) and to geologically sequester CO2 as an adsorbed phase. In this study we study the effects of adsorption of He, N2, CH4 and CO2, on the mechanical and flow properties of sub-bituminous coal from the Powder River Basin (PRB) on both intact and crushed samples. The coal samples were vacuum dried before each test, then saturated by each test gas at a series of either increasing pore pressure or increasing effective stress until steady state was reached. Thus, the amount of adsorption can be measured as a function of pore pressure Permeability was measured as a function of effective stress. Preliminary results show that the adsorption of CO2 is twice as large as CH4, and almost four times that of N2. Hysteresis is observed among pure component adsorption and desorption isotherms which are characterized Langmuir-type adsorption isotherms. Permeability decreases with increasing effective stress for He, CH4 and CO2. At constant effective stress, permeability decreases when the saturating gas changes from He to CH4 and CO2. Hysteresis of permeability with increasing and decreasing effective stress is not observed in crushed samples. The coal swells when CH4 displaces He and swells more when CO2 displaces He. Viscoplastic creep behavior is observed in the presence of CH4 and CO2 with both intact and crushed samples, which may affect maintaining permeability for long-term CO2 injection. Adsorption Isotherm of Crushed Coal Sample, WY Permeability as a function of effective stress with different gas saturation

  17. Research on sequence stratigraphy, hydrogeological units and commingled drainage associated with coalbed methane production: a case study in Zhuzang syncline of Guizhou province, China

    Science.gov (United States)

    Li, Xin; Fu, Xuehai; Ge, Yanyan; Chang, Xixi

    2016-08-01

    Exploitation of coalbed methane (CBM) involves groundwater extraction to depressurize coal reservoirs. This can involve groundwater extraction from multiple coal seams (commingled drainage). Interlayer interferences, caused by heterogeneity of hydrodynamic fields of the different coal gas reservoirs, can restrain CBM production. Understanding of the hydrogeological characteristics of each reservoir, inseparable from characteristics of the sequence stratigraphic framework, is critical for CBM exploration. Analysis of Zhuzang syncline in Guizhou province, China, found gas- and water-blocking strata near the maximum flooding surface in the upper part of each third-order stratigraphic sequence; thus, the hydrogeological units were divided vertically (SQ4, SQ3, SQ2 and SQ1) by the boundaries of the third-order sequence. The commingled-drainage CBM wells were analyzed by numerical simulation and Extenics theory, on the basis of characteristics of the hydrogeological units. Gas content, reservoir pressure and hydrodynamic parameters were found to vary between the hydrogeological units. The interlayer interference was not obvious where there was commingled drainage within single hydrogeological units with similar hydrodynamic force; this was validated by observing the consistent pressure decrease within each reservoir using historical matching. Since the source of drainage water varied from stratum SQ3 to SQ4 (containing lower hydrodynamic force compared to SQ3), it was obvious that groundwater extraction from SQ4 was restrained by SQ3, by showing obvious interlayer interference and restrained CBM production during commingled drainage across the different hydrogeological units. Reservoirs within each single hydrogeological unit tend to obtain higher CBM yield, thus take priority for commingled drainage.

  18. A contribution of hydrogenotrophic methanogenesis to the biogenic coal bed methane reserves of Southern Qinshui Basin, China.

    Science.gov (United States)

    Guo, Hongguang; Yu, Zhisheng; Thompson, Ian P; Zhang, Hongxun

    2014-11-01

    The activity of methanogens and related bacteria which inhabit the coal beds is essential for stimulating new biogenic coal bed methane (CBM) production from the coal matrix. In this study, the microbial community structure and methanogenesis were investigated in Southern Qinshui Basin in China, and the composition and stable isotopic ratios of CBM were also determined. Although geochemical analysis suggested a mainly thermogenic origin for CBM, the microbial community structure and activities strongly implied the presence of methanogens in situ. 454 pyrosequencing analysis combined with methyl coenzyme-M reductase (mcrA) gene clone library analysis revealed that the archaeal communities in the water samples from both coal seams were similar, with the dominance of hydrogenotrophic methanogen Methanobacterium. The activity and potential of these populations to produce methane were confirmed by the observation of methane production in enrichments supplemented with H2 + CO2 and formate, and the only archaea successfully propagated in the tested water samples was from the genus Methanobacterium. 454 pyrosequencing analysis also recovered the diverse bacterial communities in the water samples, which have the potential to play a role in the coal biodegradation fueling methanogens. These results suggest that the biogenic CBM was generated by coal degradation via the hydrogenotrophic methanogens and related bacteria, which also contribute to the huge CBM reserves in Southern Qinshui Basin, China.

  19. Reuse of Produced Water from CO2 Enhanced Oil Recovery, Coal-Bed Methane, and Mine Pool Water by Coal-Based Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Knutson, Chad [Univ. of Illinois, Champaign, IL (United States); Dastgheib, Seyed A. [Univ. of Illinois, Champaign, IL (United States); Yang, Yaning [Univ. of Illinois, Champaign, IL (United States); Ashraf, Ali [Univ. of Illinois, Champaign, IL (United States); Duckworth, Cole [Univ. of Illinois, Champaign, IL (United States); Sinata, Priscilla [Univ. of Illinois, Champaign, IL (United States); Sugiyono, Ivan [Univ. of Illinois, Champaign, IL (United States); Shannon, Mark A. [Univ. of Illinois, Champaign, IL (United States); Werth, Charles J. [Univ. of Illinois, Champaign, IL (United States)

    2012-07-01

    Power generation in the Illinois Basin is expected to increase by as much as 30% by the year 2030, and this would increase the cooling water consumption in the region by approximately 40%. This project investigated the potential use of produced water from CO2 enhanced oil recovery (CO2-EOR) operations; coal-bed methane (CBM) recovery; and active and abandoned underground coal mines for power plant cooling in the Illinois Basin. Specific objectives of this project were: (1) to characterize the quantity, quality, and geographic distribution of produced water in the Illinois Basin; (2) to evaluate treatment options so that produced water may be used beneficially at power plants; and (3) to perform a techno-economic analysis of the treatment and transportation of produced water to thermoelectric power plants in the Illinois Basin. Current produced water availability within the basin is not large, but potential flow rates up to 257 million liters per day (68 million gallons per day (MGD)) are possible if CO2-enhanced oil recovery and coal bed methane recovery are implemented on a large scale. Produced water samples taken during the project tend to have dissolved solids concentrations between 10 and 100 g/L, and water from coal beds tends to have lower TDS values than water from oil fields. Current pretreatment and desalination technologies including filtration, adsorption, reverse osmosis (RO), and distillation can be used to treat produced water to a high quality level, with estimated costs ranging from $2.6 to $10.5 per cubic meter ($10 to $40 per 1000 gallons). Because of the distances between produced water sources and power plants, transportation costs tend to be greater than treatment costs. An optimization algorithm was developed to determine the lowest cost pipe network connecting sources and sinks. Total water costs increased with flow rate up to 26 million liters per day (7 MGD), and the range was from $4 to $16 per cubic meter

  20. Progress of purification technology for low concentration coal-bed methane%低浓度煤层气分离提纯的研究进展

    Institute of Scientific and Technical Information of China (English)

    吕秋楠; 李小森; 徐纯刚; 陈朝阳; 李刚

    2013-01-01

    This paper reviewed the methods of methane (CH4) separation and purification from coal-bed methane (CBM),including low-temperature distillation,adsorption,membrane separation and gas hydrate separation. By the analysis of the advantages and the disadvantages of these methods,the separation efficiencies under different technical conditions were compared and discussed. Key issues needed to be solved for each method were summarized. For the low-temperature distillation method,de-oxidation is necessarily conducted for the oxygen-containing CBM. The selection of the adsorbent is the key for the adsorption method because the adsorbent determines the economy benefit directly. As for the membrane separation,the separation is affected by the selection of the membrane materials and membrane-making technology. For the hydrated-based CH4 separation,a good additive is crucial to promote the hydrate formation and enhance the CH4 separation efficiency. Finally,the separation of multi-methods or the separation by multi-stage processes is proposed for the future development of CBM separation.%  综述了应用于低浓度煤层气分离的主要方法,包括低温精馏法、吸附分离法、膜分离法和水合物法,探讨了各种方法在不同工艺条件下的分离效果,分析了它们的优缺点。文中总结了每种方法需要解决与突破的关键性问题:低温精馏法获得的甲烷浓度高,但在处理含氧煤层气时首先要脱氧;吸附分离的关键技术在于吸附剂的选择,吸附剂决定了该方法的经济效益与难易程度;对于膜法分离,影响煤层气分离效果的主要因素在于膜材料的选择及制膜工艺;对于水合物法,寻找制备具有较高分离效率的添加剂是关键。最后指出,多种方法结合、多级分离的分离方法是未来研究发展方向。

  1. The key stage and moment of coalbed gas reservior evolution in the Qinshui Basin, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Mengjun; SONG Yan; SU Xianbo; LIU Shaobo; QIN Shengfei; HONG Feng; LIN Xiaoying

    2005-01-01

    The evolution of coalbed gas reservoir is characterized by coalbed gas geochemistry and gas content. On the basis of burial history and thermal history, the forming process of coalbed gas reservoir and the gas accumulative history in the Qinshui Basin are discussed in this paper. The difference of the thermal history, geochemistry characteristic,and gas accumulative history between Yangcheng and Huozhou areas shows that the formation of coalbed gas reservoir in the Qinshui Basin is controlled by the geological process in the critical stage and the critical moment. The components and isotopes of coalbed methane are determined by the stage at which the coal maturation reaches its maximum rank. The coalbed methane accumulative history is related to the temperature and pressure of the coal burial history, because the coalbed gas is mainly in adsorptive state.It is stated that the gas content in the coal seam is controlled by the moment when the coal seam is uplifted to the shallowest position.

  2. Research report for fiscal 1998 on the basic research on the promotion of joint implementation and so forth. Coalbed methane collection and utilization project in China; 1998 nendo Chugoku ni okeru tanko methane gas kaishu riyo project chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    China is surveyed for promotion of joint implementation, which is one of the flexibility measures in the Kyoto Protocol, the Third Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change. The project aims to collect methane for global warming suppression and to use it as town gas and for power generation as well. The survey covers the 2 coalfields of Yangquan and Panjiang. The Yangquan coalfield is the largest anthracite yielding base in China, with 6 mines in operation. Power generation centering on a 100MW plant is discussed, and generation fired by a mixture of debris out of the coal preparation facility and gas is compared with another fired by town gas, on the assumption that 130-million m{sup 3} is available under the current circumstances. In the case of the Panjiang coalfield, which is expected to develop into a large coal base in the southern part of China, power generation centering on a 50MW plant fired by a mixture of debris and gas is discussed, on the assumption that 63-million m{sup 3} is collectable from the existing 5 mines. Use of town gas is also studied. When Japan's coalbed methane collection technology is applied, the gas drainage rate will be elevated to 40-35% or higher. It is desired that the use of gas drainage will be further diffused for the prevention of disasters of coal mine gas explosion. It is hoped that the use of environmentally friendly energies will be enhanced. (NEDO)

  3. Evaluation of Phytoremediation of Coal Bed Methane Product Water and Waters of Quality Similar to that Associated with Coal Bed Methane Reserves of the Powder River Basin, Montana and Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    James Bauder

    2008-09-30

    U.S. emphasis on domestic energy independence, along with advances in knowledge of vast biogenically sourced coalbed methane reserves at relatively shallow sub-surface depths with the Powder River Basin, has resulted in rapid expansion of the coalbed methane industry in Wyoming and Montana. Techniques have recently been developed which constitute relatively efficient drilling and methane gas recovery and extraction techniques. However, this relatively efficient recovery requires aggressive reduction of hydrostatic pressure within water-saturated coal formations where the methane is trapped. Water removed from the coal formation during pumping is typically moderately saline and sodium-bicarbonate rich, and managed as an industrial waste product. Current approaches to coalbed methane product water management include: surface spreading on rangeland landscapes, managed irrigation of agricultural crop lands, direct discharge to ephermeral channels, permitted discharge of treated and untreated water to perennial streams, evaporation, subsurface injection at either shallow or deep depths. A Department of Energy-National Energy Technology Laboratory funded research award involved the investigation and assessment of: (1) phytoremediation as a water management technique for waste water produced in association with coalbed methane gas extraction; (2) feasibility of commercial-scale, low-impact industrial water treatment technologies for the reduction of salinity and sodicity in coalbed methane gas extraction by-product water; and (3) interactions of coalbed methane extraction by-product water with landscapes, vegetation, and water resources of the Powder River Basin. Prospective, greenhouse studies of salt tolerance and water use potential of indigenous, riparian vegetation species in saline-sodic environments confirmed the hypothesis that species such as Prairie cordgrass, Baltic rush, American bulrush, and Nuttall's alkaligrass will thrive in saline-sodic environments

  4. Subsurface Drip Irrigation As a Methold to Beneficiallly Use Coalbed Methane Produced Water: Initial Impacts to Groundwater, Soil Water, and Surface Water

    Energy Technology Data Exchange (ETDEWEB)

    Engle, M.A.: Bern, C: Healy, R: Sams, J: Zupancic, J.: Schroeder, K.

    2009-10-18

    Coalbed methane (CBM) currently accounts for >8% of US natural gas production. Compared to traditional sources, CBM co-produces large volumes of water. Of particular interest is CBM development in the Powder River Basin of Wyoming and Montana, the 2nd largest CBM production field in the US, where CBM produced waters exhibit low to moderate TDS and relatively high sodium-adsorption ratio (SAR) that could potentially impact the surface environment. Subsurface drip irrigation (SDI) is an emerging technology for beneficial use of pre-treated CBM waters (injectate) which are emitted into the root zone of an agricultural field to aid in irrigation. The method is designed to minimize environmental impacts by storing potentially detrimental salts in the vadose zone. Research objectives include tracking the transport and fate of the water and salts from the injected CBM produced waters at an SDI site on an alluvial terrace, adjacent to the Powder River, Johnson County, Wyoming. This research utilizes soil science, geochemical, and geophysical methods. Initial results from pre-SDI data collection and the first 6-months of post-SDI operation will be presented. Substantial ranges in conductivity (2732-9830 {micro}S/cm) and dominant cation chemistry (Ca-SO{sub 4} to Na-SO{sub 4}) have been identified in pre-SDI analyses of groundwater samples from the site. Ratios of average composition of local ground water to injectate demonstrate that the injectate contains lower concentrations of most constituents except for Cr, Zn, and Tl (all below national water quality standards) but exhibits a higher SAR. Composition of soil water varies markedly with depth and between sites, suggesting large impacts from local controls, including ion exchange and equilibrium with gypsum and carbonates. Changes in chemical composition and specific conductivity along surface water transects adjacent to the site are minimal, suggesting that discharge to the Powder River from groundwater underlying the

  5. Analytical modeling of mercury injection in high-rank coalbed methane reservoirs based on pores and microfractures: a case study of the upper carboniferous Taiyuan Formation in the Heshun block of the Qinshui Basin, central China

    Science.gov (United States)

    Gu, Yang; Ding, Wenlong; Yin, Shuai; Wang, Ruyue; Mei, Yonggui; Liu, Jianjun

    2017-03-01

    The coalbed gas reservoirs in the Qinshui Basin in central China are highly heterogeneous; thus, the reservoir characteristics are difficult to assess. Research on the pore structure of a reservoir can provide a basis for understanding the occurrence and seepage mechanisms of coal reservoirs, rock physics modeling and the formulation of rational development plans. Therefore, the pore structure characteristics of the coalbed gas reservoirs in the high rank bituminous coal in the No. 15 coal seam of the Carboniferous Taiyuan Group in the Heshun coalbed methane (CBM) blocks in the northeastern Qinshui Basin were analyzed based on pressure mercury and scanning electron microscopy data. The results showed that the effective porosity system of the coal reservoir was mainly composed of pores and microfractures and that the pore throat configuration of the coal reservoir was composed of pores and microthroats. A model was developed based on the porosity and microfractures of the high rank coal rock and the mercury injection and drainage curves. The mercury injection curve model and the coal permeability are well correlated and were more reliable for the analysis of coal and rock pore system connectivity than the mercury drainage curve model. Coal rocks with developed microfractures are highly permeable; the production levels are often high during the initial drainage stages, but they decrease rapidly. A significant portion of the natural gas remains in the strata and cannot be exploited; therefore, the ultimate recovery is rather low. Coal samples with underdeveloped microfractures have lower permeabilities. While the initial production levels are lower, the production cycle is longer, and the ultimate recovery is higher. Therefore, the initial production levels of coal reservoirs with poorly developed microfractures in some regions of China may be low. However, over the long term, due to their higher ultimate recoveries and longer production cycles, the total gas

  6. 基于Aspen Plus的低浓度含氧煤层气低温精馏的模拟研究%Simulation Study on Cryogenic Distillation Process of Low-concentration Oxygen-containing Coal-bed Methane Based on Aspen Plus

    Institute of Scientific and Technical Information of China (English)

    马代辉

    2016-01-01

    针对低浓度煤层气深冷液化工艺,使用化工流程模拟软件Aspen Plus,对低温精馏过程进行了模拟研究,发现当原料气入口流量为552 kmol/h,精馏塔压力为0.34 MPa时,塔底液态甲烷的纯度为99%。分析了抽采煤层气流量波动对低温精馏效果的影响,发现当煤层气流量降低时,塔顶氮氧尾气中的甲烷含量增加,并且处于爆炸界限内;随着煤层气流量增加,塔底甲烷的纯度和回收率均降低。%To aim at the cryogenic liquefaction technology of low-concentration coal-bed methane, simulation study was made on the cryogenic distillation process with Aspen Plus software. It was found from the study that when the inlet flow rate of the feed gas was 552 kmol/h and the pressure of the distillation column was 0. 34 MPa, the purity of the liquid methane at the column bottom was 99%. Analysis was carried out on the influence of the coal-bed methane flow rate fluctuations on the cryogenic distillation. When the flow rate of coal-bed methane decreased, the methane content in nitrogen oxide gases at the top of the column increased and was within the explosion limit;with the increase of the flow rate of coal-bed methane, the purity and recovery of the methane at the column bottom decreased.

  7. Research on Nonionic Polyacrylamide Zirconium Gel Fracturing Fluids in Coalbed Methane Gas Wells%煤层气井用非离子聚丙烯酰胺锆冻胶压裂液优选

    Institute of Scientific and Technical Information of China (English)

    赵辉; 戴彩丽; 梁利; 王欣; 赵福麟

    2012-01-01

    Active water and guar gum are widely used for coalbed methane fracturing in China. Nevertheless, the application of these two types of fracturing fluid was limited due to poor rheological properties of active water and severe formation damage of guar gum fracturing fluid. Considering the temperature and low permeability of coalbed, the formulation of nonionic polyacrylamide zirconium gel fracturing fluids suitable for coalbed mechane fracturing was selected based on the analysis on the effects of different factors on the zirconium gel. The formulation is 0. 4%PAM+0. 035%ZrOCl2. The performance of the optimized formulation of nonionic polyacrylamide zirconium gel fracturing fluids was evaluated through laboratory experiments, and the results showed that,the formulation had the characteristics of shearing resistance, low filter loss, easy breaking, good proppant carrying capacity, non-residue, low formation damage and easy flowback. It is suitable for the coalbed gas reservoirs fracturing.%活性水、瓜胶压裂液是国内煤层气井压裂最常用的压裂液,但活性水压裂液流变性能差,瓜胶压裂液破胶残渣含量高对煤层的伤害大,限制了这两类压裂液在煤层压裂中的应用.为此,针对煤层温度和渗透率低的特点,在分析影响锆冻胶压裂液性能因素的基础上,优选出了适用于煤层气井压裂的非离子型聚丙烯酰胺锆冻胶压裂液配方(0.400%PAM+0.035%ZrOCl2).通过室内试验对优选出的非离子型聚丙烯酰胺锆冻胶压裂液的性能进行了评价,结果表明,该压裂液具有耐剪切、滤失量低、易破胶、携砂性能好、无残渣、对煤层伤害低、易返排的特点,适用于低温煤层压裂.

  8. A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by 13CH4

    Science.gov (United States)

    Schaefer, Hinrich; Fletcher, Sara E. Mikaloff; Veidt, Cordelia; Lassey, Keith R.; Brailsford, Gordon W.; Bromley, Tony M.; Dlugokencky, Edward J.; Michel, Sylvia E.; Miller, John B.; Levin, Ingeborg; Lowe, Dave C.; Martin, Ross J.; Vaughn, Bruce H.; White, James W. C.

    2016-04-01

    Between 1999 and 2006, a plateau interrupted the otherwise continuous increase of atmospheric methane concentration [CH4] since preindustrial times. Causes could be sink variability or a temporary reduction in industrial or climate-sensitive sources. We reconstructed the global history of [CH4] and its stable carbon isotopes from ice cores, archived air, and a global network of monitoring stations. A box-model analysis suggests that diminishing thermogenic emissions, probably from the fossil-fuel industry, and/or variations in the hydroxyl CH4 sink caused the [CH4] plateau. Thermogenic emissions did not resume to cause the renewed [CH4] rise after 2006, which contradicts emission inventories. Post-2006 source increases are predominantly biogenic, outside the Arctic, and arguably more consistent with agriculture than wetlands. If so, mitigating CH4 emissions must be balanced with the need for food production.

  9. A 21st-century shift from fossil-fuel to biogenic methane emissions indicated by ¹³CH₄.

    Science.gov (United States)

    Schaefer, Hinrich; Mikaloff Fletcher, Sara E; Veidt, Cordelia; Lassey, Keith R; Brailsford, Gordon W; Bromley, Tony M; Dlugokencky, Edward J; Michel, Sylvia E; Miller, John B; Levin, Ingeborg; Lowe, Dave C; Martin, Ross J; Vaughn, Bruce H; White, James W C

    2016-04-01

    Between 1999 and 2006, a plateau interrupted the otherwise continuous increase of atmospheric methane concentration [CH4] since preindustrial times. Causes could be sink variability or a temporary reduction in industrial or climate-sensitive sources. We reconstructed the global history of [CH4] and its stable carbon isotopes from ice cores, archived air, and a global network of monitoring stations. A box-model analysis suggests that diminishing thermogenic emissions, probably from the fossil-fuel industry, and/or variations in the hydroxyl CH4 sink caused the [CH4] plateau. Thermogenic emissions did not resume to cause the renewed [CH4] rise after 2006, which contradicts emission inventories. Post-2006 source increases are predominantly biogenic, outside the Arctic, and arguably more consistent with agriculture than wetlands. If so, mitigating CH4 emissions must be balanced with the need for food production.

  10. Consideration on Financial Management of Foreign Cooperation Project on Coalbed Methane%关于煤层气对外合作项目财务管理工作的思考

    Institute of Scientific and Technical Information of China (English)

    蒋春竹

    2012-01-01

    With more than ten years' development, China's foreign cooperation on coalbed methane has entered into a new stage of sound development. Therefore, financial management becomes very important when accelerating the exploration pace of foreign cooperation projects and realizing the breakthrough of coalbed methane commercialization. This paper will analyze the selection, training and management of fi nancial staff on foreign cooperation projects in details based on the practical work, with emphasis on the process management of cooperation project construction, including accounting files management, financial budget management and joint account audit, in a bid to summarize the previous experience for the refer ence and exchange of the financial staff on foreign cooperation projects.%国内煤层气对外合作经过十几年的发展,目前已进入良性发展的新阶段,在加快对外合作项目勘探步伐和实现煤层气商业化突破的进程中,财务管理工作非常重要。本文从实际工作出发,从对外合作财务人员的选拔、培训及管理方面进行了详细剖析;对合作项目实施的过程管理,包括会计档案管理、财务预算管理,以及联合账簿审计监督等方面进行了重点阐述,旨在总结以往工作经验,供从事对外合作项目财务管工作的人员参考和交流。

  11. Potential water-quality effects of coal-bed methane production water discharged along the upper Tongue River, Wyoming and Montana

    Science.gov (United States)

    Kinsey, Stacy M.; Nimick, David A.

    2011-01-01

    Water quality in the upper Tongue River from Monarch, Wyoming, downstream to just upstream from the Tongue River Reservoir in Montana potentially could be affected by discharge of coal-bed methane (CBM) production water (hereinafter referred to as CBM discharge). CBM discharge typically contains high concentrations of sodium and other ions that could increase dissolved-solids (salt) concentrations, specific conductance (SC), and sodium-adsorption ratio (SAR) in the river. Increased inputs of sodium and other ions have the potential to alter the river's suitability for agricultural irrigation and aquatic ecosystems. Data from two large tributaries, Goose Creek and Prairie Dog Creek, indicate that these tributaries were large contributors to the increase in SC and SAR in the Tongue River. However, water-quality data were not available for most of the smaller inflows, such as small tributaries, irrigation-return flows, and CBM discharges. Thus, effects of these inflows on the water quality of the Tongue River were not well documented. Effects of these small inflows might be subtle and difficult to determine without more extensive data collection to describe spatial patterns. Therefore, synoptic water-quality sampling trips were conducted in September 2005 and April 2006 to provide a spatially detailed profile of the downstream changes in water quality in this reach of the Tongue River. The purpose of this report is to describe these downstream changes in water quality and to estimate the potential water-quality effects of CBM discharge in the upper Tongue River. Specific conductance of the Tongue River through the study reach increased from 420 to 625 microsiemens per centimeter (.μS/cm; or 49 percent) in the downstream direction in September 2005 and from 373 to 543 .μS/cm (46 percent) in April 2006. Large increases (12 to 24 percent) were measured immediately downstream from Goose Creek and Prairie Dog Creek during both sampling trips. Increases attributed to

  12. Biogenic non-methane hydrocarbons (NMHC). Nature`s contribution to regional and global atmospheric chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Klockow, D.; Hoffman, T. [Inst. of Spectrochemistry and Applied Spectroscopy, Dortmund (Germany)

    1995-12-31

    Terrestrial vegetation provides an important source of volatile hydrocarbons, especially isoprene, monoterpenes and in addition possibly sesquiterpenes as well as oxygenated compounds. Although there exist considerable uncertainties in the estimation of the magnitude of these biogenic NMHC emissions, it is generally accepted that the majority of global NMHC release is from natural and not from anthropogenic sources. Taking into consideration the high reactivity of the mostly unsaturated biogenic emissions, their impact on tropospheric processes can be assumed to be of great importance. Together with anthropogenic NO{sub x} emissions, the highly reactive natural alkenes can act as precursors in photochemical oxidant formation and contribute to regional-scale air pollution. Their oxidation in the atmosphere and the subsequent gas-to-particle conversion of the products lead to the formation of organic aerosols. Because of the formation of phytotoxic compounds, the interaction of the biogenic hydrocarbons with ozone inside or outside the leaves and needles of plants has been suggested to play a role in forest decline. (author)

  13. HYSYS在含氧煤层气液化分离中的应用研究%Application Research of HYSYS in Liquefaction Separation of Oxygen-contained Coal-bed Methane

    Institute of Scientific and Technical Information of China (English)

    肖娅; 诸林; 靳亮; 邓骥

    2014-01-01

    在煤矿开采过程中采出的煤层气因含有空气难以加工利用,直接放空,不仅污染大气环境,而且浪费燃气资源。针对某典型含氧煤层气气源,设计了一种氮-甲烷膨胀制冷的液化精馏工艺,并利用HYSYS进行了模拟计算,结果显示,该工艺可较彻底除去氮气、氧气等杂质,获得较高浓度的甲烷产品,甲烷回收率达到99.99%。同时分析了回流比、塔板数以及入塔温度对塔底产品含氧量和甲烷含量的影响。%The coal-bed methane ( CBM) extracted during coal mining contains oxygen and is difficult to be processed and utilized, if it is directly vented, it not only pollutes the environment but also causes the resources waste. Based on a typical oxygen-contained CBM source, a liquefaction rectification process by nitrogen-methane expansion refrigeration was designed and simulation computation was made with HYSYS. The results showed that the nitrogen and oxygen in CBM can be completely removed by this process, the methane product with relatively high concentration can be got, and the methane recovery rate can reach 99. 99%. In addition, analysis was made on the influence of the reflux ratio, plate number and feed temperature on the oxygen and methane content in the bottom products.

  14. Contemporary and projected biogenic fluxes of methane and nitrous oxide in North American terrestrial ecosystems

    Science.gov (United States)

    The importance of methane (CH4) and nitrous oxide (N2O) in determining global climate change has been increasingly recognized, but terrestrial CH4 and N2O budgets and the underlying mechanisms remain far from certain. Accurate estimation of terrestrial CH4 and N2O budgets would be a critical step fo...

  15. Occurrence characteristics and prospective evaluation of coal-bed methane of physicochemical prospecting area in Dafang County of Guizhou Province%贵州省大方县理化勘查区煤层气赋存特征及远景评价

    Institute of Scientific and Technical Information of China (English)

    冯玉勇

    2014-01-01

    Physicochemical exploration area in Dafang County of Guizhou Province containing coal seam of Upper Permian Longtan Formation is mainly anticline-syncline coal-accumulating basin,and is rich in coal-bed methane resources.This article evaluates the prospective of coal-bed methane in this region comprehensively by analyzing and concluding the geological character and coal-formation condition of this region.%贵州大方理化勘查区主要含煤层为上二叠统龙潭组,为一些背向斜构造聚煤盆地,区内蕴藏着丰富的煤层气资源。文章通过对该区地质特征及成气条件的分析和总结,对煤层气资源进行综合远景评价。

  16. Design on Static VAR Generator of Beam Type Water Pump Applied to Coalbed Methane Mining%煤层气开采用游梁式抽水机静止无功发生器设计

    Institute of Scientific and Technical Information of China (English)

    白利军; 王振翀; 庄园; 王聪

    2014-01-01

    According to the power supply quality problems caused by the low power factor and high harmonic content of power distribution network for the beam type water pump applied to the coalbed methane mining area,a study on three level static VAR compensation technol-ogy was conducted.With an analysis on the causes of VAR and harmonics occurred in the power distribution network,based on diode-clamped three-level inverter,a topological structure of the static VAR generator and the voltage and current double-loop control tactics were designed and the three-level space vector pulse width modulation (SVPWM)tactics were simplified.Meanwhile,test prototype was built and applied to a production site of Lanyan Coal Bed Methane Company,Shanxi Jincheng Anthracite Mining Group.The production practice results showed that three level static VAR generator designed could effectively improve the power factor of power distribution net-work for beam type water pump applied to the coalbed methane mining and could effectively reduce the current harmonic content of the power distribution network,which could improve the power supply quality of the power distribution network.%针对应用于煤层气开采领域的游梁式抽水机配电网功率因数偏低且谐波含量较大导致的供电质量问题,进行了三电平静止无功补偿技术的研究。在分析了配电网无功、谐波产生原因的基础上,设计了基于二极管箝位型三电平逆变器的静止无功发生器拓扑结构和电压电流双闭环控制策略,简化了三电平空间矢量脉宽调制( SVPWM)策略,同时搭建了试验样机并应用于山西晋煤集团蓝焰煤层气公司生产现场。实践结果表明,电网平均功率因素提高到0.99,所设计的三电平静止无功发生器可有效提高游梁式抽水机配电网功率因数,同时有效降低配电网电流谐波含量,从而提高了配电网的供电质量。

  17. Coalbed Methane Production Technology and Technical Status and Suggestions in Yanchuan South Block%延川南区块煤层气排采工艺技术现状及建议

    Institute of Scientific and Technical Information of China (English)

    张宏录

    2012-01-01

    Yanchuan south block of coallbed methane production wells for coal from the row in the coal separa- tion to cause frequent card pump shaft screw pump, prosecutors pump cycle is short, unable to realize the con- tinuity of the coalbed methane in row. This paper introduces Yanchuan south block CBM row production Wells technology situation lifting, and find out the screw pump row in the process of mining, the main problems of the corresponding technical countermeasures to improve the whole block Yanchuan CBM development level has certain directive significance.%延川南区块煤层气部分排采井因煤粉从煤层中析出至井筒造成螺杆泵频繁卡泵,检泵周期短,无法实现煤层气的连续性排采。文中介绍了延川南区块煤层气排采井举升工艺技术现状,找出螺杆泵排采工艺中存在的主要问题,提出相应的技术对策,对提高延川南区块煤层气整体开发水平具有一定的指导意义。

  18. Comparison of biogenic methane emissions from unmanaged estuaries, lakes, oceans, rivers and wetlands

    Science.gov (United States)

    Ortiz-Llorente, M. J.; Alvarez-Cobelas, M.

    2012-11-01

    A literature review of quantitative data was carried out to conduct a cross-system study on methane emissions relating peak emissions (PE) and annual emissions (AE) in five types of non-managed ecosystems: estuaries, lakes, oceans, streams and wetlands. PE spanned eight orders of magnitude (0.015 μg CH4 m-2 h-1-300 mg CH4 m-2 h-1) while AE spanned seven (0.078-19044 g CH4 m-2 yr-1). PE and AE were strongly related worldwide (r2 = 0.93). There was no relationship between AE and latitude, with highly variable PE across latitudes and climates. The coefficient of variation (CV) was greatest for emissions in oceans and estuaries, while the highest emission rate was recorded in wetlands and lakes. Efflux from coastal areas and estuaries was higher than that from upwelling areas and deep seas. Concerning wetland types, marshes showed the highest PE with the highest wetland emissions occurring in sites dominated by big helophytes. Non-stratifying- and eutrophic lakes displayed more emissions than other lake types, but there was no environmental variable that might predict methane emissions from lakes on a worldwide basis. Generally, most ecosystem types followed a seasonal pattern of emissions, with a maximum in summer, except in estuaries which did not show any distinct pattern. Regarding the importance of hot spots within most ecosystems, more spatial variability of CH4 emissions was observed in lakes than in wetlands and oceans; however, no relationship between emissions and spatial variability was found. A positive relationship, albeit weak, was found between methane flux and either temperature or irradiance in wetlands; a narrow range of both negative and positive values of the water table promoted CH4 emissions. Previously, little was known about the factors controlling efflux from river and marine environments. Our study suggests that local conditions are important in controlling CH4 emissions, because the variability explained by the more commonly studied abiotic

  19. 焦坪矿区侏罗纪煤层地面煤层气井压裂液优选实验%Fracturing fluid experiment for coalbed methane wells of Jurassic coal in Jiaoping block

    Institute of Scientific and Technical Information of China (English)

    范耀; 茹婷; 李彬刚; 刘易非

    2014-01-01

    压裂液与储层的配伍性是影响水力压裂效果的关键因素之一。为了研究适合焦坪矿区侏罗纪煤层地面煤层气井使用的压裂液配方,通过分析储层特征,提出了相适应的压裂液配方,并借助室内模拟实验对压裂液配方进行优选评价。结果表明:活性水压裂液配方中防膨剂优选1.0%氯化钾防膨效果较好;活性水压裂液配方中助排剂优选0.05%氟炭离子表面活性剂或注入乙醇段塞,再注压裂液这两种助排剂效果较好;对于生物酶破胶压裂液配方建议进一步进行现场试验。%The compatibility of fracturing fluid and reservoir is one of the key factors influencing the effects of hydraulic fracturing. In order to study the suitable fracturing fluid formulations of coalbed methane wells of Juras-sic coal in Jiaoping block, through analysis of the characteristics of Jurassic coal reservoir, fracturing fluid formu-lations are proposed, and optimal evaluation of the fracturing fluid formulations is conducted through indoor simu-lation. The evaluation results show that anti-swelling agent of active water fracturing fluid formulation with 1%potassium chloride is better;injection of cleaning up agent of active water fracturing fluid formulations with 0.05%fluorine carbon ion surface active agent or ethanol slug, then injection of fracturing fluid have good effect;the en-zyme fracturing fluid formulation is recommended for further field test. The results have great realistic significance for hydraulic fracturing of coalbed methane wells of Jurassic coal in Jiaoping block.

  20. A Pilot-scale Demonstration of Reverse Osmosis Unit for Treatment of Coal-bed Methane Co-produced Water and Its Modeling

    Institute of Scientific and Technical Information of China (English)

    钱智; 刘新春; 余志晟; 张洪勋; 琚宜文

    2012-01-01

    This study presents the first demonstration project in China for treatment of coal-bed methane(CBM) co-produced water and recycling.The work aims to provide a research and innovation base for solving the pollution problem of CBM extraction water.The reverse osmosis(RO) unit is applied to the treatment of CBM co-produced water.The results indicate that system operation is stable,the removal efficiency of the total dissolved solids(TDS) is as high as 97.98%,and Fe,Mn,and F-are almost completely removed.There is no suspended solids(SS) detected in the treated water.Furthermore,a model for the RO membrane separation process is developed to describe the quantitative relationship between key physical quantities-membrane length,flow velocity,salt concentration,driving pressure and water recovery rate,and the water recovery restriction equation based on mass balance is developed.This model provides a theoretical support for the RO system design and optimization.The TDS in the CBM co-produced water are removed to meet the "drinking water standards" and "groundwater quality standards" of China and can be used as drinking water,irrigation water,and livestock watering.In addition,the cost for treatment of CBM co-produced water is assessed,and the RO technology is an efficient and cost-effective treatment method to remove pollutants.

  1. Thermal simulation of the formation and evolution of coalbed gas

    Institute of Scientific and Technical Information of China (English)

    DUAN Yi; WU Baoxiang; ZHENG Chaoyang; WANG Chuanyuan

    2005-01-01

    Thermal simulation experiment of gas generation from the peat and the coals were performed using the high temperature and pressure apparatus, at temperature ranging from 336.8-600℃, a pressure of 50MPa and two heating rates of 20℃/h and 2℃/h, and the evolution and formation of coalbed gas components were studied. Results show that for the coals, the gaseous products are mainly composed of hydrocarbon gases. However, for the peat the content of hydrocarbon gases in gaseous products is lower than that of non-hydrocarbon components. In the generated hydrocarbon gases methane is predominant and heavy hydrocarbon gases (C2-5) are present in small amount.Meanwhile, carbon dioxide (CO2) predominates the generated non-hydrocarbon gases, and hydrogen (H2) and sulfurated hydrogen (H2S) are existent in trace amount. It is also observed that temperature is the main factor controlling the evolution of coalbed gas generation. With increasing vitrinite reflectance, methane rapidly increases, CO2 sightly increases, and C2-5 hydrocarbons first increase and then decrease. The peat and Shanxi formation coal have a higher generative potential of coalbed gases than coals and Taiyuan formation coal, respectively, reflecting the effect of the property of organic matter on the characteristics of coalbed gas component generation. In this study, it is found that low heating rate is favorable for the generation of methane, H2and CO2, and the decomposition of C2-5 hydrocarbons. This shows that heating time plays an important controlling role in the generation and evolution of coalbed gases. The results obtained from the simulation experiment in the study of coalbed gases in natural system are also discussed.

  2. Security analysis and measures for the liquefaction process of oxygen-bearing coal-bed methane%含氧煤层气液化流程安全性分析与措施

    Institute of Scientific and Technical Information of China (English)

    邓骥; 诸林; 肖娅; 赵启龙

    2014-01-01

    There is a risk of explosion during purifying the coal-bed methane coming from un-derground drainage ,for the reason that the gas contains oxygen .In this paper ,the results of simulation with HYSYS and the flammability limit theory were combined together to analyze the security of whole process .The results showed that the explosion hazard concentrated at the end of the condensation and on the top of rectification tower .The measure to reduce the compressor outlet pressure or raise the final condensation temperature was proposed .What′s more ,the secu-rity measure was proposed to control the methane content of rectification tower gas above the up-per limit of the explosion strictly ,and then the inerting gas with nitrogen contacts with liquid ni-trogen upstream for further recovery of CH4 .The results indicate that when the value of nitrogen injection ratio is greater than 0 .6 (mole ratio ) ,there is no danger of explosion in liquefaction process ,and both methane yield and process safety are improved greatly in this way .%矿下抽采的煤层气由于混有空气而在液化中存在爆炸危险。通过将HYSYS对常规液化分离流程的模拟结果与爆炸极限理论相结合进行分析计算得出:爆炸危险主要集中在冷凝终了处和精馏塔顶部。进而提出降低压缩机出口压力或提高最终冷凝温度;严格控制精馏塔塔顶气相C H4含量在爆炸上限之上,塔顶气用N2惰化后再与液氮逆流接触以进一步回收C H4。计算表明,当N2注入比达0.6(摩尔比),气相CH4含量曲线将绕过临界点进入安全区。采取措施后CH4有较高收率且液化流程安全性得以提高。

  3. Methanization of biogenic synthetic gases with respect to direct reaction of higher hydrocarbons; Methanisierung biogener Synthesegase mit Hinblick auf die direkte Umsetzung von hoeheren Kohlenwasserstoffen

    Energy Technology Data Exchange (ETDEWEB)

    Kienberger, Thomas

    2010-07-01

    The present work deals with a process for the methanation of the synthesis-gas from allothermal fluidized bed gasification. In the proposed process, the tar and sulfur contaminated syngas is used in a fixed-bed methanation reactor without further gas treatment. Commercial nickel catalysts are applied, which offer the opportunity to bring the gas to stoichiometry, in order to remove sulfur compounds by adsorption and to reform the synthesis-gas tar-content directly in the methanation reactor. An increased catalyst consumption turns out to be disadvantageous for the process. For process development in the course of this work, a biomass-fueled allothermic fluidized bed gasifier (Q{sub BR}=5kW) as well as a polytropic temperature-controlled methanation-reactor was constructed, built up and put into operation. It is possible to operate the system fully remote-controlled, which enables long-term tests without staff on site. Within the step of modelling with the software package ASPEN Plus in advance of experiments, parametric studies of both, the gasifier as well as of the process of methanation, were performed. As a major result, it can be shown that due to the use of nickel as methanation-catalyst-material, the educt gas-conversion is independent of the synthesis-gas's H{sub 2}/CO-ratio. Gasification tests were made to investigate the allothermic fluidized bed gasifier, in order to find an optimum point of operation for the downstream methane-synthesis. In the found point of operation, due to a sufficient water-content in the synthesis gas, from the thermodynamic perspective, carbon deposits on the methanation-catalyst can be avoided. The synthesis gas has a gravimetric tar-load of 10,4 g/Nm{sup 3}, furthermore hydrogen sulfide (H{sub 2}S) with a concentration of around 8 ppm{sub v} was measured as the representative sulfur component. It this gas is led to the methanation-reactor, in contrast to attempts with a clean synthesis-gas, the equilibrium

  4. Origin and distribution of coalbed gases from the Velenje basin, Slovenia

    Energy Technology Data Exchange (ETDEWEB)

    Kanduc, T.; Pezdic, J. [Jozef Stefan Institute, Ljubljana (Slovenia)

    2005-07-01

    Coalbed gases in the Velenje basin are highly variable in both their concentrations and stable isotope composition. Major gas components are CO{sub 2} and methane. According to the geochemical results (recalculated on an air-free basis) for coalbed gases, several types of origin of CO{sub 2} and methane could be recognized: thermogenic methane, endogenic and thermogenic CO{sub 2}, microbial methane and CO{sub 2}. The phenomenon of thermogenic methane in the lignite seam could be explained by microbial CO{sub 2} reduction and/or methane oxidation processes, causing enrichment in the heavy C-13 isotope of methane. Considering geological events at the time of formation of the lignite seam in the Velenje basin, it was found that most of the gas in the lignite seam is of bacterial origin, indicating CO{sub 2} reduction processes mixed with external CO{sub 2}. A considerable fraction of the CO{sub 2} in the lignite seam is of external origin. A crucial factor determining the formation of coalbed gases in the Velenje basin was bacterial activity. The distribution of coalbed gases (CO{sub 2} and methane) is a result of the different physicochemical properties of CO{sub 2} and methane. Methane accumulates at the subsurface of the Velenje basin, while carbon dioxide remains adsorbed on the coalbed surface and in micropores of the coal structure. CO{sub 2} is the major gas component in the lignite seam and represents a permanent danger for gas outbursts. Isotopic fractionation due to migration of methane from the lignite seam to the surface is reflected in isotopically light methane in the water saturated layers. CO{sub 2} accumulating at the subsurface of the Velenje basin is mainly derived from hinterland water and oxidation of methane.

