WorldWideScience

Sample records for international coalbed methane

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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).

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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…

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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}.

  15. 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.

  16. 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

  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

    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

  18. 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.

  19. 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

    Sequestration of CO{sub 2} in coal has potential to reduce greenhouse gas emissions from coal-fired power plants while enhancing coalbed methane recovery. Data from more than 4,000 coalbed methane wells in the Black Warrior basin of Alabama provide an opportunity to quantify the carbon sequestration potential of coal and to develop a geologic screening model for the application of carbon sequestration technology. This report summarizes stratigraphy and sedimentation, structural geology, geothermics, hydrology, coal quality, gas capacity, and production characteristics of coal in the Black Warrior coalbed methane fairway and the implications of geology for carbon sequestration and enhanced coalbed methane recovery. Coal in the Black Warrior basin is distributed among several fluvial-deltaic coal zones in the Lower Pennsylvanian Pottsville Formation. Most coal zones contain one to three coal beds that are significant targets for coalbed methane production and carbon sequestration, and net coal thickness generally increases southeastward. Pottsville strata have effectively no matrix permeability to water, so virtually all flow is through natural fractures. Faults and folds influence the abundance and openness of fractures and, hence, the performance of coalbed methane wells. Water chemistry in the Pottsville Formation ranges from fresh to saline, and zones with TDS content lower than 10,000 mg/L can be classified as USDW. An aquifer exemption facilitating enhanced recovery in USDW can be obtained where TDS content is higher than 3,000 mg/L. Carbon dioxide becomes a supercritical fluid above a temperature of 88 F and a pressure of 1,074 psi. Reservoir temperature exceeds 88 F in much of the study area. Hydrostatic pressure gradients range from normal to extremely underpressured. A large area of underpressure is developed around closely spaced longwall coal mines, and areas of natural underpressure are distributed among the coalbed methane fields. The mobility and

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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

  6. 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

  7. 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。

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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。

  14. 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。

  15. 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.

  16. 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。

  17. 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

  18. 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.

  19. 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。

  20. 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.

  1. 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。

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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。

  4. 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.

  5. 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)

  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. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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。

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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。

  13. 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.

  14. 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)

  15. 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.

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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。

  3. 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

  4. 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.

  5. 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。

  6. 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。

  7. 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.

  8. 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。

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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。

  14. 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.

  15. 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.

  16. 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。

  17. 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

  18. 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。

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. Possible evidence for a methane source in Enceladus' internal ocean

    Science.gov (United States)

    Bouquet, Alexis; Mousis, Olivier; Waite, Jack H.; Picaud, Sylvain

    2014-11-01

    We investigated the possible formation of clathrate hydrates (hereafter clathrates) in Enceladus' putative internal ocean. We modeled this ocean as a terrestrial subglacial lake, with an initial composition matching the one of the plumes as determined by the Cassini-INMS mass spectrometer. We used a statistical thermodynamic model based on the description of the guest-clathrate interaction by a spherically averaged Kihara potential with a nominal set of potential parameters. We investigated the behavior of five detected volatile species prone to be trapped into clathrates: CO2, CO, CH4, N2 and H2S. Noble gases (Ar, Kr, Xe) were also considered in order to compare predictions with future measurements. Our calculations considered an ocean extending from 35 to 50 km under the ice layer, at a temperature value of 0°C. We found that the conditions for the formation of clathrates are met in the ocean. The exact structure of these clathrates (structure I or II) is not firmly determined as species known to form both are present.We found that CH4 is very efficiently trapped into clathrate phase and its proportion among dissolved species always falls below plume levels. Additional tests considering different mixtures with more CH4 do not solve this question as the efficiency of the trapping always bring CH4 levels below the expected value. This points to an subsequent dissociation of clathrates or to an additional methane source in the ocean. The fate of the clathrates depends on their density: they can either ascend to the top of the ocean, possibly reaching a region of lower pressure where they dissociate, or sink to the bottom. We found that pressure above a 20km depth would allow for dissociation. The density of the clathrates depends on which structure is formed, but we determined that a proportion of partially-filled clathrate would ascend in all cases. To establish the link with a methane source, a study of the timescale of entrapping and transfer is needed

  4. 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.

  5. 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

  6. 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

  7. 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

  8. 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)...

  9. Variability of internal frontal bore breaking above Opouawe Bank methane seep area (New Zealand)

    NARCIS (Netherlands)

    van Haren, H.; Greinert, J.

    2013-01-01

    Large internal wave breaking is observed exceeding a vertical array of 61 high-resolution temperature sensors at 1 m intervals between 7 and 67 m above the bottom. The array was moored for 5 days at 969 m of Opouawe Bank, New Zealand, a known methane seep area. As breaking internal waves dominate se

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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)

  1. Kinetics of (reversible) internal reforming of methane in solid oxide fuel cells under stationary and APU conditions

    Science.gov (United States)

    Timmermann, H.; Sawady, W.; Reimert, R.; Ivers-Tiffée, E.

    The internal reforming of methane in a solid oxide fuel cell (SOFC) is investigated and modeled for flow conditions relevant to operation. To this end, measurements are performed on anode-supported cells (ASC), thereby varying gas composition (y CO = 4-15%, yH2 = 5 - 17 % , yCO2 = 6 - 18 % , yH2O = 2 - 30 % , yCH4 = 0.1 - 20 %) and temperature (600-850 °C). In this way, operating conditions for both stationary applications (methane-rich pre-reformate) as well as for auxiliary power unit (APU) applications (diesel-POX reformate) are represented. The reforming reaction is monitored in five different positions alongside the anodic gas channel by means of gas chromatography. It is shown that methane is converted in the flow field for methane-rich gas compositions, whereas under operation with diesel reformate the direction of the reaction is reversed for temperatures below 675 °C, i.e. (exothermic) methanation occurs along the anode. Using a reaction model, a rate equation for reforming could be derived which is also valid in the case of methanation. By introducing this equation into the reaction model the methane conversion along a catalytically active Ni-YSZ cermet SOFC anode can be simulated for the operating conditions specified above.

  2. Cooling of a Diesel Reformate Fuelled Solid Oxide Fuel Cell by Internal Reforming of Methane: A Modelling Study

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiaowei; Alexander Kromp

    2013-01-01

    In this paper a system combining a diesel reformer using catalytic partial oxidation (CPOX) with the Solid Oxide Fuel Cell (SOFC) for Auxiliary Power Unit (APU) applications is modeled with respect to the cooling effect provided by internal reforming of methane in anode gas channel.A model mixture consisting of 80% n-hexadecane and 20% 1-methylnaphthalin is used to simulate the commercial diesel.The modelling consists of several steps.First,equilibrium gas composition at the exit of CPOX reformer is modelled in terms oxygen to carbon (O/C) ratio,fuel utilization ratio and anode gas recirculation.Second,product composition,especially methane content,is determined for the methanation process at the operating temperatures ranging from 500 ℃ to 520 ℃.Finally,the cooling power provided by internal reforming of methane in SOFC fuel channel is calculated for two concepts to increase the methane content of the diesel reformate.The results show that the first concept,operating the diesel reformer at low O/C ratio and/or recirculation ratio,is not realizable due to high probability of coke formation,whereas the second concept,combining a methanation process with CPOX,can provide a significant cooling effect in addition to the conventional cooling concept which needs higher levels of excess air.

  3. 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.

  4. 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

  5. 密切值法在煤层气井井型优选中的应用研究%Optimization of Coalbed Methane Well Type Based on Osculating Value Method

    Institute of Scientific and Technical Information of China (English)

    杨刚; 汪志明; 孙波; 陈添

    2013-01-01

    In view of the deficiencies in multi-objective decision methods,the application of osculating value method in CBM well type optimization was investigated. Focusing on the commonly used well types at home and abroad: perforated and fractured vertical well, U-shape horizontal well, V-shape horizontal well,and pinnate horizontal well,Eclipse software was employed to predict CBM production of every well type in this paper. Meanwhile economic evaluation taking five evaluation indexes into comprehensive account :accumulated gas production,net present value,invest recovery period,internal rate of return and risk coefficient in the process of CBM well drilling, was conducted. Osculating value method was used to optimize CBM well types for Yanchuannan Block for the first time. The research results showed that pinnate horizontal well had obvious advantages in developing CBM, with the cumulative production in 15 years of 505. 8 million cubic meters which was higher than other well types;net present value of the pinnate horizontal well was 121 million RMB,which was 5-11 times other well types; investment recovery period was 3. 96 years, which was about 1/3 of other well types; internal rate of return was 0. 28, which was about 2 times of other well types. Osculating value method evaluation results showed that the four well types schemes of this block in the order of descending superiority were pinnate horizontal well, U-shape horizontal well,perforated and fractured vertical well,V-shape horizontal well.%针对目前常用的多目标决策方法多存在缺点的现状,进行了密切值法在煤层气井井型优选中的应用研究.对国内外煤层气井常用的射孔压裂直井、U形水平井、V形水平井和羽状水平井4种井型,以数值模拟为手段,利用Eclipse软件进行了产能预测,并在此基础上进行了经济评价,然后综合考虑累计产气量、净现值、投资回收期、内部收益率和钻井风险系数等5项评价指标,

  6. 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.

  7. International Space Exploration Coordination Group Assessment of Technology Gaps for LOx/Methane Propulsion Systems for the Global Exploration Roadmap

    Science.gov (United States)

    Hurlbert, Eric A.; Whitley, Ryan; Klem, Mark D.; Johnson, Wesley; Alexander, Leslie; D'Aversa, Emanuela; Ruault, Jean-Marc; Manfletti, Chiara; Caruana, Jean-Noel; Ueno, Hiroshi; hide

    2016-01-01

    As part of the Global Exploration Roadmap (GER), the International Space Exploration Coordination Group (ISECG) formed two technology gap assessment teams to evaluate topic discipline areas that had not been worked at an international level to date. The participating agencies were ASI, CNES, DLR, ESA, JAXA, and NASA. Accordingly, the ISECG Technology Working Group (TWG) recommended two discipline areas based on Critical Technology Needs reflected within the GER Technology Development Map (GTDM): Dust Mitigation and LOX/Methane Propulsion. LOx/Methane propulsion systems are enabling for future human missions Mars by significantly reducing the landed mass of the Mars ascent stage through the use of in-situ propellant production, for improving common fluids for life support, power and propulion thus allowing for diverse redundancy, for eliminating the corrosive and toxic propellants thereby improving surface operations and resusabilty, and for inceasing the performance of propulsion systems. The goals and objectives of the international team are to determine the gaps in technology that must be closed for LOx/Methane to be used in human exploration missions in cis-lunar, lunar, and Mars mission applications. An emphasis is placed on near term lunar lander applications with extensibility to Mars. Each agency provided a status of the substantial amount of Lox/Methane propulsion system development to date and their inputs on the gaps in the technology that are remaining. The gaps, which are now opportunities for collaboration, are then discussed.

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. Breeding Ruminants that Emit Less Methane – The Role of International Collaboration

    DEFF Research Database (Denmark)

    Oddy, V H; de Haas, Y; Basarab, J

    production of 40-45%. If a methane-related trait were to be implemented by a livestock industry it will most likely be via genomic breeding values, which demand large numbers of measured animals in the reference population. Given the size of the reference population required for methane traits......, it is imperative that wherever possible groups around the world collaborate on methodologies for measurement and collection of data. This has been the primary focus of the Animal Selection Genetics and Genomics Network (ASGGN) of the Livestock Research Group of the Global Research Alliance to reduce GHG emissions...

  17. 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.

  18. 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.

  19. 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.

  20. Numerical simulation of nanosecond pulsed DBD in lean methane-air mixture for typical conditions in internal engines

    Science.gov (United States)

    Takana, Hidemasa; Nishiyama, Hideya

    2014-06-01

    Detailed two-dimensional numerical simulations of a high energy loading nanosecond dc pulse DBD in a lean methane-air mixture were conducted for plasma-assisted combustion by integrating individual models of plasma chemistry, photoionization and energy loading. The DBD streamer propagation process with radical productions was clarified at 10 atm and 600 K as under the condition of actual internal engines at ignition. Energy is loaded to the streamer first by the formation of plasma channel and then ceased due to the self-shielding effect. Because of the inversed electric field in a discharge space during decrease in applied voltage, energy is loaded to the discharge again. It was found that higher energy is loaded to the DBD streamer for larger dielectric constant even at lower applied voltage, and higher number density of oxygen radical is produced at almost the same radical production efficiency.

  1. 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.

  2. Kinetics of Internal Methane Steam Reforming in Solid Oxide Fuel Cells and Its Influence on Cell Performance– Coupling Experiments and Modeling

    NARCIS (Netherlands)

    Fan, L.; Pourquie, M.J.B.M.; Thattai, A.; Verkooijen, A.H.M.; Aravind, P.V.

    2013-01-01

    Mathematical modeling tools are useful for predicting the safe operation limits and efficiencies of SOFCs. For a particular SOFC design, variations in internal methane reforming kinetic parameters is expected to affect local gas compositions, local Nernst voltages, current densities and temperature

  3. Kinetics of Internal Methane Steam Reforming in Solid Oxide Fuel Cells and Its Influence on Cell Performance– Coupling Experiments and Modeling

    NARCIS (Netherlands)

    Fan, L.; Pourquie, M.J.B.M.; Thattai, A.; Verkooijen, A.H.M.; Aravind, P.V.

    2013-01-01

    Mathematical modeling tools are useful for predicting the safe operation limits and efficiencies of SOFCs. For a particular SOFC design, variations in internal methane reforming kinetic parameters is expected to affect local gas compositions, local Nernst voltages, current densities and temperature

  4. Internal short circuit and accelerated rate calorimetry tests of lithium-ion cells: Considerations for methane-air intrinsic safety and explosion proof/flameproof protection methods

    OpenAIRE

    Dubaniewicz, Thomas H.; DuCarme, Joseph P.

    2016-01-01

    Researchers with the National Institute for Occupational Safety and Health (NIOSH) studied the potential for lithium-ion cell thermal runaway from an internal short circuit in equipment for use in underground coal mines. In this third phase of the study, researchers compared plastic wedge crush-induced internal short circuit tests of selected lithium-ion cells within methane (CH4)-air mixtures with accelerated rate calorimetry tests of similar cells. Plastic wedge crush test results with meta...

  5. 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.

  6. 内燃机内甲烷水蒸气重整特性分析%Characteristic analysis of steam methane reforming reaction in internal combustion engine

    Institute of Scientific and Technical Information of China (English)

    高华光; 龚希武

    2016-01-01

    为了较为系统地认识甲烷水蒸气重整反应对内燃机性能的影响。应用 HSC 5.1软件对甲烷水蒸气重整反应在不同反应温度和水碳比的工况下进行分析,然后应用Chemkin‐pro程序,计算了在相同供热量下甲烷水蒸气重整气在不同物质的量比下比C H4的燃C H4消耗降低率。结果表明,提高反应温度和水碳比可提高C H4的转化率;当温度为700℃、水碳比为3时,发热量提高了13.58%,在供热相同情况下,燃C H4消耗量可减少11.96%,C H4的转化率越高,循环效率越高;重整气效率比纯天然气高,随着物质的量比降低,重整气优势降低。%To obtain a better view on the effect of steam reforming of methane (SRM ) reaction on performance of internal combustion (IC) engine ,by using HSC 5 .1 software ,SRM was analyzed at different temperature and steam/methane molar ratios .Then ,by using Chemkin‐pro software ,fuel consumption reduced rate of methane was calculated in synthesis gas of SRM and methane at different equivalence ratios .The results show that the increase of temperature and steam/methane molar ratios will increase conversion rate of methane .When the temperature is 700 ℃ and steam/methane molar ratio is 3 under the same heating conditions ,heat value will increase 13 .58% ,fuel consumption will decrease 11 .96% ,and cycle efficiency of IC engine will increase with the increase of conversion rate of methane .Efficiency of synthesis gas of SRM is higher than pure methane ,unfortunately ,decreases with the decrease of the equivalent ratio .

  7. 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

  8. 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.

  9. 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.

  10. Biochemical methane potential (BMP) of solid organic substrates: evaluation of anaerobic biodegradability using data from an international interlaboratory study

    NARCIS (Netherlands)

    Raposo, F.; Fernandez-Cegri, V.; Rubia, de la M.A.; Borja, R.; Beline, F.; Cavinato, C.; Demirer, G.; Fernandez, B.; Fernandez-Polanco, M.; Frigon, J.C.; Ganesh, R.; Kaparaju, P.; Koubova, J.; Mendez, R.; Menin, G.; Peene, A.; Scherer, P.; Torrijos, M.; Uellendahl, H.; Wierinck, I.; Wilde, de V.

    2011-01-01

    BACKGROUND: This paper describes results obtained for different participating research groups in an interlaboratory study related to biochemical methane potential (BMP). In this research work, all experimental conditions influencing the test such as inoculum, substrate characteristics and

  11. Biochemical methane potential (BMP) of solid organic substrates: evaluation of anaerobic biodegradability using data from an international interlaboratory study

    NARCIS (Netherlands)

    Raposo, F.; Fernandez-Cegri, V.; Rubia, de la M.A.; Borja, R.; Beline, F.; Cavinato, C.; Demirer, G.; Fernandez, B.; Fernandez-Polanco, M.; Frigon, J.C.; Ganesh, R.; Kaparaju, P.; Koubova, J.; Mendez, R.; Menin, G.; Peene, A.; Scherer, P.; Torrijos, M.; Uellendahl, H.; Wierinck, I.; Wilde, de V.

    2011-01-01

    BACKGROUND: This paper describes results obtained for different participating research groups in an interlaboratory study related to biochemical methane potential (BMP). In this research work, all experimental conditions influencing the test such as inoculum, substrate characteristics and experiment

  12. 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

  13. 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

  14. 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

  15. Influence of the set anode potential on the performance and internal energy losses of a methane-producing microbial electrolysis cell.

    Science.gov (United States)

    Villano, Marianna; Ralo, Cláudia; Zeppilli, Marco; Aulenta, Federico; Majone, Mauro

    2016-02-01

    The effect of the set anode potential (between + 200 mV and - 200 mV vs. SHE, standard hydrogen electrode) on the performance and distribution of internal potential losses has been analyzed in a continuous-flow methane-producing microbial electrolysis cell (MEC).Both acetate removal rate (at the anode) and methane generation rate (at the cathode) were higher (1 gCOD/L day and 0.30 m(3)/m(3) day, respectively) when the anode potential was controlled at + 200 mV. However, both the yields of acetate conversion into current and current conversion into methane were very high (72-90%) under all the tested conditions. Moreover, the sum of internal potential losses decreased from 1.46 V to 0.69 V as the anode potential was decreased from + 200 mV to - 200 mV, with cathode overpotentials always representing the main potential losses. This was likely to be due to the high energy barrier which has to be overcome in order to activate the cathode reaction. Finally, the energy efficiency correspondingly increased reaching 120% when the anode was controlled at - 200 mV.

  16. 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.

  17. 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.

  18. The AMINO experiment: methane photolysis under Solar VUV irradiation on the EXPOSE-R facility of the International Space Station

    Science.gov (United States)

    Carrasco, Nathalie; Cottin, Hervé; Cloix, Mégane; Jérome, Murielle; Bénilan, Yves; Coll, Patrice; Gazeau, Marie-Claire; Raulin, François; Saiagh, Kafila; Chaput, Didier

    2015-01-01

    The scientific aim of the present campaign is to study the whole chain of methane photo-degradation, as initiated by Solar vacuum-ultraviolet irradiation in Titan's atmosphere. For this purpose, the AMINO experiment on the EXPOSE-R mission has loaded closed cells for gas-phase photochemistry in space conditions. Two different gas mixtures have been exposed, named Titan 1 and Titan 2, involving both N2-CH4 gas mixtures, without and with CO2, respectively. CO2 is added as a source of reactive oxygen in the cells. The cell contents were analysed thanks to infrared absorption spectroscopy, gas chromatography and mass spectrometry. Methane consumption leads to the formation of saturated hydrocarbons, with no detectable influence of CO2. This successful campaign provides a first benchmark for characterizing the whole methane photochemical system in space conditions. A thin film of tholin-like compounds appears to form on the cell walls of the exposed cells.

  19. Investigation of Spark Ignition and Autoignition in Methane and Air Using Computational Fluid Dynamics and Chemical Reaction Kinetics. A numerical Study of Ignition Processes in Internal Combustion Engines

    Energy Technology Data Exchange (ETDEWEB)

    Nordrik, R.