  5. Classification and evaluation of coalbed methane resources/reserves based on the Petroleum Resources Management System (PRMS) rules%基于P RMS准则的煤层气资源/储量划分与评估

    Institute of Scientific and Technical Information of China (English)

    法贵方; 衣艳静; 刘娅昭; 原瑞娥; 王忠生

    2015-01-01

    介绍了基于国际通用准则“石油资源管理系统”( PRMS)的各级煤层气资源/储量的定义及分类要求,从资产所有权、政府监管与项目审批条件、井控程度、测试程度、基础设施和销售市场、开发与生产时间以及经济参数这7个方面详细分析煤层气各级储量的划分依据。结合煤层气地质条件和工程条件、现行经济条件、操作条件以及政府相关政策等,初步制定了煤层气3P 储量和条件储量的确定原则并进行实例分析,为合理评估煤层气储量提供重要参考。%This paper introduces a set of definitions and classification requirements for coalbed methane ( CBM) resources/reserves based on the Petroleum Resources Management System (PRMS). General requirements for the classification of CBM reserves are outlined from seven perspectives: ownership considerations, governmental regulatory and project approval considerations, drilling requirements, testing requirements, infrastructure and market considerations, timing of production and development, and economic requirements. Combined with the geological and engineering conditions, current economics, operating conditions and government policies of CBM, the principles used to classify Proved, Probable, and Possible (3P) reserves and contingent resources were for⁃mulated, and demonstrated by a case analysis. These data provide important reference points for the reasonable assessment of CBM reserves.

  6. Redox controls on methane formation, migration and fate in shallow aquifers

    Science.gov (United States)

    Humez, Pauline; Mayer, Bernhard; Nightingale, Michael; Becker, Veith; Kingston, Andrew; Taylor, Stephen; Bayegnak, Guy; Millot, Romain; Kloppmann, Wolfram

    2016-07-01

    Development of unconventional energy resources such as shale gas and coalbed methane has generated some public concern with regard to the protection of groundwater and surface water resources from leakage of stray gas from the deep subsurface. In terms of environmental impact to and risk assessment of shallow groundwater resources, the ultimate challenge is to distinguish (a) natural in situ production of biogenic methane, (b) biogenic or thermogenic methane migration into shallow aquifers due to natural causes, and (c) thermogenic methane migration from deep sources due to human activities associated with the exploitation of conventional or unconventional oil and gas resources. This study combines aqueous and gas (dissolved and free) geochemical and isotope data from 372 groundwater samples obtained from 186 monitoring wells of the provincial Groundwater Observation Well Network (GOWN) in Alberta (Canada), a province with a long record of conventional and unconventional hydrocarbon exploration. We investigated whether methane occurring in shallow groundwater formed in situ, or whether it migrated into the shallow aquifers from elsewhere in the stratigraphic column. It was found that methane is ubiquitous in groundwater in Alberta and is predominantly of biogenic origin. The highest concentrations of biogenic methane (> 0.01 mM or > 0.2 mgL-1), characterized by δ13CCH4 values migration from deeper methanogenic aquifers. Of the samples, 14.1 % contained methane with δ13CCH4 values > -54 ‰, potentially suggesting a thermogenic origin, but aqueous and isotope geochemistry data revealed that the elevated δ13CCH4 values were caused by microbial oxidation of biogenic methane or post-sampling degradation of low CH4 content samples rather than migration of deep thermogenic gas. A significant number of samples (39.2 %) contained methane with predominantly biogenic C isotope ratios (δ13CCH4 migration into shallow aquifers either naturally or via anthropogenically

  7. Evaluation of Phytoremediation of Coal Bed Methane Product Water and Waters of Quality Similar to that Associated with Coal Bed Methane Reserves of the Powder River Basin, Montana and Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    James Bauder

    2008-09-30

    U.S. emphasis on domestic energy independence, along with advances in knowledge of vast biogenically sourced coalbed methane reserves at relatively shallow sub-surface depths with the Powder River Basin, has resulted in rapid expansion of the coalbed methane industry in Wyoming and Montana. Techniques have recently been developed which constitute relatively efficient drilling and methane gas recovery and extraction techniques. However, this relatively efficient recovery requires aggressive reduction of hydrostatic pressure within water-saturated coal formations where the methane is trapped. Water removed from the coal formation during pumping is typically moderately saline and sodium-bicarbonate rich, and managed as an industrial waste product. Current approaches to coalbed methane product water management include: surface spreading on rangeland landscapes, managed irrigation of agricultural crop lands, direct discharge to ephermeral channels, permitted discharge of treated and untreated water to perennial streams, evaporation, subsurface injection at either shallow or deep depths. A Department of Energy-National Energy Technology Laboratory funded research award involved the investigation and assessment of: (1) phytoremediation as a water management technique for waste water produced in association with coalbed methane gas extraction; (2) feasibility of commercial-scale, low-impact industrial water treatment technologies for the reduction of salinity and sodicity in coalbed methane gas extraction by-product water; and (3) interactions of coalbed methane extraction by-product water with landscapes, vegetation, and water resources of the Powder River Basin. Prospective, greenhouse studies of salt tolerance and water use potential of indigenous, riparian vegetation species in saline-sodic environments confirmed the hypothesis that species such as Prairie cordgrass, Baltic rush, American bulrush, and Nuttall's alkaligrass will thrive in saline-sodic environments

  8. The Occurrence and Accumulation of the Coal-bed Methane%煤层气成藏机理概论

    Institute of Scientific and Technical Information of China (English)

    侯宛宜; 张吉; 马志欣

    2016-01-01

    Coal bed methane is a combustible nature gas,which has great potential in development all over the world. It is a clean,convenient and effective gas which absorb in coal bed. And as a unconventional gas,it has great difference with con-ventional gas,mainly in the occurrence and accumulation and of cause the way to develop it. The research shows that the main occurrence of the coal bed methane is biogenetic and thermogenic,the thermogenic takes the most important place. As for ac-cumulation,it has adsorption,ionization and dissolution,and the most important part is adsorption. The coal bed methane is mainly store in coal matrix pore. And it could have entire migration and accumulation system just by adsorption,an entrapment may not be needed in this progress. The content of coal bed methane is basically decided by a series of factors such as the thickness of coal seam,the degree of coal metamorphism,the geological structure condition,the closed condition and the hydrogeological condition.%煤层气是一种天然的可燃气体,在全世界范围内具有巨大的发展潜力。它吸附在煤层中,具有洁净、方便、高效等特点。煤层气作为一种非常规天然气与常规天然气有巨大的差别,主要体现在在成藏机理和开采方式上。研究调查表明,煤层气的成因机制主要有两种类型,分别为生物成因和热成因,其中以热成因为主要因素。而煤层气的赋存机制,则为吸附、游离和溶解三种,其中吸附方式占到了很大的比例。它主要赋存在煤基质孔隙中。煤层气仅仅依靠吸附作用就可以运聚成藏,它不需要天然的圈闭存在。煤层气的含量主要由煤层厚度、煤变质程度、地质构造条件、顶底封闭条件以及水文地质条件等因素决定。

  9. Using stable isotopes of hydrogen to quantify biogenic and thermogenic atmospheric methane sources: A case study from the Colorado Front Range

    Science.gov (United States)

    Townsend-Small, Amy; Botner, E. Claire; Jimenez, Kristine L.; Schroeder, Jason R.; Blake, Nicola J.; Meinardi, Simone; Blake, Donald R.; Sive, Barkley C.; Bon, Daniel; Crawford, James H.; Pfister, Gabriele; Flocke, Frank M.

    2016-11-01

    Global atmospheric concentrations of methane (CH4), a powerful greenhouse gas, are increasing, but because there are many natural and anthropogenic sources of CH4, it is difficult to assess which sources may be increasing in magnitude. Here we present a data set of δ2H-CH4 measurements of individual sources and air in the Colorado Front Range, USA. We show that δ2H-CH4, but not δ13C, signatures are consistent in air sampled downwind of landfills, cattle feedlots, and oil and gas wells in the region. Applying these source signatures to air in ground and aircraft samples indicates that at least 50% of CH4 emitted in the region is biogenic, perhaps because regulatory restrictions on leaking oil and natural gas wells are helping to reduce this source of CH4. Source apportionment tracers such as δ2H may help close the gap between CH4 observations and inventories, which may underestimate biogenic as well as thermogenic sources.

  10. 含氧煤层气液化流程爆炸极限分析%Analysis of flammability limits for liquefaction process of oxygen-bearing coal-bed methane

    Institute of Scientific and Technical Information of China (English)

    李秋英; 王莉; 巨永林

    2011-01-01

    大部分含氧煤层气由于技术限制没有被合理利用,而是直接放空,不仅浪费资源.而且污染大气环境.针对某一典型煤层气气源条件和组分特点,设计了一种新型的液化精馏工艺流程,结合HYSYS软件模拟计算结果以及爆炸极限理论,对该液化精馏工艺流程的爆炸极限进行了分析计算,结果表明煤层气中甲烷浓度在压缩、液化以及节流过程中都高于爆炸上限,操作过程安全性比较高.但在精馏塔顶部甲烷浓度开始低于爆炸上限而导致精馏过程存在安全隐患.首先对原料气进行初步脱氧,然后再通过调整精馏塔塔底采出量来控制塔顶杂质气体中甲烷含量,使得其在整个液化及精馏流程中始终高于爆炸上限.分析结果表明,采取安全措施后整个流程都不存在爆炸危险性,甲烷回收率和产品纯度都较高,而且整个流程能耗也比较低.模拟结果显示,所设计的液化及精馏流程对不同气源具有较好的适用性,分析计算结果为含氧煤层气的杂质分离、操作过程的爆炸极限分析以及安全措施的采取提供了一定的参考.%Most of oxygen-bearing coal-bed methane (CBM) has not been utilized due to the limit in technique for production. The discharged gas leads to not only the waste of resources but also environmental pollution. In this study, a liquefaction process is proposed and designed for the typical CBM. HYSYS software is adopted to simulate the process. The flammability limits are analyzed and calculated based on the flammability limit theory and the simulated results of HYSYS. The results indicate that no flammable hazards exist in the processes of compression, liquefaction and throttling but they may appear at the top of the distillation tower. A method, in which oxygen is first removed from the feed gas with the control of the bottom flowrate (flowrate of the liquid product at column bottom), is adopted to ensure that the methane

  11. Numerical Simulation on Flow Field of Diameter-reduced Valve in Low-concentration Coal-bed Methane Liquefaction%低浓度煤层气液化中缩径阀门流场的数值模拟

    Institute of Scientific and Technical Information of China (English)

    刘令; 刘利亚; 付耀国; 甘海龙

    2015-01-01

    In this paper,the method of computational fluid dynamics was adopted,the two-equation model with k-εwas used to close the N-S equation,the structure of the diameter-reduced valve was reasonably simplified,and numerical simulation was made on the flow field,the flow stability of fluid and the local resistance coefficient of the diameter-reduced valves with different taper angle and size which were installed in the pipeline of the cryogenic liquefaction equipment of low-concentration coal-bed methane . The simulated results showed that when the angle of the diameter-reduced valve was equal to or larger than 50 o ,the fluid was seriously divorced from the boundary layer,the fluid flow produced vortex,and the diameter-reduced valve had a poor fluid-passing characteristic;under the same conditions,the local resistance coefficient increased with the increase of the taper angle of the diameter-reduced valve. The simulated results can provide reference for the selection of the valves used in the engineering pipeline.%采用计算流体力学的方法,用k—ε两方程模型封闭N—S方程,对缩径阀门结构进行合理简化,对低浓度煤层气深冷液化装备的管线中,不同变径角度和不同通径缩径阀门的流场、流体流动稳定性及局部阻力系数进行了数值模拟。模拟结果表明:缩径阀门的缩径角度在大于等于50°时,流体脱离边界层现象严重,流体流动出现漩涡,缩径阀门具有较差的过流特性;在相同流动条件下,局部阻力系数随着变径角度的增大而增大。模拟计算结果可为项目建设时管线阀的选型提供参考。

  12. Study on dynamic prediction method and parameter sensitivity analysis of coalbed methane reservoir production%煤层气藏产能动态预测方法及参数敏感性分析

    Institute of Scientific and Technical Information of China (English)

    邱先强; 任广磊; 李治平; 卢菊红; 刘银山

    2012-01-01

    Coalbed Methane (CBM) gas has a complex process of desorplion-diffusion-seepage in the stage of development, causing the changes of pore structure and impaction on production to some extent. Therefore, it is necessary to take the self-regulating effect on pore changes into consideration when studying the material balance of CBM reservoirs. On the basis of the establishment of the model, we infer the CBM reservoir material balance equation. Combined with gas, aquatic energy equation and the relative permeability curves as well as the deviation factor with increasing pressure, we conduct dynamic predict of CBM reservoir production. It is of high reliability by matching the predicted results and the actual production data. Based on the parameter sensitivity analysis, we obtain that in the late production of CBM wells, on the condition of different sensitivity, reservoir pressure and time exhibit an exponential correlation, and the impaction of reservoir pressure on gas well production. Comprehensive analysis of the results shows that the CBM reservoir production of good self-regulating effect, high permeability, high Langerhans pressure and big seam thickness is relatively high.%煤层气体在开发阶段经历了解吸—扩散—渗流的复杂过程,会引起孔隙结构的变化,对产能造成一定影响.因此,研究煤层气藏的物质平衡时,需要考虑自调节效应对孔隙变化的影响.通过建立模型,推导了煤层气藏的物质平衡方程,结合气、水产能方程以及相渗曲线,并且考虑偏差因子随压力的变化,对煤层气藏产能进行动态预测,预测结果通过与实际生产数据历史拟合,验证了模型具有较高的可靠性.通过参数敏感性分析,得出煤层气井生产中后期不同敏感性条件下储层压力与时间成指数对应关系及其对气井生产的影响.综合分析结果表明,自调节效应好、渗透率高、朗氏压力高和煤层厚度大的煤层气藏产能相对较高.

  13. Authigenic carbonate mounds from active methane seeps on the southern Aquitaine Shelf (Bay of Biscay, France): Evidence for anaerobic oxidation of biogenic methane and submarine groundwater discharge during formation

    Science.gov (United States)

    Pierre, Catherine; Demange, Jérome; Blanc-Valleron, Marie-Madeleine; Dupré, Stéphanie

    2017-02-01

    The widespread methane emissions that were discovered in 2013 on the Aquitaine Shelf at water depth between 140 and 220 m are associated with authigenic carbonate crusts that cover meter-high subcircular reliefs of 10-100 m in diameter. These authigenic carbonates are primarily aragonite plus calcite and dolomite, which cement the fine- to medium-grained sandy sediment. The carbonate cement is often pierced by numerous circular cavities of 5-10 μm in diameter that are considered to be moulds of gas bubbles. Conversely, micron-sized cavities in the aragonite crystals are attributed to dissolution features, in relation to the production of CO2 during the aerobic oxidation of methane. The oxygen isotopic compositions of bulk carbonate (+1.7 to +3.7‰) and aragonite cements obtained from microsampling (-0.1 to +1.4‰) indicate that these carbonates were precipitated in mixtures of seawater and freshwater, i.e., in the context of submarine groundwater discharge at the seafloor. The carbon isotopic compositions of authigenic carbonates (-51.9 to -38.1‰) and of aragonite cements (-49.9 to -29.3‰) show that the dissolved inorganic carbon of pore fluids was mostly produced by the anaerobic oxidation of biogenic methane and also partly from the groundwater system.

  14. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2003-03-10

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The originally-stated, major objectives of the current project are to (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project has developed, an important additional objective has been added to the above original list. Namely, we have been encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we have participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities

  15. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

    K.A.M. Gasem; R.L. Robinson, Jr.; J.E. Fitzgerald; Z. Pan; M. Sudibandriyo

    2003-04-30

    The authors' long-term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure, and adsorbent types. The originally-stated, major objectives of the current project are to: (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen, and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane, and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. As this project developed, an important additional objective was added to the above original list. Namely, we were encouraged to interact with industry and/or governmental agencies to utilize our expertise to advance the state of the art in coalbed adsorption science and technology. As a result of this additional objective, we participated with the Department of Energy and industry in the measurement and analysis of adsorption behavior as part of two distinct investigations. These include (a) Advanced Resources International (ARI) DOE Project DE-FC26-00NT40924, ''Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Mixtures on Wet Tiffany Coal'', and (b) the DOE-NETL Project, ''Round Robin: CO{sub 2} Adsorption on Selected Coals''. These activities, contributing

  16. Geologic cross section, gas desorption, and other data from four wells drilled for Alaska rural energy project, Wainwright, Alaska, coalbed methane project, 2007-2009

    Science.gov (United States)

    Clark, Arthur C.; Roberts, Stephen B.; Warwick, Peter D.

    2010-01-01

    Energy costs in rural Alaskan communities are substantial. Diesel fuel, which must be delivered by barge or plane, is used for local power generation in most off-grid communities. In addition to high costs incurred for the purchase and transport of the fuel, the transport, transfer, and storage of fuel products pose significant difficulties in logistically challenging and environmentally sensitive areas. The Alaska Rural Energy Project (AREP) is a collaborative effort between the United States Geological Survey (USGS) and the Bureau of Land Management Alaska State Office along with State, local, and private partners. The project is designed to identify and evaluate shallow (methane (CBM) and geothermal in the vicinity of rural Alaskan communities where these resources have the potential to serve as local-use power alternatives. The AREP, in cooperation with the North Slope Borough, the Arctic Slope Regional Corporation, and the Olgoonik Corporation, drilled and tested a 1,613 ft continuous core hole in Wainwright, Alaska, during the summer of 2007 to determine whether CBM represents a viable source of energy for the community. Although numerous gas-bearing coal beds were encountered, most are contained within the zone of permafrost that underlies the area to a depth of approximately 1,000 ft. Because the effective permeability of permafrost is near zero, the chances of producing gas from these beds are highly unlikely. A 7.5-ft-thick gas-bearing coal bed, informally named the Wainwright coal bed, was encountered in the sub-permafrost at a depth of 1,242 ft. Additional drilling and testing conducted during the summers of 2008 and 2009 indicated that the coal bed extended throughout the area outlined by the drill holes, which presently is limited to the access provided by the existing road system. These tests also confirmed the gas content of the coal reservoir within this area. If producible, the Wainwright coal bed contains sufficient gas to serve as a long

  17. Genetic and temporal relations between formation waters and biogenic methane: Upper Devonian Antrim Shale, Michigan Basin, USA

    Science.gov (United States)

    Martini, A. M.; Walter, L. M.; Budai, J. M.; Ku, T. C. W.; Kaiser, C. J.; Schoell, M.

    1998-05-01

    Controversy remains regarding how well geochemical criteria can distinguish microbial from thermogenic methane. Natural gas in most conventional deposits has migrated from a source rock to a reservoir, rarely remaining associated with the original or cogenetic formation waters. We investigated an unusual gas reservoir, the Late Devonian Antrim Shale, in which large volumes of variably saline water are coproduced with gas. The Antrim Shale is organic-rich, of relatively low thermal maturity, extensively fractured, and is both source and reservoir for methane that is generated dominantly by microbial activity. This hydrogeologic setting permits integration of chemical and isotopic compositions of coproduced water and gas, providing a unique opportunity to characterize methane generating mechanisms. The well-developed fracture network provides a conduit for gas and water mass transport within the Antrim Shale and allows invasion of meteoric water from overlying aquifers in the glacial drift. Steep regional concentration gradients in chemical and isotopic data are observed for formation waters and gases; dilute waters grade into dense brines (300,000 ppm) over lateral distances of less than 30 km. Radiogenic ( 14C and 3H) and stable isotope ( 18O and D) analyses of shallow Antrim Shale formation waters and glacial drift groundwaters indicate recharge times from modern to 20,000 yr BP. Carbon isotope compositions of methane from Antrim Shale wells are typical of the established range for thermogenic or mixed gas (δ 13C = -47 to -56‰). However, the unusually high δ 13C values of CO 2 coproduced with methane (˜+22‰) and dissolved inorganic carbon (DIC) in formation waters (˜+28‰) require bacterial mediation. The δD values of methane and coproduced formation water provide the strongest evidence of bacterial methanogenesis. Methane/[ethane + propane] ratios and δ 13C values for ethane indicate: (1) the presence of a thermogenic gas component that increases

  18. Evolution of the CBM reservoir-forming dynamic system with mixed secondary biogenic and thermogenic gases in the Huainan Coalfield, China

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong; CUI Yongjun; TAO Mingxin; PENG Gelin; JIN Xianglan; LI Guihong

    2005-01-01

    The secondary biogenic gas is an important original type of the coalbed methane (CBM) in China. Based on the analyses of sedimentary and burial history of the Permian coal-bearing strata, combined with thermal history and gas generation process of coals, the CBM reservoirforming dynamic system with mixed secondary biogenic and thermogenic gases in the Huainan Coalfield is subdivided into four evolutionary stages as follows: (i) shallowly-buried peat and early biogenic gas stage; (ii) deeply buried coal seams and thermogenic gas stage; (iii) exhumation of coal-bearing strata and adsorbed gas lost stage; and (iv)re-buried coal-bearing strata and secondary biogenic gas supplement stage. The Huainan CBM reservoir-forming model has the features of the basin-centered gas accumulation. The evolution of the reservoir-forming dynamic system proves that the thermogenic gas is not the main gas source for the Huainan CBM reservoir. Only the secondary biogenic gases as an additional source replenish into the coal bed after basin-uplift, erosional unroofing and subsequent scattering of thermogenic gases. Then this kind of mixed CBM reservoirs can be formed under suitable conditions.

  19. Multiphysics of carbon dioxide sequestration in coalbeds: A review with a focus on geomechanical characteristics of coal

    Directory of Open Access Journals (Sweden)

    Mohsen S. Masoudian

    2016-02-01

    Full Text Available To reduce the emissions of carbon dioxide (CO2 into the atmosphere, it is proposed to inject anthropogenic CO2 into deep geological formations. Deep un-mineable coalbeds are considered to be possible CO2 repositories because coal is able to adsorb a large amount of CO2 inside its microporous structure. However, the response of coalbeds is complex because of coupled flow and mechanical processes. Injection of CO2 causes coal to swell, which leads to reductions in permeability and hence makes injection more difficult, and at the same time leads to changes in the mechanical properties which can affect the stress state in the coal and overlying strata. The mechanical properties of coal under storage conditions are of importance when assessing the integrity and safety of the storage scheme. On the other hand, the geomechanical response of coalbed will also influence the reservoir performance of coalbed. This paper provides an overview of processes associated with coalbed geosequestration of CO2 while the importance of geomechanical characteristics of coalbeds is highlighted. The most recent findings about the interactions between gas transport and geomechanical characteristics of coal will be discussed and the essence will be delivered. The author suggests areas for future research efforts to further improve the understanding of enhanced coalbed methane (ECBM and coalbed geosequestration of CO2.

  20. The distribution of methane in groundwater in Alberta (Canada) and associated aqueous geochemistry conditions

    Science.gov (United States)

    Humez, Pauline; Mayer, Bernhard; Nightingale, Michael; Becker, Veith; Kingston, Andrew; Taylor, Stephen; Millot, Romain; Kloppmann, Wolfram

    2016-04-01

    Development of unconventional energy resources such as shale gas and coalbed methane has generated some public concern with regard to the protection of groundwater and surface water resources from leakage of stray gas from the deep subsurface. In terms of environmental impact to and risk assessment of shallow groundwater resources, the ultimate challenge is to distinguish: (a) natural in-situ production of biogenic methane, (b) biogenic or thermogenic methane migration into shallow aquifers due to natural causes, and (c) thermogenic methane migration from deep sources due to human activities associated with the exploitation of conventional or unconventional oil and gas resources. We have conducted a NSERC-ANR co-funded baseline study investigating the occurrence of methane in shallow groundwater of Alberta (Canada), a province with a long record of conventional and unconventional hydrocarbon exploration. Our objective was to assess the occurrence and sources of methane in shallow groundwaters and to also characterize the hydrochemical environment in which the methane was formed or transformed through redox processes. Ultimately our aim was to determine whether methane was formed in-situ or whether it migrated from deeper formations into shallow aquifers. Combining hydrochemical and dissolved and free geochemical gas data from 372 groundwater samples obtained from 186 monitoring wells of the provincial groundwater observation well network (GOWN) in Alberta, it was found that methane is ubiquitous in groundwater in Alberta and is predominantly of biogenic origin. The highest concentrations of dissolved biogenic methane (> 0.01 mM or > 0.2 mg/L), characterized by δ13CCH4 values gas concentrations and a wide range of δ13CCH4 values in baseline groundwater samples, no conclusive evidence was found for deep thermogenic gas that had migrated in significant amounts into shallow aquifers either naturally or via anthropogenically induced pathways. This study shows that the

  1. Project identification for methane reduction options

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, T.

    1996-12-31

    This paper discusses efforts directed at reduction in emission of methane to the atmosphere. Methane is a potent greenhouse gas, which on a 20 year timeframe may present a similar problem to carbon dioxide. In addition, methane causes additional problems in the form of smog and its longer atmospheric lifetime. The author discusses strategies for reducing methane emission from several major sources. This includes landfill methane recovery, coalbed methane recovery, livestock methane reduction - in the form of ruminant methane reduction and manure methane recovery. The author presents examples of projects which have implemented these ideas, the economics of the projects, and additional gains which come from the projects.

  2. Control factors of coalbed methane well depressurization cone under drainage well network in southern Qinshui basin%沁水盆地南部煤层气井网排采压降漏斗的控制因素

    Institute of Scientific and Technical Information of China (English)

    刘世奇; 桑树勋; 李梦溪; 刘会虎; 王立龙

    2012-01-01

    Under the condition of drainage by well network, this study established a mathematic model of coalbed methane (CBM) well depressurization cone from drainage stage to initial pro- duction-gas stage on the basis of the radial fluid flow theory, superposition principle of pres- sure drop, and the production data of 15 CBM wells in southern Qinshui basin. Visualization of the depressurization cone was realized using Matlab. Based on the analysis of the shape and e- volution characteristics of depressurization cones, this study proposes a defining method for single well depressurization cone and evaluation methodology for superposition degree of composite depressurization cone, and discusses the control factors of the shape for depressurization cone. The results show that: from drainage stage to initial production-gas stage, when the per- meability is bigger than 8 X 10.3 ptm2 , ground water level is higher than 680 m and daily aver- age displacement is less than 3 ma/d, daily average gas production of CBM wells are usually larger than 250 mS/d, the ratio of flush-flow radius to depth of depressurization cone is gener- ally less than 40, and the flush-flow radius is relatively small, accompanied by a rise in decrea- sing amplitude of pressure, and the depressurization cone belongs to the first type; when the permeability is bigger than 8 × 10-3μm2 , ground water level is lower than 680 m and daily av- erage displacement is less than 3 ma/d, daily average gas production of CBM wells are usually less than 250 ma/d and the ratio of flush-flow radius to depth of depressurization cone is gener- ally more than 40, and the flush-flow radius is relatively big, replaced by a drop in decreasing amplitude of pressure, and this depressurization cone belongs to the second type; the ratio of maximum radius of superposed area to well spacing is higher, the degree of superposition improves, the area of superposition increases, and the decrease amplitude of the coal reservoir pressure

  3. A review on utilization of combustible waste gas (II):Landfill gas,flare gas,associated gas and coalbed methane%可燃废气利用技术研究进展(Ⅱ):填埋气、火炬气、伴生天然气和煤矿瓦斯

    Institute of Scientific and Technical Information of China (English)

    王一坤; 陈国辉; 雷小苗; 王长安; 邓磊; 车得福

    2014-01-01

    The utilization of combustible waste gas is an important way of energy conservation and emission reduction.The progress in utilization technologies of landfill gas,flare gas,associated gas and coalbed methane has been presented.Due to the very low utilization ratio and insufficient resourceful utilization of landfill gas,the waste landfill treatment of which the leachate treatment and efficient LFG extraction and utilization are the key technologies should be widely popularized.Generally,the flare gas is fired to provide heat which is then recycled by waste heat boiler.Sometimes it can be directly burned in gas turbine for power generation.With low yield,the associated gas can be used as the inj ection fluid for oil production,or for field power generation.When the yield is high and stable,the associated gas can be transported by pipe-lines,liquid natural gas (LNG)and compressed natural gas (CNG)ships.The optimal utilization of low concentration coalbed methane is for gas-steam combined cycle power generation,of which the power gen-eration efficiency can reach up to higher than 45%.Usually,the coalbed methane is applied as assistant air in mine-mouth power plants,for the technical requirements and cost of this method are the lowest.%可燃废气利用是实现我国节能减排的重要途径之一。介绍了目前填埋气、火炬气、伴生天然气和煤矿瓦斯几种可燃废气的利用技术和工业应用现状。其中:填埋气的利用率很低,资源化利用技术不足,需大力推广以渗滤液处理、高效LFG抽排及利用为核心的填埋垃圾处理工艺;火炬气通常引入燃油或燃气锅炉加以利用,也可以将火炬气燃烧后利用余热锅炉回收热量,或者作为中等热值的气体,直接引入燃气轮机燃烧发电;伴生天然气的产量不高时,可以将其回注驱油或就地发电,产量高且稳定时,可以采用管道输送、液化天然气(LNG)和压缩天然气(CNG

  4. 井下注气强化煤层气抽采效果的工程试验与数值模拟%Test and numerical simulation on effect of enhanced coalbed methane drawing by injecting gas under coal mine

    Institute of Scientific and Technical Information of China (English)

    李志强; 王兆丰

    2011-01-01

    为提高特低渗透煤层的煤层气抽采效果,在重庆天府矿业公司850 m深井,采用注入组分为78%的N2的方法,进行了强化注抽煤层气的工业性试验.分别试验了单孔与多孔干扰情况下自然涌出、负压抽采、注气涌出、边注边抽和间歇注气试验.结果表明:在常规抽采达到极限后进行注气,甲烷抽采时间-浓度曲线呈现先上升后下降的单峰波形状态,间歇注抽的甲烷浓度高于边注边抽的甲烷浓度,但衰减较快,注气距离短,长时边注边抽的注抽效果好于间歇注抽效果.注气孔网间距4 m,渗透率1.112×10-4mD的煤层,连续注抽5 d后,抽采率由卸压后负压极限抽采的52.4%提高到58.6%.建立了空气注采甲烷的渗流理论方程,计算了合理的注气孔网间距、注气时间、压力等技术参数,讨论了注气技术方法的适用条件和辅助技术,为推广这一技术提供了工程与理论参考.同时,提出了抽采后注气的变定解条件渗流方程解算的科学问题.%In order to improve the extraction effect of ultra-low permeability coalbed methane, injecting and drawing industry test of enhanced coalbed methane recovery is carried out by injecting concentration 78% N2 under 850 m depth coal mine of Tianfu Mining Co. Ltd. , in Chongqing. The experiments of free methane emission, vacuum pumping, side injecting and side emission, side injecting and side drawing and intermittent injecting are tested under the condition of single hole and multi holes respectively. The testing results indicate that time-concentration curve of methane drawing is a single peak wave curve which increases and decreases during injecting N2 after reaching the limits of ordinary extraction. The methane concentration of intermittent injecting gas is greater than that of side injecting and side drawing. However, the former declines rapidly and has a shorter migration distance than the latter. The injecting effect of long time side

  5. Assessment of contaminants associated with coal bed methane-produced water and its suitability for wetland creation or enhancement projects

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Extraction of methane gas from coal seams has become a significant energy source in the Powder River Basin of northeastern Wyoming. In Wyoming, coalbed methane (CBM)...

  6. 我国煤层气清洁开发利用法规障碍及政策建议%Legal or Regulatory Barriers to the Clean Development and Utilization of China’s Coal-Bed Methane and Policy Suggestions

    Institute of Scientific and Technical Information of China (English)

    伏虎

    2015-01-01

    利用CO2注入和置换进行煤层气清洁开发兼具经济效益和环境效益,是一类具备潜在价值的新型能源技术应用方向。发达国家尝试将煤层气清洁开发利用机制纳入原有的能源法规框架下,但存在着不成体系、相关规定冲突等问题;我国当前更多的是指引性的科技规划,缺少操作性强、针对行业发展的具体做法。需要在借鉴国外做法的基础上,设计适应我国能源特点和技术储备的煤层气清洁开发利用政策法规:立足于碳封存机制与煤层气产业的契合点进行顶层设计,从外部效应入手鼓励CO2-ECBM产业发展;对于CO2-ECBM比照新能源项目的金融支持政策,创新成本分担机制;集中优势资源发展领军企业,实现CO2-ECBM规模化技术突破。%Clean development of coal-bed methane by using CO2 injection and displacement has both economic and environmental beneifts, which will be the application direction of new energy technology with potential value. In developed countries, they have tried to incorporate the mechanism for CBM clean development and utilization into the original energy regulatory framework. But their approach is not in any systematic manner, and there are conlficts between the relevant provisions. However, in China, we have more guiding science and technology plan, rather than operable, speciifc approach for the industry development. This paper proposes some measures for setting up policies and regulations concerning clean development and utilization of coal-bed methane that ift in with China’s characteristics of energy and technical reserves in addition to drawing lessons from foreign countries. These measures include:based on the integrating point of carbon sequestration mechanism and coal-bed gas industry, top-level design should be carried out;encouraging CO2-ECBM industrial development according to the external effect; cost-sharing mechanisms must be innovated in the

  7. Geochemistry of coalbed gas - a review

    Science.gov (United States)

    Clayton, J.L.

    1998-01-01

    Coals are both sources and reservoirs of large amounts of gas that has received increasing attention in recent years as a largely untapped potential energy resource. Coal mining operations, such as ventilation of coalbed gas from underground mines, release coalbed CH4 into the atmosphere, an important greehouse gas whose concentration in the atmosphere is increasing. Because of these energy and environmental issues, increased research attention has been focused on the geochemistry of coalbed gas in recent years. This paper presents a summary review of the main aspects of coalbed gas geochemistry and current research advances.Coals are both sources and reservoirs of large amounts of gas that has received increasing attention in recent years as a largely untapped potential energy resource. Coal mining operations, such as ventilation of coalbed gas from underground mines, release coalbed CH4 into the atmosphere, an important greenhouse gas whose concentration in the atmosphere is increasing. Because of these energy and environmental issues, increased research attention has been focused on the geochemistry of coalbed gas in recent years. This paper presents a summary review of the main aspects of coalbed gas geochemistry and current research advances.

  8. The problems which need attention in standard system of coalbed gas and its application%煤层气标准体系及其在应用中应注意的问题

    Institute of Scientific and Technical Information of China (English)

    肖文钊

    2015-01-01

    对现行煤层气标准及正在制定的煤层气标准进行综合分析,系统地论述了煤层气标准的科学体系。结合煤层气含量测试方法标准中存在的问题,指出煤层气标准应用中应注意的事项,提出应加强煤层气基础标准和方法标准的制定工作并协调标准体系中各标准之间的关系。%Synthesized analysis for existing coalbed methane standards and coalbed methane standards which is being written was done, scientific system of coalbed methane standards were systematically discussed.Combing the problems of the coalbed methane content measurement method, this article mainly indicated notices which need attention in application of coalbed methane standard, it was also indicated that coalbed gas basic standard and method standard formulation should be enhanced, and the relationship among every standard in the standard system should be coordinated.

  9. Methane drainage with horizontal boreholes in advance of longwall mining: an analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gabello, D.P.; Felts, L.L.; Hayoz, F.P.

    1981-05-01

    The US Department of Energy (DOE) Morgantown Energy Technology Center has implemented a comprehensive program to demonstrate the technical and economic viability of coalbed methane as an energy resource. The program is directed toward solution of technical and institutional problems impeding the recovery and use of large quantities of methane contained in the nation's minable and unminable coalbeds. Conducted in direct support of the DOE Methane Recovery from Coalbeds Project, this study analyzes the economic aspects of a horizontal borehole methane recovery system integrated as part of a longwall mine operation. It establishes relationships between methane selling price and annual mine production, methane production rate, and the methane drainage system capital investment. Results are encouraging, indicating that an annual coal production increase of approximately eight percent would offset all associated drainage costs over the range of methane production rates and capital investments considered.

  10. PEaCH4 v.2.0: A modelling platform to predict early diagenetic processes in marine sediments with a focus on biogenic methane - Case study: Offshore Namibia

    Science.gov (United States)

    Arning, Esther T.; Häußler, Steffen; van Berk, Wolfgang; Schulz, Hans-Martin

    2016-07-01

    The modelling of early diagenetic processes in marine sediments is of interest in marine science, and in the oil and gas industry, here, especially with respect to methane occurrence and gas hydrate formation as resources. Early diagenesis in marine sediments evolves from a complex web of intertwining (bio)geochemical reactions. It comprises microbially catalysed reactions and inorganic mineral-water-gas interactions. A model that will describe and consider all of these reactions has to be complex. However, it should be user-friendly, as well as to be applicable for a broad community and not only for experts in the field of marine chemistry. The presented modelling platform PeaCH4 v.2.0 combines both aspects, and is Microsoft Excel©-based. The modelling tool is PHREEQC (version 2), a computer programme for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. The conceptual PEaCH4 model is based on the conversion of sediment-bound degradable organic matter. PEaCH4 v.2.0 was developed to quantify and predict early diagenetic processes in marine sediments with the focus on biogenic methane formation and its phase behaviour, and allows carbon mass balancing. In regard to the irreversible degradation of organic matter, it comprises a "reaction model" and a "kinetic model" to predict methane formation. Both approaches differ in their calculations and outputs as the "kinetic model" considers the modelling time to integrate temperature dependent biogenic methane formation in its calculations, whereas the "reaction model" simply relies on default organic matter degradation. With regard to the inorganic mineral-water-gas interactions, which are triggered by irreversible degradation of organic matter, PEaCH4 v.2.0 is based on chemical equilibrium thermodynamics, appropriate mass-action laws, and their temperature dependent equilibrium constants. The programme is exemplarily presented with the example of upwelling sediments off Namibia

  11. Organic petrology and coalbed gas content, Wilcox Group (Paleocene-Eocene), northern Louisiana

    Science.gov (United States)

    Hackley, P.C.; Warwick, P.D.; Breland, F.C.

    2007-01-01

    Wilcox Group (Paleocene-Eocene) coal and carbonaceous shale samples collected from four coalbed methane test wells in northern Louisiana were characterized through an integrated analytical program. Organic petrographic analyses, gas desorption and adsorption isotherm measurements, and proximate-ultimate analyses were conducted to provide insight into conditions of peat deposition and the relationships between coal composition, rank, and coalbed gas storage characteristics. The results of petrographic analyses indicate that woody precursor materials were more abundant in stratigraphically higher coal zones in one of the CBM wells, consistent with progradation of a deltaic depositional system (Holly Springs delta complex) into the Gulf of Mexico during the Paleocene-Eocene. Comparison of petrographic analyses with gas desorption measurements suggests that there is not a direct relationship between coal type (sensu maceral composition) and coalbed gas storage. Moisture, as a function of coal rank (lignite-subbituminous A), exhibits an inverse relationship with measured gas content. This result may be due to higher moisture content competing for adsorption space with coalbed gas in shallower, lower rank samples. Shallower ( 600??m) coal samples containing less moisture range from under- to oversaturated with respect to their CH4 adsorption capacity.

  12. Methane production from coal by a single methanogen

    Science.gov (United States)

    Mayumi, Daisuke; Mochimaru, Hanako; Tamaki, Hideyuki; Yamamoto, Kyosuke; Yoshioka, Hideyoshi; Suzuki, Yuichiro; Kamagata, Yoichi; Sakata, Susumu

    2016-10-01

    Coal-bed methane is one of the largest unconventional natural gas resources. Although microbial activity may greatly contribute to coal-bed methane formation, it is unclear whether the complex aromatic organic compounds present in coal can be used for methanogenesis. We show that deep subsurface-derived Methermicoccus methanogens can produce methane from more than 30 types of methoxylated aromatic compounds (MACs) as well as from coals containing MACs. In contrast to known methanogenesis pathways involving one- and two-carbon compounds, this “methoxydotrophic” mode of methanogenesis couples O-demethylation, CO2 reduction, and possibly acetyl-coenzyme A metabolism. Because MACs derived from lignin may occur widely in subsurface sediments, methoxydotrophic methanogenesis would play an important role in the formation of natural gas not limited to coal-bed methane and in the global carbon cycle.

  13. Assessment of environmental health and safety issues associated with the commercialization of unconventional gas recovery: methane from coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Ethridge, L.J.; Cowan, C.E.; Riedel, E.F.

    1980-07-01

    Potential public health and safety problems and the potential environmental impacts from the recovery of gas from coalbeds are identified and examined. The technology of methane recovery is described and economic and legal barriers to production are discussed. (ACR)

  14. Study of parameters affecting enhanced coal bed methane

    Energy Technology Data Exchange (ETDEWEB)

    Katyal, S.; Valix, M.; Thambimuthu, K. [University of Sydney, Sydney, NSW (Australia). Dept. of Chemical Engineering

    2007-02-15

    Laboratory and field scale trials conducted so far indicate that injection of CO{sub 2} and N{sub 2} into deep coalbeds has the potential to enhance coalbed methane (ECBM) recovery while simultaneously sequestering CO{sub 2}. The work has identified that the fundamental processes involved in CO{sub 2} sequestration/CBM recovery in deep coalbeds are not fully understood and further research is needed to advance this technology. ECBM is affected by several parameters; prominent among them are coal characteristics, in-situ conditions prevailing in deep coalbeds, and changes arising from the interaction of coal with various fluids. These parameters do not act independently, thereby making it difficult to isolate their impacts separately. An attempt has been made in this article to classify these parameters and understand their role in ECBM. Past work in this area is reviewed and the future work that is critical for an improved understanding of ECBM recovery is discussed.

  15. Methanogenic pathways of coal-bed gas in the Powder River Basin, United States: The geologic factor

    Science.gov (United States)

    Flores, R.M.; Rice, C.A.; Stricker, G.D.; Warden, A.; Ellis, M.S.

    2008-01-01

    Coal-bed gas of the Tertiary Fort Union and Wasatch Formations in the Powder River Basin in Wyoming and Montana, U.S. was interpreted as microbial in origin by previous studies based on limited data on the gas and water composition and isotopes associated with the coal beds. To fully evaluate the microbial origin of the gas and mechanisms of methane generation, additional data for 165 gas and water samples from 7 different coal-bed methane-bearing coal-bed reservoirs were collected basinwide and correlated to the coal geology and stratigraphy. The C1/(C2 + C3) ratio and vitrinite reflectance of coal and organic shale permitted differentiation between microbial gas and transitional thermogenic gas in the central part of the basin. Analyses of methane ??13C and ??D, carbon dioxide ??13C, and water ??D values indicate gas was generated primarily from microbial CO2 reduction, but with significant gas generated by microbial methyl-type fermentation (aceticlastic) in some areas of the basin. Microbial CO2 reduction occurs basinwide, but is generally dominant in Paleocene Fort Union Formation coals in the central part of the basin, whereas microbial methyl-type fermentation is common along the northwest and east margins. Isotopically light methane ??13C is distributed along the basin margins where ??D is also depleted, indicating that both CO2-reduction and methyl-type fermentation pathways played major roles in gas generation, but gas from the latter pathway overprinted gas from the former pathway. More specifically, along the northwest basin margin gas generation by methyl-type fermentation may have been stimulated by late-stage infiltration of groundwater recharge from clinker areas, which flowed through highly fractured and faulted coal aquifers. Also, groundwater recharge controlled a change in gas composition in the shallow Eocene Wasatch Formation with the increase of nitrogen and decrease of methane composition of the coal-bed gas. Other geologic factors, such as

  16. SEQUESTERING CARBON DIOXIDE IN COALBEDS

    Energy Technology Data Exchange (ETDEWEB)

    K.A.M. Gasem; R.L. Robinson, Jr.; L.R. Radovic

    2001-12-26

    The authors' long term goal is to develop accurate prediction methods for describing the adsorption behavior of gas mixtures on solid adsorbents over complete ranges of temperature, pressure and adsorbent types. The major objectives of the project are to (1) measure the adsorption behavior of pure CO{sub 2}, methane, nitrogen and their binary and ternary mixtures on several selected coals having different properties at temperatures and pressures applicable to the particular coals being studied, (2) generalize the adsorption results in terms of appropriate properties of the coals to facilitate estimation of adsorption behavior for coals other than those studied experimentally, (3) delineate the sensitivity of the competitive adsorption of CO{sub 2}, methane and nitrogen to the specific characteristics of the coal on which they are adsorbed; establish the major differences (if any) in the nature of this competitive adsorption on different coals, and (4) test and/or develop theoretically-based mathematical models to represent accurately the adsorption behavior of mixtures of the type for which measurements are made. The specific accomplishments of this project during this reporting period are summarized in three broad categories outlining experimentation, model development, and coal characterization.

  17. Alaska Coal Geology, Resources, and Coalbed Methane Potential

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Estimated Alaska coal resources are largely in Cretaceous and Tertiary rocks distributed in three major provinces. Northern Alaska-Slope, Central Alaska-Nenana, and...

  18. Coal induced production of a rhamnolipid biosurfactant by Pseudomonas stutzeri, isolated from the formation water of Jharia coalbed.

    Science.gov (United States)

    Singh, Durgesh Narain; Tripathi, Anil Kumar

    2013-01-01

    A strain of Pseudomonas stutzeri was isolated form an enrichment of perchlorate reducing bacteria from the formation water collected from an Indian coalbed which solubilized coal and produced copious amount of biosurfactant when coal was added to the medium. It produced maximum biosurfactant with lignite coal followed by olive oil and soybean oil which was able to emulsify several aromatic hydrocarbons including kerosene oil, diesel oil, hexane, toluene etc. Haemolytic test, growth inhibition of Bacillus subtilis and FTIR analysis showed rhamnolipid nature of the biosurfactant. The stability of the coal induced biosurfactant in pH range of 4-8 and up to 25% NaCl concentration and 100 °C temperature suggests that due to its ability to produce biosurfactant and solubilize coal P. stutzeri may be useful in the coalbed for in situ biotransformation of coal into methane and in the bioremediation of PAHs from oil contaminated sites including marine environments.

  19. Hydropower's Biogenic Carbon Footprint

    Science.gov (United States)

    Pfister, Stephan

    2016-01-01

    Global warming is accelerating and the world urgently needs a shift to clean and renewable energy. Hydropower is currently the largest renewable source of electricity, but its contribution to climate change mitigation is not yet fully understood. Hydroelectric reservoirs are a source of biogenic greenhouse gases and in individual cases can reach the same emission rates as thermal power plants. Little is known about the severity of their emissions at the global scale. Here we show that the carbon footprint of hydropower is far higher than previously assumed, with a global average of 173 kg CO2 and 2.95 kg CH4 emitted per MWh of electricity produced. This results in a combined average carbon footprint of 273 kg CO2e/MWh when using the global warming potential over a time horizon of 100 years (GWP100). Nonetheless, this is still below that of fossil energy sources without the use of carbon capture and sequestration technologies. We identified the dams most promising for capturing methane for use as alternative energy source. The spread among the ~1500 hydropower plants analysed in this study is large and highlights the importance of case-by-case examinations. PMID:27626943

  20. CO{sub 2} sequestration in an unmineable coalbed - San Juan Basin, Colorado, USA

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, D.; Jensen, J.R. [BP Amoco, Sunbury-on-Thames (United Kingdom)

    2001-07-01

    BP Amoco (BPA) is investigating the sequestration of approximately 464 tonnes per day of vented CO{sub 2} from gas processing plant by injecting the CO{sub 2} into a non-mineable natural gas producing coal in the Colorado portion of the San Juan Basin. Removed CO{sub 2} from this production will be re-injected into the coalbed for sequestration. BPA has concentrated efforts on utilizing nitrogen to enhance the recovery of methane from coals and currently operates the largest and most significant project of its kind. On a pilot basis, CO{sub 2} sequestration, as an enhanced recovery process for Fruitland coals, has also been undertaken in the San Juan Basin (SJB). The two gases behave differently in coals. CO{sub 2} is readily adsorbed on the coal and therefore displaces the methane whereas the nitrogen strips the methane from the coals by reducing the partial pressure of the methane. Injection, production and reservoir data will be used to evaluate the success of the CO{sub 2} sequestration. BPA will use its proprietary GCOMP Reservoir Model to investigate the flow and adsorption of CO{sub 2}, simulate the process, compare field results with model predictions, and adjust the model to better match actual field performance. Preliminary simulations indicate that some incremental methane production will be recovered, while sequestering nearly all of the injected CO{sub 2} in the coals seams. 3 figs.

  1. Analysis of hydrocarbons generated in coalbeds

    Science.gov (United States)

    Butala, Steven John M.

    This dissertation describes kinetic calculations using literature data to predict formation rates and product yields of oil and gas at typical low-temperature conditions in coalbeds. These data indicate that gas formation rates from hydrocarbon thermolysis are too low to have generated commercial quantities of natural gas, assuming bulk first-order kinetics. Acid-mineral-catalyzed cracking, transition-metal-catalyzed hydrogenolysis of liquid hydrocarbons, and catalyzed CO2 hydrogenation form gas at high rates. The gaseous product compositions for these reactions are nearly the same as those for typical natural coalbed gases, while those from thermal and catalytic cracking are more representative of atypical coalbed gases. Three Argonne Premium Coals (Upper-Freeport, Pittsburgh #8 and Lewiston-Stockton) were extracted with benzene in both Soxhlet and elevated pressure extraction (EPE) systems. The extracts were compared on the basis of dry mass yield and hydrocarbon profiles obtained by gas chromatography/mass spectrometry. The dry mass yields for the Upper-Freeport coal gave consistent results by both methods, while the yields from the Pittsburgh #8 and Lewiston-Stockton coals were greater by the EPE method. EPE required ˜90 vol. % less solvent compared to Soxhlet extraction. Single-ion-chromatograms of the Soxhlet extracts all exhibited bimodal distributions, while those of the EPE extracts did not. Hydrocarbons analyzed from Greater Green River Basin samples indicate that the natural oils in the basin originated from the coal seams. Analysis of artificially produced oil indicates that hydrous pyrolysis mimics generation of C15+ n-alkanes, but significant variations were found in the branched alkane, low-molecular-weight n-alkanes, and high-molecular-weight aromatic hydrocarbon distributions.

  2. Coalbed gas content simulation test and application

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, S. [New Star Petroleum Company, Zhengzhou (China). North China Petroleum Bureau

    2002-10-01

    With a high-pressure canister and accurate thermoregulation system of IS-100 isotherm instrument and an electronic flow meter, a coalbed gas content simulation method is established. A control program is combined with it to control data acquisition. The method simulates the whole process of gas content measurement from coring to the completion of desorption. It enables the understanding of gas desorption regularities, and for obtaining the volume of gas loss at any one time. The study would be useful for comparing the various approaches of calculating gas loss volume. 3 refs., 5 figs.

  3. Discrimination of abiogenic and biogenic alkane gases

    Institute of Scientific and Technical Information of China (English)

    DAI JinXing; MI JingKui; LI ZhiSheng; HU AnPing; YANG Chun; ZHOU QingHua; SHUAI YanHua; ZHANG Ying; MA ChengHua; ZOU CaiNeng; ZHANG ShuiChang; LI Jian; NI YunYan; HU GuoYi; LUO Xia; TAO ShiZhen; ZHU GuangYou

    2008-01-01

    We have combined the analytical data of the carbon isotope distribution pattern, R/Ra and cliche values of abiogenic and biogenic (referring to the therrnogenic and bacterial or microbial) alkane gases in China with those of alkane gases from USA, Russia, Germany, Australia and other countries. Four discrimination criteria are derived from this comparative study: 1) Carbon isotopic composition is generally greater than -30‰ for abiogenic methane and less than -30‰ for biogenic methane; 2)Abiogenic alkane gases have a carbon isotopic reversal trend (Δ13c1>Δ13c2>Δ13c3>Δ13c4) with Δ13c1>-30‰ in general; 3) Gases with R/Ra>0.5 and Δ13c1- Δ13c2>0 are of abiogenic origin; 4) Gases (methane) with CH4/3He≤106 are of abiogenic origin, whereas gases with CH4/3He≥1011 are of biogenic origin.

  4. THE UTILIZATION TECHNOLOGIES OF METHANE PRODUCED FROM UNDERGRAUND COAL SEAMS

    Directory of Open Access Journals (Sweden)

    Gökhan AYDIN

    2009-01-01

    Full Text Available A few coal mines use coalbed methane recovered from coal seams. As well as being unable to use gas means waste of an economically valuable source, it contributes to global warming. Gases recovered from coal mines can be used for various applications as an alternative source to natural gas or such as generation of power related to methane concentration. In cases the sale and/or use of gas would not be profitable, the best way for decreasing gas emissions is to destroy methane via flaring. In this study, the utilization technologies of methane are defined in detail and the examples being in practice are given.

  5. Integrating geophysics and geochemistry to evaluate coalbed natural gas produced water disposal, Powder River Basin, Wyoming

    Science.gov (United States)

    Lipinski, Brian Andrew

    Production of methane from thick, extensive coalbeds in the Powder River Basin of Wyoming has created water management issues. More than 4.1 billion barrels of water have been produced with coalbed natural gas (CBNG) since 1997. Infiltration impoundments, which are the principal method used to dispose CBNG water, contribute to the recharge of underlying aquifers. Airborne electromagnetic surveys of an alluvial aquifer that has been receiving CBNG water effluent through infiltration impoundments since 2001 reveal produced water plumes within these aquifers and also provide insight into geomorphologic controls on resultant salinity levels. Geochemical data from the same aquifer reveal that CBNG water enriched in sodium and bicarbonate infiltrates and mixes with sodium-calcium-sulfate type alluvial groundwater, which subsequently may have migrated into the Powder River. The highly sodic produced water undergoes cation exchange reactions with native alluvial sediments as it infiltrates, exchanging sodium from solution for calcium and magnesium on montmorillonite clays. The reaction may ultimately reduce sediment permeability by clay dispersion. Strontium isotope data from CBNG wells discharging water into these impoundments indicate that the Anderson coalbed of the Fort Union Formation is dewatered due to production. Geophysical methods provide a broad-scale tool to monitor CBNG water disposal especially in areas where field based investigations are logistically prohibitive, but geochemical data are needed to reveal subsurface processes undetectable by geophysical techniques. The results of this research show that: (1) CBNG impoundments should not be located near streams because they can alter the surrounding hydraulic potential field forcing saline alluvial groundwater and eventually CBNG water into the stream, (2) point bars are poor impoundment locations because they are essentially in direct hydraulic communication with the associated stream and because plants

  6. Fall may be imminent for Kansas Cherokee basin coalbed gas output

    Science.gov (United States)

    David, Newell K.

    2010-01-01

    Natural gas production in the Kansas portion of the Cherokee basin, Southeastern Kansas, for 2008 was 49.1 bcf. The great majority of Cherokee basin gas production is now coal-bed methane (CBM). The major producers are Quest Energy LLC, Dart Cherokee Basin Operating Co. LLC, and Layne Energy Operating LLC. Most CBM in Southeastern Kansas is from Middle and Upper Pennsylvanian high-volatile B and A rank bituminous coals at 800 to 1,200 ft depth. Rates of decline for the CBM wells generally decrease the longer a well produces. A gentler collective decline of 13.8% is calculated by averaging the number of new producing wells in a given year with that of the previous year. By the calculations using the gentler overall 13.8% decline rate, if more than 918 successful CBM wells are drilled in 2009, then gas production will increase from 2008 to 2009.

  7. Discrimination of abiogenic and biogenic alkane gases

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We have combined the analytical data of the carbon isotope distribution pattern, R/Ra and CH4/3He values of abiogenic and biogenic (referring to the thermogenic and bacterial or microbial) alkane gases in China with those of alkane gases from USA, Russia, Germany, Australia and other countries. Four discrimination criteria are derived from this comparative study: 1) Carbon isotopic composition is generally greater than -30‰ for abiogenic methane and less than -30‰ for biogenic methane; 2) Abiogenic alkane gases have a carbon isotopic reversal trend (δ 13C1> δ 13C2> δ 13C3> δ 13C4) with δ 13C1>-30‰ in general; 3) Gases with R/Ra >0.5 and δ 13C11 δ 13C2>0 are of abiogenic origin; 4) Gases (meth- ane) with CH4/3He≤106 are of abiogenic origin, whereas gases with CH4/3He≥1011 are of biogenic origin.

  8. Biogenic amines in beer

    OpenAIRE

    Čiháková, Dagmar

    2016-01-01

    This thesis deals with the technological process of brewing beer, describes the raw materials needed for its production, and points out the useful and harmful substances contained in beer as biogenic amines (BA). Furthermore, there are described the issues of biogenic amines in food and primarily in beer, which is a histamine, putrescine, cadaverine, tyramine and tryptamine. In the practical section BA was determined in lager bottom-fermented beers from local microbreweries and large industri...

  9. Drilling down on methane emissions in the US Four Corners region

    Science.gov (United States)

    Petron, G.

    2016-12-01

    Two years ago the Four Corners region became known as the largest methane hotspot in the US [Kort et al., 2014]. More specifically, satellite based methane columns over the San Juan Basin had the largest enhancements above the regional mean column and this feature pertained between 2003 and 2009. The methane "hotpsot" designation hides a more complex reality. The region is home to large scale coal, oil, coalbed methane and natural gas extraction and processing which all can emit methane. Portions of the Fruitland coal outcrop on the Colorado side also have been degassing methane for decades. Other minor methane sources in the area include landfills and a few animal operations. In April 2015, a large airborne and ground-based campaign investigated the Four Corners methane hotspot to further characterize methane emissions in the region. In this talk we will summarize what has been learned and which questions remain.

  10. Stratum energy of coal-bed gas reservoir and their control on the coal-bed gas reservoir formation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Stratum energy of coal-bed gas reservoir, including coal-radix flexibility energy, groundwater flexibility energy and gas flexibility energy (hereinafter "three energy"), depends on the energy homeostasis system, the core process of which is the effective transfer of energy and the geological selective process. Combining with the mechanics experimentations of coal samples, different flexibility energy has been analyzed and researched quantificationally, and a profound discussion to their controls on the coal-bed gas reservoir formation has been made. It is shown that when gas reservoir is surrounded by edge water and bottom water, the deposited energy in the early phase of forming gas reservoir is mostly coal-radix and gas flexibility energy, but the effect of groundwater flexibility energy increases while water-body increases. The deposited energy in the middle and later phase of forming gas reservoir is mostly gas flexibility energy, which is greater than 80% of all deposited energy. In the whole process, larger groundwater body exerts greater influences on gas accumulation. The paper indicated that higher stratum energy is more propitious to forming coal-bed gas reservoir. And higher coal-radix flexibility energy and gas flexibility energy are more propitious to higher yield of gas reservoirs, while higher groundwater flexibility energy is more propitious to stable yield of gas reservoirs. Therefore, the key to evaluating the coal-bed gas reservoir formation is the stratum energy of coal-bed gas reservoir.

  11. Biogenic methane from hydrothermal gasification of biomass; Biogenes Methan durch hydrothermale Vergasung von Biomasse

    Energy Technology Data Exchange (ETDEWEB)

    Schubert, M.; Vogel, F.

    2007-09-15

    This final report for the Swiss Federal Office of Energy (SFOE) reports on work done in the area of gasification of biomass. The use of dung, manure and sewage sludge as sources of energy is described and discussed. Hydrothermal gasification is proposed as an alternative to conventional gas-phase processes. The aim of the project in this respect is discussed. Here, a catalytic process that demonstrates the gasification of wet biomass to synthetic natural gas (SNG) in a continuously operating plant on a laboratory scale is being looked at. Difficulties encountered in preliminary tests are discussed. Long-term catalyst stability and the installations for the demonstration of the process are discussed, and gasification tests with ethanol are commented on.

  12. New Reactions to Obtain Aromatics and Hydrogen through Methane's Direct Catalytic Dehydroaromatization

    Institute of Scientific and Technical Information of China (English)

    XU Yide; XIE Maosong; BAO Xinhe; LIN Liwu; WANG Linsheng

    2007-01-01

    @@ Methane is the main component of natural gas and coal-bed gas. Structurally, its molecule is highly symmetric and hence, it becomes one of the most stable hydrocarbon compounds in nature. For a long time in the past, the research of methane transformation is a permanent "hot spot" and disciplinary frontier for chemists as it can be catalyzed directly into top-quality fuel and chemicals.

  13. Formation Conditions and Existing Evidences of Biogenic Gas in the Mohe Basin,China%漠河盆地生物气形成条件及存在证据

    Institute of Scientific and Technical Information of China (English)

    苗忠英; 王晶; 潘春孚; 何大祥; 赵兴齐

    2013-01-01

    Biogenic methane is an important resource which exists in conventional microbial gas reservoir,and unconventional microbial gas,such as hydrate,shale gas,coalbed methane,and so on.By the analysis of the living environment of microbes,such as temperature,salinity,p H,living space,nutrient substrates,and so on,and combined with the evidence for active microbe,it's thought that:(1) The appropriate formation water salinity,moderate pH,abundant nutrition are beneficial for the microbial life activities.(2) The phenomenon of GC presenting bulge phenomenon,the detected 25-norhopane,ethene and propene,the δ13 C1 <-60‰,and the emergence of biogenic gas in the adjacent areas,and so on,is the evidences of the existence of biogenic gas in the area.(3) Influenced by the seasonal variation,the primary biogenic gases of acetate fermentation are formed periodically;the reduced secondary biogenic gases of carbon dioxide are formed in the micro-fractures member of Upper Jurassic.In the Mohe Basin,biogenic gas is not only the important natural gas resource style,but also one of the potential gas sources of hydrate.%生物气不仅能以常规生物气藏的形式存在,而且还能以水合物、页岩气或煤层气等非常规形式存在,是非常重要的天然气资源.通过分析漠河盆地微生物生存所需的温度、盐度、酸碱度、生存空间和营养底物来源等条件,并结合微生物生命活动的证据认为:①漠河盆地地层水盐度不高、酸碱度适中、营养底物充足,具备微生物生命活动所需的基本条件;②饱和烃气相色谱出现“鼓包”现象,检测出25-降藿烷、乙烯和丙烯,δ13 C1值小于-60‰,以及相邻地区发现生物气等现象是该区存在生物气的证据;③第四系受季节变换的影响,可周期性生成乙酸发酵型原生生物气;上侏罗统微裂缝发育段可形成CO2还原型次生生物气.生物气不仅是漠河盆地重要的天然气资源类型,也是天然气水合物潜在的气源之一.

  14. The mechanism of the flowing ground water impacting on coalbed gas content

    Institute of Scientific and Technical Information of China (English)

    QIN Shengfei; SONG Yan; TANG Xiuyi; FU Guoyou

    2005-01-01

    The hydrogeological condition affects the coalbed gas storage dramatically. In an area of stronger hydrodynamics, the coal has a lower gas content, while a higher gas content exists in an area of weaker hydrodynamics. Obviously, the flowing groundwater is harmful to coalbed gas preservation. But few researches focus on the mechanism of how the flowing water diminishes the coalbed gas content.Based on the phenomenon that the flowing groundwater not only makes coalbed gas content lower, but also fractionates the carbon isotope, this research puts forward an idea that it is the water solution that diminishes the coalbed gas content,rather than the water-driven action or the gas dissipation through cap rocks. Only water-soluble action can both fractionate the carbon isotope and lessen the coalbed gas content,and it is an efficient way to take gas away and affect the gas content.

  15. Attempts to regionally quantify methane from plants; Ansaetze zur regionalen Quantifizierung von Methan aus Pflanzen

    Energy Technology Data Exchange (ETDEWEB)

    Draxler, S. [Technisches Buero fuer Technische Chemie, Vienna (Austria); Keppler, F. [Max-Planck-Institut fuer Chemie (Otto-Hahn-Institut), Mainz (Germany)

    2008-02-15

    Methane as a gas influencing our climate is of high importance according to the Kyoto-Protocol. The more precisely we can determine anthropogenic and biogenic sources, the more effective measures we can take to reduce the gas. Direct emission of methane from plants apparently contributes significantly to the total emission but has not been accounted for in emission balances until now. A model was created to calculate methane emission for a short time period in regional resolution for Lower Austria and to relate the results to known literature. First model results suggest that the amount of methane released from plants in relation to emissions from other known sources are of importance. (orig.)

  16. The evolution and distribution of methane in Lake Champlain sediments

    Energy Technology Data Exchange (ETDEWEB)

    Thibodeau, P.M. (Univ. of Vermont, Burlington, VT (United States). Dept. of Geology)

    1993-03-01

    Regions of Lake Champlain sediments are acoustically impenetrable to the energy emitted from high resolution, low energy sub-bottom seismic profiling apparatus. This anomolous behavior is caused by the presence of interstitial methane gas which absorbs the wave energy and thus prevents the formation of well-defined seismic boundaries. Through gas chromatographic and carbon isotope analyses, the methane gas contained in the recent sediments of Lake Champlain has been demonstrated to be biogenic in origin. The production of biogenic methane occurs as a result of a series of coupled oxidation-reduction reactions occurring within the upper two meters beneath the sediment-water interface.

  17. Stored CO2 and Methane Leakage Risk Assessment and Monitoring Tool Development: CO2 Capture Project Phase 2 (CCP2)

    Energy Technology Data Exchange (ETDEWEB)

    Dan Kieki

    2008-09-30

    The primary project goal is to develop and test tools for optimization of ECBM recovery and geologic storage of CO{sub 2} in coalbeds, in addition to tools for monitoring CO{sub 2} sequestration in coalbeds to support risk assessment. Three critical topics identified are (1) the integrity of coal bed methane geologic and engineered systems, (2) the optimization of the coal bed storage process, and (3) reliable monitoring and verification systems appropriate to the special conditions of CO{sub 2} storage and flow in coals.

  18. Research and Development Concerning Coalbed Natural Gas

    Energy Technology Data Exchange (ETDEWEB)

    William Ruckelshaus

    2008-09-30

    The Powder River Basin in northeastern Wyoming is one of the most active areas of coalbed natural gas (CBNG) development in the western United States. This resource provides clean energy but raises environmental concerns. Primary among these is the disposal of water that is co-produced with the gas during depressurization of the coal seam. Beginning with a few producing wells in Wyoming's Powder River Basin (PRB) in 1987, CBNG well numbers in this area increased to over 13,600 in 2004, with projected growth to 20,900 producing wells in the PRB by 2010. CBNG development is continuing apace since 2004, and CBNG is now being produced or evaluated in four other Wyoming coal basins in addition to the PRB, with roughly 3500-4000 new CBNG wells permitted statewide each year since 2004. This is clearly a very valuable source of clean fuel for the nation, and for Wyoming the economic benefits are substantial. For instance, in 2003 alone the total value of Wyoming CBNG production was about $1.5 billion, with tax and royalty income of about $90 million to counties, $140 million to the state, and $27 million to the federal government. In Wyoming, cumulative CBNG water production from 1987 through December 2004 was just over 380,000 acre-feet (2.9 billion barrels), while producing almost 1.5 trillion cubic feet (tcf) of CBNG gas statewide. Annual Wyoming CBNG water production in 2003 was 74,457 acre-feet (577 million barrels). Total production of CBNG water across all Wyoming coal fields could total roughly 7 million acre-feet (55.5 billion barrels), if all of the recoverable CBNG in the projected reserves of 31.7 tcf were produced over the coming decades. Pumping water from coals to produce CBNG has been designated a beneficial water use by the Wyoming State Engineer's Office (SEO), though recently the SEO has limited this beneficial use designation by requiring a certain gas/water production ratio. In the eastern part of the PRB where CBNG water is generally of good

  19. Research and Development Concerning Coalbed Natural Gas

    Energy Technology Data Exchange (ETDEWEB)

    William Ruckelshaus

    2008-09-30

    The Powder River Basin in northeastern Wyoming is one of the most active areas of coalbed natural gas (CBNG) development in the western United States. This resource provides clean energy but raises environmental concerns. Primary among these is the disposal of water that is co-produced with the gas during depressurization of the coal seam. Beginning with a few producing wells in Wyoming's Powder River Basin (PRB) in 1987, CBNG well numbers in this area increased to over 13,600 in 2004, with projected growth to 20,900 producing wells in the PRB by 2010. CBNG development is continuing apace since 2004, and CBNG is now being produced or evaluated in four other Wyoming coal basins in addition to the PRB, with roughly 3500-4000 new CBNG wells permitted statewide each year since 2004. This is clearly a very valuable source of clean fuel for the nation, and for Wyoming the economic benefits are substantial. For instance, in 2003 alone the total value of Wyoming CBNG production was about $1.5 billion, with tax and royalty income of about $90 million to counties, $140 million to the state, and $27 million to the federal government. In Wyoming, cumulative CBNG water production from 1987 through December 2004 was just over 380,000 acre-feet (2.9 billion barrels), while producing almost 1.5 trillion cubic feet (tcf) of CBNG gas statewide. Annual Wyoming CBNG water production in 2003 was 74,457 acre-feet (577 million barrels). Total production of CBNG water across all Wyoming coal fields could total roughly 7 million acre-feet (55.5 billion barrels), if all of the recoverable CBNG in the projected reserves of 31.7 tcf were produced over the coming decades. Pumping water from coals to produce CBNG has been designated a beneficial water use by the Wyoming State Engineer's Office (SEO), though recently the SEO has limited this beneficial use designation by requiring a certain gas/water production ratio. In the eastern part of the PRB where CBNG water is generally of good

  20. The growing role of methane in anthropogenic climate change

    Science.gov (United States)

    Saunois, M.; Jackson, R. B.; Bousquet, P.; Poulter, B.; Canadell, J. G.

    2016-12-01

    Unlike CO2, atmospheric methane concentrations are rising faster than at any time in the past two decades and, since 2014, are now approaching the most greenhouse-gas-intensive scenarios. The reasons for this renewed growth are still unclear, primarily because of uncertainties in the global methane budget. New analysis suggests that the recent rapid rise in global methane concentrations is predominantly biogenic-most likely from agriculture-with smaller contributions from fossil fuel use and possibly wetlands. Additional attention is urgently needed to quantify and reduce methane emissions. Methane mitigation offers rapid climate benefits and economic, health and agricultural co-benefits that are highly complementary to CO2 mitigation.

  1. Coal bed methane deposit law in Yiliang syncline coal mining area%彝良向斜煤矿区瓦斯赋存特征

    Institute of Scientific and Technical Information of China (English)

    乔军伟; 张光超

    2013-01-01

    通过对彝良向斜煤矿区主要可采煤层瓦斯含量的测定,分析了地质构造、埋藏深度、围岩性质、煤层厚度及煤变质程度对瓦斯赋存的影响作用.研究了该区煤层瓦斯赋存规律,对东部煤层瓦斯含量异常区进行详细的分析,并对其成因进行了初步探讨,其结论对于该区后续煤矿开采具有重要的指导意义.%Though testing the coal-bed methane content of main coal bed in Yiliang syncline coal mining area, obtained the factors influencing the coal-bed methane content is geological structures, burial depth, nature of rock and coal seam thickness and coal rank. Analyzed the coal-bed methane occurrence regularity and coal-bed methane abnormal area on the eastern section, and investigated the causes of formation. The conclusion is of a great guiding significance for the follow-up coal mining.

  2. Coal seam methane distribution and its significance in Pingdingshan mining area

    Institute of Scientific and Technical Information of China (English)

    郭德勇; 周心权; 沈少川; 张晓萍

    2002-01-01

    A study aimed at the coal seam group E and F in Pingdingshan mining area has been completed. This study is on the relationship of the coal-seam methane reserve to coal thickness, coal rank, coal seam depth, surrounding rock and geological structure and other factors. The study indicates that different geological factor plays different role in controlling the law of coal-seam methane reserve. The coal-seam methane rich area, which was formed because of various factors and comprehensive effect, is the coal and methane outburst-prone area, and also the key area for coal-bed methane recovery. Among all factors, coal seam depth and geological structure is more important factor in affecting coal-seam methane content in Pingdingshan mining area.

  3. Enhanced Microbial Pathways for Methane Production from Oil Shale

    Energy Technology Data Exchange (ETDEWEB)

    Paul Fallgren

    2009-02-15

    Methane from oil shale can potentially provide a significant contribution to natural gas industry, and it may be possible to increase and continue methane production by artificially enhancing methanogenic activity through the addition of various substrate and nutrient treatments. Western Research Institute in conjunction with Pick & Shovel Inc. and the U.S. Department of Energy conducted microcosm and scaled-up reactor studies to investigate the feasibility and optimization of biogenic methane production from oil shale. The microcosm study involving crushed oil shale showed the highest yield of methane was produced from oil shale pretreated with a basic solution and treated with nutrients. Incubation at 30 C, which is the estimated temperature in the subsurface where the oil shale originated, caused and increase in methane production. The methane production eventually decreased when pH of the system was above 9.00. In the scaled-up reactor study, pretreatment of the oil shale with a basic solution, nutrient enhancements, incubation at 30 C, and maintaining pH at circumneutral levels yielded the highest rate of biogenic methane production. From this study, the annual biogenic methane production rate was determined to be as high as 6042 cu. ft/ton oil shale.

  4. The Application of Methane Clumped Isotope Measurements to Determine the Source of Large Methane Seeps in Alaskan Lakes

    Science.gov (United States)

    Douglas, P. M.; Stolper, D. A.; Eiler, J. M.; Sessions, A. L.; Walter Anthony, K. M.

    2014-12-01

    Natural methane emissions from the Arctic present an important potential feedback to global warming. Arctic methane emissions may come from either active microbial sources or from deep fossil reservoirs released by the thawing of permafrost and melting of glaciers. It is often difficult to distinguish between and quantify contributions from these methane sources based on stable isotope data. Analyses of methane clumped isotopes (isotopologues with two or more rare isotopes such as 13CH3D) can complement traditional stable isotope-based classifications of methane sources. This is because clumped isotope abundances (for isotopically equilibrated systems) are a function of temperature and can be used to identify pathways of methane generation. Additionally, distinctive effects of mixing on clumped isotope abundances make this analysis valuable for determining the origins of mixed gasses. We find large variability in clumped isotope compositions of methane from seeps in several lakes, including thermokarst lakes, across Alaska. At Lake Sukok in northern Alaska we observe the emission of dominantly thermogenic methane, with a formation temperature of at least 100° C. At several other lakes we find evidence for mixing between thermogenic methane and biogenic methane that forms in low-temperature isotopic equilibrium. For example, at Eyak Lake in southeastern Alaska, analysis of three methane samples results in a distinctive isotopic mixing line between a high-temperature end-member that formed between 100-170° C, and a biogenic end-member that formed in isotopic equilibrium between 0-20° C. In this respect, biogenic methane in these lakes resembles observations from marine gas seeps, oil degradation, and sub-surface aquifers. Interestingly, at Goldstream Lake in interior Alaska, methane with strongly depleted clumped-isotope abundances, indicative of disequilibrium gas formation, is found, similar to observations from methanogen culture experiments.

  5. Coalbed natural gas exploration, drilling activities, and geologic test results, 2007-2010

    Science.gov (United States)

    Clark, Arthur C.

    2014-01-01

    The U.S. Geological Survey, in partnership with the U.S. Bureau of Land Management, the North Slope Borough, and the Arctic Slope Regional Corporation conducted a four-year study designed to identify, define, and delineate a shallow coalbed natural gas (CBNG) resource with the potential to provide locally produced, affordable power to the community of Wainwright, Alaska. From 2007 through 2010, drilling and testing activities conducted at three sites in or near Wainwright, identified and evaluated an approximately 7.5-ft-thick, laterally continuous coalbed that contained significant quantities of CBNG. This coalbed, subsequently named the Wainwright coalbed, was penetrated at depths ranging from 1,167 ft to 1,300 ft below land surface. Core samples were collected from the Wainwright coalbed at all three drill locations and desorbed-gas measurements were taken from seventeen 1-ft-thick sections of the core. These measurements indicate that the Wainwright coalbed contains enough CBNG to serve as a long-term energy supply for the community. Although attempts to produce viable quantities of CBNG from the Wainwright coalbed proved unsuccessful, it seems likely that with proper well-field design and by utilizing currently available drilling and reservoir stimulation techniques, this CBNG resource could be developed as a long-term economically viable energy source for Wainwright.

  6. Preface for the Special Column of Methane Transformation

    Institute of Scientific and Technical Information of China (English)

    Ye Wang

    2009-01-01

    @@ Methane is the main constituent of natural gas, coal-bed gas, landfill gas and methane hydrate resources. These resources may be used more efficiently as clean fuels or as chemical feedstocks if methane can be effectively transformed into liquid fuels or chemicals. However, methane only possesses C-H bonds and is a very stable organic molecule hard to functionalize. The C-H activation, particularly the selective functionalization of C-H bonds in saturated hydrocarbons, remains a difficult challenge in chemistry. The present technology for chemical utilization of methane involves the steam reforming of methane to synthesis gas and the subsequent transformation of synthesis gas to methanol or hydrocarbon fuels via methanol synthesis or Fischer-Tropsch synthesis. However, the steam reforming of methane is a high-cost process. The development of more efficient and economical processes for methane transformation is a dream of all chemists and chemical engineers. I think that this is also one of the most important themes of the Journal of Natural Gas Chemistry.

  7. Methane Flux

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Methane (CH4) flux is the net rate of methane exchange between an ecosystem and the atmosphere. Data of this variable were generated by the USGS LandCarbon project...

  8. Biogenic gas in the Cambrian-Ordovcian Alum Shale (Denmark and Sweden)

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, H.M.; Wirth, R.; Biermann, S.; Arning, E.T. [Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ, Potsdam (Germany); Krueger, M.; Straaten, N. [BGR Hannover (Germany); Bechtel, A. [Montanuniv. Leoben (Austria); Berk, W. van [Technical Univ. of Clausthal (Germany); Schovsbo, N.H. [Geological Survey of Denmark and Greenland - GEUS, Copenhagen (Denmark); Crabtree, Stephen [Gripen Gas (Sweden)

    2013-08-01

    Shale gas is mainly produced from thermally mature black shales. However, biogenic methane also represents a resource which is often underestimated. Today biogenic methane is being produced from the Upper Devonian Antrim Shale in the Michigan Basin which was the most successfully exploited shale gas system during the 1990-2000 decade in the U.S.A. before significant gas production from the Barnett Shale started (Curtis et al., 2008). The Cambro-Ordovician Alum Shale in northern Europe has thermal maturities ranging from overmature in southern areas (Denmark and southern Sweden) to immature conditions (central Sweden). Biogenic methane is recorded during drilling in central Sweden. The immature Alum Shale in central Sweden has total organic carbon (TOC) contents up to 20 wt%. The hydrogen index HI ranges from 380 to 560 mgHC/gTOC at very low oxygen index (OI) values of around 4 mg CO{sub 2}/gTOC, Tmax ranges between 420 - 430 C. The organic matter is highly porous. In general, the Alum Shale is a dense shale with intercalated sandy beds which may be dense due to carbonate cementation. Secondary porosity is created in some sandy beds due to feldspar dissolution and these beds serve as gas conduits. Methane production rates with shale as substrate in the laboratory are dependent on the kind of hydrocarbon-degrading microbial enrichment cultures used in the incubation experiments, ranging from 10-620 nmol/(g*d). In these experiments, the CO{sub 2} production rate was always higher than for methane. Like the northern part of North America, also Northern European has been covered by glaciers during the Pleistocene and similar geological processes may have developed leading to biogenic shale gas formation. For the Antrim Shale one hypothesis suggests that fresh waters, recharged from Pleistocene glaciation and modern precipitation, suppressed basinal brine salinity along the northern margins of the Michigan Basin to greater depths and thereby enhancing methanogenesis

  9. Demonstration of an ethane spectrometer for methane source identification.

    Science.gov (United States)

    Yacovitch, Tara I; Herndon, Scott C; Roscioli, Joseph R; Floerchinger, Cody; McGovern, Ryan M; Agnese, Michael; Pétron, Gabrielle; Kofler, Jonathan; Sweeney, Colm; Karion, Anna; Conley, Stephen A; Kort, Eric A; Nähle, Lars; Fischer, Marc; Hildebrandt, Lars; Koeth, Johannes; McManus, J Barry; Nelson, David D; Zahniser, Mark S; Kolb, Charles E

    2014-07-15

    Methane is an important greenhouse gas and tropospheric ozone precursor. Simultaneous observation of ethane with methane can help identify specific methane source types. Aerodyne Ethane-Mini spectrometers, employing recently available mid-infrared distributed feedback tunable diode lasers (DFB-TDL), provide 1 s ethane measurements with sub-ppb precision. In this work, an Ethane-Mini spectrometer has been integrated into two mobile sampling platforms, a ground vehicle and a small airplane, and used to measure ethane/methane enhancement ratios downwind of methane sources. Methane emissions with precisely known sources are shown to have ethane/methane enhancement ratios that differ greatly depending on the source type. Large differences between biogenic and thermogenic sources are observed. Variation within thermogenic sources are detected and tabulated. Methane emitters are classified by their expected ethane content. Categories include the following: biogenic (gas (1-6%), wet gas (>6%), pipeline grade natural gas (natural gas liquids (>30%). Regional scale observations in the Dallas/Fort Worth area of Texas show two distinct ethane/methane enhancement ratios bridged by a transitional region. These results demonstrate the usefulness of continuous and fast ethane measurements in experimental studies of methane emissions, particularly in the oil and natural gas sector.