    1993-12-01

    The processes in the combustion chamber of internal combustion engines have received increased attention in recent years because their efficiencies are important both economically and environmentally. This doctoral thesis studies the ignition phenomena by means of numerical simulation methods. The fundamental physical relations include flow field conservation equations, thermodynamics, chemical reaction kinetics, transport properties and spark modelling. Special attention is given to the inclusion of chemical kinetics in the flow field equations. Using his No Transport of Radicals Concept method, the author reduces the computational efforts by neglecting the transport of selected intermediate species. The method is validated by comparison with flame propagation data. A computational method is described and used to simulate spark ignition in laminar premixed methane-air mixtures and the autoignition process of a methane bubble surrounded by hot air. The spark ignition simulation agrees well with experimental results from the literature. The autoignition simulation identifies the importance of diffusive and chemical processes acting together. The ignition delay times exceed the experimental values found in the literature for premixed ignition delay, presumably because of the mixing process and lack of information on low temperature reactions in the skeletal kinetic mechanism. Transient turbulent methane jet autoignition is simulated by means of the KIVA-II code. Turbulent combustion is modelled by the Eddy Dissipation Concept. 90 refs., 81 figs., 3 tabs.

  20. 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.

  1. 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.

  2. 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.

  3. 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...

  4. International Methane Hydrate Research and Development Workshop (6th) held in Bergen, Norway on May 13-15, 2008

    Science.gov (United States)

    2009-07-22

    Hydrae in Changing Environments. …………………………………………………………………. 73 3. J. Brugada and K. Soga. Geomechanical Study of Methane Hydrate Soil... geomechanic sediment properties, biogeochemical influence on hydrate formation and stability, and sediment thermodynamics. 5. Theoretical modeling needs...further development in rock physics flow simulations, geomechanical sediment properties, and environmental system cycling. 6. Production testing

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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,

  12. Internal reforming over nickel/zirconia anodes in SOFCS operating on methane: influence of anode formulation, pre-treatment and operating conditions

    Energy Technology Data Exchange (ETDEWEB)

    Finnerty, C.M.; Ormerod, R.M. [Birchall Centre of Inorganic Chemistry and Materials Science, Department of Chemistry, Keele Univ. (United Kingdom)

    2000-03-01

    Internal methane reforming over nickel/zirconia cermet anodes has been studied in detail using a thin-walled extruded zirconia tubular SOFC reactor. The influence of anode formulation, anode pre-treatment, operating temperature and methane/steam ratio on the reforming characteristics, resistance to carbon deposition and durability of the anode have been investigated under actual operating conditions. Post-reaction TPO has been used to determine the amount of carbon deposition and its strength of interaction with the anode. A 90-vol.% nickel/zirconia anode shows higher activity than a 50-vol.% Ni anode at higher reforming temperatures, and shows very good durability. Pre-reducing the anodes in H{sub 2} at 1173 K leads to a more active reforming catalyst. Carbon is removed from the anodes in two processes during TPO, suggesting two types of carbon species. As the reforming temperature increases both carbon types are removed at higher temperature, and there is an increase in the relative population of the more strongly bound form of carbon. (orig.)

  13. Methane emission from wetland rice fields.

    OpenAIRE

    H.A.C. Denier van der Gon

    1996-01-01

    Methane (CH 4 ) is an important greenhouse gas and plays a key role in tropospheric and stratospheric chemistry. Wetland rice fields are an important source of methane, accounting for approximately 20% of the global anthropogenic methane emission. Methane fluxes from wetland rice fields in the Philippines were monitored with a closed chamber technique in close cooperation with the International Rice Research Institute (IRRI). The field studies were complemented by laboratory and greenhouse ex...

  14. Internal short circuit and accelerated rate calorimetry tests of lithium-ion cells: Considerations for methane-air intrinsic safety and explosion proof/flameproof protection methods.

    Science.gov (United States)

    Dubaniewicz, Thomas H; DuCarme, Joseph P

    2016-09-01

    Researchers with the National Institute for Occupational Safety and Health (NIOSH) studied the potential for lithium-ion cell thermal runaway from an internal short circuit in equipment for use in underground coal mines. In this third phase of the study, researchers compared plastic wedge crush-induced internal short circuit tests of selected lithium-ion cells within methane (CH4)-air mixtures with accelerated rate calorimetry tests of similar cells. Plastic wedge crush test results with metal oxide lithium-ion cells extracted from intrinsically safe evaluated equipment were mixed, with one cell model igniting the chamber atmosphere while another cell model did not. The two cells models exhibited different internal short circuit behaviors. A lithium iron phosphate (LiFePO4) cell model was tolerant to crush-induced internal short circuits within CH4-air, tested under manufacturer recommended charging conditions. Accelerating rate calorimetry tests with similar cells within a nitrogen purged 353-mL chamber produced ignitions that exceeded explosion proof and flameproof enclosure minimum internal pressure design criteria. Ignition pressures within a 20-L chamber with 6.5% CH4-air were relatively low, with much larger head space volume and less adiabatic test conditions. The literature indicates that sizeable lithium thionyl chloride (LiSOCl2) primary (non rechargeable) cell ignitions can be especially violent and toxic. Because ignition of an explosive atmosphere is expected within explosion proof or flameproof enclosures, there is a need to consider the potential for an internal explosive atmosphere ignition in combination with a lithium or lithium-ion battery thermal runaway process, and the resulting effects on the enclosure.

  15. 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.

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. International Space Exploration Coordination Group Assessment of Technology Gaps for LOx/Methane Propulsion Systems for the Global Exploration Roadmap

    OpenAIRE

    Hurlbert, Eric A.; Manfletti, Chiara; Sippel, Martin

    2016-01-01

    As part of the Global Exploration Roadmap (GER), the International Space Exploration Coordination Group (ISECG) formed two technology gap assessment teams to evaluate topic discipline areas that had not been worked at an international level to date. The participating agencies were ASI, CNES, DLR, ESA, JAXA, and NASA. Accordingly, the ISECG Technology Working Group (TWG) recommended two discipline areas based on Critical Technology Needs reflected within the GER Technology Development Map (GTD...

  12. 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.

  13. 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.

  14. Further study of the intrinsic safety of internally shorted lithium and lithium-ion cells within methane-air.

    Science.gov (United States)

    Dubaniewicz, Thomas H; DuCarme, Joseph P

    2014-11-01

    National Institute for Occupational Safety and Health (NIOSH) researchers continue to study the potential for lithium and lithium-ion battery thermal runaway from an internal short circuit in equipment for use in underground coal mines. Researchers conducted cell crush tests using a plastic wedge within a 20-L explosion-containment chamber filled with 6.5% CH4-air to simulate the mining hazard. The present work extends earlier findings to include a study of LiFePO4 cells crushed while under charge, prismatic form factor LiCoO2 cells, primary spiral-wound constructed LiMnO2 cells, and crush speed influence on thermal runaway susceptibility. The plastic wedge crush was a more severe test than the flat plate crush with a prismatic format cell. Test results indicate that prismatic Saft MP 174565 LiCoO2 and primary spiral-wound Saft FRIWO M52EX LiMnO2 cells pose a CH4-air ignition hazard from internal short circuit. Under specified test conditions, A123 systems ANR26650M1A LiFePO4 cylindrical cells produced no chamber ignitions while under a charge of up to 5 A. Common spiral-wound cell separators are too thin to meet intrinsic safety standards provisions for distance through solid insulation, suggesting that a hard internal short circuit within these cells should be considered for intrinsic safety evaluation purposes, even as a non-countable fault. Observed flames from a LiMnO2 spiral-wound cell after a chamber ignition within an inert atmosphere indicate a sustained exothermic reaction within the cell. The influence of crush speed on ignitions under specified test conditions was not statistically significant.

  15. Further study of the intrinsic safety of internally shorted lithium and lithium-ion cells within methane-air

    OpenAIRE

    Dubaniewicz, Thomas H.; DuCarme, Joseph P.

    2014-01-01

    National Institute for Occupational Safety and Health (NIOSH) researchers continue to study the potential for lithium and lithium-ion battery thermal runaway from an internal short circuit in equipment for use in underground coal mines. Researchers conducted cell crush tests using a plastic wedge within a 20-L explosion-containment chamber filled with 6.5% CH4-air to simulate the mining hazard. The present work extends earlier findings to include a study of LiFePO4 cells crushed while under c...

  16. 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.

  17. 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.

  18. Additive effect of Ce, Mo and K to nickel-cobalt aluminate supported solid oxide fuel cell for direct internal reforming of methane

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Bu Ho; Park, Jungdeok; Yoon, Heechul; Kim, Hyeon Hui; Kim, Lim; Chung, Jong Shik [POSTECH, Pohang (Korea, Republic of)

    2014-01-15

    Direct internal reforming of methane (steam/carbon=0.031, 850 .deg. C) is tested using button cells of Ni-YSZ/YSZ/LSM in which the anode layer is supported either on Ni-YSZ or on Ni-CoAl{sub 2}O{sub 4}. The Ni-CoAl{sub 2}O{sub 4} supported cell shows little degradation with operating time, as a result of higher resistance against carbon deposition, whereas the Ni-YSZ supported cell deactivates quickly and suffers fracture in 50 h. Upon incorporation of additives such as K, Ce, or Mo into the Ni-CoAl{sub 2}O{sub 4} support, cells with 0.5 wt% CeO{sub 2} exhibit the best stable performance as a result of reduced coke formation. Cells with 0.5 wt% Mo exhibit the lowest performance. Although no carbon deposit is detected in the cells with K{sub 2}CO{sub 3} additives, their performance is worse than that in the CeO{sub 2} case, and, in constant-current mode, there is a sudden voltage drop to zero after a certain period of time; this time becomes shorter with increasing K content. The injection of potassium into the anode side facilitates the generation of OH{sup -} and CO{sub 3}{sup 2-} in the anode and promotes the diffusion of these ions to the cathode. Increased polarization resistance at the cathode and increased electrolyte resistance result in such a sudden failure.

  19. Methane clathrates in the solar system.

    Science.gov (United States)

    Mousis, Olivier; Chassefière, Eric; Holm, Nils G; Bouquet, Alexis; Waite, Jack Hunter; Geppert, Wolf Dietrich; Picaud, Sylvain; Aikawa, Yuri; Ali-Dib, Mohamad; Charlou, Jean-Luc; Rousselot, Philippe

    2015-04-01

    We review the reservoirs of methane clathrates that may exist in the different bodies of the Solar System. Methane was formed in the interstellar medium prior to having been embedded in the protosolar nebula gas phase. This molecule was subsequently trapped in clathrates that formed from crystalline water ice during the cooling of the disk and incorporated in this form into the building blocks of comets, icy bodies, and giant planets. Methane clathrates may play an important role in the evolution of planetary atmospheres. On Earth, the production of methane in clathrates is essentially biological, and these compounds are mostly found in permafrost regions or in the sediments of continental shelves. On Mars, methane would more likely derive from hydrothermal reactions with olivine-rich material. If they do exist, martian methane clathrates would be stable only at depth in the cryosphere and sporadically release some methane into the atmosphere via mechanisms that remain to be determined. In the case of Titan, most of its methane probably originates from the protosolar nebula, where it would have been trapped in the clathrates agglomerated by the satellite's building blocks. Methane clathrates are still believed to play an important role in the present state of Titan. Their presence is invoked in the satellite's subsurface as a means of replenishing its atmosphere with methane via outgassing episodes. The internal oceans of Enceladus and Europa also provide appropriate thermodynamic conditions that allow formation of methane clathrates. In turn, these clathrates might influence the composition of these liquid reservoirs. Finally, comets and Kuiper Belt Objects might have formed from the agglomeration of clathrates and pure ices in the nebula. The methane observed in comets would then result from the destabilization of clathrate layers in the nuclei concurrent with their approach to perihelion. Thermodynamic equilibrium calculations show that methane-rich clathrate

  20. A New Energy Source

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Foreign energy companies are flocking to China to participate in the development of a potentially meaningful new energy source, coalbed methane, which is found in coal deposits. China United Coalbed Methane Co. Ltd. signed a contract with U.S.-based Orion Energy International Inc. on April 5 to jointly exploit the resource in the Sanjiao region of coal-rich Shanxi Province. Covering an area of some 462 square km, Sanjiao is home to rich coalbed methane reserves with thick, multi-level coalbeds that have ...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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)

  11. Handbook methane potential; Handbok metanpotential

    Energy Technology Data Exchange (ETDEWEB)

    Carlsson, My (AnoxKaldnes AB (Sweden)); Schnurer, Anna (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden))

    2011-07-15

    Before using a organic material for biogas production it is essential to evaluate the methane production potential. The methane potential is one important tool possible to use during planning of new plants but also when new materials are considered for already running biogas plants. The chemical composition of different organic material varies extensively and this will have an impact on both the degradability and the methane potential. Information about the methane potential of a specific material can sometimes be found in the literature or can be calculated after a chemical/ physical or biological characterization. Here, the BMP test (Biochemical Methane Potential) is a commonly used method. Today the BMP test is a commonly used method to determine the methane potential. Many national and international research groups, consultants as well as personal at biogas plants are using this method and there is a lot of data available in the literature from such tests. In addition there are several protocols giving guidelines on how to execute a BMP-test. The BMP-test is performed in many different ways, not always under optimized conditions, and there is a lack of information on how to interpret the obtained data. This report summarizes knowledge from the literature and the experience from a Swedish referee group, consisting of persons being active performers of BMP-tests. The report does not include a standardized protocol as the procedure can be performed in different ways depending on available equipment and on the type of material to be tested. Instead the report discusses different factors of great importance for a successful test giving reliable results. The report also summarizes important information concerning the interpretation and how to present results in order to allow comparison of data from different test.

  12. 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.

  13. Methane hydrates in nature - Current knowledge and challenges

    Science.gov (United States)

    Collett, Timothy S.

    2014-01-01

    Recognizing the importance of methane hydrate research and the need for a coordinated effort, the United States Congress enacted the Methane Hydrate Research and Development Act of 2000. At the same time, the Ministry of International Trade and Industry in Japan launched a research program to develop plans for a methane hydrate exploratory drilling project in the Nankai Trough. India, China, the Republic of Korea, and other nations also have established large methane hydrate research and development programs. Government-funded scientific research drilling expeditions and production test studies have provided a wealth of information on the occurrence of methane hydrates in nature. Numerous studies have shown that the amount of gas stored as methane hydrates in the world may exceed the volume of known organic carbon sources. However, methane hydrates represent both a scientific and technical challenge, and much remains to be learned about their characteristics and occurrence in nature. Methane hydrate research in recent years has mostly focused on: (1) documenting the geologic parameters that control the occurrence and stability of methane hydrates in nature, (2) assessing the volume of natural gas stored within various methane hydrate accumulations, (3) analyzing the production response and characteristics of methane hydrates, (4) identifying and predicting natural and induced environmental and climate impacts of natural methane hydrates, (5) analyzing the methane hydrate role as a geohazard, (6) establishing the means to detect and characterize methane hydrate accumulations using geologic and geophysical data, and (7) establishing the thermodynamic phase equilibrium properties of methane hydrates as a function of temperature, pressure, and gas composition. The U.S. Department of Energy (DOE) and the Consortium for Ocean Leadership (COL) combined their efforts in 2012 to assess the contributions that scientific drilling has made and could continue to make to advance

  14. 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.

  15. 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

  16. 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...

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. Methane, a greenhouse gas: measures to reduce and valorize anthropogenic emissions; Le methane, un gaz a effet de serre: mesures de reduction et de valorisation des emissions anthropiques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-03-15

    This report first presents the greenhouse effect properties of methane (one of the six gases the emissions of which must be reduced according to the Kyoto protocol), comments the available data on methane emission assessment in the World, in Europe and in France, and outlines the possibilities of improvement of data and indicators on a short and middle term. It describes how methane can be captured and valorized, indicates the concerned quantities. Notably, it discussed the management of methane generating and spreading practices (from waste water treatment, from domestic wastes), how to reduce methane emissions in agriculture. It finally proposes elements aimed at elaborating a national and international policy regarding methane emission reductions

  2. 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.

  3. 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。

  4. 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

  5. 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

  6. 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.

  7. 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 .

  8. Methane recovery from landfill in China

    Energy Technology Data Exchange (ETDEWEB)

    Gaolai, L.

    1996-12-31

    GEF has approved a special project for a demonstration project for Methane Recovery from the Urban Refuse Land Fill. This paper will introduce the possibility of GHG reduction from the landfill in China, describe the activities of the GEF project, and the priorities for international cooperation in this field. The Global Environment Facility (GEF) approved the project, China Promoting Methane Recovery and Unlization from Mixed Municipal Refuse, at its Council meeting in last April. This project is the first one supported by international organization in this field.

  9. The implementation of artificial neural networks to model methane oxidation in landfill soil covers[Includes the CSCE forum on professional practice and career development : 1. international engineering mechanics and materials specialty conference : 1. international/3. coastal, estuarine and offshore engineering specialty conference : 2. international/8. construction specialty conference

    Energy Technology Data Exchange (ETDEWEB)

    Szeto, A.; Albanna, M.; Warith, M. [Ottawa Univ., ON (Canada). Faculty of Civil and Environmental Engineering

    2009-07-01

    The disposal of solid waste significantly contributes to the total anthropogenic emissions of methane (CH{sub 4}), a greenhouse gas that negatively affects climate change. The oxidation of methane in landfill bio-covers takes place through the use of methanotrophic bacteria which provides a sink for methane. The rate at which methane is biologically oxidized depends on several parameters. This study provided a better understanding of the oxidation of methane in landfill soil covers through modeling methane oxidation with artificial neural networks (ANNs). An ANN was trained and tested to model methane oxidation in various batch scale systems for 3 types of soils. Input data consisted of temperature, moisture content, soil composition and the nutrient content added to the system. Model results were in good agreement with experimental results reported by other researchers. It was concluded that the use of ANNs to model methane oxidation in batch scale bio-covers can address the large number of complicated physical and biochemical processes that occur within the landfill bio-cover. 10 refs., 7 tabs., 5 figs.

  10. 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.

  11. Mass balance inverse modelling of methane in the 1990s using a Chemistry Transport Model

    OpenAIRE

    T. M. Butler; Simmonds, I.; Rayner, P. J.

    2004-01-01

    International audience; A mass balance inverse modelling procedure is applied with a time-dependent methane concentration boundary condition and a chemical transport model to relate observed changes in the surface distribution of methane mixing ratios during the 1990s to changes in its surface sources. The model reproduces essential features of the global methane cycle, such as the latitudinal distribution and seasonal cycle of fluxes, without using a priori knowledge of methane fluxes. A det...

  12. 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.

  13. 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.

  14. Global Methane Biogeochemistry

    Science.gov (United States)

    Reeburgh, W. S.

    2003-12-01

    . Methane absorbs infrared radiation in the troposphere, as do CO2 and H2O, and is an important greenhouse gas (Lacis et al., 1981; Ramanathan et al., 1985).A number of review articles on atmospheric CH4 have appeared during the last 15 years. Cicerone and Oremland (1988) reviewed evidence for the temporal atmospheric increase, updated source estimates in the global CH4 budget, and placed constraints on the global budget, emphasizing that the total is well constrained, but that the constituent sources may be uncertain by a factor of 2 or more. This paper was part of a special section in Global Biogeochemical Cycles that resulted from a 1987 American Chemical Society Symposium, "Atmospheric Methane: Formation and Fluxes form the Biosphere and Geosphere." Tyler (1991) and Wahlen (1993) emphasized new information on stable isotopes of CH4 and 14CH4, respectively. Several reviews deal with the microbially mediated CH4 oxidation. King (1992) reviewed the ecology of microbial CH4 oxidation, emphasizing the important role of this process in global CH4 dynamics. R. S. Hanson and T. E. Hanson (1996) reviewed the physiology and taxonomy of methylotrophic bacteria, their role in the global carbon cycle, and the ecology of methanotrophic bacteria. Conrad (1996) reviewed the role of soils and soil microbial communities as controllers of CH4 fluxes, as well as those of H2, CO, OCS, N2O, and NO. Two meetings focusing on CH4 biogeochemistry were held in 1991: an NATO Advanced Science Workshop held at Mt. Hood, OR, and the Tenth International Symposium on Environmental Biogeochemistry (ISEB). A dedicated issue of Chemosphere (26(1-4), 1993) contains contributions from the NATO workshop; two additional volumes (Khalil, 1993 and Khalil, 2000) contain a report of the workshop and updates of important topics. Contributions to the ISEB meeting are presented in Oremland (1993). Wuebbles and Hayhoe (2002) reviewed the effects of CH4 on atmospheric chemistry and examined the direct and indirect

  15. 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

  16. 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

  17. 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 ...

  18. 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.

  19. 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.

  20. 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

  1. Multiparametric methane sensor for environmental monitoring

    Science.gov (United States)

    Borecki, M.; Duk, M.; Kociubiński, A.; Korwin-Pawlowski, M. L.