  10. Addressing biogenic greenhouse gas emissions from hydropower in LCA.

    Science.gov (United States)

    Hertwich, Edgar G

    2013-09-03

    The ability of hydropower to contribute to climate change mitigation is sometimes questioned, citing emissions of methane and carbon dioxide resulting from the degradation of biogenic carbon in hydropower reservoirs. These emissions are, however, not always addressed in life cycle assessment, leading to a bias in technology comparisons, and often misunderstood. The objective of this paper is to review and analyze the generation of greenhouse gas emissions from reservoirs for the purpose of technology assessment, relating established emission measurements to power generation. A literature review, data collection, and statistical analysis of methane and CO2 emissions are conducted. In a sample of 82 measurements, methane emissions per kWh hydropower generated are log-normally distributed, ranging from micrograms to 10s of kg. A multivariate regression analysis shows that the reservoir area per kWh electricity is the most important explanatory variable. Methane emissions flux per reservoir area are correlated with the natural net primary production of the area, the age of the power plant, and the inclusion of bubbling emissions in the measurement. Even together, these factors fail to explain most of the variation in the methane flux. The global average emissions from hydropower are estimated to be 85 gCO2/kWh and 3 gCH4/kWh, with a multiplicative uncertainty factor of 2. GHG emissions from hydropower can be largely avoided by ceasing to build hydropower plants with high land use per unit of electricity generated.

  11. Carbon and hydrogen isotopic composition and generation pathway of biogenic gas in China

    Institute of Scientific and Technical Information of China (English)

    SHEN Ping; WANG Xiaofeng; XU Yin; SHI Baoguang; XU Yongchang

    2009-01-01

    The carbon and hydrogen isotopic composition of biogenic gas is of great importance for the study of its generation pathway and reservoiring characteristics. In this paper, the formation pathways and reservoiring characteristics of biogenic gas reservoirs in China are described in terms of the carbon and hydrogen isotopic compositions of 31 gas samples from 10 biogenic gas reservoirs. The study shows that the hydrogen isotopic compositions of these biogenic gas reservoirs can be divided into three intervals:δDCH4>-200‰,-250‰<δDCH4<-200‰ and δDCH4<-250‰. The forerunners believed that the main generation pathway of biogenic gas under the condition of continental fresh water is acetic fermentation. Our research results showed that the generation pathway of biogenic gas under the condition of marine facies is typical CO2- reduction, the biogenic gas has heavy hydrogen isotopic composition: its δDCH4 values are higher than -200‰; that the biogenic gas under the condition of continental facies also was generated by the same way, but its hydrogen isotopic composition is lighter than that of biogenetic gas generated under typical marine facies condition: -250‰<δDCH4<-200‰, the δDCH4 values may be related to the salinity of the water medium in ancient lakes. From the relevant data of the Qaidam Basin, it can be seen that the hydrogen isotopic composition of biogenic methane has the same variation trend with increasing salinity of water medium. There are biogenic gas reservoirs formed in transitional regions under the condition of continental facies. These gas reservoirs resulted from both CO2- reduction and acetic fermentation, the formation of which may be related to the non-variant salinity of ancient water medium and the relatively high geothermal gradient, as is the case encountered in the Baoshan Basin. The biogenic gas generating in these regions has light hydrogen isotopic composition: δDCH4<-250‰, and relatively heavy carbon isotopic

  12. Formation and retention of methane in coal

    Energy Technology Data Exchange (ETDEWEB)

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  13. Deep subsurface drip irrigation using coal-bed sodic water: part II. geochemistry

    Science.gov (United States)

    Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.

    2013-01-01

    Waters with low salinity and high sodium adsorption ratios (SARs) present a challenge to irrigation because they degrade soil structure and infiltration capacity. In the Powder River Basin of Wyoming, such low salinity (electrical conductivity, EC 2.1 mS cm-1) and high-SAR (54) waters are co-produced with coal-bed methane and some are used for subsurface drip irrigation(SDI). The SDI system studied mixes sulfuric acid with irrigation water and applies water year-round via drip tubing buried 92 cm deep. After six years of irrigation, SAR values between 0 and 30 cm depth (0.5-1.2) are only slightly increased over non-irrigated soils (0.1-0.5). Only 8-15% of added Na has accumulated above the drip tubing. Sodicity has increased in soil surrounding the drip tubing, and geochemical simulations show that two pathways can generate sodic conditions. In soil between 45-cm depth and the drip tubing, Na from the irrigation water accumulates as evapotranspiration concentrates solutes. SAR values >12, measured by 1:1 water-soil extracts, are caused by concentration of solutes by factors up to 13. Low-EC (-1) is caused by rain and snowmelt flushing the soil and displacing ions in soil solution. Soil below the drip tubing experiences lower solute concentration factors (1-1.65) due to excess irrigation water and also contains relatively abundant native gypsum (2.4 ± 1.7 wt.%). Geochemical simulations show gypsum dissolution decreases soil-water SAR to 14 and decreasing EC in soil water to 3.2 mS cm-1. Increased sodicity in the subsurface, rather than the surface, indicates that deep SDI can be a viable means of irrigating with sodic waters.

  14. Deep subsurface drip irrigation using coal-bed sodic water: part I. water and solute movement

    Science.gov (United States)

    Bern, Carleton R.; Breit, George N.; Healy, Richard W.; Zupancic, John W.; Hammack, Richard

    2013-01-01

    Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300-480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

  15. Deep subsurface drip irrigation using coal-bed sodic water: Part I. Water and solute movement

    Energy Technology Data Exchange (ETDEWEB)

    Bern, Carleton R; Breit, George N; Healy, Richard W; Zupancic, John W; Hammack, Richard

    2013-02-01

    Water co-produced with coal-bed methane (CBM) in the semi-arid Powder River Basin of Wyoming and Montana commonly has relatively low salinity and high sodium adsorption ratios that can degrade soil permeability where used for irrigation. Nevertheless, a desire to derive beneficial use from the water and a need to dispose of large volumes of it have motivated the design of a deep subsurface drip irrigation (SDI) system capable of utilizing that water. Drip tubing is buried 92 cm deep and irrigates at a relatively constant rate year-round, while evapotranspiration by the alfalfa and grass crops grown is seasonal. We use field data from two sites and computer simulations of unsaturated flow to understand water and solute movements in the SDI fields. Combined irrigation and precipitation exceed potential evapotranspiration by 300–480 mm annually. Initially, excess water contributes to increased storage in the unsaturated zone, and then drainage causes cyclical rises in the water table beneath the fields. Native chloride and nitrate below 200 cm depth are leached by the drainage. Some CBM water moves upward from the drip tubing, drawn by drier conditions above. Chloride from CBM water accumulates there as root uptake removes the water. Year over year accumulations indicated by computer simulations illustrate that infiltration of precipitation water from the surface only partially leaches such accumulations away. Field data show that 7% and 27% of added chloride has accumulated above the drip tubing in an alfalfa and grass field, respectively, following 6 years of irrigation. Maximum chloride concentrations in the alfalfa field are around 45 cm depth but reach the surface in parts of the grass field, illustrating differences driven by crop physiology. Deep SDI offers a means of utilizing marginal quality irrigation waters and managing the accumulation of their associated solutes in the crop rooting zone.

  16. Assessment of Permian coalbed gas resources of the Karoo Basin Province, South Africa and Lesotho, 2016

    Science.gov (United States)

    Schenk, Christopher J.; Brownfield, Michael E.; Tennyson, Marilyn E.; Klett, Timothy R.; Mercier, Tracey J.; Hawkins, Sarah J.; Gaswirth, Stephanie B.; Marra, Kristen R.; Finn, Thomas M.; Le, Phuong A.; Leathers-Miller, Heidi M.

    2017-02-21

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 5.27 trillion cubic feet of coalbed gas in the Karoo Basin Province.

  17. Assessment of coalbed gas resources of the Central and South Sumatra Basin Provinces, Indonesia, 2016

    Science.gov (United States)

    Schenk, Christopher J.; Klett, Timothy R.; Tennyson, Marilyn E.; Mercier, Tracey J.; Brownfield, Michael E.; Pitman, Janet K.; Gaswirth, Stephanie B.; Finn, Thomas M.

    2016-12-09

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 20 trillion cubic feet of undiscovered, technically recoverable coalbed gas resource in the Central and South Sumatra Basin Provinces of Indonesia.

  18. Evidence of sulfate-dependent anaerobic methane oxidation ...

    Science.gov (United States)

    The rapid development of unconventional gas resources has been accompanied by an increase in public awareness regarding the potential effects of drilling operations on drinking water sources. Incidents have been reported involving blowouts (e.g., Converse County, WY; Lawrence Township, PA; Aliso Canyon, CA) and home/property explosions (e.g., Bainbridge Township, OH; Dimock, PA; Huerfano County, CO) caused by methane migration in the subsurface within areas of natural gas development. We evaluated water quality characteristics in the northern Raton Basin of Colorado and documented the response of the Poison Canyon aquifer system several years after upward migration of methane gas occurred from the deeper Vermejo Formation coalbed production zone. Results show persistent secondary water quality impacts related to the biodegradation of methane. We identify four distinct characteristics of groundwater methane attenuation in the Poison Canyon aquifer: (i) consumption of methane and sulfate and production of sulfide and bicarbonate, (ii) methane loss coupled to production of higher-molecular-weight (C2+) gaseous hydrocarbons, (iii) patterns of 13C enrichment and depletion in methane and dissolved inorganic carbon, and (iv) a systematic shift in sulfur and oxygen isotope ratios of sulfate, indicative of microbial sulfate reduction. We also show that the biogeochemical response of the aquifer system has not mobilized naturally occurring trace metals, including arsenic,

  19. Preliminary investigation of biogenic gas production in Indonesian low rank coals and implications for a renewable energy source

    Science.gov (United States)

    Susilawati, Rita; Papendick, Sam L.; Gilcrease, Patrick C.; Esterle, Joan S.; Golding, Suzanne D.; Mares, Tennille E.

    2013-11-01

    Indonesia has abundant coal resources at depths suitable to contain substantial volumes of naturally occurring methane, which are currently being explored. Most Indonesian coals are thermally immature, but are composed of hydrogen-rich organic components that are presumed to make them excellent substrates for biogenic methane production. Gas isotope results from pilot wells in South Sumatra, reported in this study, are interpreted to indicate biogenic origins for the methane. Corresponding formation water samples were collected and incubated, and show the presence of indigenous microbial communities capable of producing methane from Indonesian and Australian coal. Although these results are only preliminary, they are promising and support the possibility of Indonesia developing bio renewable energy from coal seams.

  20. Attributing Atmospheric Methane to Anthropogenic Emission Sources.

    Science.gov (United States)

    Allen, David

    2016-07-19

    Methane is a greenhouse gas, and increases in atmospheric methane concentration over the past 250 years have driven increased radiative forcing of the atmosphere. Increases in atmospheric methane concentration since 1750 account for approximately 17% of increases in radiative forcing of the atmosphere, and that percentage increases by approximately a factor of 2 if the effects of the greenhouse gases produced by the atmospheric reactions of methane are included in the assessment. Because of the role of methane emissions in radiative forcing of the atmosphere, the identification and quantification of sources of methane emissions is receiving increased scientific attention. Methane emission sources include biogenic, geogenic, and anthropogenic sources; the largest anthropogenic sources are natural gas and petroleum systems, enteric fermentation (livestock), landfills, coal mining, and manure management. While these source categories are well-known, there is significant uncertainty in the relative magnitudes of methane emissions from the various source categories. Further, the overall magnitude of methane emissions from all anthropogenic sources is actively debated, with estimates based on source sampling extrapolated to regional or national scale ("bottom-up analyses") differing from estimates that infer emissions based on ambient data ("top-down analyses") by 50% or more. To address the important problem of attribution of methane to specific sources, a variety of new analytical methods are being employed, including high time resolution and highly sensitive measurements of methane, methane isotopes, and other chemical species frequently associated with methane emissions, such as ethane. This Account describes the use of some of these emerging measurements, in both top-down and bottom-up methane emission studies. In addition, this Account describes how data from these new analytical methods can be used in conjunction with chemical mass balance (CMB) methods for source

  1. Stimulation by ammonium-based fertilizers of methane oxidation in soil around rice roots

    NARCIS (Netherlands)

    Bodelier, P.L.E.; Roslev, P.; Henckel, T.; Frenzel, P.

    2000-01-01

    Methane is involved in a number of chemical and physical processes in the Earths atmosphere, including global warming(1), Atmospheric methane originates mainly from biogenic sources, such as rice paddies and natural wetlands; the former account for at least 30% of the global annual emission of metha

  2. Contribution by the methanogenic endosymbionts of anaerobic ciliates to methane production in Dutch freshwater sediments

    NARCIS (Netherlands)

    Hoek, van A.H.A.M.; Alen, T.A.; Vogels, G.D.; Hackstein, J.H.P.

    2006-01-01

    Biogenic methane contributes substantially to the atmospheric methane concentration and thus to global warming. This trace gas is predominantly produced by strictly anaerobic methanogenic archaea, which thrive in the most divergent ecological niches, e. g. paddy fields, sediments, landfills, and the

  3. Ground and Airborne Methane Measurements Using Optical Parametric Amplifiers

    Science.gov (United States)

    Numata, Kenji; Riris, Haris; Li, Steve; Wu, Stewart; Kawa, Stephan R.; Abshire, James Brice; Dawsey, Martha; Ramanathan, Anand

    2011-01-01

    We report on ground and airborne methane measurements with an active sensing instrument using widely tunable, seeded optical parametric generation (OPG). The technique has been used to measure methane, CO2, water vapor, and other trace gases in the near and mid-infrared spectral regions. Methane is a strong greenhouse gas on Earth and it is also a potential biogenic marker on Mars and other planetary bodies. Methane in the Earth's atmosphere survives for a shorter time than CO2 but its impact on climate change can be larger than CO2. Carbon and methane emissions from land are expected to increase as permafrost melts exposing millennial-age carbon stocks to respiration (aerobic-CO2 and anaerobic-CH4) and fires. Methane emissions from c1athrates in the Arctic Ocean and on land are also likely to respond to climate warming. However, there is considerable uncertainty in present Arctic flux levels, as well as how fluxes will change with the changing environment. For Mars, methane measurements are of great interest because of its potential as a strong biogenic marker. A remote sensing instrument that can measure day and night over all seasons and latitudes can localize sources of biogenic gas plumes produced by subsurface chemistry or biology, and aid in the search for extra-terrestrial life. In this paper we report on remote sensing measurements of methane using a high peak power, widely tunable optical parametric generator (OPG) operating at 3.3 micrometers and 1.65 micrometers. We have demonstrated detection of methane at 3.3 micrometers and 1650 nanometers in an open path and compared them to accepted standards. We also report on preliminary airborne demonstration of methane measurements at 1.65 micrometers.

  4. Hydraulic and Seismic Properties of Methane-Bearing Coal

    Science.gov (United States)

    Kneafsey, T. J.; Gritto, R.; Tomutsa, L.

    2002-12-01

    In the last 10 years, coalbed methane (CBM) has transformed from being a coal mine hazard to a low-risk source of long term dry natural gas. The benefit of this clean burning natural gas as an energy source in conjunction with vast amounts stored in coal basins has led to the development of an industry that produces CBM. Reduction of carbon emissions to the atmosphere through carbon dioxide injection into coal has added another benefit to the production of CMB, as carbon dioxide may be used to desorb methane from coal seams. In order to successfully produce CBM, more information is needed on the migration of methane through fractures and cleats and on the replacement of methane by carbon dioxide in the coal seam. Laboratory experiments are underway to address these questions. Tests on core samples are being performed under in-situ pressure to gain insights on processes occurring in CBM extraction and carbon dioxide sequestration. A variety of techniques are being used including measuring physical properties, electrical resistivity, and saturation and phase location using x-ray computed tomography. Simultaneously measurements of seismic waves are performed including P- and S-wave velocities as well as amplitudes of body waves as a function of methane and carbon dioxide concentration in coal. The results can be used to design an experiment to monitor time-lapse changes and thus the production of gas from a coal seam during methane production.

  5. Arctic methane

    NARCIS (Netherlands)

    Dyupina, E.; Amstel, van A.R.

    2013-01-01

    What are the risks of a runaway greenhouse effect from methane release from hydrates in the Arctic? In January 2013, a dramatic increase of methane concentration up to 2000 ppb has been measured over the Arctic north of Norway in the Barents Sea. The global average being 1750 ppb. It has been

  6. Arctic methane

    NARCIS (Netherlands)

    Dyupina, E.; Amstel, van A.R.

    2013-01-01

    What are the risks of a runaway greenhouse effect from methane release from hydrates in the Arctic? In January 2013, a dramatic increase of methane concentration up to 2000 ppb has been measured over the Arctic north of Norway in the Barents Sea. The global average being 1750 ppb. It has been sugges

  7. The experiment study on slippage effect of the coal-bed methane transfusion

    Institute of Scientific and Technical Information of China (English)

    PENG Xiao-hua; PAN Yi-shan; XIAO Xiao-chun; CHEN Chang-hua

    2008-01-01

    When the gas flow in the compact porous medium at low speed,it has slippage effect which is caused by the gas molecular collision whit the solidskeleton.Using the gas transfusion slippage effect at researching the coal bed transfusion rule,established the transfusion mathematical model of the coal bed which had considered the slippage effect.Observing the influence of the different toencircle presses,the different hole press and the different actual stress to the coal bed by using the three-axles permeameter.Thus summarized the transfusion rule of the coal bed.The experiment indicates that the bigger of the surrounding pressure,the more obvious of the slippage effect.At the same condition of axial pressure and the surrounding pressure,with the increase of the hole pressure,the coal permeability became bigger and then smaller.The coal body effective tress and the permeability curve nearly also has the same change tendency.Thus we can draws the conclusion that the transfusion of the gas in the coal bed generally has the slippage effect.

  8. Assessment of CO2 storage performance of the Enhanced Coalbed Methane pilot site in Kaniow

    NARCIS (Netherlands)

    Bergen, F. van; Winthaegen, P.; Pagnier, H.; Krzystolik, P.; Jura, B.; Skiba, J.; Wageningen, N. van

    2009-01-01

    A pilot site for CO2 storage in coal seams was set-up in Poland, as has been reported on previous GHGT conferences. This site consisted of one injection and one production well. About 760 ton of CO2 has been injected into the reservoir from August 2004 to June 2005. Breakthrough of the injected CO2

  9. The experiment study on slippage effect of the coal-bed methane transfusion

    Institute of Scientific and Technical Information of China (English)

    PENG Xiao-hua; PAN Yi-shan; XIAO Xiao-chun; CHEN Chang-hua

    2008-01-01

    When the gas flow in the compact porous medium at low speed, it has slippage effect which is caused by the gas molecular collision whit the solidskeleton. Using the gas transfusion slippage effect at researching the coal bed transfusion rule, established the transfusion mathematical model of the coal bed which had considered the slippage effect. Observing the influence of the different toencircle presses, the different hole press and the different actual stress to the coal bed by using the three-axles permeameter. Thus sum-marized the transfusion rule of the coal bed. The experiment indicates that the bigger of the surrounding pressure, the more obvious of the slippage effect. At the same condition of axial pressure and the surrounding pressure, with the increase of the hole pressure, the coal permeability became bigger and then smaller. The coal body effective tress and the permeability curve nearly also has the same change tendency. Thus we can draws the conclusion that the transfusion of the gas in the coal bed generally has the slippage effect.

  10. The coalbed methane transport model and its application in the presence of matrix shrinkage

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on the theories of surface physical chemistry, theoretical formulations for permeability and porosity are presented which include both stress effect and matrix shrinkage in a single equation. Then, a three-dimensional, dual porosity, nonequilibrium adsorption, pseudosteady state mathematical model for gas and water is established and solved by the fully implicit method and the block precondition- ing orthomin algorithm. A history matching for the Qinshui Well TL003 is done. From the results, it is shown that the obvious enhancement of permeability occurs along with the passing time but the reservoir pressure of 15# coal seam cannot fulfill the critical adsorption pressure as a result of the water recharge of the aquifer. Hence, it is suggested to plug the 15# coal seam.

  11. The coalbed methane transport model and its application in the presence of matrix shrinkage

    Institute of Scientific and Technical Information of China (English)

    ZHANG XianMin; TONG DengKe

    2008-01-01

    Based on the theories of surface physical chemistry,theoretical formulations for permeability and porosity are presented which include both stress effect and ma-trix shrinkage in a single equation.Then,a three-dimensional,dual porosity,non-equilibrium adsorption,pseudosteady state mathematical model for gas and water is established and solved by the fully implicit method and the block precondition-ing orthomin algorithm.A history matching for the Qinshui Well TL003 is done.From the results,it is shown that the obvious enhancement of permeability occurs along with the passing time but the reservoir pressure of 15# coal seam cannot ful-fill the critical adsorption pressure as a result of the water recharge of the aquifer.Hence,it is suggested to plug the 15# coal seam.

  12. Assessment of CO2 storage performance of the Enhanced Coalbed Methane pilot site in Kaniow

    NARCIS (Netherlands)

    Bergen, F. van; Winthaegen, P.; Pagnier, H.; Krzystolik, P.; Jura, B.; Skiba, J.; Wageningen, N. van

    2009-01-01

    A pilot site for CO2 storage in coal seams was set-up in Poland, as has been reported on previous GHGT conferences. This site consisted of one injection and one production well. About 760 ton of CO2 has been injected into the reservoir from August 2004 to June 2005. Breakthrough of the injected CO2

  13. Mechanical effects of sorption processes in coal and implications for coalbed methane recovery

    NARCIS (Netherlands)

    Liu, J.

    2016-01-01

    In this thesis, I present the results of a theoretical and experimental study of the response of dry coal matrix material to pure CH4, pure H2O and CH4-CO2 mixtures under in-situ conditions, with the aim of providing fundamental data that can contribute to assessing future strategies for enhanced co

  14. The experiment study on slippage effect of the coal-bed methane transfusion

    Energy Technology Data Exchange (ETDEWEB)

    Peng, X.; Pan, Y.; Xiao, C.; Chen, C. [Liaoning Technical University, Fuxin (China). College of Science

    2008-12-15

    When gas flows in a compact porous medium at low speed, it has a slippage effect which is caused by molecular collisions of gas with the solid skeleton. Using the gas transfusion slippage effect for researching coal bed transfusion, a mathematical model of the coal bed was established which considered the slippage effect. The experiment indicates that the higher the surrounding pressure, the more marked is the slippage effect. At the same condition of axial pressure and surrounding pressure, with an increase of the hole pressure, the coal permeability become higher and then lower. The coal body effective stress and the permeability curve also has the same change tendency. Thus the conclusion can be drawn that the transfusion of the gas in the coal bed generally has a slippage effect. 5 refs., 3 figs.

  15. The role of CO2-enhanced coalbed methane production in the global CCS strategy

    NARCIS (Netherlands)

    Bergen, F. van; Tambach, T.; Pagnier, H.

    2011-01-01

    Subsurface coal seams are generally considered as important potential geological media for underground storage of carbon dioxide, but this is a more complex option than other storage options. The required number of wells and the uncertainties due to the complexity were generally considered as main b

  16. Finite element analysis of high-pressure hose for radial horizontal wells in coalbed methane extraction

    Institute of Scientific and Technical Information of China (English)

    Wei-Dong ZHOU; Wei SHI; Luo-Peng LI; Jing-Shuang WANG; Jun SUN

    2013-01-01

    Based on the serial-parallel model of single-layer board and the lamination theory,the forces exerted on different layers of the high-pressure hose and the resulting deformations were analyzed when the hose was radially stretched.An equation was proposed to calculate the anisotropic elastic constant of the composite layer with the wound steel wires.Furthermore,the finite element analysis (FEA) model of the high-pressure hose was established,followed by a simulation of the forces that act on different layers,and their deformations.The simulation results show that the stress imposed on the inner reinforced layer and external reinforced layer of the high-pressure hose are approximately 150 MPa and l 15 MPa,respectively,in the presence of inner pressure.The stress of the rubber coating and polyethylene coating is lower.The lowest stress occurs on the inner surface of the high-pressure hose and the rubber coating between the two composite layers.The deformation of the rubber layer in the inner surface of the high-pressure hose decreases gradually along the radial direction from the inner surface to the external surface.The deformation of the reinforced composite layer is less than that of the external surface of the rubber coating.The equivalent stress of the reinforced composite layer is higher than that caused by the inner pressure,due to the presence of both inner pressure and axial tension.

  17. Tracking solutes and water from subsurface drip irrigation application of coalbed methane–produced waters, Powder River Basin, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Engle, Mark A. [U.S. Geological Survey. Reston, VA (United States); Bern, Carleton R. [U.S. Geological Survey. Denver, CO (United States); Healy, Richard W. [U.S. Geological Survey. Denver, CO (United States); Sams, James I. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Zupancic, John W. [BeneTerra LLC. Sheridan, WY (United States); Schroeder, Karl T. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2011-09-01

    One method to beneficially use water produced from coalbed methane (CBM) extraction is subsurface drip irrigation (SDI) of croplands. In SDI systems, treated CBM water (injectate) is supplied to the soil at depth, with the purpose of preventing the buildup of detrimental salts near the surface. The technology is expanding within the Powder River Basin, but little research has been published on its environmental impacts. This article reports on initial results from tracking water and solutes from the injected CBM-produced waters at an SDI system in Johnson County, Wyoming. In the first year of SDI operation, soil moisture significantly increased in the SDI areas, but well water levels increased only modestly, suggesting that most of the water added was stored in the vadose zone or lost to evapotranspiration. The injectate has lower concentrations of most inorganic constituents relative to ambient groundwater at the site but exhibits a high sodium adsorption ratio. Changes in groundwater chemistry during the same period of SDI operation were small; the increase in groundwater-specific conductance relative to pre-SDI conditions was observed in a single well. Conversely, groundwater samples collected beneath another SDI field showed decreased concentrations of several constituents since the SDI operation. Groundwater-specific conductance at the 12 other wells showed no significant changes. Major controls on and compositional variability of groundwater, surface water, and soil water chemistry are discussed in detail. Findings from this research provide an understanding of water and salt dynamics associated with SDI systems using CBM-produced water.

  18. Biogenic amines in fermented foods

    NARCIS (Netherlands)

    Spano, G.; Russo, P.; Lonvaud-Funel, A.; Lucas, P.; Alexandre, H.; Grandvalet, C.; Coton, E.; Coton, M.; Barnavon, L.; Bach, B.; Rattray, F.; Bunte, A.; Magni, C.; Ladero, V.; Alvarez, M.; Fernández, M.; Lopez, P.; Palencia, P.F. de; Corbi, A.; Trip, H.; Lolkema, J.S.

    2010-01-01

    Food-fermenting lactic acid bacteria (LAB) are generally considered to be non-toxic and non-pathogenic. Some species of LAB, however, can produce biogenic amines (BAs). BAs are organic, basic, nitrogenous compounds, mainly formed through decarboxylation of amino acids. BAs are present in a wide rang

  19. 褐煤本源菌在煤层生物气生成中的微生物学特征%Performance of indigenous bacteria during the biogenic gas generation from brown coal

    Institute of Scientific and Technical Information of China (English)

    王爱宽; 秦勇

    2011-01-01

    have been inhibited by the acid substances created by acidogenic fermenting bacteria.The minimum activity values were 55.91%-67.61% of the peak values.The activities of coenzyme F420 had two peak times in the biogenic gas generation progress from brown coal,indicating periodic characteristics of biogenic coalbed methane generation from brown coal.

  20. Methane production in terrestrial arthropods

    Energy Technology Data Exchange (ETDEWEB)

    Hackstein, J.H.P.; Stumm, C.K. (Catholic Univ. of Nijmegen (Netherlands))

    1994-06-07

    The authors have screened more than 110 representatives of the different taxa of terrestrial arthropods for methane production in order to obtain additional information about the origins of biogenic methane. Methanogenic bacteria occur in the hindguts of nearly all tropical representatives of millipedes (Diplopoda), cockroaches (Blattaria), termites (Isoptera), and scarab beetles (Scarabaeidae), while such methanogens are absent from 66 other arthropod species investigated. Three types of symbiosis were found: in the first type, the arthropod's hindgut is colonized by free methanogenic bacteria; in the second type, methanogens are closely associated with chitinous structures formed by the host's hindgut; the third type is mediated by intestinal anaerobic protists with intracellular methanogens. Such symbiotic associations are likely to be a characteristic property of the particular taxon. Since these taxa represent many families with thousands of species, the world populations of methane-producing arthropods constitute an enormous biomass. The authors show that arthropod symbionts can contribute substantially to atmospheric methane.

  1. Coalbed gas systems, resources, and production and a review of contrasting cases from the San Juan and Powder River basins

    Energy Technology Data Exchange (ETDEWEB)

    Ayers, W.B. [Texas A& M University, College Station, TX (United States)

    2002-07-01

    Coalbed gas is stored primarily within micropores of the coal matrix in an adsorbed state and secondarily in micropores and fractures as free gas or solution gas in water. The key parameters that control gas resources and producibility are thermal maturity, maceral composition, gas content, coal thickness, fracture density, in-situ stress, permeability, burial history, and hydrologic setting. These parameters vary greatly in the producing fields of the United States and the world. In 2000, the San Juan basin accounted for more than 80% of the United States coalbed gas production. This basin contains a giant coalbed gas play, the Fruitland fairway, which has produced more than 7 tcf (0.2 Tm{sup 3}) of gas. The Fruitland coalbed gas system M and its key elements contrast with the Fort Union coalbed gas play in the Powder River basin. The Fort Union coalbed play is one of the fastest developing gas plays in the United States. Its production escalated from 14 bcf (0.4 Gm{sup 3}) in 1997 to 147.3 bcf (4.1 Gm{sup 3}) in 2000, when it accounted for 10.7% of the United States coalbed gas production. By 2001, annual production was 244.7 bcf (6.9 Gm{sup 3}). Differences between the Fruitland and Fort Union petroleum systems make them ideal for elucidating the key elements of contrasting coalbed gas petroleum systems.

  2. Monitoring of coalbed water retention ponds in the Powder River Basin using Google Earth images and an Unmanned Aircraft System

    Science.gov (United States)

    Zhou, X.; Zhou, Z.; Apple, M. E.; Spangler, L.

    2016-12-01

    To extract methane from unminable seams of coal in the Powder River Basin of Montana and Wyoming, coalbed methane (CBM) water has to be pumped and kept in retention ponds rather than discharged to the vadose zone to mix with the ground water. The water areal coverage of these ponds changes due to evaporation and repetitive refilling. The water quality also changes due to growing of microalgae (unicellular or filamentous including green algae and diatoms), evaporation, and refilling. To estimate the water coverage changes and monitor water quality becomes important for monitoring the CBM water retention ponds to provide timely management plan for the newly pumped CBM water. Conventional methods such as various water indices based on multi-spectral satellite data such as Landsat because of the small pond size ( 100mx100m scale) and low spatial resolution ( 30m scale) of the satellite data. In this study we will present new methods to estimate water coverage and water quality changes using Google Earth images and images collected from an unmanned aircraft system (UAS) (Phantom 2 plus). Because these images have only visible bands (red, green, and blue bands), the conventional water index methods that involve near-infrared bands do not work. We design a new method just based on the visible bands to automatically extract water pixels and the intensity of the water pixel as a proxy for water quality after a series of image processing such as georeferencing, resampling, filtering, etc. Differential GPS positions along the water edges were collected the same day as the images collected from the UAS. Area of the water area was calculated from the GPS positions and used for the validation of the method. Because of the very high resolution ( 10-30 cm scale), the water areal coverage and water quality distribution can be accurately estimated. Since the UAS can be flied any time, water area and quality information can be collected timely.

  3. Biochemically enhanced methane production from coal

    Science.gov (United States)

    Opara, Aleksandra

    For many years, biogas was connected mostly with the organic matter decomposition in shallow sediments (e.g., wetlands, landfill gas, etc.). Recently, it has been realized that biogenic methane production is ongoing in many hydrocarbon reservoirs. This research examined microbial methane and carbon dioxide generation from coal. As original contributions methane production from various coal materials was examined in classical and electro-biochemical bench-scale reactors using unique, developed facultative microbial consortia that generate methane under anaerobic conditions. Facultative methanogenic populations are important as all known methanogens are strict anaerobes and their application outside laboratory would be problematic. Additional testing examined the influence of environmental conditions, such as pH, salinity, and nutrient amendments on methane and carbon dioxide generation. In 44-day ex-situ bench-scale batch bioreactor tests, up to 300,000 and 250,000 ppm methane was generated from bituminous coal and bituminous coal waste respectively, a significant improvement over 20-40 ppm methane generated from control samples. Chemical degradation of complex hydrocarbons using environmentally benign reagents, prior to microbial biodegradation and methanogenesis, resulted in dissolution of up to 5% bituminous coal and bituminous coal waste and up to 25% lignite in samples tested. Research results confirm that coal waste may be a significant underutilized resource that could be converted to useful fuel. Rapid acidification of lignite samples resulted in low pH (below 4.0), regardless of chemical pretreatment applied, and did not generate significant methane amounts. These results confirmed the importance of monitoring and adjusting in situ and ex situ environmental conditions during methane production. A patented Electro-Biochemical Reactor technology was used to supply electrons and electron acceptor environments, but appeared to influence methane generation in a

  4. Map of assessed coalbed-gas resources in the United States, 2014

    Science.gov (United States)

    ,; Biewick, Laura R. H.

    2014-01-01

    This report presents a digital map of coalbed-gas resource assessments in the United States as part of the U.S. Geological Survey’s (USGS) National Assessment of Oil and Gas Project. Using a geology-based assessment methodology, the USGS quantitatively estimated potential volumes of undiscovered, technically recoverable natural gas resources within coalbed-gas assessment units (AUs). This is the third digital map product in a series of USGS unconventional oil and gas resource maps. The map plate included in this report can be printed in hardcopy form or downloaded in a Geographic Information System (GIS) data package, including an ArcGIS ArcMap document (.mxd), geodatabase (.gdb), and published map file (.pmf). In addition, the publication access table contains hyperlinks to current USGS coalbed-gas assessment publications and web pages.

  5. Antiaggregant effects of biogenic chloramines.

    Science.gov (United States)

    Murina, M A; Roshchupkin, D I; Kravchenko, N N; Petrova, A O; Sergienko, V I

    2007-09-01

    Alanine and taurine sharply potentiate antiaggregant effects of hypochlorite on platelets in platelet-rich plasma. This effect is determined by more pronounced action of chloramine derivatives, products of interaction of added amino acids with hypochlorite. Platelets are more sensitive to the inhibitory effects of amino acid chloramine derivatives (biogenic chloramines) compared to erythrocytes and neutrophils. The antiaggregant effects of biobenic amines, as covalent platelet inhibitors, in platelet-rich plasma are characterized by their increased reaction capacity with molecular targets in cells. Quantitative parameter of this initial selectivity (ratio of rate constant of inactivation of platelet receptors to rate constant of side reaction with plasma proteins) far surpasses 1. N,N-Dichlorotaurine is a perspective antiaggreant among the studied biogenic chloramines. This agent is stable and exhibits specific pharmacological activity in all test systems, including animal model of thrombosis.

  6. Biogenic Amines in Insect Antennae

    Directory of Open Access Journals (Sweden)

    Marianna I. Zhukovskaya

    2017-06-01

    Full Text Available Insect antenna is a multisensory organ, each modality of which can be modulated by biogenic amines. Octopamine (OA and its metabolic precursor tyramine (TA affect activity of antennal olfactory receptor neurons. There is some evidence that dopamine (DA modulates gustatory neurons. Serotonin can serve as a neurotransmitter in some afferent mechanosensory neurons and both as a neurotransmitter and neurohormone in efferent fibers targeted at the antennal vessel and mechanosensory organs. As a neurohormone, serotonin affects the generation of the transepithelial potential by sensillar accessory cells. Other possible targets of biogenic amines in insect antennae are hygro- and thermosensory neurons and epithelial cells. We suggest that the insect antenna is partially autonomous in the sense that biologically active substances entering its hemolymph may exert their effects and be cleared from this compartment without affecting other body parts.

  7. Methane emissions measurements of natural gas components using a utility terrain vehicle and portable methane quantification system

    Science.gov (United States)

    Johnson, Derek; Heltzel, Robert

    2016-11-01

    Greenhouse Gas (GHG) emissions are a growing problem in the United States (US). Methane (CH4) is a potent GHG produced by several stages of the natural gas sector. Current scrutiny focuses on the natural gas boom associated with unconventional shale gas; however, focus should still be given to conventional wells and outdated equipment. In an attempt to quantify these emissions, researchers modified an off-road utility terrain vehicle (UTV) to include a Full Flow Sampling system (FFS) for methane quantification. GHG emissions were measured from non-producing and remote low throughput natural gas components in the Marcellus region. Site audits were conducted at eleven locations and leaks were identified and quantified at seven locations including at a low throughput conventional gas and oil well, two out-of-service gathering compressors, a conventional natural gas well, a coalbed methane well, and two conventional and operating gathering compressors. No leaks were detected at the four remaining sites, all of which were coal bed methane wells. The total methane emissions rate from all sources measured was 5.3 ± 0.23 kg/hr, at a minimum.

  8. Effects of salinity on methane gas hydrate system

    Institute of Scientific and Technical Information of China (English)

    YANG; DingHui; XU; WenYue

    2007-01-01

    Using an approximately analytical formation,we extend the steady state model of the pure methane hydrate system to include the salinity based on the dynamic model of the methane hydrate system.The top and bottom boundaries of the methane hydrate stability zone (MHSZ) and the actual methane hydrate zone (MHZ),and the top of free gas occurrence are determined by using numerical methods and the new steady state model developed in this paper.Numerical results show that the MHZ thickness becomes thinner with increasing the salinity,and the stability is lowered and the base of the MHSZ is shifted toward the seafloor in the presence of salts.As a result,the thickness of actual hydrate occurrence becomes thinner compared with that of the pure water case.On the other hand,since lower solubility reduces the amount of gas needed to form methane hydrate,the existence of salts in seawater can actually promote methane gas hydrate formation in the hydrate stability zone.Numerical modeling also demonstrates that for the salt-water case the presence of methane within the field of methane hydrate stability is not sufficient to ensure the occurrence of gas hydrate,which can only form when the methane concentration dissolved in solution with salts exceeds the local methane solubility in salt water and if the methane flux exceeds a critical value corresponding to the rate of diffusive methane transport.In order to maintain gas hydrate or to form methane gas hydrate in marine sediments,a persistent supplied methane probably from biogenic or thermogenic processes,is required to overcome losses due to diffusion and advection.

  9. Methane and Ethane Measurements from a New TCCON Station in Los Angeles

    Science.gov (United States)

    Wunch, D.; Roehl, C. M.; Blavier, J. L.; Allen, N.; Treffers, R.; Toon, G. C.; Wennberg, P. O.

    2012-12-01

    The Los Angeles urban region emits large amounts of methane (~0.44Tg/year) into the atmosphere. It is currently unclear exactly how much of this is biogenic (landfills, cattle), and how much is from natural gas (natural seeps or fugitive emissions from the natural gas infrastructure). Since natural gas contains ethane, whereas biogenic emissions contain none, simultaneous measurements of ethane and methane offer the possibility of separating the biogenic versus natural gas emissions of methane. We investigate this using total column measurements from a new Total Carbon Column Observing Network (TCCON) remote sensing station in the Los Angeles suburb of Pasadena, which began measurements in July 2012. These measurements will be put into the context of historical remote sensing and in situ measurements described by Wennberg et al., 2012 (doi:10.1021/es301138y).

  10. Balance Analysis of Profit and Loss on Exploiting Coal-Bed Gas in China

    Institute of Scientific and Technical Information of China (English)

    肖建洪; 苗建国; 陈晓慧

    2001-01-01

    Models about four aspects according to the balance principle and practice in China were established, which involve the minimum production scale, alert production scale, safe running scale, and the goal production scale for specified profit level. It provides an effective quantitative analyzing method for the investors of coal-bed gas exploitation project.

  11. Emission of Biogenic Volatile Organic Compounds in the Arctic

    DEFF Research Database (Denmark)

    Lindwall, Frida

    Emissions of biogenic volatile organic compounds (BVOCs) from arctic ecosystems are scarcely studied and the effect of climate change on BVOC emissions even less so. BVOCs are emitted from all living organisms and play a role for atmospheric chemistry. The major part of BVOCs derives from plants...... in the atmosphere. This may warm the climate due to a prolonged lifetime of the potent greenhouse gas methane in the atmosphere. However, oxidized BVOCs may participate in formation or growth of aerosols, which in turn may mitigate climate warming. Climate change in the Arctic, an area characterized by short...... dependent and the emissions will increase in a future warmer climate. The aims of this dissertation were to study BVOC emission rates and blends from arctic ecosystems and to reveal the effect of climate change on BVOC emissions from the Arctic. BVOC emissions were measured in ambient and modified...

  12. Hydrogen generation from biogenic and fossil fuels by autothermal reforming

    Science.gov (United States)

    Rampe, Thomas; Heinzel, Angelika; Vogel, Bernhard

    Hydrogen generation for fuel cell systems by reforming technologies from various fuels is one of the main fields of investigation of the Fraunhofer ISE. Suitable fuels are, on the one hand, gaseous hydrocarbons like methane, propane but also, on the other hand, liquid hydrocarbons like gasoline and alcohols, e.g., ethanol as biogenic fuel. The goal is to develop compact systems for generation of hydrogen from fuel being suitable for small-scale membrane fuel cells. The most recent work is related to reforming according to the autothermal principle — fuel, air and steam is supplied to the reactor. Possible applications of such small-scale autothermal reformers are mobile systems and also miniature fuel cell as co-generation plant for decentralised electricity and heat generation. For small stand-alone systems without a connection to the natural gas grid liquid gas, a mixture of propane and butane is an appropriate fuel.

  13. Modeling of microbial gas generation: application to the eastern Mediterranean “Biogenic Play”

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.; Dubille, M.; Montadert, L.

    2016-07-01

    Biogenic gas is becoming increasingly important as an exploration target in the petroleum industry because it occurs in geologically predictable circumstances and in large quantities at shallow depths as free gas or gas hydrates. As accumulations of biogenic gas result in a subtle synchronization between early generation and early trapping, we integrated a macroscopic model of microbial gas generation within a 3D basin and petroleum system forward simulator. The macroscopic model is based on a microscopic model, which consists in a 1D sedimentary column that accounts for sedimentation, compaction, Darcy flow and Diffusion flow. The organic carbon is the only non-soluble element considered in this version of the model. The dissolved elements are O2, SO4 2-, H2, CH3COOH, and CH4. Methane is dissolved in water or present as a free phase if its concentration exceeds its solubility at given pressure and temperature. In this microscopic model, the transformation of substrate into biomass is described through a set of logistic equations coupled with the transport equations (advection and diffusion). Based on the microscopic considerations we developed the macroscopic model of low maturity/biogenic gas generation in which hydrocarbons are generated through first order kinetic reactions at low maturity. This macroscopic model is adapted to petroleum system modeling at basin scale with TemisFlow®, which aims to understand and predict hydrocarbon generation, migration, and accumulation. It is composed of: i) A source rock criteria which allow defining the biogenic gas source rocks potential and ii) A kinetic model of methane generation. The previous model has been successfully applied on different basins such as the Carupano Basin from the offshore Venezuela, the Magdalena Delta (offshore Colombia) and the offshore Vietnam where direct observations of low-maturity gas were available. Furthermore, it has been applied in the offshore Lebanon in order to check the viability of

  14. Groundwater methane in a potential coal seam gas extraction region

    Directory of Open Access Journals (Sweden)

    Marnie L. Atkins

    2015-09-01

    New hydrological insights for the region: Methane was found in all geological units ranging between 0.26 and 4427 μg L−1 (median 10.68 μg L−1. Median methane concentrations were highest in chloride-type groundwater (13.26 μg L−1, n = 58 while bicarbonate-type groundwater had lower concentrations (3.71 μg L−1. Groundwater from alluvial sediments had significantly higher median methane concentrations (91.46 μg L−1 than groundwater from both the basalt aquifers (0.7 μg L−1 and bedrock aquifers (4.63 μg L−1; indicating geology was a major driver of methane distribution. Methane carbon stable isotope ratios ranged from –90.9‰ to –29.5‰, suggesting a biogenic origin with some methane oxidation. No significant correlations were observed between methane concentrations and redox indicators (nitrate, manganese, iron and sulphate except between iron and methane in the Lismore Basalt (r2 = 0.66, p < 0.001, implying redox conditions were not the main predictor of methane distribution.

  15. CYANOBACTERIA FOR MITIGATING METHANE EMISSION FROM SUBMERGED PADDY FIELDS

    Energy Technology Data Exchange (ETDEWEB)

    Upasana Mishra; Shalini Anand [Department of Environmental Studies, Inderprastha Engineering College, Sahibabad, Ghaziabad (India)

    2008-09-30

    Atmospheric methane, a potent greenhouse gas with high absorption potential for infrared radiation, is responsible for one forth of the total anticipated warming. It is forming a major part of green house gases, next after carbon dioxide. Its concentration has been increasing alarmingly on an average at the rate of one percent per year. Atmospheric methane, originating mainly from biogenic sources such as paddy fields, natural wetlands and landfills, accounts for 15-20% of the world's total anthropogenic methane emission. With intensification of rice cultivation in coming future, methane emissions from paddy fields are anticipated to increase. India's share in world's rice production is next after to China and likewise total methane emission from paddy fields also. Methane oxidation through planktophytes, particularly microalgae which are autotrophic and abundant in rice rhizospheres, hold promise in controlling methane emission from submerged paddy fields. The present study is focused on the role of nitrogen fixing, heterocystous cyanobacteria and Azolla (a water fern harboring a cyanobacterium Anabaena azollae) as biological sink for headspace concentration of methane in flooded soils. In this laboratory study, soil samples containing five potent nitrogen fixer cyanobacterial strains from paddy fields, were examined for their methane reducing potential. Soil sample without cyanobacterial strain was tested and taken as control. Anabaena sp. was found most effective in inhibiting methane concentration by 5-6 folds over the control. Moist soil cores treated with chemical nitrogen, urea, in combination with cyanobacteria mixture, Azolla microphylla or cyanobacteria mixture plus Azolla microphylla exhibited significance reduction in the headspace concentration of methane than the soil cores treated with urea alone. Contrary to other reports, this study also demonstrates that methane oxidation in soil core samples from paddy fields was stimulated by

  16. Formation and retention of methane in coal. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hucka, V.J.; Bodily, D.M.; Huang, H.

    1992-05-15

    The formation and retention of methane in coalbeds was studied for ten Utah coal samples, one Colorado coal sample and eight coal samples from the Argonne Premium Coal Sample Bank.Methane gas content of the Utah and Colorado coals varied from zero to 9 cm{sup 3}/g. The Utah coals were all high volatile bituminous coals. The Colorado coal was a gassy medium volatile bituminous coal. The Argonne coals cover a range or rank from lignite to low volatile bituminous coal and were used to determine the effect of rank in laboratory studies. The methane content of six selected Utah coal seams and the Colorado coal seam was measured in situ using a special sample collection device and a bubble desorbometer. Coal samples were collected at each measurement site for laboratory analysis. The cleat and joint system was evaluated for the coal and surrounding rocks and geological conditions were noted. Permeability measurements were performed on selected samples and all samples were analyzed for proximate and ultimate analysis, petrographic analysis, {sup 13}C NMR dipolar-dephasing spectroscopy, and density analysis. The observed methane adsorption behavior was correlated with the chemical structure and physical properties of the coals.

  17. Intolerance to dietary biogenic amines : a review

    NARCIS (Netherlands)

    Jansen, SC; van Dusseldorp, M; Bottema, KC; Dubois, AEJ

    2003-01-01

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allergen intoler*, and

  18. Intolerance to dietary biogenic amines: A review

    NARCIS (Netherlands)

    Jansen, S.C.; Dusseldorp, M. van; Bottema, K.C.; Dubois, A.E.J.

    2003-01-01

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and

  19. Intolerance to dietary biogenic amines : a review

    NARCIS (Netherlands)

    Jansen, SC; van Dusseldorp, M; Bottema, KC; Dubois, AEJ

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allergen intoler*, and

  20. Intolerance to dietary biogenic amines: A review

    NARCIS (Netherlands)

    Jansen, S.C.; Dusseldorp, M. van; Bottema, K.C.; Dubois, A.E.J.

    2003-01-01

    Objective: To evaluate the scientific evidence for purported intolerance to dietary biogenic amines. Data Sources: MEDLINE was searched for articles in the English language published between January 1966 and August 2001. The keyword biogenic amin* was combined with hypersens*, allerg*, intoler*, and

  1. High-temperature removal of sulphur for biogenic gas products; Hochtemperatur-Entschwefelung fuer biogene Produktgase. Design und Optimierung - Schlussbericht/Jahresbericht

    Energy Technology Data Exchange (ETDEWEB)

    Schildhauer, T.; Biollaz, S.

    2009-12-15

    This final report for the Swiss Federal Office of Energy (SFOE) presents the results of a project concerning the development of basics ideas on the design and optimisation of high-temperature methods for the removal of sulphur from biogenic gas products. Tests made as part of the 'Methane from Wood' project at pilot installations in Switzerland and Austria are discussed. Low temperature and high-temperature methods are examined and discussed. A number of sulphur compounds were tested. Also, experiments made using nickel, HDS and CPO catalysers are discussed.

  2. Halite as a Methane Sequestration Host: A Possible Explanation for Periodic Methane Release on Mars, and a Surface-accessible Source of Ancient Martian Carbon

    Science.gov (United States)

    Fries, M. D.; Steele, Andrew; Hynek, B. M.

    2015-01-01

    We present the hypothesis that halite may play a role in methane sequestration on the martian surface. In terrestrial examples, halite deposits sequester large volumes of methane and chloromethane. Also, examples of chloromethane-bearing, approximately 4.5 Ga old halite from the Monahans meteorite show that this system is very stable unless the halite is damaged. On Mars, methane may be generated from carbonaceous material trapped in ancient halite deposits and sequestered. The methane may be released by damaging its halite host; either by aqueous alteration, aeolian abrasion, heating, or impact shock. Such a scenario may help to explain the appearance of short-lived releases of methane on the martian surface. The methane may be of either biogenic or abiogenic origin. If this scenario plays a significant role on Mars, then martian halite deposits may contain samples of organic compounds dating to the ancient desiccation of the planet, accessible at the surface for future sample return missions.

  3. Application and outlook of well logging in coal bed methane development and exploration%浅析煤层气勘探开发测井技术应用及发展

    Institute of Scientific and Technical Information of China (English)

    金力钻; 孙玉红; 王海平

    2015-01-01

    在煤层气的勘探开发中测井技术发挥着重要的作用,是煤层识别、煤层特性分析、煤层气评价等不可缺少的重要手段。本文对煤层气勘探开发测井技术发展趋势进行阐述,分析了现阶段存在的问题。%The well logging technology plays a very important role in exploration and development of coal-bed methane, which is indispensable in identification, properties analysis and evaluation of the coal bed. The development of this technology for coal-bed methane and problems exist are presented in the paper.

  4. Experiment study on process parameters of coal-bed gas separation by vacuum pressure swing adsorption%真空变压吸附分离含氧煤层气的工艺参数实验研究

    Institute of Scientific and Technical Information of China (English)

    刘应书; 杨雄; 李永玲; 张传钊; 孟宇; 杨海军

    2011-01-01

    Oxygen-containing coal-bed gas recovery using vacuum pressure swing adsorption processes is investigated expenmentally, the optimization experiment on process parameters and the structure of adsorption tower is camed out. The results show that the methane concentration in effluent gas and adsorption gas increases with the increase of adsorption time within a certain time, but the oxygen concentration in effluent gas decreases appreciably. Purge step decreases the methane and oxygen concentration of the effluent gas, but the methane concentration of desorption gas decreases with the increase of purge time. When the length-to-diameter ratio from 3.7 increased to 13. 3 with the adsorhent weight constant , the methane concentration in product increases by 2. 1 % , and the concentration of methane in effluent gas decreases by 1%. The results could provide reference for the industrial application in low concentration oxygen-containing coal-bed gas enrichment.%针对真空变压吸附富集低浓度含氧煤层气,对工艺参数和吸附塔结构进行了优化试验研究.实验结果标明,在一定的时间范围内,随着吸附时间的延长,解吸气和排放气中甲烷体积分数逐渐增大,而排放气中的氧气体积分数则小幅度降低;反吹步骤可以降低排放气中甲烷和氧气的体积分数,但反吹步骤也会降低解吸气中甲烷的体积分数;保持吸附剂不变,吸附塔高径比由3.7增大到13.3,解吸气中甲烷体积分数增大了2.1%,排放气中甲烷体积分数降低了1%.可以为低浓度含氧煤层气富集的实际应用提供参考.

  5. Accumulation of coal-bed gas in the Wangying-Liujia area of the Fuxin basin

    Institute of Scientific and Technical Information of China (English)

    Wang Bo; Jiang Bo; Xu Fengyin; Kong Xiangwen; Li Guizhong; Wang Xiaoyi; Chen Weiyin; Geng Meng

    2012-01-01

    The gas enrichment conditions in the Fuxin basin are compared to those of the Powder River basin.The coal bed depth,the gas content,the individual coal bed layer thickness,and the overall structure thickness of the Powder River basin in the U.S.were examined.The main factors affecting gas enrichment were examined.These factors include the coal-forming environment,the gas sources,the geological structure,the presence of magmatic activity,and the local hydrology.The coal-bed gas enrichment area in the Wangying-Liujia block of the Fuxin basin is then discussed by analogy.A hydrodynamic-force/dike-plugging modet based on a magma fractured bed is proposed to explain the gas enrichment in this part of the Fuxin basin.High gas production is predicted in areas having similar conditions.This work will aid future coal-bed gas exploration and development.

  6. Detection of coalbed fractures with P-wave azimuthal AVO in 3-D seismic exploration

    Institute of Scientific and Technical Information of China (English)

    LI Guofa; PENG Suping; HE Bingshou; PENG Xiaobo; YUAN Chunfang; HU Chaoyuan

    2005-01-01

    The detection of fractures is important for production and safety in coal fields. Subsurface fractures result in azimuthal anisotropy of the seismic wave, and the amplitude of reflection wave varies with offset and azimuth.In case of weak anisotropy, the reflection coefficients of P-wave are concisely denoted as the analytic function of fracture parameters. For the purpose of predicting the coalbed fracture distribution through analyzing variation of the reflection amplitudes with offset and azimuth, 3-D seismic data with full-azimuth were acquired in a coal field in Huainan, Anhui Province. The careful analysis and process of seismic data showed that the reflection amplitude of the primary coaibed varied with azimuth in much consistent with the theoretical model. The conclusion was drawn that the coal-bed fracture in this coal field could be predicted through the method of the P-wave azimuthal AVO.

  7. Hydrologic properties of coal-beds in the Powder River Basin, Montana. II. Aquifer test analysis

    Science.gov (United States)

    Weeks, E.P.

    2005-01-01

    A multiple well aquifer test to determine anisotropic transmissivity was conducted on a coal-bed in the Powder River Basin, southeastern Montana, as part of a multidisciplinary investigation to determine hydrologic conditions of coal-beds in the area. For the test, three wells were drilled equidistant from and at different angles to a production well tapping the Flowers-Goodale coal seam, a 7.6-m thick seam confined at a depth of about 110 m. The test was conducted by air-lift pumping for 9 h, and water levels were monitored in the three observation wells using pressure transducers. Drawdown data collected early in the test were affected by interporosity flow between the coal fracture network and the matrix, but later data were suitable to determine aquifer anisotropy, as the slopes of the late-time semilog time-drawdown curves are nearly identical, and the zero-drawdown intercepts are different. The maximum transmissivity, trending N87??E, is 14.9 m2/d, and the minimum transmissivity 6.8 m2/d, giving an anisotropy ratio of 2.2:1. Combined specific storage of the fractures and matrix is 2??10 -5/m, and of the fracture network alone 5??10-6/m. The principal direction of the anisotropy tensor is not aligned with the face cleats, but instead is aligned with another fracture set and with dominant east-west tectonic compression. Results of the test indicate that the Flowers-Goodale coal-bed is more permeable than many coals in the Powder River Basin, but the anisotropy ratio and specific storage are similar to those found for other coal-beds in the basin.

  8. Toward estimation of origin of methane at ancient seeps — Carbon isotopes of seep carbonates, lipid biomarkers, and adsorbed gas

    Science.gov (United States)

    Miyajima, Yusuke; Watanabe, Yumiko; Ijiri, Akira; Goto, Akiko; Jenkins, Robert; Hasegawa, Takashi; Sakai, Saburo; Matsumoto, Ryo

    2017-04-01

    Methane is generated mainly by microbial or thermal degradation of organic matter, and the origin of methane can be estimated based on its stable carbon isotopic signature. Seafloor seepages of methane-charged fluids have been a major source of methane to the ocean, and knowing the origin of methane at the methane seeps can provide valuable insights into the subsurface fluid circulation and biogeochemical processes. Methane seeps in the geological past are archived as authigenic methane-derived carbonate rocks, which precipitate via an alkalinity increase facilitated by microbially mediated anaerobic oxidation of methane. Here we attempted to estimate origins of methane at ancient seeps, based on several proxies preserved within the seep carbonates. We examined methane-seep carbonate rocks in the Japan Sea region, collected from lower Miocene to middle Pleistocene sediments at 11 sites on land, and also carbonate nodules collected from the seafloor off Joetsu, where thermogenic methane is seeping. Carbon isotopic compositions of the carbonates and lipid biomarkers of methane-oxidizing archaea within them were analyzed. In order to directly know original isotopic signatures of methane, we also attempted to extract adsorbed methane through acid dissolution of the powdered carbonates. Early-diagenetic carbonate phases show various δ13C values between -64.7 and -4.7‰ vs. VPDB, suggesting either biogenic or thermogenic, or both origins of methane. A lipid biomarker pentamethylicosane (PMI) extracted from the ancient carbonates has δ13C values mostly lower than -100‰ , whereas that from the modern methane-derived carbonate nodule has a higher value (-80‰ ). The δ13C values of the seeping methane (-36‰ ) and PMI in the modern Joetsu seep carbonate shows an offset of -44‰ . If this carbon isotope offset was similar at the ancient seeps, the δ13C values of PMI indicate that methane at ancient seeps in the Japan Sea region was biogenic in origin, with δ13C

  9. Contribution of Ash Content Related to Methane Adsorption Behaviors of Bituminous Coals

    Directory of Open Access Journals (Sweden)

    Yanyan Feng

    2014-01-01

    Full Text Available Methane adsorption isotherms on coals with varying ash contents were investigated. The textural properties were characterized by N2 adsorption/desorption isotherm at 77 K, and methane adsorption characteristics were measured at pressures up to 4.0 MPa at 298 K, 313 K, and 328 K, respectively. The Dubinin-Astakhov model and the Polanyi potential theory were employed to fit the experimental data. As a result, ash content correlated strongly to methane adsorption capacity. Over the ash range studied, 9.35% to 21.24%, the average increase in methane adsorption capacity was 0.021 mmol/g for each 1.0% rise in ash content. With the increasing ash content range of 21.24%~43.47%, a reduction in the maximum adsorption capacities of coals was observed. In addition, there was a positive correlation between the saturated adsorption capacity and the specific surface area and micropore volume of samples. Further, this study presented the heat of adsorption, the isosteric heat of adsorption, and the adsorbed phase specific heat capacity for methane adsorption on various coals. Employing the proposed thermodynamic approaches, the thermodynamic maps of the adsorption processes of coalbed methane were conducive to the understanding of the coal and gas simultaneous extraction.

  10. Coal mine methane in the Sabinas Sub-Basin, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gentzis, T. [CDX Canada Co., Calgary, AB (Canada)

    2005-07-01

    The general geology and stratigraphy of Mexico's Sabinas sub-basin was described with reference to its coal properties and gas content. Field derived data regarding cleating and reservoir pressure was presented along with gas analysis, adsorption isotherms, coal mineralogy and coal maturity. Mine methane emission data was presented along with a description of the application of in-seam methane drainage and reservoir simulation. It was concluded that the Sabinas sub-basin contains gassy coals in the Upper Cretaceous Olmos Formation, based on both historical evidence and desorption testing. The coals are at shallow depth (less than 500 m), are well cleated and have high natural fracture permeability. The double seam coal is under-pressured, and most likely under-saturated but it has high diffusivity. Sabinas coals are reported to be dry, with free gas in the cleat/fracture system and absence of mineralization. In-seam horizontal drilling prior to longwall mining resulted in a significant reduction of gas content and an increase in coal production. The Sabinas sub-basin is suitable for full-scale coalbed methane development using in-seam horizontal drilling technology. A comparison with the Maverick Basin in Texas showed that there are both similarities and differences between the Sabinas sub-basin coals in Mexico and the Maverick Basin coals in Texas. figs.

  11. Correlation between coal characteristics and methane adsorption on China's coals

    Institute of Scientific and Technical Information of China (English)

    YU Hong-guan; YUAN Jian; SONG Ji-yong; LENG Shu-wei

    2007-01-01

    It is highly important to investigate relationship between coal characteristics and methane adsorption on coal in the fields of coalbed methane recovery. Based on data examination of coal quality indexes collected from the literatures, regression equations for Langmuir adsorption constants, VL or VL/PL, and coal quality indexes for selected coal samples were developed with multiple linear regression of SPSS software according to the degree of coal metamorphosis. The regression equations built were tested with data collected from some literatures, and the influences of coal quality indexes on CH4 adsorption on coals were studied with investigation of regression equations, and the reasons of low accuracy to Langmuir constants calculated with regression equation for a few coal samples were investigated. The results show that the regression equations can be employed to predict Langmuir constants for methane adsorption isotherms on coals obtained using volumetric gas adsorption experiments, which are conducted at 30 ℃ on a wet or dried coal samples with less than 30% ash content in coal. The influence of same coal quality index with various coal rank or influence of various coal quality indexes for same coal rank on CH4 adsorption is not consistent. The regression equations have different accuracy to different coal rank, in which the VL equations supply better prediction accuracy for anthracite and higher prediction error for lower metamorphosis coal, and the PL prediction error with VL and VL/PL equations is lower to bituminous coal and higher to anthracite.

  12. Spatial patterns and source attribution of urban methane in the Los Angeles Basin

    Science.gov (United States)

    Hopkins, Francesca M.; Kort, Eric A.; Bush, Susan E.; Ehleringer, James R.; Lai, Chun-Ta; Blake, Donald R.; Randerson, James T.

    2016-03-01

    Urban areas are increasingly recognized as a globally important source of methane to the atmosphere; however, the location of methane sources and relative contributions of source sectors are not well known. Recent atmospheric measurements in Los Angeles, California, USA, show that more than a third of the city's methane emissions are unaccounted for in inventories and suggest that fugitive fossil emissions are the unknown source. We made on-road measurements to quantify fine-scale structure of methane and a suite of complementary trace gases across the Los Angeles Basin in June 2013. Enhanced methane levels were observed across the basin but were unevenly distributed in space. We identified 213 methane hot spots from unknown emission sources. We made direct measurements of ethane to methane (C2H6/CH4) ratios of known methane emission sources in the region, including cattle, geologic seeps, landfills, and compressed natural gas fueling stations, and used these ratios to determine the contribution of biogenic and fossil methane sources to unknown hot spots and to local urban background air. We found that 75% of hot spots were of fossil origin, 20% were biogenic, and 5% of indeterminate source. In regionally integrated air, we observed a wider range of C2H6/CH4 values than observed previously. Fossil fuel sources accounted for 58-65% of methane emissions, with the range depending on the assumed C2H6/CH4 ratio of source end-members and model structure. These surveys demonstrated the prevalence of fugitive methane emissions across the Los Angeles urban landscape and suggested that uninventoried methane sources were widely distributed and primarily of fossil origin.

  13. Field Exploration of Methane Seep Near Atqasuk

    Energy Technology Data Exchange (ETDEWEB)

    Katey Walter, Dennis Witmer, Gwen Holdmann

    2008-12-31

    Methane (CH{sub 4}) in natural gas is a major energy source in the U.S., and is used extensively on Alaska's North Slope, including the oilfields in Prudhoe Bay, the community of Barrow, and the National Petroleum Reserve, Alaska (NPRA). Smaller villages, however, are dependent on imported diesel fuel for both power and heating, resulting in some of the highest energy costs in the U.S. and crippling local economies. Numerous CH{sub 4} gas seeps have been observed on wetlands near Atqasuk, Alaska (in the NPRA), and initial measurements have indicated flow rates of 3,000-5,000 ft{sup 3} day{sup -1} (60-100 kg CH{sub 4} day{sup -1}). Gas samples collected in 1996 indicated biogenic origin, although more recent sampling indicated a mixture of biogenic and thermogenic gas. In this study, we (1) quantified the amount of CH{sub 4} generated by several seeps and evaluated their potential use as an unconventional gas source for the village of Atqasuk; (2) collected gas and analyzed its composition from multiple seeps several miles apart to see if the source is the same, or if gas is being generated locally from isolated biogenic sources; and (3) assessed the potential magnitude of natural CH{sub 4} gas seeps for future use in climate change modeling.

  14. Stimulation of methane generation from nonproductive coal by addition of nutrients or a microbial consortium.

    Science.gov (United States)

    Jones, Elizabeth J P; Voytek, Mary A; Corum, Margo D; Orem, William H

    2010-11-01

    Biogenic formation of methane from coal is of great interest as an underexploited source of clean energy. The goal of some coal bed producers is to extend coal bed methane productivity and to utilize hydrocarbon wastes such as coal slurry to generate new methane. However, the process and factors controlling the process, and thus ways to stimulate it, are poorly understood. Subbituminous coal from a nonproductive well in south Texas was stimulated to produce methane in microcosms when the native population was supplemented with nutrients (biostimulation) or when nutrients and a consortium of bacteria and methanogens enriched from wetland sediment were added (bioaugmentation). The native population enriched by nutrient addition included Pseudomonas spp., Veillonellaceae, and Methanosarcina barkeri. The bioaugmented microcosm generated methane more rapidly and to a higher concentration than the biostimulated microcosm. Dissolved organics, including long-chain fatty acids, single-ring aromatics, and long-chain alkanes accumulated in the first 39 days of the bioaugmented microcosm and were then degraded, accompanied by generation of methane. The bioaugmented microcosm was dominated by Geobacter sp., and most of the methane generation was associated with growth of Methanosaeta concilii. The ability of the bioaugmentation culture to produce methane from coal intermediates was confirmed in incubations of culture with representative organic compounds. This study indicates that methane production could be stimulated at the nonproductive field site and that low microbial biomass may be limiting in situ methane generation. In addition, the microcosm study suggests that the pathway for generating methane from coal involves complex microbial partnerships.

  15. Stimulation of methane generation from nonproductive coal by addition of nutrients or a microbial consortium

    Science.gov (United States)

    Jones, Elizabeth J.P.; Voytek, Mary A.; Corum, Margo D.; Orem, William H.

    2010-01-01

    Biogenic formation of methane from coal is of great interest as an underexploited source of clean energy. The goal of some coal bed producers is to extend coal bed methane productivity and to utilize hydrocarbon wastes such as coal slurry to generate new methane. However, the process and factors controlling the process, and thus ways to stimulate it, are poorly understood. Subbituminous coal from a nonproductive well in south Texas was stimulated to produce methane in microcosms when the native population was supplemented with nutrients (biostimulation) or when nutrients and a consortium of bacteria and methanogens enriched from wetland sediment were added (bioaugmentation). The native population enriched by nutrient addition included Pseudomonas spp., Veillonellaceae, and Methanosarcina barkeri. The bioaugmented microcosm generated methane more rapidly and to a higher concentration than the biostimulated microcosm. Dissolved organics, including long-chain fatty acids, single-ring aromatics, and long-chain alkanes accumulated in the first 39 days of the bioaugmented microcosm and were then degraded, accompanied by generation of methane. The bioaugmented microcosm was dominated by Geobacter sp., and most of the methane generation was associated with growth of Methanosaeta concilii. The ability of the bioaugmentation culture to produce methane from coal intermediates was confirmed in incubations of culture with representative organic compounds. This study indicates that methane production could be stimulated at the nonproductive field site and that low microbial biomass may be limiting in situ methane generation. In addition, the microcosm study suggests that the pathway for generating methane from coal involves complex microbial partnerships.

  16. Marine methane paradox explained by bacterial degradation of dissolved organic matter

    Science.gov (United States)

    Repeta, Daniel J.; Ferrón, Sara; Sosa, Oscar A.; Johnson, Carl G.; Repeta, Lucas D.; Acker, Marianne; Delong, Edward F.; Karl, David M.

    2016-12-01

    Biogenic methane is widely thought to be a product of archaeal methanogenesis, an anaerobic process that is inhibited or outcompeted by the presence of oxygen and sulfate. Yet a large fraction of marine methane delivered to the atmosphere is produced in high-sulfate, fully oxygenated surface waters that have methane concentrations above atmospheric equilibrium values, an unexplained phenomenon referred to as the marine methane paradox. Here we use nuclear magnetic resonance spectroscopy to show that polysaccharide esters of three phosphonic acids are important constituents of dissolved organic matter in seawater from the North Pacific. In seawater and pure culture incubations, bacterial degradation of these dissolved organic matter phosphonates in the presence of oxygen releases methane, ethylene and propylene gas. Moreover, we found that in mutants of a methane-producing marine bacterium, Pseudomonas stutzeri, disrupted in the C-P lyase phosphonate degradation pathway, methanogenesis was also disabled, indicating that the C-P lyase pathway can catalyse methane production from marine dissolved organic matter. Finally, the carbon stable isotope ratio of methane emitted during our incubations agrees well with anomalous isotopic characteristics of seawater methane. We estimate that daily cycling of only about 0.25% of the organic matter phosphonate inventory would support the entire atmospheric methane flux at our study site. We conclude that aerobic bacterial degradation of phosphonate esters in dissolved organic matter may explain the marine methane paradox.

  17. Ultraviolet-radiation-induced methane emissions from meteorites and the Martian atmosphere.

    Science.gov (United States)

    Keppler, Frank; Vigano, Ivan; McLeod, Andy; Ott, Ulrich; Früchtl, Marion; Röckmann, Thomas

    2012-05-30

    Almost a decade after methane was first reported in the atmosphere of Mars there is an intensive discussion about both the reliability of the observations--particularly the suggested seasonal and latitudinal variations--and the sources of methane on Mars. Given that the lifetime of methane in the Martian atmosphere is limited, a process on or below the planet's surface would need to be continuously producing methane. A biological source would provide support for the potential existence of life on Mars, whereas a chemical origin would imply that there are unexpected geological processes. Methane release from carbonaceous meteorites associated with ablation during atmospheric entry is considered negligible. Here we show that methane is produced in much larger quantities from the Murchison meteorite (a type CM2 carbonaceous chondrite) when exposed to ultraviolet radiation under conditions similar to those expected at the Martian surface. Meteorites containing several per cent of intact organic matter reach the Martian surface at high rates, and our experiments suggest that a significant fraction of the organic matter accessible to ultraviolet radiation is converted to methane. Ultraviolet-radiation-induced methane formation from meteorites could explain a substantial fraction of the most recently estimated atmospheric methane mixing ratios. Stable hydrogen isotope analysis unambiguously confirms that the methane released from Murchison is of extraterrestrial origin. The stable carbon isotope composition, in contrast, is similar to that of terrestrial microbial origin; hence, measurements of this signature in future Mars missions may not enable an unambiguous identification of biogenic methane.

  18. Modeling biogenic gas bubbles formation and migration in coarse sand

    Science.gov (United States)

    Ye, S.

    2011-12-01

    Shujun Ye Department of Hydrosciences, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210093, China; sjye@nju.edu.cn Brent E. Sleep Department of Civil Engineering, University of Toronto, Toronto, ON, M5S 1A4 CANADA; sleep@ecf.utoronto.ca Methane gas generation in porous media was investigated in an anaerobic two-dimensional sand-filled cell. Inoculation of the lower portion of the cell with a methanogenic culture and addition of methanol to the bottom of the cell led to biomass growth and formation of a gas phase. The formation, migration, distribution and saturation of gases in the cell were visualized by the charge-coupled device (CCD) camera. Gas generated at the bottom of the cell in the biologically active zone moved upwards in discrete fingers, so that gas phase saturations (gas-filled fraction of void space) in the biologically active zone at the bottom of the cell did not exceed 40-50%, while gas accumulation at the top of the cell produced gas phase saturations as high as 80%. Macroscopic invasion percolation (MIP) at near pore scale[Glass, et al., 2001; Kueper and McWhorter, 1992]was used to model gas bubbles growth in porous media. The nonwetting phase migration pathway can be yielded directly by MIP. MIP was adopted to simulate the expansion, fragmentation, and mobilization of gas clusters in the cell. The production of gas, and gas phash saturations were simulated by a continuum model - compositional simulator (COMPSIM) [Sleep and Sykes, 1993]. So a combination of a continuum model and a MIP model was used to simulate the formation, fragmentation and migration of biogenic gas bubbles. Key words: biogenic gas; two dimensional; porous media; MIP; COMPSIM

  19. The MUMBA campaign: measurements of urban, marine and biogenic air

    Science.gov (United States)

    Paton-Walsh, Clare; Guérette, Élise-Andrée; Kubistin, Dagmar; Humphries, Ruhi; Wilson, Stephen R.; Dominick, Doreena; Galbally, Ian; Buchholz, Rebecca; Bhujel, Mahendra; Chambers, Scott; Cheng, Min; Cope, Martin; Davy, Perry; Emmerson, Kathryn; Griffith, David W. T.; Griffiths, Alan; Keywood, Melita; Lawson, Sarah; Molloy, Suzie; Rea, Géraldine; Selleck, Paul; Shi, Xue; Simmons, Jack; Velazco, Voltaire

    2017-06-01

    The Measurements of Urban, Marine and Biogenic Air (MUMBA) campaign took place in Wollongong, New South Wales (a small coastal city approximately 80 km south of Sydney, Australia) from 21 December 2012 to 15 February 2013. Like many Australian cities, Wollongong is surrounded by dense eucalyptus forest, so the urban airshed is heavily influenced by biogenic emissions. Instruments were deployed during MUMBA to measure the gaseous and aerosol composition of the atmosphere with the aim of providing a detailed characterisation of the complex environment of the ocean-forest-urban interface that could be used to test the skill of atmospheric models. The gases measured included ozone, oxides of nitrogen, carbon monoxide, carbon dioxide, methane and many of the most abundant volatile organic compounds. The aerosol characterisation included total particle counts above 3 nm, total cloud condensation nuclei counts, mass concentration, number concentration size distribution, aerosol chemical analyses and elemental analysis.The campaign captured varied meteorological conditions, including two extreme heat events, providing a potentially valuable test for models of future air quality in a warmer climate. There was also an episode when the site sampled clean marine air for many hours, providing a useful additional measure of the background concentrations of these trace gases within this poorly sampled region of the globe. In this paper we describe the campaign, the meteorology and the resulting observations of atmospheric composition in general terms in order to equip the reader with a sufficient understanding of the Wollongong regional influences to use the MUMBA datasets as a case study for testing a chemical transport model. The data are available from PANGAEA (http://doi.pangaea.de/10.1594/PANGAEA.871982).

  20. Biogenic silicate accumulation in sediments, Jiaozhou Bay

    Institute of Scientific and Technical Information of China (English)

    LI Xuegang; SONG Jinming; DAI Jicui; YUAN Huamao; LI Ning; LI Fengye; SUN Song

    2006-01-01

    It has been widely recognized that low silicate content in seawater is a major limiting factor to phytoplankton primary production in Jiaozhou Bay. However the reason of Si-limitation remains poorly understood. In the present study we measured the biogenic silicate content and discussed the accumulation of silicate in Jiaozhou Bay sediment. The results show that the biogenic silica content in the sediment of the Jiaozhou Bay is obviously much higher than those in the Yellow Sea and the Bohai Sea. The BSi:TN ratios and BSi:16P ratios in the sediment are > 1 and the OC:BSi ratio in sediment is lower than these of Redfield ratio (106:16), indicating that the decomposition rate of OC is much higher than that for BSi in similar conditions. Therefore, the majority of the biogenic silicate was buried and thus did not participate in silicate recycling. Silicate accumulation in sediment may explain why Si limits the phytoplankton growth in the Jiaozhou Bay. Comparing the flux of biogenic silicate from sediments with primary production rate, it can be concluded that only 15.5% of biogenic silicate is hydrolyzed during the journey from surface to bottom in seawater, thus approximate 84.5% of biogenic silicate could reach the bottom. The silicate releasing rate from the sediment to seawater is considerably lower than that of sedimentation of biogenic silicate, indicating silicate accumulation in sediment too. In a word, the silicate accumulation in sediment is the key reason of silicate limiting to phytoplankton growth in Jiaozhou Bay.

  1. Kinetics of methane fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y. R.; Hashimoto, A. G.

    1978-01-01

    The kinetics on methane fermentation are described using published data for livestock residue, sewage sludge, and municipal refuse. Methods are presented to determine the kinetic constants and the finally attainable methane production using steady-state methane production data. The effects of temperature, loading rate, and influent substrate concentration on methane fermentation kinetics are discussed. These relationships were used to predict the rate of methane production of a pilot-scale fermentor with excellent results.

  2. Arctic Vegetation under Climate Change – Biogenic Volatile Organic Compound Emissions and Leaf Anatomy

    DEFF Research Database (Denmark)

    Schollert, Michelle

    Biogenic volatile organic compounds (BVOCs) emitted from terrestrial vegetation are highly reactive non-methane hydrocarbons which participate in oxidative reactions in the atmosphere prolonging the lifetime of methane and contribute to the formation of secondary organic aerosols. The BVOC...... measurements in this thesis were performed using a dynamic enclosure system and collection of BVOCs into adsorbent cartridges analyzed by gas chromatography-mass spectrometry following thermal desorption. Also modifications in leaf anatomy in response to the studied effects of climate change were assessed...... by the use of light microscopy and scanning electron microscopy. This thesis reports the first estimates of high arctic BVOC emissions, which suggest that arctic environments can be a considerable source of BVOCs to the atmosphere. The BVOC emissions differed qualitatively and quantitatively for the studied...

  3. Performance of the JULES land surface model for UK Biogenic VOC emissions

    Science.gov (United States)

    Hayman, Garry; Comyn-Platt, Edward; Vieno, Massimo; Langford, Ben

    2017-04-01

    Emissions of biogenic non-methane volatile organic compounds (NMVOCs) are important for air quality and tropospheric composition. Through their contribution to the production of tropospheric ozone and secondary organic aerosol (SOA), biogenic VOCs indirectly contribute to climate forcing and climate feedbacks [1]. Biogenic VOCs encompass a wide range of compounds and are produced by plants for growth, development, reproduction, defence and communication [2]. There are both biological and physico-chemical controls on emissions [3]. Only a few of the many biogenic VOCs are of wider interest and only two or three (isoprene and the monoterpenes, α- and β-pinene) are represented in chemical transport models. We use the Joint UK Land Environment Simulator (JULES), the UK community land surface model, to estimate biogenic VOC emission fluxes. JULES is a process-based model that describes the water, energy and carbon balances and includes temperature, moisture and carbon stores [4, 5]. JULES currently provides emission fluxes of the 4 largest groups of biogenic VOCs: isoprene, terpenes, methanol and acetone. The JULES isoprene scheme uses gross primary productivity (GPP), leaf internal carbon and the leaf temperature as a proxy for the electron requirement for isoprene synthesis [6]. In this study, we compare JULES biogenic VOC emission estimates of isoprene and terepenes with (a) flux measurements made at selected sites in the UK and Europe and (b) gridded estimates for the UK from the EMEP/EMEP4UK atmospheric chemical transport model [7, 8], using site-specific or EMEP4UK driving meteorological data, respectively. We compare the UK-scale emission estimates with literature estimates. We generally find good agreement in the comparisons but the estimates are sensitive to the choice of the base or reference emission potentials. References (1) Unger, 2014: Geophys. Res. Lett., 41, 8563, doi:10.1002/2014GL061616; (2) Laothawornkitkul et al., 2009: New Phytol., 183, 27, doi

  4. BIOGENIC AMINES CONTENT IN DIFFERENT WINE SAMPLES

    Directory of Open Access Journals (Sweden)

    Attila Kántor

    2015-02-01

    Full Text Available Twenty-five samples of different Slovak wines before and after filtration were analysed in order to determine the content of eight biogenic amines (tryptamine, phenylalanine, putrescine, cadaverine, histamine, tyramine, spermidine and spermine. The method involves extraction of biogenic amines from wine samples with used dansyl chloride. Ultra-high performance liquid chromatography (UHPLC was used for determination of biogenic amines equipped with a Rapid Resolution High Definition (RRHD, DAD detectors and Extend-C18 LC column (50 mm x 3.0 mm ID, 1.8 μm particle size. In this study the highest level of biogenic amine in all wine samples represent tryptamine (TRM with the highest content 170.9±5.3 mg/L in Pinot Blanc wine. Phenylalanine (PHE cadaverine (CAD, histamine (HIS and spermidine (SPD were not detected in all wines; mainly SPD was not detected in 16 wines, HIS not detected in 14 wines, PHE and CAD not detected in 2 wines. Tyramine (TYR, spermine (SPN and putrescine (PUT were detected in all wines, but PUT and SPN in very low concentration. The worst wine samples with high biogenic amine content were Saint Laurent (BF, Pinot Blanc (S and Pinot Noir (AF.