    2016-12-01

    Today, methane sensors find applications mostly in safety alarm installations, gas parameters detection and air pollution classification. Such sensors and sensors elements exists for industry and home use. Under development area of methane sensors application is dedicated to ground gases monitoring. Proper monitoring of soil gases requires reliable and maintenance-free semi-constant and longtime examination at relatively low cost of equipment. The sensors for soil monitoring have to work on soil probe. Therefore, sensor is exposed to environment conditions, as a wide range of temperatures and a full scale of humidity changes, as well as rain, snow and wind, that are not specified for classical methane sensors. Development of such sensor is presented in this paper. The presented sensor construction consists of five commercial non dispersive infra-red (NDIR) methane sensing units, a set of temperature and humidity sensing units, a gas chamber equipped with a micro-fan, automated gas valves and also a microcontroller that controls the measuring procedure. The electronics part of sensor was installed into customized 3D printed housing equipped with self-developed gas valves. The main development of proposed sensor is on the side of experimental evaluation of construction reliability and results of data processing included safety procedures and function for hardware error correction. Redundant methane sensor units are used providing measurement error correction as well as improved measurement accuracy. The humidity and temperature sensors are used for internal compensation of methane measurements as well as for cutting-off the sensor from the environment when the conditions exceed allowable parameters. Results obtained during environment sensing prove that the gas concentration readings are not sensitive to gas chamber vertical or horizontal position. It is important as vertical sensor installation on soil probe is simpler that horizontal one. Data acquired during six

  2. Use of chloroflurocarbons as internal standards for the measurement of atmospheric non-methane volatile organic compounds sampled onto solid adsorbent cartridges.

    Science.gov (United States)

    Karbiwnyk, Christine M; Mills, Craig S; Helmig, Detlev; Birks, John W

    2003-03-01

    Solid adsorbents have proven useful for determining the vertical profiles of volatile organic compounds (VOCs) using sampling platforms such as balloons, kites, and light aircraft, and those profiles provide valuable information about the sources, sinks, transformations, and transport of atmospheric VOCs. One of the largest contributions to error in VOC concentrations is the estimation of the volume of air sampled on the adsorbent cartridge. These errors arise from different sources, such as variations in pumping flow rates from changes in ambient temperature and pressure with altitude, and decrease in the sampling pump battery power. Another significant source for sampling rate variations are differences in the flow resistance of individual sampling cartridges. To improve the accuracy and precision of VOC measurements, the use of ambient chlorofluorocarbons (CFCs) as internal standards was investigated. A multibed solid adsorbent, AirToxic (Supelco), was chosen for its wide sampling range (C3-C12). Analysis was accomplished by thermal desorption and dual detection GC/FID/ECD, resulting in sensitive and selective detection of both VOCs and CFCs in the same sample. Long-lived chlorinated compounds (CFC-11, CFC-12, CFC-113, CCl4 and CH3CCl3) banned by the Montreal Protocol and subsequent amendments were studied for their ability to predict sample volumes using both ground-based and vertical profiling platforms through the boundary layer and free troposphere. Of these compounds, CFC-113 and CCl4 were found to yield the greatest accuracy and precision for sampling volume determination. Use of ambient CFC-113 and CCl4 as internal standards resulted in accuracy and precision of generally better than 10% for the prediction of sample volumes in ground-, balloon-, and aircraft-based measurements. Consequently, use of CFCs as reference compounds can yield a significant improvement of accuracy and precision for ambient VOC measurements in situations where accurate flow

  3. 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)

  4. 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....

  5. 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}.

  6. 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.

  7. Methane Hydrate Field Program: Development of a Scientific Plan for a Methane Hydrate‐Focused Marine Drilling, Logging and Coring Program

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-02-01

    This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report: Historical Methane Hydrate Project Review Report; Methane Hydrate Workshop Report; Topical Report: Marine Methane Hydrate Field Research Plan; and Final Scientific/Technical Report

  8. Methane Hydrate Field Program: Development of a Scientific Plan for a Methane Hydrate-Focused Marine Drilling, Logging and Coring Program

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2014-02-01

    This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report: Historical Methane Hydrate Project Review Report; Methane Hydrate Workshop Report; Topical Report: Marine Methane Hydrate Field Research Plan; and Final Scientific/Technical Report.

  9. 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.

  10. 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.

  11. 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

  12. Methane recovery from animal manures: A current opportunities casebook

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This Casebook examines some of the current opportunities for the recovery of methane from the anaerobic digestion of animal manures US livestock operations currently employ four types of anaerobic digester technology: Slurry, plug flow, complete mix, and covered lagoon. An introduction to the engineering economies of these technologies is provided, and possible end-use applications for the methane gas generated by the digestion process are discussed. The economic evaluations are based on engineering studies of digesters that generate electricity from the recovered methane. Regression models, which can be used to estimate digester cost and internal rate of return, are developed from the evaluations.

  13. 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...

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. 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...

  19. 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 due to savings realized in energy and material of construction costs. It was the goal of the project to identify promising routes from methane to higher hydrocarbons based on the pyrolysis of methane.

  20. Another Source of Atmospheric Methane

    Institute of Scientific and Technical Information of China (English)

    于心科

    1997-01-01

    The atmospheric concentration of methane is steadily increasin.Lacking of precise estimates of source and sink strengths for the atmospheric methane severely limits the current understanding of the global methane cycle.Agood budget of atmospheric methane can enhance our understanding of the global carbon cycle and global climate change,The known estimates of the main source and sink strengths are gresented in this paper,In terms of carbon isotopic studies,it is evidenced that the earth's primodial methane,which was trapped in the earth during its formation,may be another source of methane,with extensive,earth's degassing which is calleld the "breathing" process of the earth and played an important role in the formation of the promitive atmosphere,large amounts of methane were carried from the deep interior to the surface and then found its way into the atmosphere.

  1. Methane capture from livestock manure.

    Science.gov (United States)

    Tauseef, S M; Premalatha, M; Abbasi, Tasneem; Abbasi, S A

    2013-03-15

    It has been estimated that livestock manure contributes about 240 million metric tons of carbon dioxide equivalent of methane to the atmosphere and represents one of the biggest anthropogenic sources of methane. Considering that methane is the second biggest contributor to global warming after carbon dioxide, it is imperative that ways and means are developed to capture as much of the anthropogenic methane as possible. There is a major associated advantage of methane capture: its use as a source of energy which is comparable in 'cleanness' to natural gas. The present review dwells upon the traditional ways of methane capture used in India, China, and other developing countries for providing energy to the rural poor. It then reviews the present status of methane capture from livestock manure in developed countries and touches upon the prevalent trends.

  2. The co-oxidation of methane and dichloromethane in landfill bio-cover[Includes the CSCE forum on professional practice and career development : 1. international engineering mechanics and materials specialty conference : 1. international/3. coastal, estuarine and offshore engineering specialty conference : 2. international/8. construction specialty conference

    Energy Technology Data Exchange (ETDEWEB)

    Dagher, E.; Albanna, M.; Fernandes, L.; Warith, M. [Ottawa Univ., ON (Canada). Faculty of Engineering

    2009-07-01

    Solid waste landfills are responsible for 13 per cent of the annual global anthropogenic methane (CH{sub 4}) emissions. Landfill bio-cover systems using methanotrophic bacteria to oxidize CH{sub 4} to carbon dioxide (CO{sub 2}) and water (H{sub 2}O) is a cost effective solution for the attenuation of these fugitive greenhouse gases (GHGs). This study analyzed the affect of dichloromethane (DCM), a volatile organic compound (VOC), on the rate of methane oxidation at several environmental conditions. Compost from Trail Road, a municipal landfill in Ottawa, was used in batch experiments. Gas chromatography was used to measure the concentrations of CH{sub 4} in the absence of DCM, and under varying DCM concentrations and atmospheric temperatures. The oxidation of DCM by the methanotrophs in the presence as well as absence of CH{sub 4} was also observed, and their oxidation rates determined. The study showed that the presence of DCM plays a very significant role on the oxidative capacity of CH{sub 4} under closed conditions on a laboratory scale. The study also showed that it will be important to restrict the type of waste that can be dumped in landfills. Controlling the industrial waste of non-methane organic carbon (NMOC) dumped into municipal landfills is crucial if CH{sub 4} is to be oxidized by a bio-cover. 15 refs., 4 figs.

  3. Methane emission from rice: Stable isotopes, diurnal variations, and CO2 exchange

    Science.gov (United States)

    Chanton, J. P.; Whiting, G. J.; Blair, N. E.; Lindau, C. W.; Bollich, P. K.

    1997-03-01

    The importance of vegetation in supporting methane production and emission within flooded rice fields was demonstrated. Methane emission from Lousiana, United States, rice fields was correlated to the quantity of live aboveground biomass and the rate of CO2 exchange. The quantity of belowground methane was greater in vegetated plots relative to plots maintained free of vegetation. The diurnal maximum in the rate of methane emission was coincident with the release of the most 13C-enriched methane and a maximum in transpiration rate rather than stomatal conductance, suggesting that diurnal variations in methane emission rate are linked with transpiration, in addition to temperature. Results of isotopic measurements of belowground, lacunal, and emitted methane indicate that methane is transported from rice predominantly via molecular diffusion with a small component due to transpiration-induced bulk flow. Samples of methane collected from air-filled internal spaces within the rice culm were 13C-enriched (-53.1 ± 0.3‰) relative to emitted (-64.5 ± 1.0‰) and belowground methane (-59 ± 1.0‰) . Reproduction of these observed 13C values with a numerical model required isotopic fractionation effects associated with transport of methane into and from rice plants. The model could not conclusively confirm rhizospheric methane oxidation. However, 13C-enriched methane was observed in the floodwater overlying the flooded soil (-44.4 ± 2.2‰), consistent with the oxidation of substantial quantities of methane as it diffused across the soil-water interface.

  4. Retention and excretion of inhaled 3H and 14C radiolabeled methane in rats.

    Science.gov (United States)

    Didychuk, C; Burchart, P A; Carlisle, S M; Richardson, R B

    2014-07-01

    A radiological concern for workers at heavy water reactor nuclear facilities is the hazard presented by tritium (H) and C. Radioactive methane is one of many potential H and C containing chemicals to which Nuclear Energy Workers (NEWs) may be exposed. Current dosimetric models for H- and C-methane, recommended by the International Commission on Radiological Protection (ICRP), are based on the assumption that 1% of methane is absorbed following its inhalation. Of this 1%, all H is converted immediately to tritiated water and C is converted immediately to CO2 (50%) and organically bound carbon (50%). In the study, rats were exposed to methane standards (H-methane and C-methane) mixed with breathing air to give a final concentration of 0.27% methane and resulting in final activity concentrations of 4.2 GBq m and 0.88 GBq m for H and C, respectively. This corresponds to exposure estimates of 580 kBq g and 120 kBq g. Simultaneous exposure to H- and C-methane allowed for the direct comparison of the retention of these radionuclides and removed uncertainties concerning their relative uptake and retention. The results demonstrate that the total methane uptake from the inhaled dose was threefold less than the 1% methane uptake predicted by the ICRP dosimetric models for H- and C-methane, with the H concentration being substantially higher than anticipated in the liver. This study provided data suggesting that current ICRP dosimetric methane models overestimate the fraction of H- and C-methane that is absorbed following inhalation and assisted in providing information to better understand the metabolism of inhaled H and C radiolabeled methane.

  5. Impact of transport model errors on the global and regional methane emissions estimated by inverse modelling

    NARCIS (Netherlands)

    Locatelli, R.; Bousquet, P.; Chevallier, F.; Fortems-Cheney, A.; Szopa, S.; Saunois, M.; Agusti-Panareda, A.; Bergmann, D.; Bian, H.; Cameron-Smith, P.; Chipperfield, M.P.; Gloor, E.; Houweling, S.; Kawa, S.R.; Krol, M.C.; Patra, P.K.; Prinn, R.G.; Rigby, M.; Saito, R.; Wilson, C.

    2013-01-01

    A modelling experiment has been conceived to assess the impact of transport model errors on methane emissions estimated in an atmospheric inversion system. Synthetic methane observations, obtained from 10 different model outputs from the international TransCom-CH4 model inter-comparison exercise, ar

  6. 焦作矿区煤层气开发的水文地质条件分析%Analysis on hydrogeological condition for coal bed methane exploitation in Jiaozuo coal-mine area

    Institute of Scientific and Technical Information of China (English)

    付江伟; 傅雪海; 胡晓; 刘爱华

    2011-01-01

    水文地质条件对煤层气的富集高产起着重要的控制作用.在系统研究焦作矿区水文地质特征的基础上,分析了水文地质条件对煤层气赋存、渗流、运移及煤层气生产的影响.焦作矿区水文地质条件,整体上有利于煤层气的赋存,但局部地下水强径流带,煤层气以水流为载体被逸散;岩溶裂隙发育区,煤系埋藏较浅而且又接近地表水体的区域,断裂发育且有可能成为导水通道的区域,地表水可能进入煤层,不利于煤层气的开采.煤层气勘探开发选择井位时,在其他条件相同情况下,煤层气井应选择存离断层较远的稍深部位.煤层气生产应合理处理可能造成的环境地质问题.%Hydrogeological conditions play an important role in high concentration of coal-bed methane.Based on the systematic study of hydro-geological characteristics in Jiaozuo Mining Area, the influence made by hydrogeological conditions on the occurrence, seepage, migration, recoverability and production of coal bed methane was analyzed.Hydrogeological conditions in Jiaozuo are over ally beneficial to the occurrence of coal bed methane, but in the strong runoff zone with local groundwater, coal bed methane migrate taking water flow as a carrier.Karsts-cranny developing area, coal region of measures exposed or buried in shallow and also closed to the surface water, which can flow into the seam through fissures will adversely affected coal bed methane mining.More developing fractures may become the water-channels, so when we select wells for coal-bed methane exploration and development, at the same conditions of other cases, the coal bed methane wells should be selected in deeper and more distant from the site of the fault.Coal bed methane production should be reasonable to deal with potential environmental geological problems.

  7. 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......, ultraviolet radiation and reactive oxygen species. Further, we analyze rates of measured emission of aerobically produced CH4 in pectin and in plant tissues from different studies and argue that pectin is very far from the sole contributing precursor. Hence, scaling up of aerobic CH4 emission needs to take...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  8. Coal Bed Methane Primer

    Energy Technology Data Exchange (ETDEWEB)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of

  9. Methanogens, Methane and Gastrointestinal Motility

    Science.gov (United States)

    Triantafyllou, Konstantinos; Chang, Christopher

    2014-01-01

    Anaerobic fermentation of the undigested polysaccharide fraction of carbohydrates produces hydrogen in the intestine which is the substrate for methane production by intestinal methanogens. Hydrogen and methane are excreted in the flatus and in breath giving the opportunity to indirectly measure their production using breath testing. Although methane is detected in 30%-50% of the healthy adult population worldwide, its production has been epidemiologically and clinically associated with constipation related diseases, like constipation predominant irritable bowel syndrome and chronic constipation. While a causative relation is not proven yet, there is strong evidence from animal studies that methane delays intestinal transit, possibly acting as a neuromuscular transmitter. This evidence is further supported by the universal finding that methane production (measured by breath test) is associated with delayed transit time in clinical studies. There is also preliminary evidence that antibiotic reduction of methanogens (as evidenced by reduced methane production) predicts the clinical response in terms of symptomatic improvement in patients with constipation predominant irritable bowel syndrome. However, we have not identified yet the mechanism of action of methane on intestinal motility, and since methane production does not account for all constipation associated cases, there is need for high quality clinical trials to examine methane as a biomarker for the diagnosis or as a biomarker that predicts antibiotic treatment response in patients with constipation related disorders. PMID:24466443

  10. Treating Coalbed Natural Gas Produced Water for Beneficial Use By MFI Zeolite Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Robert Lee; Liangxiong Li

    2008-03-31

    Desalination of brines produced from oil and gas fields is an attractive option for providing potable water in arid regions. Recent field-testing of subsurface sequestration of carbon dioxide for climate management purposes provides new motivation for optimizing efficacy of oilfield brine desalination: as subsurface reservoirs become used for storing CO{sub 2}, the displaced brines must be managed somehow. However, oilfield brine desalination is not economical at this time because of high costs of synthesizing membranes and the need for sophisticated pretreatments to reduce initial high TDS and to prevent serious fouling of membranes. In addition to these barriers, oil/gas field brines typically contain high concentrations of multivalent counter cations (eg. Ca{sup 2+} and SO{sub 4}{sup 2-}) that can reduce efficacy of reverse osmosis (RO). Development of inorganic membranes with typical characteristics of high strength and stability provide a valuable option to clean produced water for beneficial uses. Zeolite membranes have a well-defined subnanometer pore structure and extreme chemical and mechanical stability, thus showing promising applicability in produced water purification. For example, the MFI-type zeolite membranes with uniform pore size of {approx}0.56 nm can separate ions from aqueous solution through a mechanism of size exclusion and electrostatic repulsion (Donnan exclusion). Such a combination allows zeolite membranes to be unique in separation of both organics and electrolytes from aqueous solutions by a reverse osmosis process, which is of great interest for difficult separations, such as oil-containing produced water purification. The objectives of the project 'Treating Coalbed Natural Gas Produced Water for Beneficial Use by MFI Zeolite Membranes' are: (1) to conduct extensive fundamental investigations and understand the mechanism of the RO process on zeolite membranes and factors determining the membrane performance, (2) to improve

  11. Methane from wood

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, T. F.; Barreto, L.; Kypreos, S.; Stucki, S

    2005-07-15

    The role of wood-based energy technologies in the Swiss energy system in the long-term is examined using the energy-system Swiss MARKAL model. The Swiss MARKAL model is a 'bottom-up' energy-systems optimization model that allows a detailed representation of energy technologies. The model has been developed as a joint effort between the Energy Economics Group (EEG) at Paul Scherrer Institute PSI) and the University of Geneva and is currently used at PSI-EEG. Using the Swiss MARKAL model, this study examines the conditions under which wood-based energy technologies could play a role in the Swiss energy system, the most attractive pathways for their use and the policy measures that could support them. Given the involvement of PSI in the ECOGAS project, especial emphasis is put on the production of bio-SNG from wood via gasification and methanation of syngas and on hydrothermal gasification of woody biomass. Of specific interest as weIl is the fraction of fuel used in passenger cars that could be produced by locally harvested wood. The report is organized as follows: Section 2 presents a brief description of the MARKAL model. Section 3 describes the results of the base case scenario, which represents a plausible, 'middle-of-the-road' development of the Swiss energy system. Section 4 discusses results illustrating the conditions under which the wood-based methanation technology could become competitive in the Swiss energy market, the role of oil and gas prices, subsidies to methanation technologies and the introduction of a competing technology, namely the wood-based Fischer-Tropsch synthesis. FinaIly, section 5 outlines some conclusions from this analysis. (author)

  12. Instruments for Methane Gas Detection

    Directory of Open Access Journals (Sweden)

    Mr. Sibu Thomas

    2014-05-01

    Full Text Available This paper gives the explanation of different instruments for detecting methane gas in detail. This paper discusses their working principles. Methane gas detection is essentially required in the areas like in coal mines, power plant, Waste Water Treatment, Boiler Rooms etc. This paper also discusses their roles in various applications.

  13. A Methane Balloon Inflation Chamber

    Science.gov (United States)

    Czerwinski, Curtis J.; Cordes, Tanya J.; Franek, Joe

    2005-01-01

    The various equipments, procedure and hazards in constructing the device for inflating a methane balloon using a standard methane outlet in a laboratory are described. This device is fast, safe, inexpensive, and easy to use as compared to a hydrogen gas cylinder for inflating balloons.

  14. Methane adsorption on activated carbon

    NARCIS (Netherlands)

    Perl, Andras; Koopman, Folkert; Jansen, Peter; Rooij, Marietta de; Gemert, Wim van

    2014-01-01

    Methane storage in adsorbed form is a promising way to effectively and safely store fuel for vehicular transportation or for any other potential application. In a solid adsorbent, nanometer wide pores can trap methane by van der Waals forces as high density fluid at low pressure and room temperature

  15. Methane emissions from the Marcellus Shale in southwestern Pennsylvania and northern West Virginia based on airborne measurements

    Science.gov (United States)

    Ren, Xinrong; Hall, Dolly L.; Vinciguerra, Timothy; Benish, Sarah E.; Stratton, Phillip R.; Ahn, Doyeon; Hansford, Jonathan R.; Cohen, Mark D.; Sahu, Sayantan; He, Hao; Grimes, Courtney; Salawitch, Ross J.; Ehrman, Sheryl H.; Dickerson, Russell R.

    2017-04-01

    Natural gas production in the U.S. has increased rapidly over the past decade, along with concerns about methane (CH4) leakage (total fugitive emissions), and climate impacts. Quantification of CH4 emissions from oil and natural gas (O&NG) operations is important for establishing scientifically sound, cost-effective policies for mitigating greenhouse gases. We use aircraft measurements and a mass balance approach for three flight experiments in August and September 2015 to estimate CH4 emissions from O&NG operations in the southwestern Marcellus Shale region. We estimate the mean ± 1σ CH4 emission rate as 36.7 ± 1.9 kg CH4 s-1 (or 1.16 ± 0.06 Tg CH4 yr-1) with 59% coming from O&NG operations. We estimate the mean ± 1σ CH4 leak rate from O&NG operations as 3.9 ± 0.4% with a lower limit of 1.5% and an upper limit of 6.3%. This leak rate is broadly consistent with the results from several recent top-down studies but higher than the results from a few other observational studies as well as in the U.S. Environmental Protection Agency CH4 emission inventory. However, a substantial source of CH4 was found to contain little ethane (C2H6), possibly due to coalbed CH4 emitted either directly from coalmines or from wells drilled through coalbed layers. Although recent regulations requiring capture of gas from the completion venting step of the hydraulic fracturing appear to have reduced losses, our study suggests that for a 20 year time scale, energy derived from the combustion of natural gas extracted from this region will require further controls before it can exert a net climate benefit compared to coal.