  5. Biogenic amines in raw and processed seafood

    Directory of Open Access Journals (Sweden)

    Pierina eVisciano

    2012-06-01

    Full Text Available The presence of biogenic amines in raw and processed seafood, associated with either time/temperature conditions or food technologies is discussed in the present paper from a safety and prevention point of view. In particular, storage temperature, handling practices, presence of microbial populations with decarboxylase activity and availability of free amino acids are considered the most important factors affecting the production of biogenic amines in raw seafood. On the other hand, some food technological treatments such as salting, ripening, fermentation or marination can increase the levels of biogenic amines in processed seafood. The consumption of high amount of biogenic amines, above all histamine, can result in food borne poisoning which is a worldwide problem. The European Regulation established as maximum limits for histamine, in fishery products from fish species associated with high histidine amounts, values ranging from 100 to 200 mg/kg, while for products which have undergone enzyme maturation treatment in brine, the aforementioned limits rise to 200 and 400 mg/kg. Preventive measures and emerging methods aiming at controlling the production of biogenic amines are also reported for potential application in seafood industries.

  6. Models of methane behaviour in auxiliary ventilation of underground coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Torano, Javier; Torno, Susana; Menendez, Mario; Gent, Malcolm; Velasco, Judith [Mining and Civil Works Research Groups, School of Mines, Oviedo University, Asturias (Spain)

    2009-10-01

    Studies have been conducted in a roadway excavated in a coalbed of a deep underground coal mine located in Northern Spain (Hullera Vasco Leonesa SA), by both airflow velocity and methane concentration measurements. Modelling of ventilation and methane behaviour of that roadway by Computational Fluid Dynamics (CFD), through software Ansys CFX 10.0, is presented. A good correlation was found between the experimental data and the results predicted by CFD. Then a comparison of the results obtained by conventional methods with the results obtained by CFD 4D modelling, for the auxiliary ventilation in a dead-end roadway, was made. Although conventional methods give satisfactory results when considering methane dilution, this research proves that there may be some roadway zones in which methane concentration is higher than regulation values. This is owing to the airflow and methane behaviour in the roadway with the presence of dead zones, and the fact that only a part of the airflow provided by the fan reaches the working face. CFD modelling allows us to know in which zones of the roadway it may be necessary to reinforce forcing ventilation by additional systems, such as a forcing system with exhaust overlap, jet fans, spray fan systems or compressed air injectors. (author)

  7. Effects of Biogenic Supplementation on Xenobiotic Degradation

    Directory of Open Access Journals (Sweden)

    Truong Van-Hieu

    2016-06-01

    Full Text Available Activated sludge acclimated to 2,4-D was used to degrade 2,4-D in batch reactions. Biogenic substrates of sucrose and peptone, in varying concentrations, separately and combined, were supplemented to the degradation reactions to find if, how and why biogenic supplementations were beneficial to the degradation of the xenobiotic. With the biogenic supplement as a variable and other reaction conditions, optimal constant supplementation schemes were found which suit as feasible ways for enhancing the degradation rate of 2,4-D. Among the number of supplementation combinations, the ones having optimal advantage were 50 mg/L of sucrose, 80 mg/L of peptone, each separately, and 20 mg/L sucrose and 40 mg/L peptone combined.

  8. Biogenic metals in advanced water treatment.

    Science.gov (United States)

    Hennebel, Tom; De Gusseme, Bart; Boon, Nico; Verstraete, Willy

    2009-02-01

    Microorganisms can change the oxidation state of metals and concomitantly deposit metal oxides and zerovalent metals on or into their cells. The microbial mechanisms involved in these processes have been extensively studied in natural environments, and researchers have recently gained interest in the applications of microbe-metal interactions in biotechnology. Because of their specific characteristics, such as high specific surface areas and high catalytic reactivity, biogenic metals offer promising perspectives for the sorption and (bio)degradation of contaminants. In this review, the precipitation of biogenic manganese and iron species and the microbial reduction of precious metals, such as palladium, platinum, silver and gold, are discussed with specific attention to the application of these biogenic metals in innovative remediation technologies in advanced water treatment.

  9. Ancient and methane-derived carbon subsidizes contemporary food webs

    Science.gov (United States)

    Delvecchia, Amanda G.; Stanford, Jack A.; Xu, Xiaomei

    2016-11-01

    While most global productivity is driven by modern photosynthesis, river ecosystems are supplied by locally fixed and imported carbon that spans a range of ages. Alluvial aquifers of gravel-bedded river floodplains present a conundrum: despite no possibility for photosynthesis in groundwater and extreme paucity of labile organic carbon, they support diverse and abundant large-bodied consumers (stoneflies, Insecta: Plecoptera). Here we show that up to a majority of the biomass carbon composition of these top consumers in four floodplain aquifers of Montana and Washington is methane-derived. The methane carbon ranges in age from modern to up to >50,000 years old and is mostly derived from biogenic sources, although a thermogenic contribution could not be excluded. We document one of the most expansive ecosystems to contain site-wide macroinvertebrate biomass comprised of methane-derived carbon and thereby advance contemporary understanding of basal resources supporting riverine productivity.

  10. Synthesis of hydroxyapatite from biogenic wastes

    Directory of Open Access Journals (Sweden)

    Teerawat Laonapakul

    2015-09-01

    Full Text Available Hydroxyapatite (HAp is a major component of human bone, teeth and hard tissue. It is one of only a few bioactive materials. Since HAp is the most widely used ceramic biomaterial, various techniques have been developed to synthesize HAp. In recent years, the use of natural biogenic structures and materials for medical proposes has been motivated by limitations in producing synthetic materials. This article mainly focuses on the use of biogenic wastes to prepare HAp. These include bio-wastes, marine corals, eggshells, seashells and bio-membranes. In the present review, useful information about HAp preparation methodologies has been summarized for further research and development.

  11. Biogenic crust dynamics on sand dunes

    CERN Document Server

    Kinast, Shai; Yizhaq, Hezi; Ashkenazy, Yosef

    2012-01-01

    Sand dunes are often covered by vegetation and biogenic crusts. Despite their significant role in dune stabilization, biogenic crusts have rarely been considered in studies of dune dynamics. Using a simple model, we study the existence and stability ranges of different dune-cover states along gradients of rainfall and wind power. Two ranges of alternative stable states are identified: fixed crusted dunes and fixed vegetated dunes at low wind power, and fixed vegetated dunes and active dunes at high wind power. These results suggest a cross-over between two different forms of desertification.

  12. Photochemistry of methane in the earth's early atmosphere

    Science.gov (United States)

    Kasting, J. F.; Zahnle, K J.; Walker, J. C. G.

    1983-01-01

    The photochemical behavior of methane in the early terrestrial atmosphere is investigated with a detailed model in order to determine how much CH4 might have been present and what types of higher hydroocarbons could have been formed. It is found that any primordial methane accumulated during the course of earth accretion would have been dissipated by photochemical reactions in the atmosphere in a geologically short period of time after the segregation of the core. Abiotic sources of methane are not likely to have been large enough to sustain CH4 mixing ratios as high as 10 to the -6th, the threshold for a possible methane greenhouse, with a CO-rich atmosphere being a possible exception. After the origin of life an increasing biogenic source of methane may have driven CH4 mixing ratios well above 10 to the 6th. The rise of atmospheric oxygen in the early Proterozoic may have led to a more rapid photochemical destruction of methane, lowering the mixing ratio to its present value.

  13. Dispersion forces in methane

    NARCIS (Netherlands)

    Lekkerkerker, H.N.W.; Coulon, P.; Luyckx, R.

    1977-01-01

    The coefficients of the R-6 and R-7 terms in the series representation of the dispersion interaction between two methane molecules and between methane and helium, neon and argon are calculated by a variation method.

  14. Organosulfate Formation in Biogenic Secondary Organic Aerosol

    Science.gov (United States)

    Organosulfates of isoprene, α-pinene, and β-pinene have recently been identified in both laboratory-generated and ambient secondary organic aerosol (SOA). In this study, the mechanism and ubiquity of organosulfate formation in biogenic SOA is investigated by a comprehensive seri...

  15. Formation and Reactivity of Biogenic Iron Microminerals

    Energy Technology Data Exchange (ETDEWEB)

    Beveridge, Terrance J.; Glasauer, Susan; Korenevsky, Anton; Ferris, F. Grant

    2000-08-08

    The overall purpose of the project is to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals and their impact on the solubility of metal contaminants. The research addresses how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

  16. Formation and Reactivity of Biogenic Iron Microminerals

    Energy Technology Data Exchange (ETDEWEB)

    Beveridge, Terrance J.; Ferris, F. Grant

    2001-08-15

    The overall purpose of the project was to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals and their impact on the solubility of metal contaminants. The research addressed how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

  17. Laboratory Experiments on Environmental Friendly Means to Improve Coalbed Methane Production by Carbon Dioxide/Flue Gas Injection

    NARCIS (Netherlands)

    Mazumder, S.; Wolf, K.H.A.A.; Van Hemert, P.; Busch, A.

    2008-01-01

    Scaled in situ laboratory core flooding experiments with CO2, N2 and flue gas were carried out on coal in an experimental high P,T device. These experiments will be able to give an insight into the design of the injection system, management, control of the operations and the efficiency of an ECBM pr

  18. Numerical Simulation of Coalbed Methane Seepage in Pinnate Horizontal Well Based on Multi-Flow Coupling Model

    OpenAIRE

    Tingting Jiang; Xiujuan Yang; Xiangzhen Yan; Yunhong Ding; Xin Wang; Tongtao Wang

    2012-01-01

    The motive of the study is to establish a seepage flow model of pinnate horizontal well in infinite reservoir according to the characteristics of 3D distribution of CBM pinnate horizontal well. Taking flow pressure drop along the main and branch boreholes into consideration, the fluid flow formulas of CBM pinnate horizontal well are proposed. The corresponding calculation program has been achieved based on C++ computer language to analyze the effects of branch symmetry, angle between main and...

  19. Log evaluation of a coalbed methane (CBM) reservoir: a case study in the southern Qinshui basin, China

    Science.gov (United States)

    Jie, Hou; Changchun, Zou; Zhaohui, Huang; Liang, Xiao; Yuqing, Yang; Guohua, Zhang; Wenwen, Wang

    2014-02-01

    Proximate analysis components, gas content, porosity and permeability are the most important parameters for CBM reservoir evaluation. Based on the analysis of the conventional well log response of the no. 3 and no. 15 CBM seams in the southern Qinshui basin of China, regression analysis is used to establish the prediction models of the components of proximate analysis. The Langmuir rank equation is used to calculate the gas content. Variable matrix density is used to evaluate the total porosity. Based on the dual lateral log interaction method, a fracture porosity estimation model is established and the coal fracture permeability is predicted by using the Faivre-Sibbit method in the two CBM seams. Comparisons between the estimated and measured data of proximate analysis components, gas content, porosity and permeability indicate that the established models are credible. The absolute errors between the estimated moisture (Mad), ash (Aad), volatile (Vdaf), fixed carbon (FCad) and the measured results of coal in two coal seams are less than 0.41%, 9.47%, 3.61% and 9.41%, respectively. The absolute errors between the estimated and measured gas content are less than 4.05 cm3 g-1. The absolute errors of estimated total porosity and the analysed results of coal are less than 0.84%. Field samples show that Mad, Aad and Vdaf are less than 1.00%, 10.00%-25.00% and 10.00-15.00%, respectively, in the no. 3 and no. 15 CBM seams in the southern Qinshui basin. The FCad is close to 70.00%. The gas content ranges from 7.00 cm3 g-1 to 20.00 cm3 g-1 in the no. 3 coal seam and from 10.00 cm3 g-1 to 30.00 cm3 g-1 in the no. 15 coal seam. The total porosity is close to 5.50% and the fracture porosity is generally less than 2.50%. Fracture permeability is mainly distributed from 0.001 to 10 mD. The results indicate that the conventional well logs are effective in CBM reservoir evaluation.

  20. 煤层气排采中的技术管理%Technological Management in Coalbed Methane Production

    Institute of Scientific and Technical Information of China (English)

    任源峰

    2003-01-01

    结合近年来我国煤层气排采方面的经验教训,参照国外煤层气开采的成功经验,对煤层气排采中的生产管理提出了相应观点,对煤层气排采工艺技术水平的提高提供了有益的帮助.

  1. Laboratory Experiments on Environmental Friendly Means to Improve Coalbed Methane Production by Carbon Dioxide/Flue Gas Injection

    NARCIS (Netherlands)

    Mazumder, S.; Wolf, K.H.A.A.; Van Hemert, P.; Busch, A.

    2008-01-01

    Scaled in situ laboratory core flooding experiments with CO2, N2 and flue gas were carried out on coal in an experimental high P,T device. These experiments will be able to give an insight into the design of the injection system, management, control of the operations and the efficiency of an ECBM

  2. Potential for Coalbed Methane Development in China%中国煤层气潜力及发展展望

    Institute of Scientific and Technical Information of China (English)

    黄志斌; 郭艺; 李长清; 张政和; 许勇

    2012-01-01

    本文分析了煤层气勘探开发利用取得的进展和面临的主要问题,分析了煤层气商品率、利用率低和矿权重叠的深层原因,提出了加大政策扶持力度的多项措施,提出了实施国家发展改革委提出的煤层气大公司战略的框架方案,论证了建设沁水煤层气南下管道工程拉动煤层气快速发展的总体部署,论述了煤层气企业兼顾瓦斯治理的可行性及紧迫性。%This paper discusses the achievements and development potential and the main challenges towards the 12th- five- year- plan. The authors recommend government support and indirect financial incentives are essential for the CBM sector to grow fast, call on to establish a giant CBM group basing the CUCBM, suggest the NDRC to support the Qinshui - Changsha CBM pipeline project to develop the markets in advance, encour- aging CBM companies to invest CMM development.

  3. Methane as a biomarker in the search for extraterrestrial life: Lessons learned from Mars analog hypersaline environments

    Science.gov (United States)

    Bebout, B.; Tazaz, A.; Kelley, C. A.; Poole, J. A.; Davila, A.; Chanton, J.

    2010-12-01

    Methane released from discrete regions on Mars, together with previous reports of methane determined with ground-based telescopes, has revived the possibility of past or even extant life near the surface on Mars, since 90% of the methane on Earth has a biological origin. This intriguing possibility is supported by the abundant evidence of large bodies of liquid water, and therefore of conditions conducive to the origin of life, early in the planet's history. The detection and analysis of methane is at the core of NASA’s strategies to search for life in the solar system, and on extrasolar planets. Because methane is also produced abiotically, it is important to generate criteria to unambiguously assess biogenicity. The stable carbon and hydrogen isotopic signature of methane, as well as its ratio to other low molecular weight hydrocarbons (the methane/(ethane + propane) ratio: C1/(C2 + C3)), has been suggested to be diagnostic for biogenic methane. We report measurements of the concentrations and stable isotopic signature of methane from hypersaline environments. We focus on hypersaline environments because spectrometers orbiting Mars have detected widespread chloride bearing deposits resembling salt flats. Other evaporitic minerals, e.g., sulfates, are also abundant in several regions, including those studied by the Mars Exploration Rovers. The presence of evaporitic minerals, together with the known evolution of the Martian climate, from warmer and wetter to cold and hyper-arid, suggest that evaporitic and hypersaline environments were common in the past. Hypersaline environments examined to date include salt ponds located in Baja California, the San Francisco Bay, and the Atacama Desert. Methane was found in gas produced both in the sediments, and in gypsum- and halite-hosted (endolithic) microbial communities. Maximum methane concentrations were as high as 40% by volume. The methane carbon isotopic (δ13C) composition showed a wide range of values, from about

  4. Assessment of coalbed gas resources of the Kalahari Basin Province of Botswana, Zimbabwe, and Zambia, Africa, 2016

    Science.gov (United States)

    Brownfield, Michael E.; Schenk, Christopher J.; Klett, Timothy R.; Tennyson, Marilyn E.; Mercier, Tracey J.; Gaswirth, Stephanie B.; Marra, Kristen R.; Hawkins, Sarah J.; Finn, Thomas M.; Le, Phuong A.; Leathers-Miller, Heidi M.

    2017-02-24

    Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 4.5 trillion cubic feet of coalbed gas in the Kalahari Basin Province of Botswana, Zambia, and Zimbabwe, Africa.

  5. Biogenic isoprene and implications for oxidant levels in Beijing during the 2008 Olympic Games

    Science.gov (United States)

    Chang, Chih-Chung; Shao, Min; Chou, Charles C. K.; Liu, Shaw-Chen; Zhu, Tong; Lee, Kun-Zhang; Lai, Cheng-Hsun; Lin, Po-Hsiung; Wang*, Jia-Lin

    2014-05-01

    As the host of the 2008 Summer Olympic Games, Beijing implemented a series of stringent, short-term air quality control measures to reduce the emissions of anthropogenic air pollutants. Large reductions in the daily average concentrations of primary pollutants, e.g., non-methane hydrocarbons (NMHCs) and nitrogen oxides (NOx) of approximately 50% were observed at the air quality observatory of Peking University. Nevertheless, high levels of ozone were present during the control period. Although anthropogenic precursors were greatly reduced, the meteorological conditions in summer, including high temperature and light flux, are conducive to the production of large amounts of biogenic isoprene, which is extremely reactive. The diurnal pattern of isoprene showed daily maximum mixing ratios of 0.83 ppbv at noon and a minimum at night, reflecting its primarily biogenic properties. Using the ratio of isoprene to vehicle exhaust tracers, approximately 92% of the daytime isoprene was estimated from biogenic sources, and only 8% was attributed to vehicular emissions. In terms of OH reactivity and the ozone formation potential (OFP), biogenic isoprene with its midday surge can contribute approximately 20% of the total OFPs and 40-50% of the total OH reactivities of the 65 measured NMHCs during the midday hours. The discrepancy between decreased precursor levels and the observed high ozone was most likely caused by a combination of many factors. The changes in the partition among the components of oxidation products (O3, NO2 and NOz) and the contribution of air pollutants from regional sources outside Beijing should be two primary reasons. Furthermore, the influences of biogenic isoprene as well as the non-linearity of O3-VOC-NOx chemistry are other major concerns that can reduce the effectiveness of the control measures for decreasing ozone formation. Although anthropogenic precursors were greatly reduced during the Olympic Games, the presence of sufficient biogenic isoprene

  6. Biogenic isoprene and implications for oxidant levels in Beijing during the 2008 Olympic Games

    Science.gov (United States)

    Chang, C.-C.; Shao, M.; Chou, C. C. K.; Liu, S.-C.; Wang, J.-L.; Lee, K.-Z.; Lai, C.-H.; Zhu, T.; Lin, P.-H.

    2013-10-01

    As the host of the 2008 Summer Olympic Games, Beijing implemented a series of stringent, short-term air quality control measures to reduce the emissions of anthropogenic air pollutants. Large reductions in the daily average concentrations of primary pollutants, e.g., non-methane hydrocarbons (NMHCs) and nitrogen oxides (NOx) of approximately 50% were observed at the air quality observatory of Peking University. Nevertheless, high levels of ozone were present during the control period. Although anthropogenic precursors were greatly reduced, the meteorological conditions in summer, including high temperature and light flux, are conducive to the production of large amounts of biogenic isoprene, which is extremely reactive. The diurnal pattern of isoprene showed daily maximum mixing ratios of 0.83 ppbv at noon and a minimum at night, reflecting its primarily biogenic properties. Using the ratio of isoprene to vehicle exhaust tracers, approximately 92% of the daytime isoprene was estimated from biogenic sources, and only 8% was attributed to vehicular emissions. In terms of OH reactivity and the ozone formation potential (OFP), biogenic isoprene with its midday surge can contribute approximately 20% of the total OFPs and 40-50% of the total OH reactivities of the 65 measured NMHCs during the midday hours. The discrepancy between decreased precursor levels and the observed high ozone was most likely caused by a combination of many factors. The changes in the partition among the components of oxidation products (O3, NO2 and NOz) and the contribution of air pollutants from regional sources outside Beijing should be two primary reasons. Furthermore, the influences of biogenic isoprene as well as the non-linearity of O3-VOC-NOx chemistry are other major concerns that can reduce the effectiveness of the control measures for decreasing ozone formation. Although anthropogenic precursors were greatly reduced during the Olympic Games, sufficient biogenic isoprene and moderate NOx

  7. A New Coal Mine Methane Utilization Device%一种新型煤矿煤层气利用装置

    Institute of Scientific and Technical Information of China (English)

    王思文; 张保生; 王金锋; 王莹

    2012-01-01

    Coalbed methane thermal storage type Stirling engine system based on porous medium burner is power utilization method which adapts to characteristics of low coal mine methane concentration and big flectuation in China. Through organically combining good adaptability of porous medium burner to low - concentration gas source with the external combustion characteristics of the Stifling engine, the device builds Stirling engine system drived by the porous medium burner, and the connection between the two devices is a- chieved by heat accumulator, which further alleviates the impact of coalbed methane gas source fluctuations on the system.%基于多孔介质燃烧器的煤层气储热式斯特林发动机系统是一种适应我国煤矿煤层气浓度低、波动大特点的发电利用方式。该装置通过将多孔介质燃烧器对低浓度气源的良好适应性和斯特林发动机的外燃特性有机结合,构建多孔介质燃烧器驱动斯特林发动机系统,并采用储热器实现二者的连接,以进一步缓解煤层气气源波动对系统的冲击。

  8. Carbon cycle in the paleoenvironment: an abrupt increase of biogenic carbon in the end-Cretaceous atmosphere

    Directory of Open Access Journals (Sweden)

    Ryunosuke Kikuchi

    2017-01-01

    Full Text Available A knowledge of what has happened in the past seems helpful in improving the predictability of the link between global-scale phenomena and the carbon cycle; this paper therefore attempts to reconstruct the end-Cretaceous carbon cycle (65 million years ago by means of modeling. The performed simulation suggests that a great amount (130 gigatons at least of biogenic carbon was rapidly injected to the atmosphere. Methane originating from gas hydrate (GH is the most likely candidate for the input of biogenic carbon at the end of the ereCretaceous period because it is considered that thick GH stability zones were damaged by perturbations associated with the Chicxulub asteroid impact, and the vast amount of methane was released to the atmosphere as a gas blast. Though GH deposits are greater than other major reservoirs of carbon, these deposits are not commonly categorized as typical carbon reservoirs in terms of the global carbon cycle. How to integrate GH-related methane with well-known carbon reservoirs remains for a future study in order to improve the predictability of the future carbon cycle.

  9. Methane adsorption-induced coal swelling measured with an optical method

    Institute of Scientific and Technical Information of China (English)

    Tang Shuheng; Wan Yi; Duan Lijiang; Xia Zhaohui; Zhang Songhang

    2015-01-01

    In order to quantify the effect of matrix shrinkage on reservoir permeability during coalbed methane production, coal samples from Huozhou, Changzhi and Jincheng areas in Shanxi province (classified as high-volatile bituminous coal, low-volatile bituminous coal and anthracite, respectively) were collected, and adsorption-induced coal swelling in methane were determined by an optical method at 40 ?C and pressure up to 12 MPa. All three coals showed similar behavior-that swelling increased as a function of pressure up to about 10 MPa but thereafter no further increase in swelling was observed. Swelling in the direction perpendicular to the bedding plane is greater than that parallel to the bedding plane, and the differences are about 7.77–8.33%. The maximum volumetric swelling ranges from 2.73% to 3.21%-increasing with increasing coal rank. The swelling data can be described by a modified DR model. In addition, swelling increases with the amount of adsorption. However, the increase shows a relatively slower stage followed by a relatively faster stage instead of a linear increase. Based on the assumption that sorption-induced swelling/shrinkage of coal in methane is reversible, the permeability increases induced by coal shrinkage during methane desorption was analyzed, and the results indicate that the permeability change is larger for higher rank coal in the same unit of pressure depletion.

  10. Bacterial dominance in subseafloor sediments characterized by methane hydrates

    Science.gov (United States)

    Briggs, Brandon R.; Inagaki, Fumio; Morono, Yuki; Futagami, Taiki; Huguet, Carme; Rosell-Mele, Antoni; Lorenson, T.D.; Colwell, Frederick S.

    2015-01-01

    The degradation of organic carbon in subseafloor sediments on continental margins contributes to the largest reservoir of methane on Earth. Sediments in the Andaman Sea are composed of ~ 1% marine-derived organic carbon and biogenic methane is present. Our objective was to determine microbial abundance and diversity in sediments that transition the gas hydrate occurrence zone (GHOZ) in the Andaman Sea. Microscopic cell enumeration revealed that most sediment layers harbored relatively low microbial abundance (103–105 cells cm−3). Archaea were never detected despite the use of both DNA- and lipid-based methods. Statistical analysis of terminal restriction fragment length polymorphisms revealed distinct microbial communities from above, within, and below the GHOZ, and GHOZ samples were correlated with a decrease in organic carbon. Primer-tagged pyrosequences of bacterial 16S rRNA genes showed that members of the phylum Firmicutes are predominant in all zones. Compared with other seafloor settings that contain biogenic methane, this deep subseafloor habitat has a unique microbial community and the low cell abundance detected can help to refine global subseafloor microbial abundance.

  11. 煤层气发电厂预处理系统及控制%Coal-bed Methane Power Plant Pretreatment System and Control

    Institute of Scientific and Technical Information of China (English)

    赵德悦

    2015-01-01

    主要介绍煤层气发电流程中的气体预处理系统及其控制系统 ,包括预处理系统的作业流程、主要设备功能、控制系统、技术参数等 ,并对其进行了详细分析和讨论.%This paper mainly introduces a gas pretreatment process of coal-bed methane power generation system and its control sys-tem ,including the pretreatment system's working process ,main equipment ,control system and technical parameters ,etc .

  12. Methane in Sediments From Three Tropical, Coastal Lagoons on the Yucatan Peninsula, Mexico

    Science.gov (United States)

    Young, B.; Paytan, A.; Miller, L.; Herrera-Silveira, J.

    2002-12-01

    coastal ecosystems. Laboratory experiments using sediment from the upper 20 cm in Celestun lagoon resulted in high rates of biogenic production of methane from the addition of trimethylamine, hydrogen, and, while additions of formate and acetate stimulated methane production to a lesser extent. This indicates that methane production in these sediments may be highly responsive to natural or anthropogenic changes in substrate availability. By synthesizing laboratory data and extensive field measurements from the lagoons, we hope to shed light on the factors controlling methane cycling in these sediments, and to better estimate methane flux to the atmosphere from these ecosystems.

  13. Stable carbon isotopic signature of methane from high-emitting wetland sites in discontinuous permafrost landscape

    Science.gov (United States)

    Marushchak, Maija; Liimatainen, Maarit; Lind, Saara; Biasi, Christina; Martikainen, Pertti

    2017-04-01

    The rising methane concentration in the atmosphere during the past years has been associated with a concurrent change in the carbon isotopic signature: The atmospheric methane is getting more and more depleted in the heavy carbon isotope. The decreasing 13C/12C ratio indicates an increasing contribution of methane from biogenic sources, most importantly wetlands and inland waters, whose global emissions are still poorly constrained. From the climate change perspective, arctic and subarctic wetlands are particularly interesting due to the strong warming and permafrost thaw predicted for these regions that will cause changes in the methane dynamics. Coupling methane flux inventories with determination of the stable isotopic signature can provide useful information about the pathways of methane production, consumption and transport in these ecosystems. Here, we present data on the emissions and carbon isotopic composition of methane from subarctic tundra wetlands at the Seida study site, Northeast European Russia. In this landscape, underlain by discontinuous permafrost, waterlogged fens represent sites of high carbon turnover and high methane release. Despite they cover less than 15% of the region, their methane emissions comprise 98% of the regional mean (± SD) release of 6.7 (± 1.8) g CH4 m-2 y-1 (Marushchak et al. 2016). The methane emission from the studied fens was clearly depleted in 13C compared to the pore water methane. The bulk mean δ13CH4 (± SD) over the growing season was -68.2 (± 2.0) ‰ which is similar to the relatively few values previously reported from tundra wetlands. We explain the depleted methane emissions by the high importance of passive transport via aerenchymous plants, a process that discriminates against the heavier isotopes. This idea is supported by the strong positive correlation observed between the methane emission and the vascular leaf area index (LAI), and the inverse relationship between the δ13CH4 of emitted methane and LAI

  14. Formation and Reactivity of Biogenic Iron Microminerals

    Energy Technology Data Exchange (ETDEWEB)

    Beveridge, Terrance J.; Ferris, F. Grant

    1999-06-01

    The overall purpose of the project is to explore and quantify the processes that control the formation and reactivity of biogenic iron microminerals, and the impact of these processes on the solubility of metal contaminants, e.g., uranium, chromium and nickel. The research addresses how surface components of bacterial cells, extracellular organic material, and the aqueous geochemistry of the DIRB microenvironment impacts the mineralogy, chemical state and micromorphology of reduced iron phases.

  15. Isotopic constraints on methane's global sources and ENSO-dependence

    Science.gov (United States)

    Schaefer, Hinrich; Mikaloff Fletcher, Sara; Veidt, Cora; Lassey, Keith; Brailsford, Gordon; Bromley, Tony; Dlugokencky, Ed; Englund Michel, Sylvia; Miller, John; Levin, Ingeborg; Lowe, Dave; Martin, Ross; Vaughn, Bruce; White, James; Nichol, Sylvia

    2017-04-01

    Atmospheric levels of the potent greenhouse gas methane (CH4) have been rising since the industrial revolution, except for a plateau during the early 2000s. Stable carbon isotopes in methane (delta-13CH4) provide constraints on the budget changes associated with the plateau's onset and its end. We present a reconstruction of annual global delta-13CH4 averages based on a global network of stations, whose trends are indicative of global methane source and sink activity. A box model analysis shows that from the mid-1990s methane emissions with the characteristic thermogenic delta-13CH4 signature reduced, implying persistently lower emissions from fossil fuel productions as the cause of the plateau. However, variations in hydroxyl, the main CH4 sink, provide an equably plausible explanation for the plateau onset that may also account for strong variability in emission-vs-removal rates during the plateau period. In contrast, the renewed CH4 rise since 2006 can only be explained by increasing emissions with a biogenic isotope signature, i.e. agriculture or wetlands. We present correlation studies that test whether ENSO activity controls atmospheric delta-13CH4, and by extension methane levels, through tropical wetland emissions.

  16. Cytotoxicity and genotoxicity of biogenic silver nanoparticles

    Science.gov (United States)

    Lima, R.; Feitosa, L. O.; Ballottin, D.; Marcato, P. D.; Tasic, L.; Durán, N.

    2013-04-01

    Biogenic silver nanoparticles with 40.3 ± 3.5 nm size and negative surface charge (- 40 mV) were prepared with Fusarium oxysporum. The cytotoxicity of 3T3 cell and human lymphocyte were studied by a TaliTM image-based cytometer and the genotoxicity through Allium cepa and comet assay. The results of BioAg-w (washed) and BioAg-nw (unwashed) biogenic silver nanoparticles showed cytotoxicity exceeding 50 μg/mL with no significant differences of response in 5 and 10 μg/mL regarding viability. Results of genotoxicity at concentrations 5.0 and 10.0 ug/mL show some response, but at concentrations 0.5 and 1.0 μg/mL the washed and unwashed silver nanoparticles did not present any effect. This in an important result since in tests with different bacteria species and strains, including resistant, MIC (minimal inhibitory concentration) had good answers at concentrations less than 1.9 μg/mL. This work concludes that biogenic silver nanoparticles may be a promising option for antimicrobial use in the range where no cyto or genotoxic effect were observed. Furthermore, human cells were found to have a greater resistance to the toxic effects of silver nanoparticles in comparison with other cells.

  17. Rett syndrome - Stimulation of endogenous biogenic amines

    Science.gov (United States)

    Pelligra, R.; Norton, R. D.; Wilkinson, R.; Leon, H. A.; Matson, W. R.

    1992-01-01

    Transient hypercapnic hyperoxemia was induced in two Rett syndrome children by the administration of a gaseous mixture of 80 percent O2 and 20 percent CO2. Time course studies of neurotransmitters and their metabolites showed an immediate and marked increase in central biogenic amine turnover following inhalation of the gas mixture. The increased turnover of biogenic amines was associated with improved clinical changes. This suggests a coupled relationship and provides further support for an etiological role of neurotransmitter dysfunction in Rett syndrome. In a complementary study, elevation of pulmonary CO2 by application of a simple rebreathing device resulted in improvement of abnormal blood gases and elimination of the Cheyne-Stokes-like respiratory pattern of the Rett syndrome. Near normalization of the EEG occurred when a normal respiratory pattern was imposed by means of a respirator. Taken together, these results lead to the preliminary conclusion that cerebral hypoxemia secondary to abnormal respiratory function may contribute to diminished production of biogenic amines in Rett syndrome.

  18. High Time Resolution Measurements of Methane Fluxes From Enteric Fermentation in Cattle Rumen

    Science.gov (United States)

    Floerchinger, C. R.; Herndon, S.; Fortner, E.; Roscioli, J. R.; Kolb, C. E.; Knighton, W. B.; Molina, L. T.; Zavala, M.; Castelán, O.; Ku Vera, J.; Castillo, E.

    2013-12-01

    Methane accounts for roughly 20% of the global radiative climate forcing in the last two and a half centuries. Methane emissions arise from a number of anthropogenic and biogenic sources. In some areas enteric fermentation in livestock produces over 90% of agricultural methane. In the spring of 2013, as a part of the Short Lived Climate Forcer-Mexico field campaign, the Aerodyne Mobile Laboratory in partnership with the Molina Center for the Environment studied methane production associated with enteric fermentation in the rumen of cattle. A variety of different breeds and stocks being raised in two agricultural and veterinary research facilities located in different areas of Mexico were examined. Methane fluxes were quantified using two methods: 1) an atmospherically stable gaseous tracer release was collocated with small herds in a pasture, allowing tracer ratio flux measurements; 2) respiratory CO2 was measured in tandem with methane in the breath of individual animals allowing methane production to be related to metabolism. The use of an extensive suite of very high time response instruments allows for differentiation of individual methane producing rumination events and respiratory CO2 from possible background interferences. The results of these studies will be presented and compared to data from traditional chamber experiments.

  19. Development and utilization strategies for recovery and utilization of coal mine methane

    Energy Technology Data Exchange (ETDEWEB)

    Byrer, C.W.; Layne, A.W.; Guthrie, H.D.

    1995-10-01

    The U.S. Department of Energy (DOE), at its Morgantown Energy Technology Center, has been involved in natural gas research since the 1970`s. DOE has assessed the potential of gas in coals throughout the U.S. and promoted research and development for recovery and use of methane found in minable and unminable coalbeds. DOE efforts have focused on the use of coal mine methane for regional economic gas self-sufficiency, energy parks, self-help initiatives, and small-power generation. This paper focuses on DOE`s past and present efforts to more effectively and efficiently recover and use this valuable domestic energy source. The Climate Change Action Plan (CCAP) (1) lists a series of 50 voluntary initiatives designed to reduce greenhouse gas emissions, such as methane from mining operations, to their 1990 levels. Action No. 36 of the CCAP expands the DOE research, development, and demonstration (RD&D) efforts to broaden the range of cost-effective technologies and practices for recovering methane associated with coal mining operations. The major thrust of Action No. 36 is to reduce methane emissions associated with coal mining operations from target year 2000 levels by 1.5 MMT of carbon equivalent. Crosscutting activities in the DOE Natural Gas Program supply the utilization sectors will address RD&D to reduce methane emissions released from various mining operations, focusing on recovery and end use technology systems to effectively drain, capture, and utilize the emitted gas. Pilot projects with industry partners will develop and test the most effective methods and technology systems for economic recovery and utilization of coal mine gas emissions in regions where industry considers efforts to be presently non-economic. These existing RD&D programs focus on near-term gas recovery and gathering systems, gas upgrading, and power generation.

  20. The future of methane

    Energy Technology Data Exchange (ETDEWEB)

    Howell, D.G.

    1995-12-31

    Natural gas, mainly methane, produces lower CO{sub 2}, CO, NO{sub x}, SO{sub 2} and particulate emissions than either oil or coal; thus further substitutions of methane for these fuels could help mitigate air pollution. Methane is, however, a potent greenhouse gas and the domestication of ruminants, cultivation of rice, mining of coal, drilling for oil, and transportation of natural gas have all contributed to a doubling of the amount of atmospheric methane since 1800. Today nearly 300,000 wells yearly produce ca. 21 trillion cubic feet of methane. Known reserves suggest about a 10 year supply at the above rates of recovery; and the potential for undiscovered resources is obscured by uncertainty involving price, new technologies, and environmental restrictions steming from the need to drill an enormous number of wells, many in ecologically sensitive areas. Until all these aspects of methane are better understood, its future role in the world`s energy mix will remain uncertain. The atomic simplicity of methane, composed of one carbon and four hydrogen atoms, may mask the complexity and importance of this, the most basic of organic molecules. Within the Earth, methane is produced through thermochemical alteration of organic materials, and by biochemical reactions mediated by metabolic processes of archaebacteria; some methane may even be primordial, a residue of planetary accretion. Methane also occurs in smaller volumes in landfills, rice paddies, termite complexes, ruminants, and even many humans. As an energy source, its full energy potential is controversial. Methane is touted by some as a viable bridge to future energy systems, fueled by the sun and uranium and carried by electricity and hydrogen.

  1. The Potential for Methane Isotopologue Channels in GOSAT-2

    Science.gov (United States)

    Malina, Edward; Yoshida, Yukio; Matsunaga, Tsuneo; Muller, Jan-Peter

    2017-04-01

    Of the major Greenhouse Gases (GHGs) currently considered as having a major impact on atmospheric chemistry, Methane is amongst the most important (IPCC, 2014). Methane concentration in the atmosphere has been documented to be rising steadily over the past century, aside from an unexplained short period in the middle of the last decade (Heimann., 2011), leading to renewed efforts to understand global atmospheric Methane. Atmospheric Methane is primarily composed of two key isotopologues, 12CH4 and 13CH4, which have a natural abundance of about 98% and 1.1% respectively. It is a well-established fact that different sources of Methane (i.e. biogenic sources such as methanogens, or non-biogenic such as industrial hydrocarbon burning) vary in the abundance of these isotopologues (Etiope, 2009). The global identification of the ratios of these isotopologues could vastly increase knowledge of global Methane sources, and shed some light on global Methane growth. GOSAT-2 due to be launched in 2018 is a follow on from the original GOSAT mission launched in 2009. GOSAT-2 aims to continue the legacy of GOSAT by providing global measurements of Methane and Carbon Dioxide on a global basis in order to monitor GHG emissions. GOSAT-2 in the context of this study has a significant advantage over GOSAT, which is the extension of the sensitivity of band 3 to 2330nm from 2080nm where significant numbers of Methane spectral lines are located. In this study we apply the well-established Information Content (IC) analysis techniques originally proposed by Rodgers (2000) to determine the potential benefit of retrieving total column Methane isotopologue concentrations assuming bands 2 and 3 of the GOSAT-2/TANSO-FTS-2 instrument. The value of such studies has been proven on multiple occasions and can provide guidance on appropriate potential retrieval setups. Due to the fact that there has been limited research in this area, no 'a priori' state vectors or Variance Covariance Matrices (VCMs

  2. Non-methane volatile organic compound flux from a subarctic mire in Northern Sweden

    OpenAIRE

    Bäckstrand, Kristina; Crill, Patrick M.; Mastepanov, Mikhail; Christensen, Torben R.; Bastviken, David

    2011-01-01

    Biogenic NMVOCs are mainly formed by plants and microorganisms. They have strong impact on the local atmospheric chemistry when emitted to the atmosphere. The objective of this study was to determine if there are significant emissions of non-methane volatile organic compounds (NMVOCs) from a subarctic mire in northern Sweden. Subarctic peatlands in discontinuous permafrost regions are undergoing substantial environmental changes due to their high sensitivity to climate warming and there is ne...

  3. IODP Expedition 337: Deep Coalbed Biosphere off Shimokita - Microbial processes and hydrocarbon system associated with deeply buried coalbed in the ocean

    Science.gov (United States)

    Inagaki, Fumio; Hinrichs, Kai-Uwe; Kubo, Yusuke; IODP Expedition 337 Scientists

    2016-06-01

    The Integrated Ocean Drilling Program (IODP) Expedition 337 was the first expedition dedicated to subseafloor microbiology that used riser-drilling technology with the drilling vessel Chikyu. The drilling Site C0020 is located in a forearc basin formed by the subduction of the Pacific Plate off the Shimokita Peninsula, Japan, at a water depth of 1180 m. Primary scientific objectives during Expedition 337 were to study the relationship between the deep microbial biosphere and a series of ˜ 2 km deep subseafloor coalbeds and to explore the limits of life in the deepest horizons ever probed by scientific ocean drilling. To address these scientific objectives, we penetrated a 2.466 km deep sedimentary sequence with a series of lignite layers buried around 2 km below the seafloor. The cored sediments, as well as cuttings and logging data, showed a record of dynamically changing depositional environments in the former forearc basin off the Shimokita Peninsula during the late Oligocene and Miocene, ranging from warm-temperate coastal backswamps to a cool water continental shelf. The occurrence of small microbial populations and their methanogenic activity were confirmed down to the bottom of the hole by microbiological and biogeochemical analyses. The factors controlling the size and viability of ultra-deep microbial communities in those warm sedimentary habitats could be the increase in demand of energy and water expended on the enzymatic repair of biomolecules as a function of the burial depth. Expedition 337 provided a test ground for the use of riser-drilling technology to address geobiological and biogeochemical objectives and was therefore a crucial step toward the next phase of deep scientific ocean drilling.