  16. 我国煤层气发电产业发展现状%Current Situation Analysis of China's Coal-bed Methane Power Generation

    Institute of Scientific and Technical Information of China (English)

    谭超; 白红彬

    2010-01-01

    我国煤层气储量丰富,开发利用可取得多重效益,是实现循环经济,可持续发展,节能减排的有效途径.文中主要论述了煤层气发电的意义和相关扶持政策,调查了我国利用煤层气发电的技术发展和应用现状.

  17. Simulation experiment on enhancing coalbed methane production by microbes%微生物提高煤层气产量模拟实验研究

    Institute of Scientific and Technical Information of China (English)

    陈浩; 李贵中; 陈振宏; 庚勐; 邓泽; 张辉

    2016-01-01

    为解决微生物对煤层产气量的影响,通过对不同煤阶煤岩进行生物气模拟实验发现,在实验室条件下煤中微生物能利用自身物质进行生物产气。通过设置不同温度实验发现,在35℃条件下产气量要大于15℃时的产气量,说明35℃的温度更适合微生物利用煤样产气。在进行定量实验后发现,在添加外源营养物质或外源菌类的条件下能提高煤的产气量。在添加外源菌种的条件下,增产比例可达115%,而通过添加营养物质增产比例可达144%。%To verify the effect of microbes on gas generation of coal beds, microbial simulation experiments have been made on different coal ranks. The result shows that microbes in coals can produce gas by themselves under laboratory conditions. With comparison of experiments under different temperatures, the gas production under 35℃ is greater than that under 15℃, indicating that it is more suitable for microbes to produce gas under 35℃. According to quantitative experiments, it is shown that the gas production is improved by adding exogenous nutrients or exogenous bacteria. Moreover, the production enhancement ratio can reach 115% by adding exogenous bacterial species and 144% by adding nutrients.

  18. Oxygen-Methane Thruster

    Science.gov (United States)

    Pickens, Tim

    2012-01-01

    An oxygen-methane thruster was conceived with integrated igniter/injector capable of nominal operation on either gaseous or liquid propellants. The thruster was designed to develop 100 lbf (approximately 445 N) thrust at vacuum conditions and use oxygen and methane as propellants. This continued development included refining the design of the thruster to minimize part count and manufacturing difficulties/cost, refining the modeling tools and capabilities that support system design and analysis, demonstrating the performance of the igniter and full thruster assembly with both gaseous and liquid propellants, and acquiring data from this testing in order to verify the design and operational parameters of the thruster. Thruster testing was conducted with gaseous propellants used for the igniter and thruster. The thruster was demonstrated to work with all types of propellant conditions, and provided the desired performance. Both the thruster and igniter were tested, as well as gaseous propellants, and found to provide the desired performance using the various propellant conditions. The engine also served as an injector testbed for MSFC-designed refractory combustion chambers made of rhenium.

  19. Numerical Simulation of Methane Distribution and Sensor Placement in 2-Dimension Roadway

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-ping; TANG Liang; CHEN Wei; WANG Fu-zeng

    2007-01-01

    In order to provide a theoretical basis for methane sensor placement in the vertical direction of a tunnel, the software Fluent was used to simulate methane distribution. A geometric roadway model was established and divided by grids. Methane distribution in both level and vertical sections was simulated using a realizable k-ε model with the Fluent software according to a conservation equation in a turbulent state, a turbulent kinetic energy equation and a turbulent dissipation rate equation. The realizable k-ε model and the Fluent software were used to simulate methane distribution according to the principle of the conservation equation in a state of turbulent flow. The results show that after overflowing, a methane level with a certain thickness is formed. Methane density curves at three specific levels were internally consistent and methane density at higher levels is denser than that at lower levels. Methane distribution becomes thinner in the direction of wind and methane in the vertical direction becomes uniform if wind speed is high. The distance between sensors and roof should be less than 300 mm which is in agreement with mine safety regulations.

  20. Hydroxylation of methane through component interactions in soluble methane monooxygenases.

    Science.gov (United States)

    Lee, Seung Jae

    2016-04-01

    Methane hydroxylation through methane monooxygenases (MMOs) is a key aspect due to their control of the carbon cycle in the ecology system and recent applications of methane gas in the field of bioenergy and bioremediation. Methanotropic bacteria perform a specific microbial conversion from methane, one of the most stable carbon compounds, to methanol through elaborate mechanisms. MMOs express particulate methane monooxygenase (pMMO) in most strains and soluble methane monooxygenase (sMMO) under copper-limited conditions. The mechanisms of MMO have been widely studied from sMMO belonging to the bacterial multicomponent monooxygenase (BMM) superfamily. This enzyme has diiron active sites where different types of hydrocarbons are oxidized through orchestrated hydroxylase, regulatory and reductase components for precise control of hydrocarbons, oxygen, protons, and electrons. Recent advances in biophysical studies, including structural and enzymatic achievements for sMMO, have explained component interactions, substrate pathways, and intermediates of sMMO. In this account, oxidation of methane in sMMO is discussed with recent progress that is critical for understanding the microbial applications of C-H activation in one-carbon substrates.

  1. Methane production and methane consumption: a review of processes underlying wetland methane fluxes.

    NARCIS (Netherlands)

    Segers, R.

    1998-01-01

    Potential rates of both methane production and methane consumption vary over three orders of magnitude and their distribution is skew. These rates are weakly correlated with ecosystem type, incubation temperature, in situ aeration, latitude, depth and distance to oxic/anoxic interface. Anaerobic

  2. Methane production and methane consumption: a review of processes underlying wetland methane fluxes.

    NARCIS (Netherlands)

    Segers, R.

    1998-01-01

    Potential rates of both methane production and methane consumption vary over three orders of magnitude and their distribution is skew. These rates are weakly correlated with ecosystem type, incubation temperature, in situ aeration, latitude, depth and distance to oxic/anoxic interface. Anaerobic car

  3. Methane emission from wetland rice fields.

    NARCIS (Netherlands)

    Denier van der Gon, H.A.C.

    1996-01-01

    Methane (CH 4 ) is an important greenhouse gas and plays a key role in tropospheric and stratospheric chemistry. Wetland rice fields are an important source of methane, accounting for approximately 20% of the global anthropogenic methane emission. Methane fluxes fro

  4. Oceanic Methane Concentrations in Three Mexican Regions

    Science.gov (United States)

    The atmospheric concentration of methane has increased significantly over the last several decades. Methane is an important greenhouse gas, and it is important to better quantify methane sources and sinks. Dissolved methane in the ocean is produced by biological and hydrothermal ...

  5. Power recovery through thermodynamic expansion of liquid methane

    Energy Technology Data Exchange (ETDEWEB)

    Cengel, Y.A. [Univ. of Nevada, Reno, NV (United States). Dept. of Mechanical Engineering; Kimmel, H. [Ebara International Corp., Sparks, NV (United States)

    1997-09-01

    Thermodynamic aspects of a cryogenic turbine-generator assembly that admits methane at a high pressure and discharges it at a low pressure are investigated. The entire turbine-generator assembly is submerged in methane. The study is intended to quantify the effect of the turbine-generator assembly on the exit temperature of methane, the rate of heat transfer to methane, the rate of internal heat generation due to the hydraulic inefficiency of the turbine and the heat given off by generator, and the resulting temperature rise of methane, the amount of electrical power generated and potential revenues from it. The submerged turbine-generator assembly appears to be very attractive both thermodynamically and economically. The unit will put the power generation potential of the liquid methane into best use while actually lowering the temperature of liquid methane. The exit temperature of liquid methane as it expands from 113.0 K and 4.479 MPa to 0.517 MPa will range from 112.0 K in the case of an isentropic turbine, to 114.6 K in the case of an expansion valve. In the case of 75% efficient submerged turbine-generator assembly, the exit temperature will be 112.6 K. Therefore, the temperature of methane will rise by 1.6 K in the expansion valve, but it will drop by 0.4 K in the turbine-generator assembly, making this system very desirable in cryogenic applications. Heat transfer to the container of the turbine-generator assembly appears to be very small, and the temperature rise of methane due to this heat gain is negligible (under 0.007 K). The system investigated has a power generation potential of 1,085 kW, but because of the inefficiencies in the turbine and the generator, it is realistic to expect to generate about 814 kW of electric power. The turbine-generator assembly will save the facility about half a million dollars a year in electricity costs if the facility operates continuously.

  6. The strength and rheology of methane clathrate hydrate

    Science.gov (United States)

    Durham, W.B.; Kirby, S.H.; Stern, L.A.; Zhang, W.

    2003-01-01

    Methane clathrate hydrate (structure I) is found to be very strong, based on laboratory triaxial deformation experiments we have carried out on samples of synthetic, high-purity, polycrystalline material. Samples were deformed in compressional creep tests (i.e., constant applied stress, ??), at conditions of confining pressure P = 50 and 100 MPa, strain rate 4.5 ?? 10-8 ??? ?? ??? 4.3 ?? 10-4 s-1, temperature 260 ??? T ??? 287 K, and internal methane pressure 10 ??? PCH4 ??? 15 MPa. At steady state, typically reached in a few percent strain, methane hydrate exhibited strength that was far higher than expected on the basis of published work. In terms of the standard high-temperature creep law, ?? = A??ne-(E*+PV*)/RT the rheology is described by the constants A = 108.55 MPa-n s-1, n = 2.2, E* = 90,000 J mol-1, and V* = 19 cm3 mol-1. For comparison at temperatures just below the ice point, methane hydrate at a given strain rate is over 20 times stronger than ice, and the contrast increases at lower temperatures. The possible occurrence of syntectonic dissociation of methane hydrate to methane plus free water in these experiments suggests that the high strength measured here may be only a lower bound. On Earth, high strength in hydrate-bearing formations implies higher energy release upon decomposition and subsequent failure. In the outer solar system, if Titan has a 100-km-thick near-surface layer of high-strength, low-thermal conductivity methane hydrate as has been suggested, its interior is likely to be considerably warmer than previously expected.

  7. CryoFuel gas : capture and purification of methane at source

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, R. [CFS Alternative Fuels Inc., Victoria, BC (Canada)

    2002-07-01

    The mandate of CFS Alternative Fuels Incorporated, located in Victoria, British Columbia, which came into operation in 1995, is the installation and operation of gas purification and liquefaction systems using the patented small-scale cryogenic technologies which were designed by an affiliate, CryoFuel Systems Incorporated in Monroe, Washington. Liquefied Natural Gas (LNG) at 97 per cent is produced using gas processing systems from a variety of gases such as unutilized sources like stranded gas wells and coalbed methane. Waste gases like flares, landfills and bio-digesters, as well as pipeline natural gas are also used to produce LNG. The recovery of carbon dioxide at 99.8 per cent purity is possible from landfill and biogas streams. No new emissions are generated by the autonomous, modular, skid-mounted cryofuel plants. Additionally, no external utilities are required. Some of the applications of LNG are the replacement of conventional fuels in the transportation sector and in commercial and industrial applications. The technology's core design and process capabilities were verified in a one-year demonstration project. Firm orders for eight full-scale systems have been received as of April 2002.

  8. Technical design note: differential infrared thermography of methane jets

    Science.gov (United States)

    Golzke, Hendrik; Leick, Philippe; Dreizler, Andreas

    2016-10-01

    In this note a novel approach for temperature measurements of methane jets is presented. Differential infrared thermography (DIT) is a contactless, tracer-free temperature determination method for semi-transparent objects, based on an infrared camera. DIT does not rely on a specific a priori value for the emissivity, but typically assumes constant emissivity within the relevant wavelength band. This is reasonable for complex hydrocarbons (i.e. as in liquid fuel sprays) but no longer justified for the discrete absorption spectrum of simple molecules such as methane. An alternative approximation is suggested and discussed, and the feasibility of DIT for the study of supercritical methane jets in a pressure chamber at conditions relevant for internal combustion engines is demonstrated. As DIT also determines the gas emissivity, a combined two-dimensional temperature and projected density visualisation becomes possible and is shown to highlight supersonic structurues such as Mach disks.

  9. Anthropogenic methane ebullition and continuous flux measurement

    Science.gov (United States)

    Alshboul, Zeyad

    2017-04-01

    Keywords: Methane, Wastewater, Effluent, Anaerobic treatment. Municipal wastewater treatment plants (WWTPs) have shown to emit significant amount of methane during treatment processes. While most of studies cover only in-plant diffusive methane flux, magnitude and sources of methane ebullition have not well assessed. Moreover, the reported results of methane emissions from WWTPs are based on low spatial and temporal resolution. Using a continuous measurement approach of methane flux rate for effluent system and secondary clarifier treatment process at one WWTP in Southwest Germany, our results show that high percentage of methane is emitted by ebullition during the anaerobic treatment (clarification pond) with high spatial and temporal variability. Our measurements revealed that no ebullition is occur at the effluent system. The observed high contribution of methane ebullition to the total in-plant methane emission, emphasizes the need for considering in-plant methane emission by ebullition as well as the spatial and temporal variability of these emissions.

  10. Recent advances in methane activation

    Energy Technology Data Exchange (ETDEWEB)

    Huuska, M.; Kataja, K. [VTT Chemical Technology, Espoo (Finland)

    1996-12-31

    Considerable work has been done in the research and development of methane conversion technologies. Although some promising conversion processes have been demonstrated, further advances in engineering and also in the chemistry are needed before these technologies become commercial. High-temperature processes, e.g. the oxidative coupling of methane, studied thoroughly during the last 15 years, suffer from severe theoretical yield limits and poor economics. In the long term, the most promising approaches seem to be the organometallic and, especially, the biomimetic activation of methane. (author) (22 refs.)

  11. Production stages division and drainage production system deveIopment of coaIbed methane%煤层气排采阶段划分及排采制度制定

    Institute of Scientific and Technical Information of China (English)

    柳迎红; 房茂军; 廖夏

    2015-01-01

    In order to mine coalbed methane reasonably,a division of different production stages of coalbed methane was needed,different drainage and production system also should be developed. In this paper,the authors comprehensively compared and evaluated the classifi-cation criterion,each stages characteristics,the merits and demerits of different division methods which were focused on different production stages. A six-stage division method of coalbed methane drainage and production system which was combined with production control were put forward. The method divided the drainage and production process into six stages,which were no gas period,initial gas period,gas pro-duction rising period,gas production stable period,gas production decline period and abandoned period. The production control methods and technical measures of six-stage division method were investigated. The importance of quantitative study about six-stage division meth-od was also researched.%为了合理开采煤层气,需要对煤层气的不同阶段进行合理划分,并针对不同排采阶段相应制定不同的排采生产制度。综合对比评价了不同排采阶段划分方法的划分依据、阶段特征、划分方法的优缺点,提出了与生产控制相结合的煤层气排采生产六段划分法,将煤层气生产阶段划分为未见气阶段、初见气阶段、产气量上升阶段、产气量稳定阶段、产气量下降阶段和废弃阶段,给出了六段划分法在不同排采阶段生产控制方与法与技术对策,指明了六段排采阶段定量化研究的重要性。

  12. Is methane a new therapeutic gas?

    OpenAIRE

    Liu Wenwu; Wang Dong; Tao Hengyi; Sun XueJun

    2012-01-01

    Abstract Background Methane is an attractive fuel. Biologically, methanogens in the colon can use carbon dioxide and hydrogen to produce methane as a by-product. It was previously considered that methane is not utilized by humans. However, in a recent study, results demonstrated that methane could exert anti-inflammatory effects in a dog small intestinal ischemia-reperfusion model. Point of view Actually, the bioactivity of methane has been investigated in gastrointestinal diseases, but the e...

  13. The methane rating system to determine coal face methane conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cook, A.P.; van Vuuren, J.J. [Itasca Africa (Pty) Ltd, Johannesburg (South Africa)

    2001-07-01

    Methane Rating was developed from a need in South Africa to measure coal seam gas contents, as well as emission rates into the cutting zone for mechanical miners. These are then combined and compared to the average and normal conditions to provide a risk assessment tool for continuous miner operations. The last two years have seen widespread acceptance of Methane Rating as a practical and simple means of identifying seam gas contents and emission rates during mining, and of rating the changing methane conditions. The system uses proven direct methods of methane measurement to quantify the contents and emissions, combined with an innovative rating system. Each new result is compared with the expected average or normal conditions to determine its Methane Rating between 1 and 5. The present South African national database of over 340 individual samples from 31 mines shows methane contents can normally be expected between 0,2 m{sup 3}/t and 1,4 m{sub 3}/t, with emission rates during coal cutting of 20 l/t/min to 80 l/t/min. The highest risk rated mines are presently in the Secunda and eastern Witbank areas, with the lowest risk rated mines to the west of Witbank. 6 refs., 9 figs.

  14. Oxygen-Methane Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Orion Propulsion, Inc. proposes to develop an Oxygen and Methane RCS Thruster to advance the technology of alternate fuels. A successful Oxygen/CH4 RCS Thruster will...

  15. Oxygen-Methane Thruster Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Two main innovations will be developed in the Phase II effort that are fundamentally associated with our gaseous oxygen/gaseous methane RCS thruster. The first...

  16. Miniature Airborne Methane Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — KalScott Engineering, and the subcontractor, Princeton University propose the development and demonstration of compact and robust methane sensor for small Unmanned...

  17. Methane Liquid Level Sensor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Advanced Technologies Group, Inc. proposes the development of a Methane Liquid-Level Sensor, (MLS) for In-Space cryogenic storage capable of continuous monitoring of...

  18. Methane LIDAR Laser Technology Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Fibertek proposes to develop laser technology intended to meet NASA's need for innovative lidar technologies for atmospheric measurements of methane. NASA and the...

  19. Methane adsorption on activated carbon

    OpenAIRE

    Perl, Andras; Koopman, Folkert; Jansen, Peter; Rooij, Marietta de; Gemert, Wim van

    2014-01-01

    Methane storage in adsorbed form is a promising way to effectively and safely store fuel for vehicular transportation or for any other potential application. In a solid adsorbent, nanometer wide pores can trap methane by van der Waals forces as high density fluid at low pressure and room temperature. This provides the suitable technology to replace bulky and expensive cylindrical compressed natural gas tanks. Activated carbons with large surface area and high porosity are particularly suitabl...

  20. The oxidative coupling of methane

    Energy Technology Data Exchange (ETDEWEB)

    Helton, T.; Anthony, R.G.; Gadalla, A.M. (Texas A and M Univ., College Park, TX (US))

    1988-01-01

    In this paper the spinel phase of cobalt oxide is evaluated as a potential coupling catalyst for converting methane to C/sub 2/+ hydrocarbons. Thermodynamic calculations indicate that the Gibbs free energies for forming higher hydrocarbons using the spinel form of cobalt oxide are similar to the free energies obtained for manganese (III) oxide. The oxidative coupling of methane was performed in an oxidation-reduction cycle.

  1. Methane management in sewage treatment

    OpenAIRE

    Cookney, Joanna

    2011-01-01

    Poly-di-methyl-siloxane (PDMS) hollow fibre membrane modules were designed and built for the specific de-gassing of real and synthetic process liquids to understand: (i) the feasibility of operation; and (ii) classify the mass transfer characteristics to aid design at full scale. Liquid saturated with pure methane or a binary methane and carbon dioxide mixture was introduced into the shell side of the extraction unit, whilst sweep gas or vacuum was employed counter-currently as a stripping me...

  2. Hydraulic Fracturing Design of Coal-bed Gas Well%煤层气井水力压裂设计

    Institute of Scientific and Technical Information of China (English)

    张志全; 张军; 许弟龙; 胡东; 张保国; 唐艳

    2001-01-01

    针对煤层气井储层特性和压裂的特殊性,选择了拟三维模型进行水力压裂设计。针对一口具体井的资料进行了模拟计算,计算结果合理。同时就地面注液排量、压裂液稠度系数和地应力差值对裂缝几何形态的影响进行了计算和分析,并提出了相应的建议。%In consideration of reservoir charateristics and particalarity of fracturing of coal-bed gas well,a psuedo 3D fracture model is selected to design the hydraulic fracturing.A simulation calculation is performed with data from a specific well,of which the result is reasonable,at the same time calculation and analysis are conducted on the geometry of fractures based on the displacement of surface injected fluid,density coefficient of fracturing fluid and differential value of earth stress,thus related proposals are made.

  3. Quantification of methane emissions from danish landfills

    DEFF Research Database (Denmark)

    Scheutz, Charlotte; Mønster, Jacob; Kjeldsen, Peter

    2013-01-01

    Whole-landfill methane emission was quantified using a tracer technique that combines controlled tracer gas release from the landfill with time-resolved concentration measurements downwind of the landfill using a mobile high-resolution analytical instrument. Methane emissions from 13 Danish...... landfills varied between 2.6 and 60.8 kg CH4 h–1. The highest methane emission was measured at the largest (in terms of disposed waste amounts) of the 13 landfills, whereas the lowest methane emissions (2.6-6.1 kgCH4 h–1) were measured at the older and smaller landfills. At two of the sites, which had gas...... collection, emission measurements showed that the gas collection systems only collected between 30-50% of the methane produced (assuming that the produced methane equalled the sum of the emitted methane and the collected methane). Significant methane emissions were observed from disposed shredder waste...

  4. Is methane a new therapeutic gas?

    Directory of Open Access Journals (Sweden)

    Liu Wenwu

    2012-09-01

    Full Text Available Abstract Background Methane is an attractive fuel. Biologically, methanogens in the colon can use carbon dioxide and hydrogen to produce methane as a by-product. It was previously considered that methane is not utilized by humans. However, in a recent study, results demonstrated that methane could exert anti-inflammatory effects in a dog small intestinal ischemia-reperfusion model. Point of view Actually, the bioactivity of methane has been investigated in gastrointestinal diseases, but the exact mechanism underlying the anti-inflammatory effects is required to be further elucidated. Methane can cross the membrane and is easy to collect due to its abundance in natural gas. Although methane is flammable, saline rich in methane can be prepared for clinical use. These seem to be good news in application of methane as a therapeutic gas. Conclusion Several problems should be resolved before its wide application in clinical practice.

  5. Dissolved methane in rising main sewer systems: field measurements and simple model development for estimating greenhouse gas emissions.

    Science.gov (United States)

    Foley, Jeff; Yuan, Zhiguo; Lant, Paul

    2009-01-01

    At present, the potential generation of methane in wastewater collection systems is ignored under international greenhouse gas (GHG) accounting protocols, despite recent reports of substantial dissolved methane formation in sewers. This suggests that the current national GHG inventories for wastewater handling systems are likely to be underestimated for some situations. This study presents a new catalogue of field data on methane formation in rising main sewerage systems and proposes an empirically-fitted, theoretical model to predict dissolved methane concentrations, based upon the independent variables of pipeline geometry (i.e. surface area to volume ratio, A/V) and hydraulic retention time (HRT). Systems with longer HRT and/or larger A/V ratios are shown to have higher dissolved methane concentrations. This simple predictive model provides a means for water authorities to estimate the methane emissions from other pressurised sewerage systems of similar characteristics.

  6. Making methane visible

    Science.gov (United States)

    Gålfalk, Magnus; Olofsson, Göran; Crill, Patrick; Bastviken, David

    2016-04-01

    Methane (CH4) is one of the most important greenhouse gases, and an important energy carrier in biogas and natural gas. Its large-scale emission patterns have been unpredictable and the source and sink distributions are poorly constrained. Remote assessment of CH4 with high sensitivity at a m2 spatial resolution would allow detailed mapping of the near-ground distribution and anthropogenic sources in landscapes but has hitherto not been possible. Here we show that CH4 gradients can be imaged on the

  7. Methane production from steam-exploded bamboo.

    Science.gov (United States)

    Kobayashi, Fumihisa; Take, Harumi; Asada, Chikako; Nakamura, Yoshitoshi

    2004-01-01

    To convert unutilized plant biomass into a useful energy source, methane production from bamboo was investigated using a steam explosion pretreatment. Methane could not be produced from raw bamboo but methane production was enhanced by steam explosion. The maximum amount of methane produced, i.e., about 215 ml, was obtained from 1 g of exploded bamboo at a steam pressure of 3.53 MPa and a steaming time of 5 min. A negative correlation between the amount of methane produced and the amount of Klason lignin was observed in the methane fermentation of steam-exploded bamboo.

  8. Are termite mounds biofilters for methane? - Challenges and new approaches to quantify methane oxidation in termite mounds

    Science.gov (United States)

    Nauer, Philipp A.; Hutley, Lindsay B.; Bristow, Mila; Arndt, Stefan K.

    2015-04-01

    transport. Two concepts of gas-tracer-test applications in termite mounds are presented, together with 3D photogrammetric approaches to estimate volume, surface area and internal gas volume of termite mounds that enables acuare scaling of methane production and consumption. In a further phase of the project, the application of these methods in a comprehensive field survey in the Australian savanna ecosystem will give insights into major driving factors of MOX in termite mounds, a major driver of nutrient cycling in this extensive tropical ecosystem.

  9. Characterization of Methane Degradation and Methane-Degrading Microbes in Alaska Coastal Water

    Energy Technology Data Exchange (ETDEWEB)

    Kirchman, David L. [Univ. of Delaware, Lewes, DE (United States)

    2012-03-29

    The net flux of methane from methane hydrates and other sources to the atmosphere depends on methane degradation as well as methane production and release from geological sources. The goal of this project was to examine methane-degrading archaea and organic carbon oxidizing bacteria in methane-rich and methane-poor sediments of the Beaufort Sea, Alaska. The Beaufort Sea system was sampled as part of a multi-disciplinary expedition (Methane in the Arctic Shelf or MIDAS) in September 2009. Microbial communities were examined by quantitative PCR analyses of 16S rRNA genes and key methane degradation genes (pmoA and mcrA involved in aerobic and anaerobic methane degradation, respectively), tag pyrosequencing of 16S rRNA genes to determine the taxonomic make up of microbes in these sediments, and sequencing of all microbial genes (metagenomes ). The taxonomic and functional make-up of the microbial communities varied with methane concentrations, with some data suggesting higher abundances of potential methane-oxidizing archaea in methane-rich sediments. Sequence analysis of PCR amplicons revealed that most of the mcrA genes were from the ANME-2 group of methane oxidizers. According to metagenomic data, genes involved in methane degradation and other degradation pathways changed with sediment depth along with sulfate and methane concentrations. Most importantly, sulfate reduction genes decreased with depth while the anaerobic methane degradation gene (mcrA) increased along with methane concentrations. The number of potential methane degradation genes (mcrA) was low and inconsistent with other data indicating the large impact of methane on these sediments. The data can be reconciled if a small number of potential methane-oxidizing archaea mediates a large flux of carbon in these sediments. Our study is the first to report metagenomic data from sediments dominated by ANME-2 archaea and is one of the few to examine the entire microbial assemblage potentially involved in

  10. Solar enriched methane production: Assessment of plant potentialities and applications

    Directory of Open Access Journals (Sweden)

    Vincenzo Piemonte

    2010-04-01

    Full Text Available The crucial environmental issue due to fossil fuel use in our society and industries and more and more perceived by the communities is stimulating the development of innovative technologies with the scope of reducing GHGs and pollutants emissions, improving plants efficiency and exploiting renewable energy sources. The idea proposed in the present work links this context: a novel hybrid plant for the production of a mixture of methane and hydrogen (20%vol, called enriched-methane, from a steam reforming reactor whose heat duty is supplied by a concentrating solar power (CSP plant by means of a molten salt stream is here conceived, modelled and assessed. The enriched-methane mixture can be applied in methane internal combustion engines (ICE reducing CO, CO2, unburned emissions and improving engine efficiency. Moreover, the residual sensible heat of solar-heated molten salt stream can be used to generate medium-pressure steam and to produce electricity by a steam-turbine. Therefore, the plant proposed is co-generative, producing both hydrogen and electricity from a solar source. The behaviour of methane steam reforming reactor is simulated by means of a 2D mathematical model and the design of a cogenerative solar plant is proposed, evaluating its potentialities in terms of MWh of electricity produced and number of vehicles fed by enriched-methane. A single CSP module (surface requirement = 1.5 hectares coupled with a 4-tubes-and-shell shaped reactor is able to produce 686 tons/year of hydrogen, equivalent to 3.430 tons/year of 20%vol H2-CH4 mixture and 3.097 MWh/year of clean electricity.

  11. Methane as a climate gas

    Energy Technology Data Exchange (ETDEWEB)

    Karlsdottir, S.

    1996-03-01

    This paper was read at the workshop ``The Norwegian Climate and Ozone Research Programme`` held on 11-12 March 1996. Methane is a key component in the atmosphere where its concentration has increased rapidly since pre-industrial time. About 2/3 of it is caused by human activities. Changes in methane will affect the concentrations of other gases, and a model is a very important tool to study sensitivity due to changes in concentration of gases. The author used a three-dimensional global chemistry transport model to study the effect of changes in methane concentration on other trace gases. The model includes natural and anthropogenic emissions of NOx, CO, CH{sub 4} and non-methane hydrocarbons. Wet and dry deposition are also included. The chemical scheme in the model includes 49 compounds, 101 reactions, and 16 photolytic reactions. The trace gas concentrations are calculated every 30 min, using a quasi steady state approximation. Model calculations of three cases are reported and compared. Enhanced methane concentration will have strongest effect in remote regions. In polluted areas local chemistry will have remarked effect. The feedback was always positive. Average atmospheric lifetime calculated in the model was 7.6 years, which agrees with recent estimates based on observations. 8 refs.

  12. A Possible Sink for Methane on Mars

    NARCIS (Netherlands)

    Nørnberg, P.; Jensen, S. J. K.; Skibsted, J.; Jakobsen, H. J.; ten Kate, I. L.; Gunnlaugsson, H. P.; Merrison, J. P.; Finster, K.; Bak, E.; Iversen, J. J.; Kondrup, J. C.

    2014-01-01

    Mechanical simulated wind activation of mineral surfaces act as a trap for Methane through formation of covalent Si-C bonds stable up to temperatures above 250 C. This mechanism is proposed as a Methane sink on Mars.

  13. Global health benefits of mitigating ozone pollution with methane emission controls

    Science.gov (United States)

    West, J. Jason; Fiore, Arlene M.; Horowitz, Larry W.; Mauzerall, Denise L.

    2006-03-01

    Methane (CH4) contributes to the growing global background concentration of tropospheric ozone (O3), an air pollutant associated with premature mortality. Methane and ozone are also important greenhouse gases. Reducing methane emissions therefore decreases surface ozone everywhere while slowing climate warming, but although methane mitigation has been considered to address climate change, it has not for air quality. Here we show that global decreases in surface ozone concentrations, due to methane mitigation, result in substantial and widespread decreases in premature human mortality. Reducing global anthropogenic methane emissions by 20% beginning in 2010 would decrease the average daily maximum 8-h surface ozone by 1 part per billion by volume globally. By using epidemiologic ozone-mortality relationships, this ozone reduction is estimated to prevent 30,000 premature all-cause mortalities globally in 2030, and 370,000 between 2010 and 2030. If only cardiovascular and respiratory mortalities are considered, 17,000 global mortalities can be avoided in 2030. The marginal cost-effectiveness of this 20% methane reduction is estimated to be 420,000 per avoided mortality. If avoided mortalities are valued at 1 million each, the benefit is 240 per tonne of CH4 (12 per tonne of CO2 equivalent), which exceeds the marginal cost of the methane reduction. These estimated air pollution ancillary benefits of climate-motivated methane emission reductions are comparable with those estimated previously for CO2. Methane mitigation offers a unique opportunity to improve air quality globally and can be a cost-effective component of international ozone management, bringing multiple benefits for air quality, public health, agriculture, climate, and energy. human health | mortality | tropospheric ozone | air quality

  14. Methods for measuring and estimating methane emission from ruminants

    OpenAIRE

    2012-01-01

    Simple Summary Knowledge about methods used in quantification of greenhouse gasses is currently needed due to international commitments to reduce the emissions. In the agricultural sector one important task is to reduce enteric methane emissions from ruminants. Different methods for quantifying these emissions are presently being used and others are under development, all with different conditions for application. For scientist and other persons working with the topic it is very important to ...

  15. Methane production from plant biomass

    Energy Technology Data Exchange (ETDEWEB)

    Zauner, E.

    1985-01-01

    Methane fermentations of plant biomass were performed to increase basic knowledge necessary for development of suitable conversion technologies. Effects of bacterial inoculants, substrate compounds and varied process conditions were analyzed in batch and continuous fermentation experiments. Use of enriched bacterial populations precultured and adapted to plant materials was proved to be advantageous for inoculation. Methane yields and productivities as well as chemical and bacterial composition of digester fluids were determined at various loading rates and retention times during fermentation of different grass and maize silages. Recycling for favorable amounts of decomposed effluent for neutralization of supplied acid raw materials was important to achieve high methane yields. Quantity and composition of acido-, aceto- and methanogenic bacteria were not essentially influenced by changed fermentation conditions. Results of these laboratory examinations have to be completed by long run and scale up experiments to develop control parameters for plant biogas digesters.

  16. Integrated treatment process using a natural Wyoming clinoptilolite for remediating produced waters from coalbed natural gas operations

    Science.gov (United States)

    Zhao, H.; Vance, G.F.; Urynowicz, M.A.; Gregory, R.W.

    2009-01-01

    Coalbed natural gas (CBNG) development in western U.S. states has resulted in an increase in an essential energy resource, but has also resulted in environmental impacts and additional regulatory needs. A concern associated with CBNG development relates to the production of the copious quantities of potentially saline-sodic groundwater required to recover the natural gas, hereafter referred to as CBNG water. Management of CBNG water is a major environmental challenge because of its quantity and quality. In this study, a locally available Na-rich natural zeolite (clinoptilolite) from Wyoming (WY) was examined for its potential to treat CBNG water to remove Na+ and lower the sodium adsorption ratio (SAR, mmol1/2 L- 1/2). The zeolite material was Ca-modified before being used in column experiments. Column breakthrough studies indicated that a metric tonne (1000??kg) of Ca-WY-zeolite could be used to treat 60,000??L of CBNG water in order to lower SAR of the CBNG water from 30 to an acceptable level of 10??mmol1/2 L- 1/2. An integrated treatment process using Na-WY-zeolite for alternately treating hard water and CBNG water was also examined for its potential to treat problematic waters in the region. Based on the results of this study, use of WY-zeolite appears to be a cost-effective water treatment technology for maximizing the beneficial use of poor-quality CBNG water. Ongoing studies are evaluating water treatment techniques involving infiltration ponds lined with zeolite. ?? 2008 Elsevier B.V. All rights reserved.

  17. Organic compounds in produced waters from coalbed natural gas wells in the Powder River Basin, Wyoming, USA

    Science.gov (United States)

    Orem, W.H.; Tatu, C.A.; Lerch, H.E.; Rice, C.A.; Bartos, T.T.; Bates, A.L.; Tewalt, S.; Corum, M.D.

    2007-01-01

    The organic composition of produced water samples from coalbed natural gas (CBNG) wells in the Powder River Basin, WY, sampled in 2001 and 2002 are reported as part of a larger study of the potential health and environmental effects of organic compounds derived from coal. The quality of CBNG produced waters is a potential environmental concern and disposal problem for CBNG producers, and no previous studies of organic compounds in CBNG produced water have been published. Organic compounds identified in the produced water samples included: phenols, biphenyls, N-, O-, and S-containing heterocyclic compounds, polycyclic aromatic hydrocarbons (PAHs), aromatic amines, various non-aromatic compounds, and phthalates. Many of the identified organic compounds (phenols, heterocyclic compounds, PAHs) are probably coal-derived. PAHs represented the group of organic compounds most commonly observed. Concentrations of total PAHs ranged up to 23 ??g/L. Concentrations of individual compounds ranged from about 18 to compound concentrations was documented, as two wells with relatively high organic compound contents in produced water in 2001 had much lower concentrations in 2002. In many areas, including the PRB, coal strata provide aquifers for drinking water wells. Organic compounds observed in produced water are also likely present in drinking water supplied from wells in the coal. Some of the organic compounds identified in the produced water samples are potentially toxic, but at the levels measured in these samples are unlikely to have acute health effects. The human health effects of low-level, chronic exposure to coal-derived organic compounds in drinking water are currently unknown. Continuing studies will evaluate possible toxic effects from low level, chronic exposure to coal-derived organic compounds in drinking water supplies.

  18. [Advances in biomolecular machine: methane monooxygenases].

    Science.gov (United States)

    Lu, Jixue; Wang, Shizhen; Fang, Baishan

    2015-07-01

    Methane monooxygenases (MMO), regarded as "an amazing biomolecular machine", catalyze the oxidation of methane to methanol under aerobic conditions. MMO catalyze the oxidation of methane elaborately, which is a novel way to catalyze methane to methanol. Furthermore, MMO can inspire the biomolecular machine design. In this review, we introduced MMO including structure, gene and catalytic mechanism. The history and the taxonomy of MMO were also introduced.

  19. Potential methane reservoirs beneath Antarctica.

    Science.gov (United States)

    Wadham, J L; Arndt, S; Tulaczyk, S; Stibal, M; Tranter, M; Telling, J; Lis, G P; Lawson, E; Ridgwell, A; Dubnick, A; Sharp, M J; Anesio, A M; Butler, C E H

    2012-08-30

    Once thought to be devoid of life, the ice-covered parts of Antarctica are now known to be a reservoir of metabolically active microbial cells and organic carbon. The potential for methanogenic archaea to support the degradation of organic carbon to methane beneath the ice, however, has not yet been evaluated. Large sedimentary basins containing marine sequences up to 14 kilometres thick and an estimated 21,000 petagrams (1 Pg equals 10(15) g) of organic carbon are buried beneath the Antarctic Ice Sheet. No data exist for rates of methanogenesis in sub-Antarctic marine sediments. Here we present experimental data from other subglacial environments that demonstrate the potential for overridden organic matter beneath glacial systems to produce methane. We also numerically simulate the accumulation of methane in Antarctic sedimentary basins using an established one-dimensional hydrate model and show that pressure/temperature conditions favour methane hydrate formation down to sediment depths of about 300 metres in West Antarctica and 700 metres in East Antarctica. Our results demonstrate the potential for methane hydrate accumulation in Antarctic sedimentary basins, where the total inventory depends on rates of organic carbon degradation and conditions at the ice-sheet bed. We calculate that the sub-Antarctic hydrate inventory could be of the same order of magnitude as that of recent estimates made for Arctic permafrost. Our findings suggest that the Antarctic Ice Sheet may be a neglected but important component of the global methane budget, with the potential to act as a positive feedback on climate warming during ice-sheet wastage.

  20. The potential effects of sodium bicarbonate, a major constituent from coalbed natural gas production, on aquatic life

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.

    2012-01-01

    The production water from coalbed natural gas (CBNG) extraction contains many constituents. The U.S. Environmental Protection Agency has established aquatic life criteria for some of these constituents, and it is therefore possible to evaluate their risk to aquatic life. However, of the major ions associated with produced waters, chloride is the only one with an established aquatic life criterion (U.S. Environmental Protection Agency, 1988). The focus of this research was NaHCO3, a compound that is a major constituent of coalbed natural gas produced waters in the Tongue and Powder River Basins. This project included laboratory experiments, field in situ experiments, a field mixing zone study, and a fishery presence/absence assessment. Though this investigation focuses on the Tongue and Powder River Basins, the information is applicable to other watersheds where sodium bicarbonate is a principle component of product water either from CBNG or from traditional or unconventional oil and gas development. These data can also be used to separate effects of saline discharges from those potentially posed by other constituents. Finally, this research effort and the additional collaboration with USGS Water Resources and Mapping, Bureau of Land Management, US Environmental Protection Agency, State of Montana, State of Wyoming, Montana State University, University of Wyoming, and others as part of a Powder River Aquatic Task Group, can be used as a model for successful approaches to studying landscapes with energy development. The laboratory acute toxicity experiments were completed with a suite of organisms, including 7 species of fish, 5 species of invertebrates, and 1 amphibian species. Experiments performed on these multiple species resulted in LC50s that ranged from 1,120 to greater than (>) 8,000 milligrams sodium bicarbonate per liter (mg NaHCO3/L) (also defined as 769 to >8,000 milligrams bicarbonate per liter (mg HCO3-/L) or total alkalinity expressed as 608 to >4

  1. The potential effects of sodium bicarbonate, a major constituent from coalbed natural gas production, on aquatic life

    Science.gov (United States)

    Farag, Aida M.; Harper, David D.

    2012-01-01

    The production water from coalbed natural gas (CBNG) extraction contains many constituents. The U.S. Environmental Protection Agency has established aquatic life criteria for some of these constituents, and it is therefore possible to evaluate their risk to aquatic life. However, of the major ions associated with produced waters, chloride is the only one with an established aquatic life criterion (U.S. Environmental Protection Agency, 1988). The focus of this research was NaHCO3, a compound that is a major constituent of coalbed natural gas produced waters in the Tongue and Powder River Basins. This project included laboratory experiments, field in situ experiments, a field mixing zone study, and a fishery presence/absence assessment. Though this investigation focuses on the Tongue and Powder River Basins, the information is applicable to other watersheds where sodium bicarbonate is a principle component of product water either from CBNG or from traditional or unconventional oil and gas development. These data can also be used to separate effects of saline discharges from those potentially posed by other constituents. Finally, this research effort and the additional collaboration with USGS Water Resources and Mapping, Bureau of Land Management, US Environmental Protection Agency, State of Montana, State of Wyoming, Montana State University, University of Wyoming, and others as part of a Powder River Aquatic Task Group, can be used as a model for successful approaches to studying landscapes with energy development. The laboratory acute toxicity experiments were completed with a suite of organisms, including 7 species of fish, 5 species of invertebrates, and 1 amphibian species. Experiments performed on these multiple species resulted in LC50s that ranged from 1,120 to greater than (>) 8,000 milligrams sodium bicarbonate per liter (mg NaHCO3/L) (also defined as 769 to >8,000 milligrams bicarbonate per liter (mg HCO3-/L) or total alkalinity expressed as 608 to >4

  2. The potential effects of sodium bicarbonate, a major constituent from coalbed natural gas production, on aquatic life

    Science.gov (United States)

    Farag, Aïda M.; Harper, David D.