  4. Methane and Climate Change

    NARCIS (Netherlands)

    Reay, D.; Smith, P.; Amstel, van A.R.

    2010-01-01

    Methane is a powerful greenhouse gas and is estimated to be responsible for approximately one-fifth of man-made global warming. Per kilogram, it is 25 times more powerful than carbon dioxide over a 100-year time horizon -- and global warming is likely to enhance methane release from a number of sour

  5. Methane and Climate Change

    NARCIS (Netherlands)

    Reay, D.; Smith, P.; Amstel, van A.R.

    2010-01-01

    Methane is a powerful greenhouse gas and is estimated to be responsible for approximately one-fifth of man-made global warming. Per kilogram, it is 25 times more powerful than carbon dioxide over a 100-year time horizon -- and global warming is likely to enhance methane release from a number of

  6. Methane emissions from ruminants

    African Journals Online (AJOL)

    user

    2011-02-21

    Feb 21, 2011 ... Review. Livestock-environment interactions: Methane emissions from ruminants. Aluwong, T.1* ... perception of air quality by human neighbours.The three ... on the climate; the global warming potential of methane is. 21-times that of ... has serious impact on high atmosphere ozone formation. It is important ...

  7. Formation and Reactivity of Biogenic Iron Microminerals

    Energy Technology Data Exchange (ETDEWEB)

    Beveridge, Terrance J.; Ferris, F. Grant

    2002-08-10

    Radionuclide and heavy metal contaminants at DOE sites pose immediate and long-term environmental problems. Under the NABIR program, bacteria are being considered for their role in the cycling of these contaminants because they influence many redox reactions in the subsurface. Dissimilatory metal reducing bacteria (DMRB) are particularly important to controlling the biogeochemistry of subsurface environments through enzymatic reduction of iron and manganese minerals. During reduction of FeIII, biogenic FeII phases form at the cell-mineral interface which may profoundly influence metal reduction.

  8. Methane Fluxes from Subtropical Wetlands

    Science.gov (United States)

    DeLucia, N.; Gomez-Casanovas, N.; Bernacchi, C.

    2013-12-01

    It is well documented that green house gas concentrations have risen at unequivocal rates since the industrial revolution but the disparity between anthropogenic sources and natural sources is uncertain. Wetlands are one example of a natural ecosystem that can be a substantial source or sink for methane (CH4) depending on climate conditions. Due to strict anaerobic conditions required for CH4-generating microorganisms, natural wetlands are one of the main sources for biogenic CH4. Although wetlands occupy less than 5% of total land surface area, they contribute approximately 20% of total CH4 emissions to the atmosphere. The processes regulating CH4 emissions are sensitive to land use and management practices of areas surrounding wetlands. Variation in adjacent vegetation or grazing intensity by livestock can, for example, alter CH4 fluxes from wetland soils by altering nutrient balance, carbon inputs and hydrology. Therefore, understanding how these changes will affect wetland source strength is essential to understand the impact of wetland management practices on the global climate system. In this study we quantify wetland methane fluxes from subtropical wetlands on a working cattle ranch in central Florida near Okeechobee Lake (27o10'52.04'N, 81o21'8.56'W). To determine differences in CH4 fluxes associated with land use and management, a replicated (n = 4) full factorial experiment was designed for wetlands where the surrounding vegetation was (1) grazed or un-grazed and (2) composed of native vegetation or improved pasture. Net exchange of CH4 and CO2 between the land surface and the atmosphere were sampled with a LICOR Li-7700 open path CH4 analyzer and Li-7500A open path CO2/H20 analyzer mounted in a 1-m3 static gas-exchange chamber. Our results showed and verified that CH4 emissions from subtropical wetlands were larger when high soil moisture was coupled with high temperatures. The presence of cattle only amplified these results. These results help quantify

  9. Coal facies evolution of the main minable coal-bed in the Heidaigou Mine, Jungar Coalfield, Inner Mongolia, northern China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The No. 6 Coal-bed from the Heidaigou Mine, Jungar Coalfield, Inner Mongolia is a super-large Ga deposit. The dominant carrier of Ga is boehmite in coal. The study of coal facies may provide genetic enrichment information of Ga and its carrier (boehmite) in the Ga deposit. On the basis of study on coal petrology and mineralogy, it was found that the No. 6 Coal-bed from the Heidaigou Mine of Jungar was enriched in inertinites and the microlitho-types were dominated by clarodurite. The maceral morphological features and association indicate that the coal-bed was formed in a dry sedimentary environment or in a periodic dry sedimentary environment caused by the alternating variations of groundwater level. The optimum conditions for the enrichment of Ga and its particular carrier (boehmite) were dominated by four transitional conditions: (1) the upper delta plain which was the transitional zone between alluvial and lower delta plains, (2) the transitional zone between the dry and wet forest swamps, being slightly apt to the dry one, (3) the transitional tree density between the thick and loose ones, and (4) the low moor that was the transitional zone between two high moors during peat accumulation.

  10. Rising methane: post-2007 growth, geographic loci, timings and isotopic shift

    Science.gov (United States)

    Nisbet, Euan G.; Manning, Martin R.; Dlugokencky, Ed; Lowry, David; Fisher, Rebecca E.; Brownlow, Rebecca

    2017-04-01

    Atmospheric methane is rising rapidly again, after a period of stability [1]. NOAA report a global growth rate from 2007-2013 of 5.7±1.2 ppb yr-1, followed by extreme growth of 12.6±0.5 ppb in 2014 and 10.0±0.7 ppb in 2015. Growth has been accompanied by a shift in δ13C(CH4) (a measure of the 13C/12C isotope ratio in methane) to significantly more negative values since 2007. This isotopic shift has been observed in independently calibrated NOAA, Royal Holloway and NIWA-New Zealand measurements: thus the negative trend is real, global, and not a calibration artifact. Fossil fuel methane emissions, which are mostly more positive than atmospheric values, are not driving the rise in methane. Instead, the geographic loci of post-2007 growth, and the timings of the methane rise and isotopic shift suggest growth was dominated by significant increases in biogenic methane emissions, particularly in the tropics and Southern Hemisphere: for example in years with heavy rainfall under the Inter-Tropical Convergence, from wetlands and increased agricultural sources such as ruminants and rice paddies. Changes in the removal rate of methane by the OH radical or other sinks may also have occurred but do not appear fully to explain short term variations in methane isotopes. All these drivers of rising methane - wetlands, ruminants, changing sinks - may reflect underlying decade-long trends in tropical climate: methane may thus be an important climate-change signal. 1. Nisbet, E.G. et al. (2016) Rising atmospheric methane: 2007-2014 growth and isotopic shift, Global Biogeochem. Cycles, 30, doi:10.1002/ 2016GB005406.

  11. Mapping the hydraulic connection between a coalbed and adjacent aquifer: example of the coal-seam gas resource area, north Galilee Basin, Australia

    Science.gov (United States)

    Jiang, Zhenjiao; Mariethoz, Gregoire; Schrank, Christoph; Cox, Malcolm; Timms, Wendy

    2016-12-01

    Coal-seam gas production requires groundwater extraction from coal-bearing formations to reduce the hydraulic pressure and improve gas recovery. In layered sedimentary basins, the coalbeds are often separated from freshwater aquifers by low-permeability aquitards. However, hydraulic connection between the coalbed and aquifers is possible due to the heterogeneity in the aquitard such as the existence of conductive faults or sandy channel deposits. For coal-seam gas extraction operations, it is desirable to identify areas in a basin where the probability of hydraulic connection between the coalbed and aquifers is low in order to avoid unnecessary loss of groundwater from aquifers and gas production problems. A connection indicator, the groundwater age indictor (GAI), is proposed, to quantify the degree of hydraulic connection. The spatial distribution of GAI can indicate the optimum positions for gas/water extraction in the coalbed. Depressurizing the coalbed at locations with a low GAI would result in little or no interaction with the aquifer when compared to the other positions. The concept of GAI is validated on synthetic cases and is then applied to the north Galilee Basin, Australia, to assess the degree of hydraulic connection between the Aramac Coal Measure and the water-bearing formations in the Great Artesian Basin, which are separated by an aquitard, the Betts Creek Beds. It is found that the GAI is higher in the western part of the basin, indicating a higher risk to depressurization of the coalbed in this region due to the strong hydraulic connection between the coalbed and the overlying aquifer.

  12. Tropospheric methanol observations from space: constraints on the seasonality of biogenic emissions

    Science.gov (United States)

    Wells, K. C.; Millet, D. B.; Cady-Pereira, K. E.; Shephard, M. W.; Xiao, Y.; Razavi, A.; Clerbaux, C.

    2011-12-01

    Methanol is the most abundant non-methane organic compound in the atmosphere, and is an important precursor of atmospheric pollutants such as CO and formaldehyde. The recent development of methanol retrievals from nadir-viewing satellite-based platforms offers powerful new information for quantifying methanol emissions on a global scale. This study uses methanol observations from the Tropospheric Emission Spectrometer (TES) on the Aura satellite and the Infrared Atmospheric Sounding Interferometer (IASI) on the MetOp-A satellite, in conjunction with aircraft data, to investigate methanol emissions from major plant functional types in the GEOS-Chem global chemical transport model (driven with MEGAN biogenic emissions). We first evaluate the TES methanol retrievals by comparing to simulation results and flight observations from several North American field campaigns. Results show that the retrieval performs well when the degrees of freedom for signal are above 0.5. We analyze one full year of TES and IASI observations and find a persistent model underestimate in springtime, and make recommendations for an improved seasonal distribution of biogenic methanol emissions over temperate regions of the globe.

  13. Using Carbon Dioxide to Enhance Recovery of Methane from Gas Hydrate Reservoirs: Final Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    McGrail, B. Peter; Schaef, Herbert T.; White, Mark D.; Zhu, Tao; Kulkarni, Abhijeet S.; Hunter, Robert B.; Patil, Shirish L.; Owen, Antionette T.; Martin, P F.

    2007-09-01

    Carbon dioxide sequestration coupled with hydrocarbon resource recovery is often economically attractive. Use of CO2 for enhanced recovery of oil, conventional natural gas, and coal-bed methane are in various stages of common practice. In this report, we discuss a new technique utilizing CO2 for enhanced recovery of an unconventional but potentially very important source of natural gas, gas hydrate. We have focused our attention on the Alaska North Slope where approximately 640 Tcf of natural gas reserves in the form of gas hydrate have been identified. Alaska is also unique in that potential future CO2 sources are nearby, and petroleum infrastructure exists or is being planned that could bring the produced gas to market or for use locally. The EGHR (Enhanced Gas Hydrate Recovery) concept takes advantage of the physical and thermodynamic properties of mixtures in the H2O-CO2 system combined with controlled multiphase flow, heat, and mass transport processes in hydrate-bearing porous media. A chemical-free method is used to deliver a LCO2-Lw microemulsion into the gas hydrate bearing porous medium. The microemulsion is injected at a temperature higher than the stability point of methane hydrate, which upon contacting the methane hydrate decomposes its crystalline lattice and releases the enclathrated gas. Small scale column experiments show injection of the emulsion into a CH4 hydrate rich sand results in the release of CH4 gas and the formation of CO2 hydrate

  14. Biogenic aerosol over the Amazon Basin

    Science.gov (United States)

    Guyon, P.; Mayol-Bracero, O. L.; Matthias-Maser, S.; Godoi, R. H.; van Grieken, R.; Ebert, M.; Huth, J.; Maenhaut, W.; Taylor, P.; Artaxo, P.; Andreae, M. O.

    2002-12-01

    Biogenic particles form the major component of the atmospheric aerosol above and within the vast Amazonian tropical rainforest under non-polluted "background" conditions. We have employed a variety of different analytical techniques in order to try to better characterise the composition and temporal variation of this aerosol fraction. Microscopic examination reveals that many different types of biological particles are present, including fungal and fern spores, pollen grains, microbes, plant debris and insect parts. These forest-derived particles, and the elements, ions and compounds associated with them, are abundant in both the coarse and fine aerosol fractions, with the highest mass concentrations generally in the coarse fraction. There is a distinct increase in their concentrations at ground level at night. This is probably due to the formation of a shallow nocturnal inversion, which reduces dispersion of the aerosol, whilst convective mixing during the day leads to efficient dilution with air from aloft. Preferential nighttime emission of some types of biogenic particles may also contribute to the observed day-night variation.

  15. Pore-water chemistry of sediment cores off Mahanadi Basin, Bay of Bengal: Possible link to deep seated methane hydrate deposit

    Digital Repository Service at National Institute of Oceanography (India)

    Mazumdar, A.; Peketi, A.; Joao, H; Dewangan, P.; Ramprasad, T.

    ) induced sulfate consumption. The gas rich layers just below the base of hydrate stability zone (BGHSZ) is the possible source of the enhanced diffusive flux of biogenic methane (dalta13CCH4 ranging from -99.7 to - 106.3 percentage...

  16. Occurrence and origin of methane in groundwater in Alberta (Canada): Gas geochemical and isotopic approaches

    Energy Technology Data Exchange (ETDEWEB)

    Humez, P., E-mail: phumez@ucalgary.ca [Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4 (Canada); Mayer, B.; Ing, J.; Nightingale, M.; Becker, V.; Kingston, A. [Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4 (Canada); Akbilgic, O. [Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4 (Canada); UTHSC-ORNL Center for Biomedical Informatics, 910 Madison Avenue, Memphis, TN, 38104 (United States); Taylor, S. [Department of Geoscience, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4 (Canada)

    2016-01-15

    To assess potential future impacts on shallow aquifers by leakage of natural gas from unconventional energy resource development it is essential to establish a reliable baseline. Occurrence of methane in shallow groundwater in Alberta between 2006 and 2014 was assessed and was ubiquitous in 186 sampled monitoring wells. Free and dissolved gas sampling and measurement approaches yielded comparable results with low methane concentrations in shallow groundwater, but in 28 samples from 21 wells methane exceeded 10 mg/L in dissolved gas and 300,000 ppmv in free gas. Methane concentrations in free and dissolved gas samples were found to increase with well depth and were especially elevated in groundwater obtained from aquifers containing coal seams and shale units. Carbon isotope ratios of methane averaged − 69.7 ± 11.1‰ (n = 63) in free gas and − 65.6 ± 8.9‰ (n = 26) in dissolved gas. δ{sup 13}C values were not found to vary with well depth or lithology indicating that methane in Alberta groundwater was derived from a similar source. The low δ{sup 13}C values in concert with average δ{sup 2}H{sub CH4} values of − 289 ± 44‰ (n = 45) suggest that most methane was of biogenic origin predominantly generated via CO{sub 2} reduction. This interpretation is confirmed by dryness parameters typically > 500 due to only small amounts of ethane and a lack of propane in most samples. Comparison with mud gas profile carbon isotope data revealed that methane in the investigated shallow groundwater in Alberta is isotopically similar to hydrocarbon gases found in 100–250 meter depths in the WCSB and is currently not sourced from thermogenic hydrocarbon occurrences in deeper portions of the basin. The chemical and isotopic data for methane gas samples obtained from Alberta groundwater provide an excellent baseline against which potential future impact of deeper stray gases on shallow aquifers can be assessed. - Highlights: • Analysis of gas geochemical data from 186

  17. Methyl chavicol: characterization of its biogenic emission rate

    NARCIS (Netherlands)

    Bouvier-Brown, N.C.; Goldstein, A.H.; Worton, D.R.; Matross, D.M.; Gilman, J.B.; Kuster, W.C.; Welsh-Bon, D.; Warneke, C.; de Gouw, J.A.; Cahill, M.J.; Holzinger, R.

    2009-01-01

    We report measurements of ambient atmospheric mixing ratios for methyl chavicol and determine its biogenic emission rate. Methyl chavicol, a biogenic oxygenated aromatic compound, is abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California. Meth

  18. Methyl chavicol: characterization of its biogenic emission rate

    NARCIS (Netherlands)

    Bouvier-Brown, N.C.; Goldstein, A.H.; Worton, D.R.; Matross, D.M.; Gilman, J.B.; Kuster, W.C.; Welsh-Bon, D.; Warneke, C.; de Gouw, J.A.; Cahill, M.J.; Holzinger, R.

    2009-01-01

    We report measurements of ambient atmospheric mixing ratios for methyl chavicol and determine its biogenic emission rate. Methyl chavicol, a biogenic oxygenated aromatic compound, is abundant within and above Blodgett Forest, a ponderosa pine forest in the Sierra Nevada Mountains of California.

  19. Thiosulphate conversion in a methane and acetate fed membrane bioreactor.

    Science.gov (United States)

    Suarez-Zuluaga, Diego A; Timmers, Peer H A; Plugge, Caroline M; Stams, Alfons J M; Buisman, Cees J N; Weijma, Jan

    2016-02-01

    The use of methane and acetate as electron donors for biological reduction of thiosulphate in a 5-L laboratory membrane bioreactor was studied and compared to disproportionation of thiosulphate as competing biological reaction. The reactor was operated for 454 days in semi-batch mode; 30 % of its liquid phase was removed and periodically replenished (days 77, 119, 166, 258, 312 and 385). Although the reactor was operated under conditions favourable to promote thiosulphate reduction coupled to methane oxidation, thiosulphate disproportionation was the dominant microbial process. Pyrosequencing analysis showed that the most abundant microorganisms in the bioreactor were phototrophic green sulphur bacteria (GSB) belonging to the family Chlorobiaceae and thiosulphate-disproportionating bacteria belonging to the genus Desulfocapsa. Even though the reactor system was surrounded with opaque plastic capable of filtering most of the light, the GSB used it to oxidize the hydrogen sulphide produced from thiosulphate disproportionation to elemental sulphur. Interrupting methane and acetate supply did not have any effect on the microbial processes taking place. The ultimate goal of our research was to develop a process that could be applied for thiosulphate and sulphate removal and biogenic sulphide formation for metal precipitation. Even though the system achieved in this study did not accomplish the targeted conversion using methane as electron donor, it does perform microbial conversions which allow to directly obtain elemental sulphur from thiosulphate.

  20. Factors influencing biogenic amines accumulation in dairy products

    Directory of Open Access Journals (Sweden)

    Daniel M. eLinares

    2012-05-01

    Full Text Available Fermented foods are within the food products more often complained of having caused biogenic amines poisoning. Concerning milk-based fermented foods, cheese is the main product likely to contain significant levels of biogenic amines, specially tyramine, histamine and putrescine. Prompted by the increasing awareness of the risks related to dietary uptake of high biogenic amine loads, in this review we report about cheese elaboration and processing technological aspects affecting biogenic amines levels. Synthesis of biogenic amines is possible only when three conditions converge: i availability of the substrate amino acids; ii presence of microorganisms with the appropriate catabolic pathway activated; and iii environmental conditions favorable to the decarboxilation activity. These conditions depend on several factors such as milk treatment (pasteurization, use of starter cultures, NaCl concentration, time and temperature of ripening and preservation, pH… which will be discussed in this chapter.

  1. Longitudinal distributions of two formation pathways of biogenic gases in continental deposits: A case study from Sebei 1 gas field in the Qaidam Basin, western China

    Institute of Scientific and Technical Information of China (English)

    SHUAI YanHua; ZHANG ShuiChang; ZHAO WenZhi; SU AiGuo; WANG HuiTong

    2007-01-01

    The distribution of two formation pathways of biogenic methane, acetate fermentation and reduction of CO2, has been extensively studied. In general, CO2 reduction is the dominate pathway in marine environment where acetate is relatively depleted because of SRB consuming. While in terrestrial freshwater or brackish environment, acetate fermentation is initially significant, but decreases with increasing buried depth. In this paper, character of biogenic gases is profiled in the XS3-4 well of the Sebei 1 gas field in the Sanhu depression, Qaidam Basin. It indicates that those two pathways do not change strictly with increasing buried depth. CO2 reduction is important near the surface (between 50 m and 160 m), and at the mesozone (between 400 and 1650 m). While acetate fermentation is the primary pathway at two zones, from 160 to 400 m and from 1650 to 1700 m. D 13C of methane generated in those two acetate fermentation zones varies greatly, owing to different sediment circumstances. At the second zone (160-400 m), d 13C1 ranges from -65‰ to -30‰ (PDB), because the main deposit is mudstone and makes the circumstance confined. At the fourth zone of the well bottom (1650-1700 m), d 13C1 is lighter than -65‰ (PDB). Because the deposit is mainly composed of siltstone, it well connects with outer fertile groundwater and abundant nutrition has supplied into this open system. The high concentration of acetate is a forceful proof. D 13C of methane would not turn heavier during fermentation, owing to enough nutrition supply. In spite of multi-occurrence of acetate fermentation, the commercial gas accumulation is dominated by methane of CO2-reduction pathway. A certain content of alkene gases in the biogenic gases suggests that methanogensis is still active at present.

  2. Longitudinal distributions of two formation pathways of biogenic gases in continental deposits: A case study from Sebei 1 gas field in the Qaidam Basin, western China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The distribution of two formation pathways of biogenic methane, acetate fermentation and reduction of CO2, has been extensively studied. In general, CO2 reduction is the dominate pathway in marine envi- ronment where acetate is relatively depleted because of SRB consuming. While in terrestrial freshwater or brackish environment, acetate fermentation is initially significant, but decreases with increasing buried depth. In this paper, character of biogenic gases is profiled in the XS3-4 well of the Sebei 1 gas field in the Sanhu depression, Qaidam Basin. It indicates that those two pathways do not change strictly with increasing buried depth. CO2 reduction is important near the surface (between 50 m and 160 m), and at the mesozone (between 400 and 1650 m). While acetate fermentation is the primary pathway at two zones, from 160 to 400 m and from 1650 to 1700 m. δ 13C of methane generated in those two acetate fermentation zones varies greatly, owing to different sediment circumstances. At the sec- ond zone (160-400 m), δ 13C1 ranges from ?65‰ to ?30‰ (PDB), because the main deposit is mudstone and makes the circumstance confined. At the fourth zone of the well bottom (1650-1700 m), δ 13C1 is lighter than ?65‰ (PDB). Because the deposit is mainly composed of siltstone, it well connects with outer fertile groundwater and abundant nutrition has supplied into this open system. The high con- centration of acetate is a forceful proof. δ 13C of methane would not turn heavier during fermentation, owing to enough nutrition supply. In spite of multi-occurrence of acetate fermentation, the commercial gas accumulation is dominated by methane of CO2-reduction pathway. A certain content of alkene gases in the biogenic gases suggests that methanogensis is still active at present.

  3. Quantification of Methane Leaks from Abandoned Oil and Gas Wells in California

    Science.gov (United States)

    Lebel, E.; Kang, M.; Lu, H.; Jackson, R. B.

    2016-12-01

    Abandoned oil and gas wells can provide a pathway for subterranean methane and other gases to be emitted to the atmosphere. However, abandoned wells are unaccounted for in greenhouse gas emissions inventories. While relatively little is known about abandoned wells, previous studies have shown that emissions from abandoned wells contribute approximately 4-7% of anthropogenic methane emissions in Pennsylvania (Kang et al. 2014) and measure individual abandoned wells in California to estimate state-wide methane emissions from these wells. In addition to measuring methane concentrations, we measure ethane, propane, isobutane, n-butane, and 13-CH4 to understand whether this methane has a biogenic or thermogenic source. We hope that our research will determine whether or not abandoned oil and gas wells are a significant source of anthropogenic methane emissions in California. Our results along with measurements in other parts of the United States can be used to scale up methane emission estimates to the national level, accounting for the millions of abandoned wells in the country.

  4. Forecasting gob gas venthole production performances using intelligent computing methods for optimum methane control in longwall coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Karacan, C. Oezgen [National Institute for Occupational Safety and Health (NIOSH), Pittsburgh Research Laboratory, Pittsburgh, PA 15236 (United States)

    2009-09-01

    Gob gas ventholes (GGV) are used to control methane inflows into a longwall operation by capturing it within the overlying fractured strata before it enters the work environment. Thus, it is important to understand the effects of various factors, such as drilling parameters, location of borehole, applied vacuum by exhausters and mining/panel parameters in order to be able to evaluate the performance of GGVs and to predict their effectiveness in controlling methane emissions. However, a practical model for this purpose currently does not exist. In this paper, we analyzed the total gas flow rates and methane percentages from 10 GGVs located on three adjacent panels operated in Pittsburgh coalbed in Southwestern Pennsylvania section of Northern Appalachian basin. The ventholes were drilled from different surface elevations and were located at varying distances from the start-up ends of the panels and from the tailgate entries. Exhauster pressures, casing diameters, location of longwall face and mining rates and production data were also recorded. These data were incorporated into a multilayer-perceptron (MLP) type artificial neural network (ANN) to model venthole production. The results showed that the two-hidden layer model predicted total production and the methane content of the GGVs with more than 90% accuracy. The ANN model was further used to conduct sensitivity analyses about the mean of the input variables to determine the effect of each input variable on the predicted production performance of GGVs. (author)

  5. Methane and peatland restoration : the good, the bad, and the bubbly; Le methane et la restauration des tourbieres

    Energy Technology Data Exchange (ETDEWEB)

    Waddington, J.M.; Shea, K.M.; Harrison, K.; Day, S.M. [McMaster Univ., Hamilton, ON (Canada). School of Geography and Earth Science

    2008-07-01

    Peatlands are natural sources of methane (CH{sub 4}). As such, they play an important role in the global carbon cycle. Peatland CH{sub 4} emissions are expected to decrease in the coming decades according to models that predict enhanced evapotranspiration and lower water-table position. While these predictions focus primarily on diffusive CH{sub 4} fluxes, this study focused on the significance of ebullition of biogenic gas bubbles as a mechanism for the transport of CH{sub 4} to the atmosphere. It also presented a new conceptual model that addresses how changes in temperature, atmospheric pressure and peat structure can influence CH{sub 4} bubble storage and release. The higher CH{sub 4} flux that peatlands experience under warmer and drier conditions can be attributed to increased CH{sub 4} ebullition despite a decrease in CH{sub 4} flux via diffusion. Biogenic gas bubbles beneath the water table also affect hydrological processes in peat soils. Studies have shown that these bubbles reduce the saturated volumetric water content and saturated hydraulic conductivity. Zones of elevated pore-water pressure are therefore created. Each of these factors has significant hydrological and biogeochemical implications, in that they will influence directions and rates of water flow, solute transfer, and the transport of CH{sub 4} to the atmosphere. The re-establishment of these natural methane dynamics processes are important for restoring the hydrology of impacted peatlands.

  6. Regulation of anaerobic methane oxidation in sediments of the Black Sea

    Directory of Open Access Journals (Sweden)

    N. J. Knab

    2008-05-01

    Full Text Available Anaerobic oxidation of methane (AOM and sulfate reduction (SRR were investigated in sediments of the western Black Sea, where methane transport is controlled by diffusion. To understand the regulation and dynamics of methane production and oxidation in the Black Sea, rates of methanogenesis, AOM, and SRR were determined using radiotracers in combination with pore water chemistry and stable isotopes. On the shelf of the Danube paleo-delta and the Dnjepr Canyon, AOM did not consume methane effectively and upwards diffusing methane created an extended sulfate-methane transition zone (SMTZ that spread over more than 2.5 m and was located in formerly limnic sediment. Measurable AOM rates occurred mainly in the lower part of the SMTZ, sometimes even at depths where sulfate seemed to be unavailable. The inefficiency of methane oxidation appears to be linked to the limnic history of the sediment, since in all cores methane was completely oxidized at the limnic-marine transition. The upward tailing of methane was less pronounced in a core from the deep sea in the area of the Dnjepr Canyon, the only station with a SMTZ close to the marine deposits. Sulfate reduction rates were mostly extremely low, and in the SMTZ were even lower than AOM rates. Rates of bicarbonate-based methanogenesis were below detection limit in two of the cores, but δ13C values of methane indicate a biogenic origin. The most depleted δ13C-signal was found in the SMTZ of the core from the deep sea, most likely as a result of carbon recycling between AOM and methanogenesis.

  7. Total balance of biogenic fuels for thermal uses; Ganzheitliche Bilanzierung verschiedener biogener Festbrennstoffe zur thermischen Nutzung

    Energy Technology Data Exchange (ETDEWEB)

    Becher, S.; Kaltschmitt, M. [Stuttgart Univ. (Germany). Inst. fuer Energiewirtschaft und Rationelle Energieanwendung (IER)

    1996-12-31

    In this situation of unfavourable energy price levels, the use of biogenic fuels for power supply can be recommended only if it serves to reduce environmental pollution. Against this background and on the basis of a primary energy balance, the authors attempted a total balance of selected enfironmental effects (global heating and acidification potential) of biomass use as compared to fossil fuel combustion. (orig) [Deutsch] ie Nutzung biogener Festbrennstoffe zur Energienachfragedeckung ist bei dem gegenwaertigen unguenstigen Energiepreisniveau nur dann zu rechtfertigen, wenn es durch die Biomassenutzung zu einer Reduzierung der energiebedingten Umwelteffekte kommt. Vor disem Hintergrund werden ausgehend von der Primaerenergiebilanz ausgewaehlte Umwelteffekte (d.h. das Treibhaus- und das Versauerungspotential) einer Biomassenutzung im Vergleich zu einer Nutzung fossiler Energietraeger ganzheitlich bilanziert. Die wesentlichen Ergebnisse werden zusammengefasst und interpretiert. (orig)

  8. Methane prediction in collieries

    CSIR Research Space (South Africa)

    Creedy, DP

    1999-06-01

    Full Text Available The primary aim of the project was to assess the current status of research on methane emission prediction for collieries in South Africa in comparison with methods used and advances achieved elsewhere in the world....

  9. The hydrology of northern peatlands as affected by biogenic gas: Current developments and research needs

    Science.gov (United States)

    Rosenberry, D.O.; Glaser, P.H.; Siegel, D.I.

    2006-01-01

    Recent research indicates that accumulation and release of biogenic gas from northern peatlands may substantially affect future climate. Sudden release of free-phase gas bubbles into the atmosphere may preclude the conversion of methane to carbon dioxide in the uppermost oxic layer of the peat, resulting in greater contribution of methane to the atmosphere than is currently estimated. The hydrology of these peatlands also affects and is affected by this process, especially when gas is released suddenly and episodically. Indirect hydrological evidence indicates that ebullitive gas releases are relatively frequent in some peatlands and time-averaged rates may be significantly greater than diffusive releases. Estimates of free-phase gas contained in peat have ranged from 0 to nearly 20% of the peat volume. Abrupt changes in the volume of gas may alter hydraulic gradients and movement of water and solutes in peat, which in turn could alter composition and fluxes of the gas. Peat surfaces also move vertically and horizontally in response to accumulation and release of free-phase gas. Future research should address the distribution, temporal variability, and relative significance of ebullition in peatlands and the consequent hydrological responses to these gas-emission events. Copyright ?? 2006 John Wiley & Sons, Ltd.

  10. Using biogenic sulfur gases as remotely detectable biosignatures on anoxic planets.

    Science.gov (United States)

    Domagal-Goldman, Shawn D; Meadows, Victoria S; Claire, Mark W; Kasting, James F

    2011-06-01

    We used one-dimensional photochemical and radiative transfer models to study the potential of organic sulfur compounds (CS(2), OCS, CH(3)SH, CH(3)SCH(3), and CH(3)S(2)CH(3)) to act as remotely detectable biosignatures in anoxic exoplanetary atmospheres. Concentrations of organic sulfur gases were predicted for various biogenic sulfur fluxes into anoxic atmospheres and were found to increase with decreasing UV fluxes. Dimethyl sulfide (CH(3)SCH(3), or DMS) and dimethyl disulfide (CH(3)S(2)CH(3), or DMDS) concentrations could increase to remotely detectable levels, but only in cases of extremely low UV fluxes, which may occur in the habitable zone of an inactive M dwarf. The most detectable feature of organic sulfur gases is an indirect one that results from an increase in ethane (C(2)H(6)) over that which would be predicted based on the planet's methane (CH(4)) concentration. Thus, a characterization mission could detect these organic sulfur gases-and therefore the life that produces them-if it could sufficiently quantify the ethane and methane in the exoplanet's atmosphere.

  11. Biogenic catalysis of soil formation on Mars?

    Science.gov (United States)

    Bishop, J. L.

    1998-01-01

    The high iron abundance and the weak ferric iron spectral features of martian surface material are consistent with nanophase (nm-sized) iron oxide minerals as a major source of iron in the bright region soil on Mars. Nanophase iron oxide minerals, such as ferrihydrite and schwertmannite, and nanophase forms of hematite and goethite are formed by both biotic and abiotic processes on Earth. The presence of these minerals on Mars does not indicate biological activity on Mars, but it does raise the possibility. This work includes speculation regarding the possibility of biogenic soils on Mars based on previous observations and analyses. A remote sensing goal of upcoming missions should be to determine if nanophase iron oxide minerals, clay silicates and carbonates are present in the martian surface material. These minerals are important indicators for exobiology and their presence on Mars would invoke a need for further investigation and sample return from these sites.

  12. On the Biogenic Origins of Homochirality

    Science.gov (United States)

    Sojo, Victor

    2015-06-01

    Homochirality, the single-handedness of optically asymmetric chemical structures, is present in all major biological macromolecules. Terrestrial life's preference for one isomer over its mirror image in D-sugars and L-amino acids has both fascinated and puzzled biochemists for over a century. But the contrasting case of the equally fundamental phospholipids has received less attention. Although the phospholipid glycerol headgroups of archaea and bacteria are both exclusively homochiral, the stereochemistries between the two domains are opposite. Here I argue that the reason for this "dual homochirality" was a simple evolutionary choice at the independent origin of the two synthesizing enzymes. More broadly, this points to a trivial biogenic cause for the evolution of homochirality: the enzymatic processes that produce chiral biomolecules are stereospecific in nature. Once an orientation has been favored, shifting to the opposite is both difficult and unnecessary. Homochirality is thus the simplest and most parsimonious evolutionary case.

  13. Controlled cobalt doping in biogenic magnetite nanoparticles

    Science.gov (United States)

    Byrne, J. M.; Coker, V. S.; Moise, S.; Wincott, P. L.; Vaughan, D. J.; Tuna, F.; Arenholz, E.; van der Laan, G.; Pattrick, R. A. D.; Lloyd, J. R.; Telling, N. D.

    2013-01-01

    Cobalt-doped magnetite (CoxFe3 −xO4) nanoparticles have been produced through the microbial reduction of cobalt–iron oxyhydroxide by the bacterium Geobacter sulfurreducens. The materials produced, as measured by superconducting quantum interference device magnetometry, X-ray magnetic circular dichroism, Mössbauer spectroscopy, etc., show dramatic increases in coercivity with increasing cobalt content without a major decrease in overall saturation magnetization. Structural and magnetization analyses reveal a reduction in particle size to less than 4 nm at the highest Co content, combined with an increase in the effective anisotropy of the magnetic nanoparticles. The potential use of these biogenic nanoparticles in aqueous suspensions for magnetic hyperthermia applications is demonstrated. Further analysis of the distribution of cations within the ferrite spinel indicates that the cobalt is predominantly incorporated in octahedral coordination, achieved by the substitution of Fe2+ site with Co2+, with up to 17 per cent Co substituted into tetrahedral sites. PMID:23594814

  14. Composition and origin of coalbed gases in the Lower Silesian basin, southwest Poland

    Energy Technology Data Exchange (ETDEWEB)

    Kotarba, M.J.; Rice, D.D. [Stanislaw Staszic University of Mining and Metallurgy, Krakow (Poland). Faculty of Geology, Geophysics and Environmental Protection

    2001-07-01

    Coalbed gases in the Lower Silesian Coal Basin (LSCB) of Poland are highly variable in both their molecular and stable isotope compositions. Isotopic studies reveal the presence of 3 genetic types of natural gases: thermogenic (CH{sub 4}, higher gaseous hydrocarbons, and CO{sub 2}), endogenic CO{sub 2}, and microbial CH{sub 4} and CO{sub 2}. Thermogenic gases resulted from coalification processes, which were probably completed by Late Carboniferous and Early Permian time. Endogenic CO{sub 2} migrated along the deep-seated faults from upper mantle and/or magma chambers, Minor volumes of microbial CH{sub 4} and CO{sub 2} occur at shallow depths close to the abandoned mine workings. 'Late-stage' microbial processes have commenced in the Upper Cretaceous and are probably active at present. However, depth-related isotopic fractionation which has resulted from physical and physicochemical (e.g. diffusion and adsorption/desorption) processes during gas migration cannot be neglected. The strongest rock and gas outbursts occur only in those parts of coal deposits of the LSCB which are dominated by large amounts of endogenic CO{sub 2}.

  15. In situ and laboratory toxicity of coalbed natural gas produced waters with elevated sodium bicarbonate

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.; Skaar, Don

    2014-01-01

    Some tributaries in the Powder River Structural Basin, USA, were historically ephemeral, but now contain water year round as a result of discharge of coalbed natural gas (CBNG)-produced waters. This presented the opportunity to study field sites with 100% effluent water with elevated concentrations of sodium bicarbonate. In situ experiments, static renewal experiments performed simultaneously with in situ experiments, and static renewal experiments performed with site water in the laboratory demonstrated that CBNG-produced water reduces survival of fathead minnow (Pimephales promelas) and pallid sturgeon (Scaphirhynchus albus). Age affected survival of fathead minnow, where fish 2 d posthatch (dph) were more sensitive than 6 dph fish, but pallid sturgeon survival was adversely affected at both 4 and 6 dph. This may have implications for acute assays that allow for the use of fish up to 14 dph. The survival of early lifestage fish is reduced significantly in the field when concentrations of NaHCO3 rise to more than 1500 mg/L (also expressed as >1245 mg HCO3 (-) /L). Treatment with the Higgin's Loop technology and dilution of untreated water increased survival in the laboratory. The mixing zones of the 3 outfalls studied ranged from approximately 800 m to 1200 m below the confluence. These experiments addressed the acute toxicity of effluent waters but did not address issues related to the volumes of water that may be added to the watershed.

  16. Multi-model simulation of CO and HCHO in the Southern Hemisphere: comparison with observations and impact of biogenic emissions

    Science.gov (United States)

    Zeng, G.; Williams, J. E.; Fisher, J. A.; Emmons, L. K.; Jones, N. B.; Morgenstern, O.; Robinson, J.; Smale, D.; Paton-Walsh, C.; Griffith, D. W. T.

    2015-07-01

    , compared to the source regions. Decreased biogenic emissions cause decreased CO export to remote regions, which leads to increased OH; this in turn results in increased HCHO production through methane oxidation. In agreement with earlier studies, we corroborate that significant HCHO sources are likely missing in the models in the remote SH.

  17. Estimating methane gas production in peat soils of the Florida Everglades using hydrogeophysical methods

    Science.gov (United States)

    Wright, William; Comas, Xavier

    2016-04-01

    The spatial and temporal variability in production and release of greenhouse gases (such as methane) in peat soils remains uncertain, particularly for low-latitude peatlands like the Everglades. Ground penetrating radar (GPR) is a hydrogeophysical tool that has been successfully used in the last decade to noninvasively investigate carbon dynamics in peat soils; however, application in subtropical systems is almost non-existent. This study is based on four field sites in the Florida Everglades, where changes in gas content within the soil are monitored using time-lapse GPR measurements and gas releases are monitored using gas traps. A weekly methane gas production rate is estimated using a mass balance approach, considering gas content estimated from GPR, gas release from gas traps and incorporating rates of diffusion, and methanotrophic consumption from previous studies. Resulting production rates range between 0.02 and 0.47 g CH4 m-2 d-1, falling within the range reported in literature. This study shows the potential of combining GPR with gas traps to monitor gas dynamics in peat soils of the Everglades and estimate methane gas production. We also show the enhanced ability of certain peat soils to store gas when compared to others, suggesting that physical properties control biogenic gas storage in the Everglades peat soils. Better understanding biogenic methane gas dynamics in peat soils has implications regarding the role of wetlands in the global carbon cycle, particularly under a climate change scenario.

  18. Biogenic amines in Portuguese traditional foods and wines.

    Science.gov (United States)

    Ferreira, Isabel M P L V O; Pinho, Olívia

    2006-09-01

    The presence of biogenic amines in foodstuffs is an important food safety problem because of the implication of these compounds in food intolerance and intoxication. The separation and quantification of biogenic amines in foods is normally performed by chromatographic techniques. This review contains descriptions of the quantification of biogenic amines in Portuguese traditional fermented and/or ripened foods and wines, including Protected Denomination of Origin cheeses, dry-cured sausages, and Portuguese wines (including Port wines), using different analytical methods based on high-pressure liquid chromatography (UV or diode array and/or fluorometric detectors) and gas chromatography (with a mass spectrometry detector). The evolution of biogenic amines during fermentation, ripening, aging, or storage of those products was also evaluated. Biogenic amine concentrations ranged widely within individual food items, and storage, transport, and handling conditions can influence to some extent the biogenic amines present and their concentrations. Traditional foods are an important part of the Portuguese diet, and a high intake of harmful amounts of biogenic amines from traditional Portuguese fermented foods is possible. However, extensive research is needed to extend the current limited database.

  19. The 4-Corners methane hotspot: Mapping CH4 plumes at 60km through 1m resolution using space- and airborne spectrometers

    Science.gov (United States)

    Frankenberg, C.; Thorpe, A. K.; Hook, S. J.; Green, R. O.; Thompson, D. R.; Kort, E. A.; Hulley, G. C.; Vance, N.; Bue, B. D.; Aubrey, A. D.