    2012-01-01

    The production water from coalbed natural gas (CBNG) extraction contains many constituents. The U.S. Environmental Protection Agency has established aquatic life criteria for some of these constituents, and it is therefore possible to evaluate their risk to aquatic life. However, of the major ions associated with produced waters, chloride is the only one with an established aquatic life criterion (U.S. Environmental Protection Agency, 1988). The focus of this research was NaHCO3, a compound that is a major constituent of coalbed natural gas produced waters in the Tongue and Powder River Basins. This project included laboratory experiments, field in situ experiments, a field mixing zone study, and a fishery presence/absence assessment. Though this investigation focuses on the Tongue and Powder River Basins, the information is applicable to other watersheds where sodium bicarbonate is a principle component of product water either from CBNG or from traditional or unconventional oil and gas development. These data can also be used to separate effects of saline discharges from those potentially posed by other constituents. Finally, this research effort and the additional collaboration with USGS Water Resources and Mapping, Bureau of Land Management, US Environmental Protection Agency, State of Montana, State of Wyoming, Montana State University, University of Wyoming, and others as part of a Powder River Aquatic Task Group, can be used as a model for successful approaches to studying landscapes with energy development. The laboratory acute toxicity experiments were completed with a suite of organisms, including 7 species of fish, 5 species of invertebrates, and 1 amphibian species. Experiments performed on these multiple species resulted in LC50s that ranged from 1,120 to greater than (>) 8,000 milligrams sodium bicarbonate per liter (mg NaHCO3/L) (also defined as 769 to >8,000 milligrams bicarbonate per liter (mg HCO3-/L) or total alkalinity expressed as 608 to >4

  3. 46 CFR 154.703 - Methane (LNG).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Methane (LNG). 154.703 Section 154.703 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... and Temperature Control § 154.703 Methane (LNG). Unless a cargo tank carrying methane (LNG)...

  4. Nitrogen-fixing methane-utilizing bacteria

    NARCIS (Netherlands)

    Bont, de J.A.M.

    1976-01-01

    Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in common that

  5. Methane oxidation needs less stressed plants.

    Science.gov (United States)

    Zhou, Xiaoqi; Smaill, Simeon J; Clinton, Peter W

    2013-12-01

    Methane oxidation rates in soil are liable to be reduced by plant stress responses to climate change. Stressed plants exude ethylene into soil, which inhibits methane oxidation when present in the soil atmosphere. Here we discuss opportunities to use 1-aminocyclopropane-1-carboxylate deaminase to manage methane oxidation by regulating plant stress responses.

  6. Are methane production and cattle performance related?

    Science.gov (United States)

    Methane is a product of fermentation of feed in ruminant animals. Approximately 2 -12% of the gross energy consumed by cattle is released through enteric methane production. There are three primary components that contribute to the enteric methane footprint of an animal. Those components are dry ...

  7. Nitrogen-fixing methane-utilizing bacteria

    NARCIS (Netherlands)

    Bont, de J.A.M.

    1976-01-01

    Methane occurs abundantly in nature. In the presence of oxygen this gas may be metabolized by bacteria that are able to use it as carbon and energy source. Several types of bacteria involved in the oxidation of methane have been described in literature. Methane-utilizing bacteria have in

  8. Methane, vegetation and global climate change; Methan, Pflanzen und Klimawandel

    Energy Technology Data Exchange (ETDEWEB)

    Keppler, F. [Max-Planck-Institut fuer Chemie (Otto-Hahn-Institut), Mainz (Germany); Roeckmann, T. [Utrecht Univ. (Netherlands). Inst. fuer Meeres- und Atmosphaerenforschung

    2007-05-15

    In a recent publication, the authors were able to prove that plants produce and emit methane. This means a major change in the global emission balance of this climate-relevant gas. Plants are not involved in global climate change, however. (orig.)

  9. Sea of Scenarios: Reducing Uncertainties in Methane Projections

    Science.gov (United States)

    Matthews, E.; Baum, E.

    2010-12-01

    Climate-chemistry model experiments for the 21st century have relied almost exclusively on a small set of unexamined methane (and other) emission projections from economics-based models. Over the past decade, the US Environmental Protection Agency and the International Institute of Applied Systems Analysis (IIASA) provided baseline and mitigation methane scenarios. The SRES family of projections for the IPCC Third Assessment Report (2001) encompassed multiple economic, demographic, and environmental assumptions quantified by several models. In contrast to both of these efforts, plans for IPCC5 include additional scenario development consistent with end-of-century forcings ranging from 2.6 to 8.5W/m2. The largely black-box nature of emission projections used in climate-chemistry experiments and policy analyses has received little attention despite the substantial influence these inputs can exert. This lack of transparency makes assessing the likelihood, or even the plausibility, of projected emissions difficult, contributes to uncertainties in climate simulations, and leaves policy discussions lacking the practical understanding needed to decide on mitigation strategies. We report on analysis of multiple baseline and mitigation methane projections, including our own new ones, to assess the plausibility of underlying assumptions and data. We propose that this analysis can reduce uncertainties in climate predictions by restricting, not enlarging, the suite of methane scenarios to those likely to occur.

  10. Phenomenon of methane driven caused by hydraulic fracturing in methane-bearing coal seams

    Institute of Scientific and Technical Information of China (English)

    Huang Bingxiang; Cheng Qingying; Chen Shuliang

    2016-01-01

    The methane concentration of the return current will always be enhanced to a certain degree when hydraulic fracturing with bedding drilling is implemented to a gassy coal seam in an underground coal mine. The methane in coal seam is driven out by hydraulic fracturing. Thus, the phenomenon is named as methane driven effect of hydraulic fracturing. After deep-hole hydraulic fracturing at the tunneling face of the gassy coal seam, the coal methane content exhibits a‘low-high-low”distribution along exca-vation direction in the following advancing process, verifying the existence of methane driven caused by hydraulic fracturing in methane-bearing coal seam. Hydraulic fracturing causes the change of pore-water and methane pressure in surrounding coal. The uneven distribution of the pore pressure forms a pore pressure gradient. The free methane migrates from the position of high pore (methane) pressure to the position of low pore (methane) pressure. The methane pressure gradient is the fundamental driving force for methane-driven coal seam hydraulic fracturing. The uneven hydraulic crack propagation and the effect of time (as some processes need time to complete and are not completed instantaneously) will result in uneven methane driven. Therefore, an even hydraulic fracturing technique should be used to avoid the negative effects of methane driven; on the other hand, by taking fully advantage of methane driven, two technologies are presented.

  11. Cryptic Methane Emissions from Upland Forest Ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Megonigal, Patrick [Smithsonian Institution, Washington, DC (United States); Pitz, Scott [Johns Hopkins Univ., Baltimore, MD (United States); Smithsonian Institution, Washington, DC (United States)

    2016-04-19

    This exploratory research on Cryptic Methane Emissions from Upland Forest Ecosystems was motivated by evidence that upland ecosystems emit 36% as much methane to the atmosphere as global wetlands, yet we knew almost nothing about this source. The long-term objective was to refine Earth system models by quantifying methane emissions from upland forests, and elucidate the biogeochemical processes that govern upland methane emissions. The immediate objectives of the grant were to: (i) test the emerging paradigm that upland trees unexpectedly transpire methane, (ii) test the basic biogeochemical assumptions of an existing global model of upland methane emissions, and (iii) develop the suite of biogeochemical approaches that will be needed to advance research on upland methane emissions. We instrumented a temperate forest system in order to explore the processes that govern upland methane emissions. We demonstrated that methane is emitted from the stems of dominant tree species in temperate upland forests. Tree emissions occurred throughout the growing season, while soils adjacent to the trees consumed methane simultaneously, challenging the concept that forests are uniform sinks of methane. High frequency measurements revealed diurnal cycling in the rate of methane emissions, pointing to soils as the methane source and transpiration as the most likely pathway for methane transport. We propose the forests are smaller methane sinks than previously estimated due to stem emissions. Stem emissions may be particularly important in upland tropical forests characterized by high rainfall and transpiration, resolving differences between models and measurements. The methods we used can be effectively implemented in order to determine if the phenomenon is widespread.

  12. Baseline study of methane emission from anaerobic ponds of palm oil mill effluent treatment.

    Science.gov (United States)

    Yacob, Shahrakbah; Ali Hassan, Mohd; Shirai, Yoshihito; Wakisaka, Minato; Subash, Sunderaj

    2006-07-31

    The world currently obtains its energy from the fossil fuels such as oil, natural gas and coal. However, the international crisis in the Middle East, rapid depletion of fossil fuel reserves as well as climate change have driven the world towards renewable energy sources which are abundant, untapped and environmentally friendly. Malaysia has abundant biomass resources generated from the agricultural industry particularly the large commodity, palm oil. This paper will focus on palm oil mill effluent (POME) as the source of renewable energy from the generation of methane and establish the current methane emission from the anaerobic treatment facility. The emission was measured from two anaerobic ponds in Felda Serting Palm Oil Mill for 52 weeks. The results showed that the methane content was between 35.0% and 70.0% and biogas flow rate ranged between 0.5 and 2.4 L/min/m(2). Total methane emission per anaerobic pond was 1043.1 kg/day. The total methane emission calculated from the two equations derived from relationships between methane emission and total carbon removal and POME discharged were comparable with field measurement. This study also revealed that anaerobic pond system is more efficient than open digesting tank system for POME treatment. Two main factors affecting the methane emission were mill activities and oil palm seasonal cropping.

  13. Development and evaluation of a suite of isotope reference gases for methane in air

    Science.gov (United States)

    Sperlich, Peter; Uitslag, Nelly A. M.; Richter, Jürgen M.; Rothe, Michael; Geilmann, Heike; van der Veen, Carina; Röckmann, Thomas; Blunier, Thomas; Brand, Willi A.

    2016-08-01

    Measurements from multiple laboratories have to be related to unifying and traceable reference material in order to be comparable. However, such fundamental reference materials are not available for isotope ratios in atmospheric methane, which led to misinterpretations of combined data sets in the past. We developed a method to produce a suite of synthetic CH4-in-air standard gases that can be used to unify methane isotope ratio measurements of laboratories in the atmospheric monitoring community. Therefore, we calibrated a suite of pure methane gases of different methanogenic origin against international referencing materials that define the VSMOW (Vienna Standard Mean Ocean Water) and VPDB (Vienna Pee Dee Belemnite) isotope scales. The isotope ratios of our pure methane gases range between -320 and +40 ‰ for δ2H-CH4 and between -70 and -40 ‰ for δ13C-CH4, enveloping the isotope ratios of tropospheric methane (about -85 and -47 ‰ for δ2H-CH4 and δ13C-CH4 respectively). Estimated uncertainties, including the full traceability chain, are JRAS-M16 (Jena Reference Air Set - Methane 2016) and will be available to the atmospheric monitoring community. JRAS-M16 may be used as unifying isotope scale anchor for isotope ratio measurements in atmospheric methane, so that data sets can be merged into a consistent global data frame.

  14. Steam Methane Reformation Testing for Air-Independent Solid Oxide Fuel Cell Systems

    Science.gov (United States)

    Mwara, Kamwana N.

    2015-01-01

    Recently, NASA has been looking into utilizing landers that can be propelled by LOX-CH (sub 4), to be used for long duration missions. Using landers that utilize such propellants, also provides the opportunity to use solid oxide fuel cells as a power option, especially since they are able to process methane into a reactant through fuel reformation. One type of reformation, called steam methane reformation, is a process to reform methane into a hydrogen-rich product by reacting methane and steam (fuel cell exhaust) over a catalyst. A steam methane reformation system could potentially use the fuel cell's own exhaust to create a reactant stream that is hydrogen-rich, and requires less internal reforming of the incoming methane. Also, steam reformation may hold some advantages over other types of reforming, such as partial oxidation (PROX) reformation. Steam reformation does not require oxygen, while up to 25 percent can be lost in PROX reformation due to unusable CO (sub 2) reformation. NASA's Johnson Space Center has conducted various phases of steam methane reformation testing, as a viable solution for in-space reformation. This has included using two different types of catalysts, developing a custom reformer, and optimizing the test system to find the optimal performance parameters and operating conditions.

  15. Methane on the greenhouse agenda

    Science.gov (United States)

    Hogan, Kathleen B.; Hoffman, John S.; Thompson, Anne M.

    1991-01-01

    Options for reducing methane emissions, which could have a significant effect on global warming, are addressed. Emissions from landfills, coal mining, oil and natural gas systems, ruminants, animal wastes and wastewater, rice cultivation, and biomass burning are considered. Methods for implementing these emission reductions are discussed.

  16. 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.

  17. Methane generation from waste materials

    Science.gov (United States)

    Samani, Zohrab A.; Hanson, Adrian T.; Macias-Corral, Maritza

    2010-03-23

    An organic solid waste digester for producing methane from solid waste, the digester comprising a reactor vessel for holding solid waste, a sprinkler system for distributing water, bacteria, and nutrients over and through the solid waste, and a drainage system for capturing leachate that is then recirculated through the sprinkler system.

  18. Coal Mine Methane in Russia

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    This paper discusses coal mine methane emissions (CMM) in the Russian Federation and the potential for their productive utilisation. It highlights specific opportunities for cost-effective reductions of CMM from oil and natural gas facilities, coal mines and landfills, with the aim of improving knowledge about effective policy approaches.

  19. Methane Dynamics in Flooded Lands

    Science.gov (United States)

    Methane (CH4) is the second most important anthropogenic greenhouse gas with a heat trapping capacity 34 times greater than that of carbon dioxide on a100 year time scale. Known anthropogenic CH4 sources include livestock production, rice agriculture, landfills, and natural gas m...

  20. Ductile flow of methane hydrate

    Science.gov (United States)

    Durham, W.B.; Stern, L.A.; Kirby, S.H.

    2003-01-01

    Compressional creep tests (i.e., constant applied stress) conducted on pure, polycrystalline methane hydrate over the temperature range 260-287 K and confining pressures of 50-100 MPa show this material to be extraordinarily strong compared to other icy compounds. The contrast with hexagonal water ice, sometimes used as a proxy for gas hydrate properties, is impressive: over the thermal range where both are solid, methane hydrate is as much as 40 times stronger than ice at a given strain rate. The specific mechanical response of naturally occurring methane hydrate in sediments to environmental changes is expected to be dependent on the distribution of the hydrate phase within the formation - whether arranged structurally between and (or) cementing sediments grains versus passively in pore space within a sediment framework. If hydrate is in the former mode, the very high strength of methane hydrate implies a significantly greater strain-energy release upon decomposition and subsequent failure of hydrate-cemented formations than previously expected.

  1. Methane clathrates in the Solar System

    CERN Document Server

    Mousis, Olivier; Holm, Nils G; Bouquet, Alexis; Waite, Jack Hunter; Geppert, Wolf Dietrich; Picaud, Sylvain; Aikawa, Yuri; Ali-Dib, Mohamad; Charlou, Jean-Luc; Rousselot, Philippe

    2015-01-01

    We review the reservoirs of methane clathrates that may exist in the different bodies of the Solar System. Methane was formed in the interstellar medium prior to having been embedded in the protosolar nebula gas phase. This molecule was subsequently trapped in clathrates that formed from crystalline water ice during the cooling of the disk and incorporated in this form in the building blocks of comets, icy bodies, and giant planets. Methane clathrates may play an important role in the evolution of planetary atmospheres. On Earth, the production of methane in clathrates is essentially biological, and these compounds are mostly found in permafrost regions or in the sediments of continental shelves. On Mars, methane would more likely derive from hydrothermal reactions with olivine-rich material. If they do exist, martian methane clathrates would be stable only at depth in the cryosphere and sporadically release some methane into the atmosphere via mechanisms that remain to be determined.

  2. Response of the Black Sea methane budget to massive short-term submarine inputs of methane

    DEFF Research Database (Denmark)

    Schmale, O.; Haeckel, M.; McGinnis, D. F.

    2011-01-01

    A steady state box model was developed to estimate the methane input into the Black Sea water column at various water depths. Our model results reveal a total input of methane of 4.7 Tg yr(-1). The model predicts that the input of methane is largest at water depths between 600 and 700 m (7......% of the total input), suggesting that the dissociation of methane gas hydrates at water depths equivalent to their upper stability limit may represent an important source of methane into the water column. In addition we discuss the effects of massive short-term methane inputs (e. g. through eruptions of deep......-water mud volcanoes or submarine landslides at intermediate water depths) on the water column methane distribution and the resulting methane emission to the atmosphere. Our non-steady state simulations predict that these inputs will be effectively buffered by intense microbial methane consumption...

  3. Opaque closed chambers underestimate methane fluxes of Phragmites australis (Cav.) Trin. ex Steud.

    Science.gov (United States)

    Günther, Anke; Jurasinski, Gerald; Huth, Vytas; Glatzel, Stephan

    2014-04-01

    Closed chamber measurements for methane emission estimation are often carried out with opaque chambers to avoid heating of the headspace. However, mainly in wetlands, some plants possess an internal convective gas transport which quickly responds to changes in irradiation. These plants have also been found to often channel a large part of the released methane in temperate fens. We compare methane fluxes derived from transparent versus opaque chambers on Carex-, Phragmites-, and Typha-dominated stands of a temperate fen. Transparent chamber fluxes almost doubled opaque chamber fluxes in the convective transporting Phragmites stand. In Typha, a trend of higher fluxes determined with the transparent chambers was detectable, whereas in Carex, transparent and opaque chamber fluxes did not differ significantly. Thus, opaque chambers bias the outcome of methane measurements, depending on dominant vegetation. We recommend the use of transparent chambers when determining emissions of convective plants or extrapolating fluxes to larger scales.

  4. 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

  5. Impact of transport model errors on the global and regional methane emissions estimated by inverse modelling

    Directory of Open Access Journals (Sweden)

    R. Locatelli

    2013-04-01

    Full Text Available A modelling experiment has been conceived to assess the impact of transport model errors on the methane emissions estimated by an atmospheric inversion system. Synthetic methane observations, given by 10 different model outputs from the international TransCom-CH4 model exercise, are combined with a prior scenario of methane emissions and sinks, and integrated into the PYVAR-LMDZ-SACS inverse system to produce 10 different methane emission estimates at the global scale for the year 2005. The same set-up has been used to produce the synthetic observations and to compute flux estimates by inverse modelling, which means that only differences in the modelling of atmospheric transport may cause differences in the estimated fluxes. In our framework, we show that transport model errors lead to a discrepancy of 27 Tg CH4 per year at the global scale, representing 5% of the total methane emissions. At continental and yearly scales, transport model errors have bigger impacts depending on the region, ranging from 36 Tg CH4 in north America to 7 Tg CH4 in Boreal Eurasian (from 23% to 48%. At the model gridbox scale, the spread of inverse estimates can even reach 150% of the prior flux. Thus, transport model errors contribute to significant uncertainties on the methane estimates by inverse modelling, especially when small spatial scales are invoked. Sensitivity tests have been carried out to estimate the impact of the measurement network and the advantage of higher resolution models. The analysis of methane estimated fluxes in these different configurations questions the consistency of transport model errors in current inverse systems. For future methane inversions, an improvement in the modelling of the atmospheric transport would make the estimations more accurate. Likewise, errors of the observation covariance matrix should be more consistently prescribed in future inversions in order to limit the impact of transport model errors on estimated methane

  6. Variability of geochemical properties in a microbially dominated coalbed gas system from the eastern margin of the Illinois Basin, USA

    Science.gov (United States)

    Strapoc, D.; Mastalerz, Maria; Schimmelmann, A.; Drobniak, A.; Hedges, S.

    2008-01-01

    This study outlines gas characteristics along the southeastern margins of the Illinois Basin and evaluates regional versus local gas variations in Seelyville and Springfield coal beds. Our findings suggest that high permeability and shallow (100-250??m) depths of these Indiana coals allowed inoculation with methanogenic microbial consortia, thus leading to widespread microbial methane generation along the eastern marginal part of the Illinois Basin. Low maturity coals in the Illinois Basin with a vitrinite reflectance Ro ~ 0.6% contain significant amounts of coal gas (~ 3??m3/t, 96??scf/t) with ??? 97??vol.% microbial methane. The amount of coal gas can vary significantly within a coal seam both in a vertical seam section as well as laterally from location to location. Therefore sampling of an entire core section is required for accurate estimates of coal gas reserves. ?? 2008 Elsevier B.V. All rights reserved.

  7. Effects of coalbed natural gas development on fish assemblages in tributary streams of the Powder and Tongue rivers

    Science.gov (United States)

    Davis, W.N.; Bramblett, R.G.; Zale, A.V.

    2010-01-01

    1. Extraction of coalbed natural gas (CBNG) often results in disposal of large quantities of CBNG product water, which may affect aquatic ecosystems. We evaluated the effects of CBNG development on fish assemblages in tributary streams of the Powder and Tongue rivers. We used treatment and control, impact versus reference sites comparisons, surveys of CBNG product-water streams and in situ fish survival approaches to determine if CBNG development affected fish assemblages.2. Several of our results suggested that CBNG development did not affect fish assemblages. Species richness and index of biotic integrity (IBI) scores were similar in streams with and streams without CBNG development, and overall biotic integrity was not related to the number or density of CBNG wells. Fish occurred in one stream that was composed largely or entirely of CBNG product water. Sentinel fish survived in cages at treatment sites where no or few fish were captured, suggesting that factors such as lack of stream connectivity rather than water quality limited fish abundance at these sites. Fish species richness did not differ significantly from 1994 to 2006 in comparisons of CBNG-developed and undeveloped streams. Biotic integrity declined from 1994 to 2006; however, declines occurred at both impact and reference sites, possibly because of long-term drought.3. Some evidence suggested that CBNG development negatively affected fish assemblages, or may do so over time. Specific conductivity was on average higher in treatment streams and was negatively related to biotic integrity. Four IBI species richness metrics were negatively correlated with the number or density of CBNG wells in the catchment above sampling sites. Bicarbonate, one of the primary ions in product water, was significantly higher in developed streams and may have limited abundance of longnose dace (Rhinichthys cataractae). Total dissolved solids, alkalinity, magnesium and sulphate were significantly higher in developed streams

  8. 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

  9. 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

  10. Herds of methane chambers grazing bubbles

    Science.gov (United States)

    Grinham, Alistair; Dunbabin, Matthew

    2014-05-01

    Water to air methane emissions from freshwater reservoirs can be dominated by sediment bubbling (ebullitive) events. Previous work to quantify methane bubbling from a number of Australian sub-tropical reservoirs has shown that this can contribute as much as 95% of total emissions. These bubbling events are controlled by a variety of different factors including water depth, surface and internal waves, wind seiching, atmospheric pressure changes and water levels changes. Key to quantifying the magnitude of this emission pathway is estimating both the bubbling rate as well as the areal extent of bubbling. Both bubbling rate and areal extent are seldom constant and require persistent monitoring over extended time periods before true estimates can be generated. In this paper we present a novel system for persistent monitoring of both bubbling rate and areal extent using multiple robotic surface chambers and adaptive sampling (grazing) algorithms to automate the quantification process. Individual chambers are self-propelled and guided and communicate between each other without the need for supervised control. They can maintain station at a sampling site for a desired incubation period and continuously monitor, record and report fluxes during the incubation. To exploit the methane sensor detection capabilities, the chamber can be automatically lowered to decrease the head-space and increase concentration. The grazing algorithms assign a hierarchical order to chambers within a preselected zone. Chambers then converge on the individual recording the highest 15 minute bubbling rate. Individuals maintain a specified distance apart from each other during each sampling period before all individuals are then required to move to different locations based on a sampling algorithm (systematic or adaptive) exploiting prior measurements. This system has been field tested on a large-scale subtropical reservoir, Little Nerang Dam, and over monthly timescales. Using this technique

  11. [Copper in methane oxidation: a review].

    Science.gov (United States)

    Su, Yao; Kong, Jiao-Yan; Zhang, Xuan; Xia, Fang-Fang; He, Ruo

    2014-04-01

    Methane bio-oxidation plays an important role in the global methane balance and warming mitigation, while copper has a crucial function in methane bio-oxidation. On one side, copper is known to be a key factor in regulating the expression of the genes encoding the two forms of methane monooxygenases (MMOs) and is the essential metal element of the particulate methane monooxygenase (pMMO). On the other side, the content and fractionation of copper in the environment have great effects on the distribution of methanotrophs and their metabolic capability of methane and non-methane organic compounds, as well as on the copper-specific uptake systems in methanotrophs. Thus, it is meaningful to know the role of copper in methane bio-oxidation for comprehensive understanding of this process and is valuable for guiding the application of methanotrophs in greenhouse gas removal and pollution remediation. In this paper, the roles of copper in methane oxidation were reviewed, including the effect of copper on methanotrophic community structure and activity, the expression and activity of MMOs as well as the copper uptake systems in methanotrophs. The future studies of copper and methane oxidation were also discussed.

  12. Methane recovery from animal manures: A current opportunities casebook

    Energy Technology Data Exchange (ETDEWEB)

    Lusk, P. [Resource Development Associates, Marietta, GA (United States)

    1994-12-01

    One manure management system provides not only pollution prevention but also converts a manure management problem into a new profit center. Economic evaluations and case studies of operating systems indicate that the anaerobic digestion of livestock manures is a commercially-available bioconversion technology with considerable potential for providing profitable co-products including a cost-effective renewable fuel for livestock production operations. This Casebook examines some of the current opportunities for the recovery of methane from the anaerobic digestion of animal manures. The economic evaluations are based on engineering studies of digesters that generate electricity from the recovered methane. Regression models, which can be used to estimate digester cost and internal rate of return, are developed from the evaluations. Finally, anaerobic digestion has considerable potential beyond agribusiness. Examples of digesters currently employed by other industries are provided.

  13. Modeling of microscale variations in methane fluxes

    Energy Technology Data Exchange (ETDEWEB)

    Kettunen, A.

    2002-07-01

    The current study analyzes the different modes of variation in methane fluxes from different microsites of a boreal mire. The results emphasize the importance of microsite characteristics, water table and vegetation cover for methane fluxes. Water level affects the moisture and oxygen profiles in peat matrix which are reflected to methane production and oxidation rates and the corresponding microbial populations. Vascular plants promote methane production by providing substrates in the form of root exudates and fine root litter, enhance methane oxidation by transporting oxygen to water saturated peat layers and accelerate methane transport by liberating methane from peat to the atmosphere via the aerenchymous tissue. The model presented in this study connects the methane fluxes to the seasonal photosynthetic cycle of plants at the microsite level while the thermal and hydrological conditions in peat are used as an operational framework. Overall, the model dynamically combines the microbial processes in peat to changing environmental factors in the level of peatland ecosystem. Sensitivity analysis of the model reveals the importance of substrate supply to methane fluxes. Furthermore, the model outcome is sensitive to increased capability of the vascular plants to transport oxygen downwards. Lack of oxygen and partly methane keep methane oxidation at a very low level. Any changes in model parameters or environmental conditions that compensate for these lacks have a remarkable decreasing effect on simulated flux. Simulated methane flux decreases considerably if the duration of simulated dry period increases, threshold for a dramatic change lying between 4 and 6 weeks of drought. Increase in air temperature enhances methane flux especially if the effect of increased temperature on gross primary production is taken into account. (orig.)

  14. Photocatalytic conversion of methane to methanol

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, C.E.; Noceti, R.P.; D`Este, J.R. [Pittsburgh Energy Technology Center, PA (United States)

    1995-12-31

    A long-term goal of our research group is the exploration of novel pathways for the direct oxidation of methane to liquid fuels, chemicals, and intermediates. The use of three relatively abundant and inexpensive reactants, light, water, and methane, to produce methanol is attractive. The products of reaction, methanol and hydrogen, are both commercially desirable, methanol being used as is or converted to a variety of other chemicals, and the hydrogen could be utilized in petroleum and/or chemical manufacturing. Methane is produced as a by-product of coal gasification. Depending upon reactor design and operating conditions, up to 18% of total gasifier product may be methane. In addition, there are vast proven reserves of geologic methane in the world. Unfortunately, a large fraction of these reserves are in regions where there is little local demand for methane and it is not economically feasible to transport it to a market. There is a global research effort under way in academia, industry, and government to find methods to convert methane to useful, more readily transportable and storable materials. Methanol, the initial product of methane oxidation, is a desirable product of conversion because it retains much of the original energy of the methane while satisfying transportation and storage requirements. Investigation of direct conversion of methane to transportation fuels has been an ongoing effort at PETC for over 10 years. One of the current areas of research is the conversion of methane to methanol, under mild conditions, using light, water, and a semiconductor photocatalyst. The use of three relatively abundant and inexpensive reactants, light, water, and methane, to produce methanol, is attractive. Research in the laboratory is directed toward applying the techniques developed for the photocatalytic splitting of the water and the photochemical conversion of methane.

  15. Assessment of potential effects of water produced from coalbed natural gas development on macroinvertebrate and algal communities in the Powder River and Tongue River, Wyoming and Montana, 2010

    Science.gov (United States)

    Peterson, David A.; Hargett, Eric G.; Feldman, David L.

    2011-01-01

    Ongoing development of coalbed natural gas in the Powder River structural basin in Wyoming and Montana led to formation of an interagency aquatic task group to address concerns about the effects of the resulting production water on biological communities in streams of the area. Ecological assessments, made from 2005–08 under the direction of the task group, indicated biological condition of the macroinvertebrate and algal communities in the middle reaches of the Powder was lower than in the upper or lower reaches. On the basis of the 2005–08 results, sampling of the macroinvertebrate and algae communities was conducted at 18 sites on the mainstem Powder River and 6 sites on the mainstem Tongue River in 2010. Sampling-site locations were selected on a paired approach, with sites located upstream and downstream of discharge points and tributaries associated with coalbed natural gas development. Differences in biological condition among site pairs were evaluated graphically and statistically using multiple lines of evidence that included macroinvertebrate and algal community metrics (such as taxa richness, relative abundance, functional feeding groups, and tolerance) and output from observed/expected (O/E) macroinvertebrate models from Wyoming and Montana. Multiple lines of evidence indicated a decline in biological condition in the middle reaches of the Powder River, potentially indicating cumulative effects from coalbed natural gas discharges within one or more reaches between Flying E Creek and Wild Horse Creek in Wyoming. The maximum concentrations of alkalinity in the Powder River also occurred in the middle reaches. Biological condition in the upper and lower reaches of the Powder River was variable, with declines between some site pairs, such as upstream and downstream of Dry Fork and Willow Creek, and increases at others, such as upstream and downstream of Beaver Creek. Biological condition at site pairs on the Tongue River showed an increase in one case

  16. Incentives for Methane Mitigation and Energy-Efficiency Improvements in Case of Ukraine’s Natural Gas Transmission System

    Energy Technology Data Exchange (ETDEWEB)

    Roshchanka, Volha; Evans, Meredydd

    2014-06-01

    Reducing methane losses is a concern for climate change policy and energy policy. The energy sector is the major source of methane emissions into the atmosphere. Reducing methane emissions and avoiding combustion can be very cost-effective, but various barriers prevent such energy-efficiency measures from taking place. To date, few examples of industry-wide improvements exist. One example of substantial investments into upgrading natural gas transmission system comes from Ukraine. The Ukrainian transmission company, Ukrtransgaz, reduced its own system’s natural gas consumption by 68 percent in 2011 compared to the level in 2005. Evaluating reductions in methane emissions is challenging because of lack of accurate data and gaps in accounting methodologies. At the same time, Ukraine’s transmission system has undergone improvements that, at the very least, have contained methane emissions, if not substantially reduced them. In this paper, we describe recent developments in Ukraine’s natural gas transmission system and analyze the incentives that forced the sector to pay close attention to its methane losses. Ukraine is one of most energy-intensive countries, among the largest natural gas consumers in the world, and a significant emitter of methane. The country is also dependent on imports of natural gas. A combination of steep increases in the price of imported natural gas, and comprehensive domestic environmental and energy policies, regional integration policy, and international environmental agreements has created conditions for successful methane emission and combustion reductions. Learning about such case studies can help us design better policies elsewhere.

  17. Factors Affecting Methane Emission from Rice Paddies

    Institute of Scientific and Technical Information of China (English)

    于心科; 王卫东; 等

    1995-01-01

    A comparative study of rice paddies and the uncovered water field in Taoyuan(Hunan) showed that methane emission from rice-vegetated paddy fields in 1993 was different from that in 1992(I,e,lower in rates and irregular in pattern).Climate has obvious influence on methane emission .And ebullition made a considerable contribution to the total flux of methane emission from rice paddies (45%).This implies that the intensification of paddy cultivation of rice might not be,as was proposed,the main con-tributor to the observed gradual increasing of atmospheric methane.24-hour automatic measurements of atmospheric temperature,air temperature and methane concentration in the static sampling boxes revealed that temperature,in addition to fertilization and irrigation style,is one of the most important factors that control the emission of methane from rice paddies.

  18. Evidence for methane in Martian meteorites.

    Science.gov (United States)

    Blamey, Nigel J F; Parnell, John; McMahon, Sean; Mark, Darren F; Tomkinson, Tim; Lee, Martin; Shivak, Jared; Izawa, Matthew R M; Banerjee, Neil R; Flemming, Roberta L

    2015-06-16

    The putative occurrence of methane in the Martian atmosphere has had a major influence on the exploration of Mars, especially by the implication of active biology. The occurrence has not been borne out by measurements of atmosphere by the MSL rover Curiosity but, as on Earth, methane on Mars is most likely in the subsurface of the crust. Serpentinization of olivine-bearing rocks, to yield hydrogen that may further react with carbon-bearing species, has been widely invoked as a source of methane on Mars, but this possibility has not hitherto been tested. Here we show that some Martian meteorites, representing basic igneous rocks, liberate a methane-rich volatile component on crushing. The occurrence of methane in Martian rock samples adds strong weight to models whereby any life on Mars is/was likely to be resident in a subsurface habitat, where methane could be a source of energy and carbon for microbial activity.

  19. Methane Pyrolysis and Disposing Off Resulting Carbon

    Science.gov (United States)

    Sharma, P. K.; Rapp, D.; Rahotgi, N. K.

    1999-01-01

    Sabatier/Electrolysis (S/E) is a leading process for producing methane and oxygen for application to Mars ISPP. One significant problem with this process is that it produces an excess of methane for combustion with the amount of oxygen that is produced. Therefore, one must discard roughly half of the methane to obtain the proper stoichiometric methane/oxygen mixture for ascent from Mars. This is wasteful of hydrogen, which must be brought from Earth and is difficult to transport to Mars and store on Mars. To reduced the problem of transporting hydrogen to Mars, the S/E process can be augmented by another process which reduces overall hydrogen requirement. Three conceptual approaches for doing this are (1) recover hydrogen from the excess methane produced by the S/E process, (2) convert the methane to a higher hydrocarbon or other organic with a lower H/C ratio than methane, and (3) use a separate process (such as zirconia or reverse water gas shift reaction) to produce additional oxygen, thus utilizing all the methane produced by the Sabatier process. We report our results here on recovering hydrogen from the excess methane using pyrolysis of methane. Pyrolysis has the advantage that it produces almost pure hydrogen, and any unreacted methane can pass through the S/E process reactor. It has the disadvantage that disposing of the carbon produced by pyrolysis presents difficulties. Hydrogen may be obtained from methane by pyrolysis in the temperature range 10000-12000C. The main reaction products are hydrogen and carbon, though very small amounts of higher hydrocarbons, including aromatic hydrocarbons are formed. The conversion efficiency is about 95% at 12000C. One needs to distinguish between thermodynamic equilibrium conversion and conversion limited by kinetics in a finite reactor.

  20. Ebullitive methane emissions from oxygenated wetland streams.

    Science.gov (United States)

    Crawford, John T; Stanley, Emily H; Spawn, Seth A; Finlay, Jacques C; Loken, Luke C; Striegl, Robert G

    2014-11-01

    Stream and river carbon dioxide emissions are an important component of the global carbon cycle. Methane emissions from streams could also contribute to regional or global greenhouse gas cycling, but there are relatively few data regarding stream and river methane emissions. Furthermore, the available data do not typically include the ebullitive (bubble-mediated) pathway, instead focusing on emission of dissolved methane by diffusion or convection. Here, we show the importance of ebullitive methane emissions from small streams in the regional greenhouse gas balance of a lake and wetland-dominated landscape in temperate North America and identify the origin of the methane emitted from these well-oxygenated streams. Stream methane flux densities from this landscape tended to exceed those of nearby wetland diffusive fluxes as well as average global wetland ebullitive fluxes. Total stream ebullitive methane flux at the regional scale (103 Mg C yr(-1) ; over 6400 km(2) ) was of the same magnitude as diffusive methane flux previously documented at the same scale. Organic-rich stream sediments had the highest rates of bubble release and higher enrichment of methane in bubbles, but glacial sand sediments also exhibited high bubble emissions relative to other studied environments. Our results from a database of groundwater chemistry support the hypothesis that methane in bubbles is produced in anoxic near-stream sediment porewaters, and not in deeper, oxygenated groundwaters. Methane interacts with other key elemental cycles such as nitrogen, oxygen, and sulfur, which has implications for ecosystem changes such as drought and increased nutrient loading. Our results support the contention that streams, particularly those draining wetland landscapes of the northern hemisphere, are an important component of the global methane cycle.

  1. Methane storage in porous activated carbons

    OpenAIRE

    Perl, András; Gemert, Wim van

    2014-01-01

    Locally produced methane, - either as biomethane or power-to-gas product, has to be stored to provide a reliable gas source for the fluctuating demand of any local gas distribution network. Additionally, methane is a prominent transportation fuel but its suitability for vehicular application depends on the ability to store an adequate amount in the onboard fuel tank. Adsorption in porous materials could enable a simple, safe and cost-effective method for storing methane at ambient temperature...

  2. Dangerous effects of methane gas in atmosphere

    OpenAIRE

    Mohajan, Haradhan

    2011-01-01

    This paper discusses the effects of methane gas which causes sever global warming in the atmosphere. Global warming becomes main issue in economics in the 21st century. Because global climate change becomes more dangerous and every nation realized that this is due to greenhouse gas emissions. Methane is dangerous greenhouse gas, since it is 21 times more global warming potential than carbon dioxide. All the nations talk about the reduction of only carbon dioxide and no nation stress on methan...

  3. Methane storage in dry water gas hydrates.

    Science.gov (United States)

    Wang, Weixing; Bray, Christopher L; Adams, Dave J; Cooper, Andrew I

    2008-09-03

    Dry water stores 175 v(STP)/v methane at 2.7 MPa and 273.2 K in a hydrate form which is close to the Department of Energy volumetric target for methane storage. Dry water is a silica-stabilized free-flowing powder (95% wt water), and fast methane uptakes were observed (90% saturation uptake in 160 min with no mixing) as a result of the relatively large surface-to-volume ratio of this material.

  4. Ebullitive methane emissions from oxygenated wetland streams

    Science.gov (United States)

    Crawford, John T.; Stanley, Emily H.; Spawn, Seth A.; Finlay, Jacques C.; Striegl, Robert G.

    2014-01-01

    Stream and river carbon dioxide emissions are an important component of the global carbon cycle. Methane emissions from streams could also contribute to regional or global greenhouse gas cycling, but there are relatively few data regarding stream and river methane emissions. Furthermore, the available data do not typically include the ebullitive (bubble-mediated) pathway, instead focusing on emission of dissolved methane by diffusion or convection. Here, we show the importance of ebullitive methane emissions from small streams in the regional greenhouse gas balance of a lake and wetland-dominated landscape in temperate North America and identify the origin of the methane emitted from these well-oxygenated streams. Stream methane flux densities from this landscape tended to exceed those of nearby wetland diffusive fluxes as well as average global wetland ebullitive fluxes. Total stream ebullitive methane flux at the regional scale (103 Mg C yr−1; over 6400 km2) was of the same magnitude as diffusive methane flux previously documented at the same scale. Organic-rich stream sediments had the highest rates of bubble release and higher enrichment of methane in bubbles, but glacial sand sediments also exhibited high bubble emissions relative to other studied environments. Our results from a database of groundwater chemistry support the hypothesis that methane in bubbles is produced in anoxic near-stream sediment porewaters, and not in deeper, oxygenated groundwaters. Methane interacts with other key elemental cycles such as nitrogen, oxygen, and sulfur, which has implications for ecosystem changes such as drought and increased nutrient loading. Our results support the contention that streams, particularly those draining wetland landscapes of the northern hemisphere, are an important component of the global methane cycle.

  5. Atmospheric methane removal by methane-oxidizing bacteria immobilized on porous building materials

    NARCIS (Netherlands)

    Ganendra, G; De Muynck, W; Ho, A.; Hoefman, S.; De Vos, P.; Boeckx, P.; Boon, N.

    2014-01-01

    Biological treatment using methane-oxidizing bacteria (MOB) immobilized on six porous carrier materials have been used to mitigate methane emission. Experiments were performed with different MOB inoculated in building materials at high (similar to 20 % (v/v)) and low (similar to 100 ppmv) methane

  6. NOVEL SPECTRUM ABSORPTION OPTICAL FIBER METHANE SENSOR

    Institute of Scientific and Technical Information of China (English)

    Wang Shutao; Che Rensheng

    2005-01-01

    Based on spectrum principle and analyzing the infrared absorption spectrum of methane, a kind of optical fiber methane gas sensor and its system are developed. DFBLD(Distributed feedback laser diode) in 1 300 nm waveband is used as illuminant and phase-detecting technology is used to carry out harmonic wave detecting the concentration of methane. The sensitivity can arrive at 10-5.Experiments results show that the performance targets of the sensor such as sensitivity can basically satisfy the requests of methane detection.