    2015-12-01

    The SCIAMACHY instrument onboard the European research satellite ENVISAT detected a large methane hotspot in the 4-Corners area, specifically in New Mexico and Colorado. Total methane emissions in this region were estimated to be on the order of 0.5Tg/yr, presumably related to coal-bed methane exploration. Here, we report on NASA efforts to augment the TOPDOWN campaign intended to enable regional methane source inversions and identify source types in this area. The Jet Propulsion Laboratory was funded to fly two airborne imaging spectrometers, viz. AVIRIS-NG and HyTES. In April 2015, we used both instruments to continuously map about 2000km2 in the 4-Corners area at 1-5m spatial resolution, with special focus on the most enhanced areas as observed from space. During our weeklong campaign, we detected more than 50 isolated and strongly enhanced methane plumes, ranging from coal mine venting shafts and gas processing facilities through individual well-pads, pipeline leaks and outcrop. Results could be immediately shared with ground-based teams and TOPDOWN aircraft so that ground-validation and identification was feasible for a number of sources. We will provide a general overview of the JPL-led mapping campaign efforts and show individual results, derive source strength estimates and discuss how the results fit in with space borne estimates.

  20. BIOGENIC AMINES CONTENT IN SELECTED WINES DURING WINEMAKING

    Directory of Open Access Journals (Sweden)

    Radka Flasarová

    2012-02-01

    Full Text Available The aim of this study was to describe the development of selected biogenic amines (histamine; tyramine; phenylethylamine; putrescine; agmatine; and cadaverine during the winemaking in 10 selected species grown in Central Europe in 2008. The analysis was performed using ion-exchange chromatography by the sodium-citrate buffers with the post-column ninhydrin derivatization and photometric detection. A comparison of the content of biogenic amines in red and wine varieties showed that red wines have higher concentrations of biogenic amines.

  1. Methane Emissions from Upland Forests

    Science.gov (United States)

    Megonigal, Patrick; Pitz, Scott; Wang, Zhi-Ping

    2016-04-01

    Global budgets ascribe 4-10% of atmospheric methane sinks to upland soils and assume that soils are the sole surface for methane exchange between upland forests and the atmosphere. The dogma that upland forests are uniformly atmospheric methane sinks was challenged a decade ago by the discovery of abiotic methane production from plant tissue. Subsequently a variety of relatively cryptic microbial and non-microbial methane sources have been proposed that have the potential to emit methane in upland forests. Despite the accumulating evidence of potential methane sources, there are few data demonstrating actual emissions of methane from a plant surface in an upland forest. We report direct observations of methane emissions from upland tree stems in two temperate forests. Stem methane emissions were observed from several tree species that dominate a forest located on the mid-Atlantic coast of North America (Maryland, USA). Stem emissions occurred throughout the growing season while soils adjacent to the trees simultaneously consumed methane. Scaling fluxes by stem surface area suggested the forest was a net methane source during a wet period in June, and that stem emissions offset 5% of the soil methane sink on an annual basis. High frequency measurements revealed diurnal cycles in stem methane emission rates, pointing to soils as the methane source and transpiration as the most likely pathway for gas transport. Similar observations were made in an upland forest in Beijing, China. However, in this case the evidence suggested the methane was not produced in soils, but in the heartwood by microbial or non-microbial processes. These data challenge the concept that forests are uniform sinks of methane, and suggest that upland forests are smaller methane sinks than previously estimated due to stem emissions. Tree emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration.

  2. Reduction of Non-CO2 Gas Emissions Through The In Situ Bioconversion of Methane

    Energy Technology Data Exchange (ETDEWEB)

    Scott, A R; Mukhopadhyay, B; Balin, D F

    2012-09-06

    The primary objectives of this research were to seek previously unidentified anaerobic methanotrophs and other microorganisms to be collected from methane seeps associated with coal outcrops. Subsurface application of these microbes into anaerobic environments has the potential to reduce methane seepage along coal outcrop belts and in coal mines, thereby preventing hazardous explosions. Depending upon the types and characteristics of the methanotrophs identified, it may be possible to apply the microbes to other sources of methane emissions, which include landfills, rice cultivation, and industrial sources where methane can accumulate under buildings. Finally, the microbes collected and identified during this research also had the potential for useful applications in the chemical industry, as well as in a variety of microbial processes. Sample collection focused on the South Fork of Texas Creek located approximately 15 miles east of Durango, Colorado. The creek is located near the subsurface contact between the coal-bearing Fruitland Formation and the underlying Pictured Cliffs Sandstone. The methane seeps occur within the creek and in areas adjacent to the creek where faulting may allow fluids and gases to migrate to the surface. These seeps appear to have been there prior to coalbed methane development as extensive microbial soils have developed. Our investigations screened more than 500 enrichments but were unable to convince us that anaerobic methane oxidation (AMO) was occurring and that anaerobic methanotrophs may not have been present in the samples collected. In all cases, visual and microscopic observations noted that the early stage enrichments contained viable microbial cells. However, as the levels of the readily substrates that were present in the environmental samples were progressively lowered through serial transfers, the numbers of cells in the enrichments sharply dropped and were eliminated. While the results were disappointing we acknowledge that

  3. Methane synthesis under mild conditions for decentralized applications; Methansynthese unter milden Bedingungen fuer dezentrale Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, Michael [DBFZ Deutsches Biomasseforschungszentrum gGmbH, Leipzig (Germany); Roensch, Stefan

    2016-08-01

    It is a central aim of the German government to significantly reduce the emission of greenhouse gases in the next years. One possibility to reach this aim is the substitution of fossil fuels, especially natural gas, by fuels from biogenic sources (Bio-SNG). However, it is a drawback of Bio-SNG that the production costs are considerably higher than those of fossil natural gas. This work provides an approach to reduce the production costs of Bio-SNG. It is the aim to reduce the process parameters of the methane synthesis. At the same time, it has to be ensured that high methane yields are achieved even at those mild conditions. A procedure for the optimization of the methanation catalyst activity will be presented. If the catalyst is as active as possible even at mild conditions, it will be possible to produce Bio-SNG cost efficient even in small, decentralized scale.

  4. Biogenic hydrogen and methane production from Chlorella vulgaris and Dunaliella tertiolecta biomass

    Directory of Open Access Journals (Sweden)

    Lakaniemi Aino-Maija

    2011-09-01

    Full Text Available Abstract Background Microalgae are a promising feedstock for biofuel and bioenergy production due to their high photosynthetic efficiencies, high growth rates and no need for external organic carbon supply. In this study, utilization of Chlorella vulgaris (a fresh water microalga and Dunaliella tertiolecta (a marine microalga biomass was tested as a feedstock for anaerobic H2 and CH4 production. Results Anaerobic serum bottle assays were conducted at 37°C with enrichment cultures derived from municipal anaerobic digester sludge. Low levels of H2 were produced by anaerobic enrichment cultures, but H2 was subsequently consumed even in the presence of 2-bromoethanesulfonic acid, an inhibitor of methanogens. Without inoculation, algal biomass still produced H2 due to the activities of satellite bacteria associated with algal cultures. CH4 was produced from both types of biomass with anaerobic enrichments. Polymerase chain reaction-denaturing gradient gel electrophoresis profiling indicated the presence of H2-producing and H2-consuming bacteria in the anaerobic enrichment cultures and the presence of H2-producing bacteria among the satellite bacteria in both sources of algal biomass. Conclusions H2 production by the satellite bacteria was comparable from D. tertiolecta (12.6 ml H2/g volatile solids (VS and from C. vulgaris (10.8 ml H2/g VS, whereas CH4 production was significantly higher from C. vulgaris (286 ml/g VS than from D. tertiolecta (24 ml/g VS. The high salinity of the D. tertiolecta slurry, prohibitive to methanogens, was the probable reason for lower CH4 production.

  5. Biogenic methane production in formation waters from a large gas field in the North Sea.

    Science.gov (United States)

    Gray, Neil D; Sherry, Angela; Larter, Stephen R; Erdmann, Michael; Leyris, Juliette; Liengen, Turid; Beeder, Janiche; Head, Ian M

    2009-05-01

    Methanogenesis was investigated in formation waters from a North Sea oil rimmed gas accumulation containing biodegraded oil, which has not been subject to seawater injection. Activity and growth of hydrogenotrophic methanogens was measured but acetoclastic methanogenesis was not detected. Hydrogenotrophic methanogens showed activity between 40 and 80 degrees C with a temperature optimum (ca. 70 degrees C) consistent with in situ reservoir temperatures. They were also active over a broad salinity range, up to and consistent with the high salinity of the waters (90 g l(-1)). These findings suggest the methanogens are indigenous to the reservoir. The conversion of H(2) and CO(2) to CH(4) in methanogenic enrichments was enhanced by the addition of inorganic nutrients and was correlated with cell growth. Addition of yeast extract also stimulated methanogenesis. Archaeal 16S rRNA gene sequences recovered from enrichment cultures were closely related to Methanothermobacter spp. which have been identified in other high-temperature petroleum reservoirs. It has recently been suggested that methanogenic oil degradation may be a major factor in the development of the world's heavy oils and represent a significant and ongoing process in conventional deposits. Although an oil-degrading methanogenic consortium was not enriched from these samples the presence and activity of communities of fermentative bacteria and methanogenic archaea was demonstrated. Stimulation of methanogenesis by addition of nutrients suggests that in situ methanogenic biodegradation of oil could be harnessed to enhance recovery of stranded energy assets from such petroleum systems.

  6. Origin of organism-dependent biogenic silica quartz formation.

    Science.gov (United States)

    Sato, Kiminori

    2011-12-15

    Organism-dependent biogenic quartz formation in the steady-state environment is a phenomenon that can address the global environmental issues such as diagenetic evolution, biogeochemical cycling, and reservoir formation, but detailed studies have not been performed so far. Here, steady-state quartz formation is studied for amorphous silica of different biogenic origin on the basis of the recently established mechanistic model [Sato et al., J. Phys. Chem. C 2011, 115, 18131]. Amorphous silica originated from rice husks possesses angstrom-scale pores larger by 1.3 Å than those originated from diatom algae. The slight difference of pore size dramatically reduces activation energies of water diffusion by 78% and reactions of water molecules at pore surfaces by 47%, resulting in the reduction of activation energy of biogenic quartz formation by 64%. The present findings evidence that angstrom-scale pores intrinsically residing in the amorphous matrix are the organism-dependent origin of steady-state biogenic quartz formation.

  7. Biogenic amines in meat and fermented meat products

    Directory of Open Access Journals (Sweden)

    Joanna Stadnik

    2010-09-01

    Full Text Available Recent trends in food quality and safety promote an increasing search for trace compounds that can affect human health. Biogenic amines belong to this group of substances. They can cause distinctive pharmacological, physiological and toxic effects in organisms. Their amounts are usually increasing as a consequence of the use of poor quality raw materials, during controlled or spontaneous microbial fermentation or in the course of food spoilage. The origin of biogenic amines makes them suitable as chemical indicators of the hygienic quality and freshness of some foods being associated to the degree of food fermentation or degradation. The development of appropriate manufacturing technologies to obtain products free or nearly free from biogenic amines is a challenge for the meat industry. This review briefly summarises current knowledge on the biological implications of biogenic amines on human health and collects data on the factors affecting their formation in meat and fermented meat products.

  8. incidence of biogenic amines in foods implications for the gambia

    African Journals Online (AJOL)

    Temechegn

    These could be controlled for a better and improved food quality. ... usually operate cold chain facilities and market their products to retailers in cartons and to household ... A survey on free biogenic amine content of fresh and preserved.

  9. The global methane budget 2000-2012 : main points and next steps

    Science.gov (United States)

    Bousquet, Philippe; Saunois, Marielle; Poulter, Ben; Canadell, Pep; Jackson, Rob; Dlugokencky, Edward J.

    2017-04-01

    With a lifetime around 9 years in the atmosphere and a diversity of emission types, atmospheric methane, the second anthropogenic greenhouse gas after carbon dioxide, is a major target for climate change mitigation. Atmospheric observations include a large variety of in-situ and remote-sensed observations from the surface or from space. These data are assimilated in atmospheric inversion to infer methane emissions and sinks (top-down approaches). In parallel, a large international effort is conducted to model processes emitting methane at the surface (e.g. wetland emissions) or destroying methane in the atmosphere (e.g. OH radicals), but also to compile inventories of anthropogenic emissions (bottom-up approaches). Large uncertainties remain in the spatio-temporal quantification of methane sources and sinks. Here, we present a synthesis of global and regional methane emissions and sinks for the period 2000-2012, using an integrated approach to combine: atmospheric measurements, chemistry-transport models, ecosystem models, emission inventories, and climate-chemistry models. Robust and not robust emission estimates are extracted for global to regional scales and presented from an ensemble of atmospheric inversions and of process-based models. We discuss scenarios of methane emissions and sinks (process-based and region-based) possibly explaining the sustained atmospheric increase since 2007. We show in particular that US methane emissions are not likely to contribute significantly to the positive atmospheric trend, that none of the IPCC atmospheric scenarios represents the recent trajectory of concentrations, and that biogenic sources are probably the largest contributors to the positive anomaly in emissions, with a likely dominance of tropical and anthropogenic sources. We also show that Chinese emissions and trends have most likely be over estimated in some inventories. We finally propose possible future activities for the methane component of the Global Carbon

  10. Sources and sinks of methane beneath polar ice

    Science.gov (United States)

    Priscu, J. C.; Adams, H. E.; Hand, K. P.; Dore, J. E.; Matheus-Carnevali, P.; Michaud, A. B.; Murray, A. E.; Skidmore, M. L.; Vick-Majors, T.

    2014-12-01

    Several icy moons of the outer solar system carry subsurface oceans containing many times the volume of liquid water on Earth and may provide the greatest volume of habitable space in our solar system. Functional sub-ice polar ecosystems on Earth provide compelling models for the habitability of extraterrestrial sub-ice oceans. A key feature of sub-ice environments is that most of them receive little to no solar energy. Consequently, organisms inhabiting these environments must rely on chemical energy to assimilate either carbon dioxide or organic molecules to support their metabolism. Methane can be utilized by certain bacteria as both a carbon and energy source. Isotopic data show that methane in Earth's polar lakes is derived from both biogenic and thermogenic sources. Thermogenic sources of methane in the thermokarst lakes of the north slope of Alaska yield supersaturated water columns during winter ice cover that support active populations of methanotrophs during the polar night. Methane in the permanently ice-covered lakes of the McMurdo Dry Valleys, Antarctica varies widely in concentration and is produced either by contemporary methanogenesis or is a relic from subglacial flow. Rate measurements revealed that microbial methane oxidation occurs beneath the ice in both the arctic and Antarctic lakes. The first samples collected from an Antarctic subglacial environment beneath 800 m of ice (Subglacial Lake Whillans) revealed an active microbial ecosystem that has been isolated from the atmosphere for many thousands of years. The sediments of Lake Whillans contained high levels of methane with an isotopic signature that indicates it was produced via methanogenesis. The source of this methane appears to be from the decomposition of organic carbon deposited when this region of Antarctica was covered by the sea. Collectively, data from these sub-ice environments show that methane transformations play a key role in microbial community metabolism. The discovery of

  11. Atmospheric constraints on the methane emissions from the East Siberian Shelf

    Directory of Open Access Journals (Sweden)

    A. Berchet

    2015-09-01

    Full Text Available Sub-sea permafrost and hydrates in the East Siberian Arctic Ocean Continental Shelf (ESAS constitute a substantial carbon pool, and a potentially large source of methane to the atmosphere. Previous studies based on interpolated oceanographic campaigns estimated atmospheric emissions from this area at 8–17 Tg CH4 y−1. Here, we propose insights based on atmospheric observations to evaluate these estimates. Isotopic observations suggest a biogenic origin (either terrestrial or marine of the methane in air masses originating from ESAS during summer 2010. The comparison of high-resolution simulations of atmospheric methane mole fractions to continuous methane observations during the entire year 2012 confirms the high variability and heterogeneity of the methane releases from ESAS. Simulated mole fractions including a 8 Tg CH4 y−1 source from ESAS are found largely overestimated compared to the observations in winter, whereas summer signals are more consistent with each other. Based on a comprehensive statistical analysis of the observations and of the simulations, annual methane emissions from ESAS are estimated in a range of 0.5–4.3 Tg CH4 y−1.

  12. Evidence for the microbial in situ conversion of oil to methane in the Dagang oilfield

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez, N.; Richnow, H.H. [Helmholtz-Zentrum fuer Umweltforschung (UFZ), Leipzig (Germany). Abt. Isotopenbiogeochemie; Cai, M. [Helmholtz-Zentrum fuer Umweltforschung (UFZ), Leipzig (Germany). Abt. Isotopenbiogeochemie; University of Science and Technology, Beijing (China). School of Civil and Environment Engineering; Straaten, N.; Krueger, M. [Bundesanstalt fuer Geowissenschaften und Rohstoffe BGR Geozentrum (BGR), Hannover (Germany). Fachbereich Geochemie der Rohstoffe; Yao, Jun [University of Science and Technology, Beijing (China). School of Civil and Environment Engineering

    2013-08-01

    In situ biotransformation of oil to methane was investigated in a reservoir in Dagang, China using chemical fingerprinting, isotopic analyses, and molecular and biological methods. The reservoir is highly methanogenic despite chemical indications of advanced oil degradation, such as depletion of n-alkanes, alkylbenzenes, and light polycyclic aromatic hydrocarbon (PAHs) fractions or changes in the distribution of several alkylated polycyclic aromatic hydrocarbons. The degree of degradation strongly varied between different parts of the reservoir, ranging from severely degraded to nearly undegraded oil compositions. Geochemical data from oil, water and gas samples taken from the reservoir are consistent with in situ biogenic methane production linked to aliphatic and aromatic hydrocarbon degradation. Microcosms were inoculated with production and injection waters in order to characterize these processes in vitro. Subsequent degradation experiments revealed that autochthonous microbiota are capable of producing methane from {sup 13}C-labelled n-hexadecane or 2-methylnaphthalene, and suggest that further methanogenesis may occur from the aromatic and polyaromatic fractions of Dagang reservoir fluids. The microbial communities from produced oil-water samples were composed of high numbers of microorganisms (on the order to 10{sup 7}), including methane-producing Archaea within the same order of magnitude. In summary, the investigated sections of the Dagang reservoir may have significant potential for testing the viability of in situ conversion of oil to methane as an enhanced recovery method, and biodegradation of the aromatic fractions of the oil may be an important methane source. (orig.)

  13. Microbial methane production in deep aquifer associated with the accretionary prism in Japan.

    Science.gov (United States)

    Kimura, Hiroyuki; Nashimoto, Hiroaki; Shimizu, Mikio; Hattori, Shohei; Yamada, Keita; Koba, Keisuke; Yoshida, Naohiro; Kato, Kenji

    2010-04-01

    To identify the methanogenic pathways present in a deep aquifer associated with an accretionary prism in Southwest Japan, a series of geochemical and microbiological studies of natural gas and groundwater derived from a deep aquifer were performed. Stable carbon isotopic analysis of methane in the natural gas and dissolved inorganic carbon (mainly bicarbonate) in groundwater suggested that the methane was derived from both thermogenic and biogenic processes. Archaeal 16S rRNA gene analysis revealed the dominance of H(2)-using methanogens in the groundwater. Furthermore, the high potential of methane production by H(2)-using methanogens was shown in enrichments using groundwater amended with H(2) and CO(2). Bacterial 16S rRNA gene analysis showed that fermentative bacteria inhabited the deep aquifer. Anaerobic incubations using groundwater amended with organic substrates and bromoethanesulfonate (a methanogen inhibitor) suggested a high potential of H(2) and CO(2) generation by fermentative bacteria. To confirm whether or not methane is produced by a syntrophic consortium of H(2)-producing fermentative bacteria and H(2)-using methanogens, anaerobic incubations using the groundwater amended with organic substrates were performed. Consequently, H(2) accumulation and rapid methane production were observed in these enrichments incubated at 55 and 65 degrees C. Thus, our results suggested that past and ongoing syntrophic biodegradation of organic compounds by H(2)-producing fermentative bacteria and H(2)-using methanogens, as well as a thermogenic reaction, contributes to the significant methane reserves in the deep aquifer associated with the accretionary prism in Southwest Japan.

  14. Fluxed of nitrous oxide and methane in a lake border ecosystem in northern Germany

    Energy Technology Data Exchange (ETDEWEB)

    Rusch, H.; Rembges, D.; Papke, H.; Rennenberg, H. [Fraunhofer Inst. for Atmospheric Environmental Research, Garmisch-Partenkirchen (Germany)

    1995-12-31

    Methane and nitrous oxide are radiatively active trace gases. This accounts for approximately 20 % of the total anticipated greenhouse effect. The atmospheric mixing ratio of both gases has increased significantly during the last decades at a rate of 0.25 % yr{sup -l} for N{sub 2}O and a rate of 1 % yr{sup -1} for CH{sub 4}. Whether this increase is caused by enhanced biogenic production of both gases or is due to decreased global sinks, has not been definitely elucidated. Soils are an important source of methane and nitrous oxide. Natural wetlands, e.g., have a similar global source strength of methane as rice paddies. On the other hand, well aerated grasslands have been shown to be a sink for atmospheric methane due to methane oxidation. Nitrous oxide is emitted by a wide range of soil types. Its rate of emission is strongly enhanced by nitrogen fertilization. In the present study, fluxes of methane and nitrous oxide were determined in a lake border ecosystem along a toposequence from reed to dry pasture. The aim of this study was to characterize the influence of soil type, land use and season on the flux rates of these greenhouse gases. (author)

  15. Organosulfate formation in biogenic secondary organic aerosol.

    Science.gov (United States)

    Surratt, Jason D; Gómez-González, Yadian; Chan, Arthur W H; Vermeylen, Reinhilde; Shahgholi, Mona; Kleindienst, Tadeusz E; Edney, Edward O; Offenberg, John H; Lewandowski, Michael; Jaoui, Mohammed; Maenhaut, Willy; Claeys, Magda; Flagan, Richard C; Seinfeld, John H

    2008-09-11

    Organosulfates of isoprene, alpha-pinene, and beta-pinene have recently been identified in both laboratory-generated and ambient secondary organic aerosol (SOA). In this study, the mechanism and ubiquity of organosulfate formation in biogenic SOA is investigated by a comprehensive series of laboratory photooxidation (i.e., OH-initiated oxidation) and nighttime oxidation (i.e., NO3-initiated oxidation under dark conditions) experiments using nine monoterpenes (alpha-pinene, beta-pinene, d-limonene, l-limonene, alpha-terpinene, gamma-terpinene, terpinolene, Delta(3)-carene, and beta-phellandrene) and three monoterpenes (alpha-pinene, d-limonene, and l-limonene), respectively. Organosulfates were characterized using liquid chromatographic techniques coupled to electrospray ionization combined with both linear ion trap and high-resolution time-of-flight mass spectrometry. Organosulfates are formed only when monoterpenes are oxidized in the presence of acidified sulfate seed aerosol, a result consistent with prior work. Archived laboratory-generated isoprene SOA and ambient filter samples collected from the southeastern U.S. were reexamined for organosulfates. By comparing the tandem mass spectrometric and accurate mass measurements collected for both the laboratory-generated and ambient aerosol, previously uncharacterized ambient organic aerosol components are found to be organosulfates of isoprene, alpha-pinene, beta-pinene, and limonene-like monoterpenes (e.g., myrcene), demonstrating the ubiquity of organosulfate formation in ambient SOA. Several of the organosulfates of isoprene and of the monoterpenes characterized in this study are ambient tracer compounds for the occurrence of biogenic SOA formation under acidic conditions. Furthermore, the nighttime oxidation experiments conducted under highly acidic conditions reveal a viable mechanism for the formation of previously identified nitrooxy organosulfates found in ambient nighttime aerosol samples. We estimate

  16. Biogenic amines in italian pecorino cheese.

    Science.gov (United States)

    Schirone, Maria; Tofalo, Rosanna; Visciano, Pierina; Corsetti, Aldo; Suzzi, Giovanna

    2012-01-01

    The quality of distinctive artisanal cheeses is closely associated with the territory of production and its traditions. Pedoclimatic characteristics, genetic autochthonous variations, and anthropic components create an environment so specific that it would be extremely difficult to reproduce elsewhere. Pecorino cheese is included in this sector of the market and is widely diffused in Italy (∼62.000t of production in 2010). Pecorino is a common name given to indicate Italian cheeses made exclusively from pure ewes' milk characterized by a high content of fat matter and it is mainly produced in the middle and south of Italy by traditional procedures from raw or pasteurized milk. The microbiota plays a major role in the development of the organoleptic characteristics of the cheese but it can also be responsible for the accumulation of undesirable substances, such as biogenic amines (BA). Bacterial amino acid decarboxylase activity and BA content have to be investigated within the complex microbial community of raw milk cheese for different cheese technologies. The results emphasize the necessity of controlling the indigenous bacterial population responsible for high production of BA and the use of competitive adjunct cultures could be suggested. Several factors can contribute to the qualitative and quantitative profiles of BA's in Pecorino cheese such as environmental hygienic conditions, pH, salt concentration, water activity, fat content, pasteurization of milk, decarboxylase microorganisms, starter cultures, temperature and time of ripening, storage, part of the cheese (core, edge), and the presence of cofactor (pyridoxal phosphate, availability of aminases and deaminases). In fact physico-chemical parameters seem to favor biogenic amine-positive microbiota; both of these environmental factors can easily be modulated, in order to control growth of undesirable microorganisms. Generally, the total content of BA's in Pecorino cheeses can range from about 100-2400

  17. On Mineral Retrosynthesis of a Complex Biogenic Scaffold

    OpenAIRE

    Ashit Rao; José L Arias; Helmut Cölfen

    2017-01-01

    Synergistic relations between organic molecules and mineral precursors regulate biogenic mineralization. Given the remarkable material properties of the egg shell as a biogenic ceramic, it serves as an important model to elucidate biomineral growth. With established roles of complex anionic biopolymers and a heterogeneous organic scaffold in egg shell mineralization, the present study explores the regulation over mineralization attained by applying synthetic polymeric counterparts (polyethyle...

  18. Geochemical characteristics and origin of light hydrocarbons in biogenic gas

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The light hydrocarbon geochemical characteristics of biogenic gases from Sebei 1 gas field in the Qaidam Basin, Baoshan gas field in the Baoshan Basin and Alaxin gas field, Puqian gas pool, Aonan gas pool in the Songliao Basin are studied and the origin is discussed based on the composition and isotope data of gases. The isoalkane contents among light hydrocarbons in natural gas show a negative relationship with δ13C1 values. The isoalkane contents of the gases with δ13C1 values of less than ?60‰ are also high with more than 40% among light hydrocarbons in Sebei 1 gas field and Puqian gas pool. Moreover, the 2,2-dimethylbutane and 2-methylpentane, mainly sourced from bacteria, have predominance among isoalkanes, which suggests that light hydrocarbons in biogenic gases from these gas fields or pools were probably generated by microbial action. However, the cycloalkane contents among light hydrocarbons in biogenic gas are related to δ13C1 values positively. In Alaxin gas field and Aonan gas pool, where δ13C1 values of biogenic gases are less than ?60‰, the average contents of cycloalkane are higher than 44%. Light hydrocarbons among biogenic gases from these gas fields were probably generated by catalysis. The isoalkane and cycloalkane contents among light hydrocarbons from biogenic gases in the Baoshan gas field are both high, which might be generated by these two actions. The results show that the data of light hydrocarbons in biogenic gas can provide important information for understanding the generation mechanisms of light hydrocarbons during geological evolution and identifying biogenic gas and low mature gas.

  19. Abiotic Reductive Immobilization of U(VI) by Biogenic Mackinawite

    Energy Technology Data Exchange (ETDEWEB)

    Veeramani, Harish; Scheinost, Andreas; Monsegue, Niven; Qafoku, Nikolla; Kukkadapu, Ravi K.; Newville, Mathew; Lanzirotti, Anthony; Pruden, Amy; Murayama, Mitsuhiro; Hochella, Michael F.

    2013-03-01

    During subsurface bioremediation of uranium-contaminated sites, indigenous metal and sulfate-reducing bacteria may utilize a variety of electron acceptors, including ferric iron and sulfate that could lead to the formation of various biogenic minerals in-situ. Sulfides, as well as structural and adsorbed Fe(II) associated with biogenic Fe(II)-sulfide phases, can potentially catalyze abiotic U6+ reduction via direct electron transfer processes. In the present work, the propensity of biogenic mackinawite (Fe1+xS, x = 0 to 0.11) to reduce U6+ abiotically was investigated. The biogenic mackinawite produced by Shewanella putrefaciens strain CN32 was characterized by employing a suite of analytical techniques including TEM, SEM, XAS and Mössbauer analyses. Nanoscale and bulk analyses (microscopic and spectroscopic techniques, respectively) of biogenic mackinawite after exposure to U6+ indicate the formation of nanoparticulate UO2. This study suggests the relevance of Fe(II) and sulfide bearing biogenic minerals in mediating abiotic U6+ reduction, an alternative pathway in addition to direct enzymatic U6+ reduction.

  20. Biogenic amine production by lactic acid bacteria isolated from cider.

    Science.gov (United States)

    Garai, G; Dueñas, M T; Irastorza, A; Moreno-Arribas, M V

    2007-11-01

    To study the occurrence of histidine, tyrosine and ornithine decarboxylase activity in lactic acid bacteria (LAB) isolated from natural ciders and to examine their potential to produce detrimental levels of biogenic amines. The presence of biogenic amines in a decarboxylase synthetic broth and in cider was determined by reversed-phase high-performance liquid chromatography (RP-HPLC). Among the 54 LAB strains tested, six (five lactobacilli and one oenococci) were biogenic amine producers in both media. Histamine and tyramine were the amines formed by the LAB strains investigated. Lactobacillus diolivorans were the most intensive histamine producers. This species together with Lactobacillus collinoides and Oenococcus oeni also seemed to produce tyramine. No ability to form histamine, tyramine or putrescine by Pediococus parvulus was observed, although it is a known biogenic amine producer in wines and beers. This study demonstrated that LAB microbiota growing in ciders had the ability to produce biogenic amines, particularly histamine and tyramine, and suggests that this capability might be strain-dependent rather than being related to a particular bacterial species. Production of biogenic amines by food micro-organisms has continued to be the focus of intensive study because of their potential toxicity. The main goal was to identify the microbial species capable of producing these compounds in order to control their presence and metabolic activity in foods.

  1. Biogeochemical aspects of atmospheric methane

    OpenAIRE

    Cicerone, RJ; Oremland, RS

    1988-01-01

    Methane is the most abundant organic chemical in Earth's atmosphere, and its concentration is increasing with time, as a variety of independent measurements have shown. Photochemical reactions oxidize methane in the atmosphere; through these reactions, methane exerts strong influence over the chemistry of the troposphere and the stratosphere and many species including ozone, hydroxyl radicals, and carbon monoxide. Also, through its infrared absorption spectrum, methane is an important greenho...

  2. Converting biogenic dimethyl ether into fuels

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Michael; Otto, Thomas N.; Dinjus, Eckhard [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Katalyseforschung und -technologie (IKFT)

    2013-06-01

    In the seventies, the MtG (''methanol-to-gasoline'') process was an alternative to the Fischer-Tropsch process developed in the thirties of the past century. The MtG process is performed with dimethyl ether (DME) as an intermediate. Hydrocarbons (C{sub 1}-C{sub 10}) directly synthesised via DME with the assistance of zeolites as catalysts offers considerable advantages over the MtG process. Zeolites play an important role in the production of biomass-based fuels from synthesis gas. Known and mature technologies exist for synthesis gas of fossil origin (coal, natural gas, petroleum). These established technologies may also be transferred to synthesis gas of biogenous origin. Dimethyl ether produced from biomass-based synthesis gas is a central intermediate product. In the MtG and DtG (''dimethyl ether-to-gasoline'') process H-ZSM-5 zeolites are of major significance. Modification of H-ZSM-5 catalysts is the basis of customized product synthesis. Hierarchic structures of zeolites change the diffusion properties of the crystals and can help to achieve a more selective range of products. (orig.)

  3. 低渗透煤层气注热开采热-流-固耦合数学模型及数值模拟%Numerical simulation of the coupled thermal-fluid-solid mathematical models during extracting methane in low-permeability coal bed by heat injection

    Institute of Scientific and Technical Information of China (English)

    杨新乐; 任常在; 张永利; 郭仁宁

    2013-01-01

    In order to obtain seepage rules and production of coal-bed methane in the process of heat injection exploitation,a coupled thermal-fluid-solid mathematical models of coal-bed mathane was established based on results that permeability,porosity of coal increases with temperature,stress and thermal conductivity coefficient of gas,Young' s modulus,Poisson' s ratio as a function of the temperature,combined with seepage mechanics,rock mechanics,heat transfer and so on.Multi-well exploitation way was used to simulate seepage rules during extracting methane in low-permeability coal bed by heat injection after three fields were discreted.The numerical simulation results show that after 10 d heat injection and 100 d coal-bed methane mining,the average velocity of heat transfer is 66.25 mm/h in coal bed under the action of conductivity of coal bed and convection of coal-bed methane,and pressure drop of reservoir cauesd by heat injection is 2.45 times without heat injection,and production of coal-bed methane under the conditons of heat injection is 2.2 time without heat injection.It is a effective way to production improvement of low permeability coal-bed methane.%为得到低渗透煤层气藏注热开采过程中煤层气渗流运移规律,探索原地煤层在注入蒸汽加热后对煤层气产量的影响,基于煤体渗透率、孔隙度随温度、应力,气体导热系数、杨氏模量、泊松比随温度变化的关系,综合运用渗流力学、岩石力学、传热学等相关理论,建立了低渗透煤层气注热开采过程煤层气渗流热-流-固多物理场耦合数学模型,采用多井开采方式进行了注热开采过程煤层气渗流规律的数值模拟.数值模拟结果表明:煤层注热10 d抽采100 d后,由于煤层的导热并伴有煤层气的对流传热,煤层平均传热速度为66.25 mm/h,注热开采造成储层压力降是无注热抽采压力降的2.45倍,在温度应力耦合作用下,煤层气注热抽

  4. Direct Activation Of Methane

    KAUST Repository

    Basset, Jean-Marie

    2013-07-15

    Heteropolyacids (HPAs) can activate methane at ambient temperature (e.g., 20.degree. C.) and atmospheric pressure, and transform methane to acetic acid, in the absence of any noble metal such as Pd). The HPAs can be, for example, those with Keggin structure: H.sub.4SiW.sub.12O.sub.40, H.sub.3PW.sub.12O.sub.40, H.sub.4SiMo.sub.12O.sub.40, or H.sub.3PMo.sub.12O.sub.40, can be when supported on silica.

  5. Measurements of methane emissions from natural gas gathering facilities and processing plants: measurement methods

    Directory of Open Access Journals (Sweden)

    J. R. Roscioli

    2014-12-01

    Full Text Available Increased natural gas production in recent years has spurred intense interest in methane (CH4 emissions associated with its production, gathering, processing, transmission and distribution. Gathering and processing facilities (G&P facilities are unique in that the wide range of gas sources (shale, coal-bed, tight gas, conventional, etc. results in a wide range of gas compositions, which in turn requires an array of technologies to prepare the gas for pipeline transmission and distribution. We present an overview and detailed description of the measurement method and analysis approach used during a 20-week field campaign studying CH4 emissions from the natural gas G&P facilities between October 2013 and April 2014. Dual tracer flux measurements and onsite observations were used to address the magnitude and origins of CH4 emissions from these facilities. The use of a second tracer as an internal standard revealed plume-specific uncertainties in the measured emission rates of 20–47%, depending upon plume classification. Combining downwind methane, ethane (C2H6, carbon monoxide (CO, carbon dioxide (CO2, and tracer gas measurements with onsite tracer gas release allows for quantification of facility emissions, and in some cases a more detailed picture of source locations.

  6. Biogenic and non-biogenic Si pools in terrestrial ecosystems: results from a novel analysis method

    Science.gov (United States)

    Barao, Lucia; Vandevenne, Floor; Clymans, Wim; Meire, Patrick; Frings, Patrick; Conley, Daniel; Struyf, Eric

    2015-04-01

    Silicon (Si) is a chemical element frequently associated with highly abundant silicate minerals in the Earth crust. Over millions of years, the interaction of such minerals with the atmosphere and hydrosphere produces a myriad of processed compounds, and the mineral weathering consumes CO2 during the process. The weathering of minerals also triggers the export of dissolved Si (DSi) to coastal waters and the ocean. Here, DSi is deposited in diatom frustules, in an amorphous biogenic form (BSi). Diatoms account for 50% of the primary production and are crucial for the export of carbon into the deep sea. In recent years, it was acknowledged that terrestrial systems filter the Si transition from the terrestrial mineral to the marine and coastal biological pool, by the incorporation of DSi into plants. In this process, DSi is taken up by roots together with other nutrients and precipitates in plant cells in amorphous structures named phytoliths. After dead, plant tissues become mixed in the top soil, where BSi is available for dissolution and will control the DSi availability in short time scales. Additionally, Si originated from soil forming processes can also significantly interfere with the global cycle. The Si cycle in terrestrial ecosystems is a key factor to coastal ecology, plant ecology, biogeochemistry and agro-sciences, but the high variability of different biogenic and non-biogenic Si pools remains as an obstacle to obtain accurate measurements. The traditional methods, developed to isolate diatoms in ocean sediments, only account for simple mineral corrections. In this dissertation we have adapted a novel continuous analysis method (during alkaline extraction) that uses Si-Al ratios and reactivity to differ biogenic from non-biogenic fractions. The method was originally used in marine sediments, but we have developed it to be applicable in a wide range of terrestrial, aquatic and coastal ecosystems. We first focused on soils under strong human impact in

  7. Latent methane in fossil coals

    Energy Technology Data Exchange (ETDEWEB)

    A.D. Alexeev; E.V. Ulyanova; G.P. Starikov; N.N. Kovriga [Academy of Sciences of Ukraine, Donetsk (Ukraine). Institute for Physics of Mining Processes

    2004-07-01

    It is established experimentally using 1H NMR wide line spectroscopy that methane can exist in coals not only in open or closed porosity and fracture systems but also in solid solutions in coal substance, in particular, under methane pressure 2 MPa or higher. Methane dissolved in coal minerals reversibly modifies their lattice parameters as determined from X-ray diffraction analysis. Co-existence of these methane forms in fossil coals causes multi-step desorption kinetics. It is shown experimentally that the long-term latent methane desorption is effected mainly by closed porosity, which in turn is determined by coal rank. 21 refs., 3 figs., 2 tabs.

  8. Methane - quick fix or tough target? New methods to reduce emissions.

    Science.gov (United States)

    Nisbet, E. G.; Lowry, D.; Fisher, R. E.; Brownlow, R.

    2016-12-01

    Methane is a cost-effective target for greenhouse gas reduction efforts. The UK's MOYA project is designed to improve understanding of the global methane budget and to point to new methods to reduce future emissions. Since 2007, methane has been increasing rapidly: in 2014 and 2015 growth was at rates last seen in the 1980s. Unlike 20thcentury growth, primarily driven by fossil fuel emissions in northern industrial nations, isotopic evidence implies present growth is driven by tropical biogenic sources such as wetlands and agriculture. Discovering why methane is rising is important. Schaefer et al. (Science, 2016) pointed out the potential clash between methane reduction efforts and food needs of a rising, better-fed (physically larger) human population. Our own work suggests tropical wetlands are major drivers of growth, responding to weather changes since 2007, but there is no acceptable way to reduce wetland emission. Just as sea ice decline indicates Arctic warming, methane may be the most obvious tracker of climate change in the wet tropics. Technical advances in instrumentation can do much in helping cut urban and industrial methane emissions. Mobile systems can be mounted on vehicles, while drone sampling can provide a 3D view to locate sources. Urban land planning often means large but different point sources are typically clustered (e.g. landfill or sewage plant near incinerator; gas wells next to cattle). High-precision grab-sample isotopic characterisation, using Keeling plots, can separate source signals, to identify specific emitters, even where they are closely juxtaposed. Our mobile campaigns in the UK, Kuwait, Hong Kong and E. Australia show the importance of major single sources, such as abandoned old wells, pipe leaks, or unregulated landfills. If such point sources can be individually identified, even when clustered, they will allow effective reduction efforts to occur: these can be profitable and/or improve industrial safety, for example in the

  9. Methane emissions from grasslands.

    NARCIS (Netherlands)

    Pol-van Dasselaar, van den A.

    1998-01-01

    IntroductionMethane (CH 4 ) is an important greenhouse gas. The concentration of greenhouse gases in the atmosphere has been increasing since pre-industrial times, mainly due to human activities. This increase gives concern, because it may cause global warming due to an enhanced greenhous

  10. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...

  11. Direct Aromaization of Methane

    Energy Technology Data Exchange (ETDEWEB)

    George Marcelin

    1997-01-15

    The thermal decomposition of methane offers significant potential as a means of producing higher unsaturated and aromatic hydrocarbons when the extent of reaction is limited. Work in the literature previous to this project had shown that cooling the product and reacting gases as the reaction proceeds would significantly reduce or eliminate the formation of solid carbon or heavier (Clo+) materials. This project studied the effect and optimization of the quenching process as a means of increasing the amount of value added products during the pyrolysis of methane. A reactor was designed to rapidly quench the free-radical combustion reaction so as to maximize the yield of aromatics. The use of free-radical generators and catalysts were studied as a means of lowering the reaction temperature. A lower reaction temperature would have the benefits of more rapid quenching as well as a more feasible commercial process