  7. Methane emission during municipal wastewater treatment.

    Science.gov (United States)

    Daelman, Matthijs R J; van Voorthuizen, Ellen M; van Dongen, Udo G J M; Volcke, Eveline I P; van Loosdrecht, Mark C M

    2012-07-01

    Municipal wastewater treatment plants emit methane. Since methane is a potent greenhouse gas that contributes to climate change, the abatement of the emission is necessary to achieve a more sustainable urban water management. This requires thorough knowledge of the amount of methane that is emitted from a plant, but also of the possible sources and sinks of methane on the plant. In this study, the methane emission from a full-scale municipal wastewater facility with sludge digestion was evaluated during one year. At this plant the contribution of methane emissions to the greenhouse gas footprint were slightly higher than the CO₂ emissions related to direct and indirect fossil fuel consumption for energy requirements. By setting up mass balances over the different unit processes, it could be established that three quarters of the total methane emission originated from the anaerobic digestion of primary and secondary sludge. This amount exceeded the carbon dioxide emission that was avoided by utilizing the biogas. About 80% of the methane entering the activated sludge reactor was biologically oxidized. This knowledge led to the identification of possible measures for the abatement of the methane emission.

  8. Microchannel Methanation Reactors Using Nanofabricated Catalysts Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Makel Engineering, Inc. (MEI) and the Pennsylvania State University (Penn State) propose to develop and demonstrate a microchannel methanation reactor based on...

  9. GRI methane chemistry program review meeting

    Energy Technology Data Exchange (ETDEWEB)

    Dignon, J.; Grant, K.; Grossman, A.; Wuebles, D.; Brasseur, G.; Madronich, S.; Huang, T.; Chang, J.; Lott, B.

    1997-02-01

    Methane is an important greenhouse gas which affects the atmosphere directly by the absorption and re-emission of infrared radiation as well as indirectly, through chemical interactions. Emissions of several important greenhouse gases (GHGS) including methane are increasing, mainly due to human activity. Higher concentrations of these gases in the atmosphere are projected to cause a decrease in the amount of infrared radiation escaping to space, and a subsequent warming of global climate. It is therefore vital to understand not only the causes of increased production of methane and other GHGS, but the effect of higher GHG concentrations on climate, and the possibilities for reductions of these emissions. In GRI-UIUC methane project, the role of methane in climate change and greenhouse gas abatement strategies is being studied using several distinct approaches. First, a detailed treatment of the mechanisms controlling each important methane source and sink, and hence the atmospheric concentration of methane, is being developed for use with the UIUC Integrated Science Assessment Model. The focus of this study is to resolve the factors which determine methane emissions and removal, including human population, land use, energy demand, global temperature, and regional concentrations of the hydroxyl radical, carbon monoxide, nitrous oxides, non-methane hydrocarbons, water vapor, tropospheric and stratospheric ozone.

  10. Diel methane emission patterns from Scirpus lacustris and Phragmites australis

    NARCIS (Netherlands)

    Van der Nat, J.W.A.; Middelburg, J.J.; Van Meteren, D.; Wielemaker, A.

    1998-01-01

    In mature Phragmites australis and Scirpus lacustris vegetated sediment methane was emitted almost exclusively by plant- mediated transport, whereas in unvegetated, but otherwise identical sediment, methane was emitted almost exclusively by ebullition. Diel variations in methane emission, with

  11. Diel methane emission patterns from Scirpus lacustris and Phragmites australis

    NARCIS (Netherlands)

    Van der Nat, J.W.A.; Middelburg, J.J.; Van Meteren, D.; Wielemaker, A.

    1998-01-01

    In mature Phragmites australis and Scirpus lacustris vegetated sediment methane was emitted almost exclusively by plant- mediated transport, whereas in unvegetated, but otherwise identical sediment, methane was emitted almost exclusively by ebullition. Diel variations in methane emission, with highe

  12. PHYSICAL SIMULATION AND ANALYSIS OF METHANE TRANSPORT IN COAL SEAM

    Institute of Scientific and Technical Information of China (English)

    罗新荣; 俞启香

    1994-01-01

    This paper studies the effect of ground stress, pore gas pressure and adsorbed methane on methane transport in coal seam, and researches into the applicability of Darcy's law to methane transport. The additional expansion stress of coal induced by adsorbed methane is measured. The paper establishes the constitutive equation of methane transport, taking ground stress, pore gas pressure and Klinkcnburg's effects into considcration, The features of methane transport under the condition of given stress or strain have been analyzed.

  13. Experiments on Methane Displacement by Carbon Dioxide in Large Coal Specimens

    Science.gov (United States)

    Liang, Weiguo; Zhao, Yangsheng; Wu, Di; Dusseault, Maurice B.

    2011-09-01

    changes in the microstructure of the coal itself. Artificial stimulation (e.g. hydraulic fracturing) to improve coalbed transport properties for either CO2 sequestration or enhanced coal bed methane recovery will be necessary. The interactions of large-scale induced fractures with the fabric at the scale of observable fissures and fractures in the laboratory specimens, as well as to the pore scale processes associated with adsorption and desorption, remain of profound interest and a great challenge.

  14. 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

  15. Estimation of future methane production from Hellenic landfills

    Energy Technology Data Exchange (ETDEWEB)

    Tsatsarelis, T.; Karagiannidis, A. [Aristotle Univ., Thessaloniki (Greece). Lab. of Heat Transfer and Environmental Engineering

    2009-07-15

    Organic waste decomposition leads to the production of Landfill Gas (LFG). LFG mainly consists of methane (CH{sub 4}) and carbon dioxide (CO{sub 2}). It is common understanding now that LFG should be considered either as a significant source of pollution and risk (if migrating uncontrollably to the air and ground), or as a significant source of renewable energy (if extracted and processed accordingly). There are two possible solutions for dealing with LFG emissions. In the case of low methane ratios, LFG should be extracted and flared or oxidized in biofilters. On the other hand, in the case of high methane content, LFG becomes an evidently valuable energy resource, as it is then able to sustain the fuelling of engines producing electricity and thermal energy. More specifically, it can be used as a supplementary or primary fuel to increase the production of electric power, as a pipeline quality gas and vehicle fuel, or even as a supply of heat and carbon dioxide for greenhouses and various industrial processes. Technologies that utilize LFG include internal combustion engines, gas turbines, fuel cells and boiler systems. The main objective of this research was to predict expected methane generation in Hellenic sanitary landfills, in order to evaluate its potential for energy production and to ensure health and safety in and around these sites on the long term. The study was performed for the period 2008--2028 with the use of a multi-phase model and included a sensitivity analysis in order to determine the impact of certain waste parameters. In this context, two 'extreme' reference scenarios were formulated and assessed, one anticipating fulfillment of the EU landfill directive (which sets limits to the amount of biodegradable and packaging materials to be deposited in sanitary landfills) whereas a second (do-nothing scenario) assuming no such timely compliance. The model used here for methane estimation is a multi-phase model developed by the Norwegian

  16. Modeling of methane bubbles released from large sea-floor area: Condition required for methane emission to the atmosphere

    OpenAIRE

    Yamamoto, A.; Yamanaka, Y.; Tajika, E.

    2009-01-01

    Massive methane release from sea-floor sediments due to decomposition of methane hydrate, and thermal decomposition of organic matter by volcanic outgassing, is a potential contributor to global warming. However, the degree of global warming has not been estimated due to uncertainty over the proportion of methane flux from the sea-floor to reach the atmosphere. Massive methane release from a large sea-floor area would result in methane-saturated seawater, thus some methane would reach the atm...

  17. Plasma catalytic reforming of methane

    Energy Technology Data Exchange (ETDEWEB)

    Bromberg, L.; Cohn, D.R.; Rabinovich, A. [Massachusetts Inst. of Technology, Cambridge, MA (United States). Plasma Science and Fusion Center; Alexeev, N. [Russian Academy of Sciences, Moscow (Russian Federation). Baikov Inst. of Metallurgy

    1998-08-01

    Thermal plasma technology can be efficiently used in the production of hydrogen and hydrogen-rich gases from methane and a variety of fuels. This paper describes progress in plasma reforming experiments and calculations of high temperature conversion of methane using heterogeneous processes. The thermal plasma is a highly energetic state of matter that is characterized by extremely high temperatures (several thousand degrees Celsius) and high degree of dissociation and substantial degree of ionization. The high temperatures accelerate the reactions involved in the reforming process. Hydrogen-rich gas (50% H{sub 2}, 17% CO and 33% N{sub 2}, for partial oxidation/water shifting) can be efficiently made in compact plasma reformers. Experiments have been carried out in a small device (2--3 kW) and without the use of efficient heat regeneration. For partial oxidation/water shifting, it was determined that the specific energy consumption in the plasma reforming processes is 16 MJ/kg H{sub 2} with high conversion efficiencies. Larger plasmatrons, better reactor thermal insulation, efficient heat regeneration and improved plasma catalysis could also play a major role in specific energy consumption reduction and increasing the methane conversion. A system has been demonstrated for hydrogen production with low CO content ({approximately} 1.5%) with power densities of {approximately} 30 kW (H{sub 2} HHV)/liter of reactor, or {approximately} 10 m{sup 3}/hr H{sub 2} per liter of reactor. Power density should further increase with increased power and improved design.

  18. Methane emission from wetland rice fields

    NARCIS (Netherlands)

    Denier van der Gon, H.A.C.

    1996-01-01


    Methane (CH 4 ) is an important greenhouse gas and plays a key role in tropospheric and stratospheric chemistry. Wetland rice fields are an important source of methane, accounting for approximately 20% of the global anthropogenic

  19. Methane storage in porous activated carbons

    NARCIS (Netherlands)

    Perl, András; Gemert, Wim van

    2014-01-01

    Locally produced methane, - either as biomethane or power-to-gas product, has to be stored to provide a reliable gas source for the fluctuating demand of any local gas distribution network. Additionally, methane is a prominent transportation fuel but its suitability for vehicular application depends

  20. Thermophilic methane production and oxidation in compost.

    Science.gov (United States)

    Jäckel, Udo; Thummes, Kathrin; Kämpfer, Peter

    2005-04-01

    Methane cycling within compost heaps has not yet been investigated in detail. We show that thermophilic methane oxidation occurred after a lag phase of up to one day in 4-week old, 8-week old and mature (>10-week old) compost material. The potential rate of methane oxidation was between 2.6 and 4.1 micromol CH4(gdw)(-1)h(-1). Profiles of methane concentrations within heaps of different ages indicated that 46-98% of the methane produced was oxidised by methanotrophic bacteria. The population size of thermophilic methanotrophs was estimated at 10(9) cells (gdw)(-1), based on methane oxidation rates. A methanotroph (strain KTM-1) was isolated from the highest positive step of a serial dilution series. This strain belonged to the genus Methylocaldum, which contains thermotolerant and thermophilic methanotrophs. The closest relative organism on the basis of 16S rRNA gene sequence identity was M. szegediense (>99%), a species originally isolated from hot springs. The temperature optimum (45-55 degrees C) for methane oxidation within the compost material was identical to that of strain KTM-1, suggesting that this strain was well adapted to the conditions in the compost material. The temperatures measured in the upper layer (0-40 cm) of the compost heaps were also in this range, so we assume that these organisms are capable of effectively reducing the potential methane emissions from compost.

  1. Towards Understanding Methane Emissions from Abandoned Wells

    Science.gov (United States)

    Reconciliation of large-scale top-down methane measurements and bottom-up inventories requires complete accounting of source types. Methane emissions from abandoned oil and gas wells is an area of uncertainty. This presentation reviews progress to characterize the potential inv...

  2. Mechanistic insights into heterogeneous methane activation.

    Science.gov (United States)

    Latimer, Allegra A; Aljama, Hassan; Kakekhani, Arvin; Yoo, Jong Suk; Kulkarni, Ambarish; Tsai, Charlie; Garcia-Melchor, Max; Abild-Pedersen, Frank; Nørskov, Jens K

    2017-02-01

    While natural gas is an abundant chemical fuel, its low volumetric energy density has prompted a search for catalysts able to transform methane into more useful chemicals. This search has often been aided through the use of transition state (TS) scaling relationships, which estimate methane activation TS energies as a linear function of a more easily calculated descriptor, such as final state energy, thus avoiding tedious TS energy calculations. It has been shown that methane can be activated via a radical or surface-stabilized pathway, both of which possess a unique TS scaling relationship. Herein, we present a simple model to aid in the prediction of methane activation barriers on heterogeneous catalysts. Analogous to the universal radical TS scaling relationship introduced in a previous publication, we show that a universal TS scaling relationship that transcends catalysts classes also seems to exist for surface-stabilized methane activation if the relevant final state energy is used. We demonstrate that this scaling relationship holds for several reducible and irreducible oxides, promoted metals, and sulfides. By combining the universal scaling relationships for both radical and surface-stabilized methane activation pathways, we show that catalyst reactivity must be considered in addition to catalyst geometry to obtain an accurate estimation for the TS energy. This model can yield fast and accurate predictions of methane activation barriers on a wide range of catalysts, thus accelerating the discovery of more active catalysts for methane conversion.

  3. Small Molecule Catalysts for Harvesting Methane Gas

    Energy Technology Data Exchange (ETDEWEB)

    Baker, S. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ceron-Hernandez, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Oakdale, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lau, E. Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-12-06

    As the average temperature of the earth increases the impact of these changes are becoming apparent. One of the most dramatic changes to the environment is the melting of arctic permafrost. The disappearance of the permafrost has resulted in release of streams of methane that was trapped in remote areas as gas hydrates in ice. Additionally, the use of fracking has also increased emission of methane. Currently, the methane is either lost to the atmosphere or flared. If these streams of methane could be brought to market, this would be an abundant source of revenue. A cheap conversion of gaseous methane to a more convenient form for transport would be necessary to economical. Conversion of methane is a difficult reaction since the C-H bond is very stable (104 kcal/mole). At the industrial scale, the Fischer-Tropsch reaction can be used to convert gaseous methane to liquid methanol but is this method is impractical for these streams that have low pressures and are located in remote areas. Additionally, the Fischer-Tropsch reaction results in over oxidation of the methane leading to many products that would need to be separated.

  4. Raman Spectroscopic Studies of Methane Gas Hydrates

    DEFF Research Database (Denmark)

    Hansen, Susanne Brunsgaard; Berg, Rolf W.

    2009-01-01

    A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory.......A brief review of the Raman spectroscopic studies of methane gas hydrates is given, supported by some new measurements done in our laboratory....

  5. Abiotic production of methane in terrestrial planets.

    Science.gov (United States)

    Guzmán-Marmolejo, Andrés; Segura, Antígona; Escobar-Briones, Elva

    2013-06-01

    On Earth, methane is produced mainly by life, and it has been proposed that, under certain conditions, methane detected in an exoplanetary spectrum may be considered a biosignature. Here, we estimate how much methane may be produced in hydrothermal vent systems by serpentinization, its main geological source, using the kinetic properties of the main reactions involved in methane production by serpentinization. Hydrogen production by serpentinization was calculated as a function of the available FeO in the crust, given the current spreading rates. Carbon dioxide is the limiting reactant for methane formation because it is highly depleted in aqueous form in hydrothermal vent systems. We estimated maximum CH4 surface fluxes of 6.8×10(8) and 1.3×10(9) molecules cm(-2) s(-1) for rocky planets with 1 and 5 M⊕, respectively. Using a 1-D photochemical model, we simulated atmospheres with volume mixing ratios of 0.03 and 0.1 CO2 to calculate atmospheric methane concentrations for the maximum production of this compound by serpentinization. The resulting abundances were 2.5 and 2.1 ppmv for 1 M⊕ planets and 4.1 and 3.7 ppmv for 5 M⊕ planets. Therefore, low atmospheric concentrations of methane may be produced by serpentinization. For habitable planets around Sun-like stars with N2-CO2 atmospheres, methane concentrations larger than 10 ppmv may indicate the presence of life.

  6. Separation and capture of CO2 from large stationary sources and sequestration in geological formations--coalbeds and deep saline aquifers.

    Science.gov (United States)

    White, Curt M; Strazisar, Brian R; Granite, Evan J; Hoffman, James S; Pennline, Henry W

    2003-06-01

    The topic of global warming as a result of increased atmospheric CO2 concentration is arguably the most important environmental issue that the world faces today. It is a global problem that will need to be solved on a global level. The link between anthropogenic emissions of CO2 with increased atmospheric CO2 levels and, in turn, with increased global temperatures has been well established and accepted by the world. International organizations such as the United Nations Framework Convention on Climate Change (UNFCCC) and the Intergovernmental Panel on Climate Change (IPCC) have been formed to address this issue. Three options are being explored to stabilize atmospheric levels of greenhouse gases (GHGs) and global temperatures without severely and negatively impacting standard of living: (1) increasing energy efficiency, (2) switching to less carbon-intensive sources of energy, and (3) carbon sequestration. To be successful, all three options must be used in concert. The third option is the subject of this review. Specifically, this review will cover the capture and geologic sequestration of CO2 generated from large point sources, namely fossil-fuel-fired power gasification plants. Sequestration of CO2 in geological formations is necessary to meet the President's Global Climate Change Initiative target of an 18% reduction in GHG intensity by 2012. Further, the best strategy to stabilize the atmospheric concentration of CO2 results from a multifaceted approach where sequestration of CO2 into geological formations is combined with increased efficiency in electric power generation and utilization, increased conservation, increased use of lower carbon-intensity fuels, and increased use of nuclear energy and renewables. This review covers the separation and capture of CO2 from both flue gas and fuel gas using wet scrubbing technologies, dry regenerable sorbents, membranes, cryogenics, pressure and temperature swing adsorption, and other advanced concepts. Existing

  7. The Problems that Jiangxi Province Faces in Developing and Utilizing Coal-Bed Gases and Some Suggestions%江西省煤层气开发利用存在的问题及建议

    Institute of Scientific and Technical Information of China (English)

    黄孝波; 汪恩满

    2014-01-01

    The problems that Jiangxi province faces in developing and utilizing coal-bed gases include the following: weak basic research, lack of the thorough study, complex geological conditions and being dififcult to be developed, low estimated value of coal-bed gases resources, unreasonable mining right setup, dififculty in the use of coal-bed gases, and poor policy and system. On account of this, this paper proposes some measures with a view to furthering initiatives in this regard. These measures lay emphasis on the following: strengthening the basic geological research; increasing financial input to promote economic development and policy leading to arouse the enthusiasm of enterprises to explore and develop coal-bed gases;training professionals and improving facilities;strengthening the management of mining rights and differentiating mining rights reasonably.%江西省煤层气(煤矿瓦斯)开发利用中存在如下问题:基础研究工作薄弱,研究不够深入;地质条件复杂,开发难度大;煤层气资源估算值偏低;矿业权设置不合理;瓦斯利用困难;政策与制度不完善。江西省煤层气(瓦斯)开发利用建议:加强基础地质研究,加大经济投入;加强政策引导,调动瓦斯勘探开发的积极性;完善煤层气(瓦斯)配套人员与设施;加强矿业权管理,合理划分矿业权。

  8. Enteric methane emissions from German dairy cows

    DEFF Research Database (Denmark)

    Dammgen, U; Rosemann, C; Haenel, H D

    2012-01-01

    Up to now, the German agricultural emission inventory used a model for the assessment of methane emissions from enteric fermentation that combined an estimate of the energy and feed requirements as a function of performance parameters and diet composition, with the constant methane conversion rate......, as stated by IPCC. A methane emission model was selected here that is based on German feed data. It was combined with the hitherto applied model describing energy requirements. The emission rates thus calculated deviate from those previously obtained. In the new model, the methane conversion rate is back......-calculated from emission rates and gross energy intake rates. For German conditions of animal performance and diet composition, the national means of methane conversion rates range between 71 kJ MJ(-1) and 61 kJ MJ(-1) for low and high performances (4700 kg animal(-1) a(-1) in 1990 to 7200 kg animal(-1) a(-1...

  9. Enteric methane emissions from German dairy cows

    DEFF Research Database (Denmark)

    Dammgen, U; Rosemann, C; Haenel, H D

    2012-01-01

    Up to now, the German agricultural emission inventory used a model for the assessment of methane emissions from enteric fermentation that combined an estimate of the energy and feed requirements as a function of performance parameters and diet composition, with the constant methane conversion rate......, as stated by IPCC. A methane emission model was selected here that is based on German feed data. It was combined with the hitherto applied model describing energy requirements. The emission rates thus calculated deviate from those previously obtained. In the new model, the methane conversion rate is back......-calculated from emission rates and gross energy intake rates. For German conditions of animal performance and diet composition, the national means of methane conversion rates range between 71 kJ MJ(-1) and 61 kJ MJ(-1) for low and high performances (4700 kg animal(-1) a(-1) in 1990 to 7200 kg animal(-1) a(-1...