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Full-Text Articles in Entire DC Network
Evaluation Of Tropical And Subtropical Forage Grasses In The Northwest Region Of Rio Grande Do Sul, Brazil, R B. Medeiros, J M. Souza, J E. G. Zambra
Evaluation Of Tropical And Subtropical Forage Grasses In The Northwest Region Of Rio Grande Do Sul, Brazil, R B. Medeiros, J M. Souza, J E. G. Zambra
IGC Proceedings (1977-2023)
A collection of 137 accessions of tropical and subtropical grasses of Pennisetum purpureum (53), Panicum maximum (10), Brachiaria spp. (9), Hemarthria altissima (19), Setaria spp. (11), Digitaria spp. (22), Cynodon spp.(7) and Paspalum spp. (6) was evaluated for frost tolerance (FT), dry matter yield per cut (DMYC), number of cuts (NC) and accumulated dry matter yield per year (ADMY). Crude protein content (CPC), leaf/stem ratio (L/S), pubescence (P) and animal preference under grazing (AP) were also recorded in 20 entries of in P. purpureum. Data exploration involved cluster analysis and ordination, revealing the most promising entries among and within …
Evaluation Under Grazing Of Two Festuca Arundinacia Cultivars With Contrasting Growth Patterns, A Mazzanti, M H. Wade
Evaluation Under Grazing Of Two Festuca Arundinacia Cultivars With Contrasting Growth Patterns, A Mazzanti, M H. Wade
IGC Proceedings (1977-2023)
Two cultivars of Festuca arundinacea, one of temperate origin (El Palenque: PAL) with higher spring and summer growth and one of North African origin (Maris Kasba: MK) with higher winter growth, were compared under grazing during three years. They were grazed continuously, using a “put and take” system, by young steers and the swards maintained at equal heights, but which varied slightly between seasons. Daily live weight gain (LWG) and instantaneous stocking rate (ISR) were used to estimate productivity per unit area. There was no difference between cultivars in LWG, but consistent and important differences in ISR: MK carrying …
Relationships Among Some Lolium And Festuca Species, G Charmet, F Balfourier, C Ravel
Relationships Among Some Lolium And Festuca Species, G Charmet, F Balfourier, C Ravel
IGC Proceedings (1977-2023)
Molecular markers were used to investigate phylogenetic relationships among the 8 species of ryegrass (Lolium) and 11 species of fescue (Festuca). Nine sequences of non-coding chloroplastic or mitochondrial DNA were amplified through PCR, then digested by 20 restriction enzymes. Restriction sites data were used to draw an UPGMA tree. The main features are: 1) a clear-cut distinction between fine-leaved fescues (subg. Festuca) and broad-leaved fescues (subg. Schedonorus), which include the ryegrasses. 2) among the broad-leaved fescues, meadow fescue and tall fescue are very closely related, which may indicate that they share a common maternal …
Breeding Reed Canarygrass As An Energy Or Fibre Crop By Using Local Collected Wild Populations, E Lindvall
Breeding Reed Canarygrass As An Energy Or Fibre Crop By Using Local Collected Wild Populations, E Lindvall
IGC Proceedings (1977-2023)
Reed canarygrass (Phalaris arundinacea L.) has become interesting as an industrial crop in Sweden. The grass can be used as biofuel or fibre raw material for pulp production. New varieties have to be developed, with a quality different from forage varieties. High stem/ leaf-ratio, low content of ash and elements like silica, potassium and chlorine are important breeding goals. A Swedish project, aiming to evaluate local reed canarygrass populations, shows that there is some variation in these morphological and chemical characters which can be utilised in a breeding program.
Compared Productivity Of Local Ecotypes And Selected Cultivars Of Perennial Ryegrass (Lolium Perenne) In High Belgium, P Limbourg, Ph Lecomte
Compared Productivity Of Local Ecotypes And Selected Cultivars Of Perennial Ryegrass (Lolium Perenne) In High Belgium, P Limbourg, Ph Lecomte
IGC Proceedings (1977-2023)
The objective of the trials was to compare the productivity of local ecotypes of perennial ryegrass (Lolium perenne) issued from old permanent pastures of High Belgium to that of adapted cultivars. During 3 consecutive years 2 local ecotypes were compared, in pure seedling at 2 different levels of nitrogenous manure, to 2 cultivars frequently used in seed mixtures for pastures. Results obtained using a cutting cycle wich simulated grazing did not reveal significant differences in terms of forage production or feeding value. These results explain the weak increase in forage production recorded in pastures renovated by reseeding as …
Salix Babylonica, A Traditional Fodder With Promising Potential, K Wangdi, W Roder, P Thinlay
Salix Babylonica, A Traditional Fodder With Promising Potential, K Wangdi, W Roder, P Thinlay
IGC Proceedings (1977-2023)
In Bhutan, tree fodders are important for ruminant nutrition, especially during the dry winter season. Salix babylonica is the preferred species for temperate regions. Farmers above 2000 m plant it widely for fodder, fuel, and fencing. Lack of fodder availability during the dry season, and competition with other crops are its main disadvantages. Crude protein content of S. babylonica leaves declined from 25% in May to 11% in October. Voluntary intake was 78 and 85 g dry matter/W0.75 and live weight gain 330 and 64 g day-1 for growing bulls and sheep, respectively. Dry matter disappearance after 48 hours of …
Purification Of Eutrophic Hydro-Environments And The Utilization For New Biomass Forage Resources By Aquatic Plants In Asia, K Kabata, C Okamoto, B Montien-Art, T Nakazono, T Odahara, M Kikuchi
Purification Of Eutrophic Hydro-Environments And The Utilization For New Biomass Forage Resources By Aquatic Plants In Asia, K Kabata, C Okamoto, B Montien-Art, T Nakazono, T Odahara, M Kikuchi
IGC Proceedings (1977-2023)
Water pollution, especially eutrophication, has become a serious world-wide problem in recent years. On the other hand, forage is in short supply during the dry season in Asia (especially in Southeast Asia). The purpose of this paper is to describe the development of new forage resources from among aquatic plants. In conclusion, it is suggested that three emergent plants (Zizania latifolia Turcz., Pontederia cordata L., Paspalum distichum L.) are useful as new forage species because of their absorptive ability for nitrogen and phosphorus from eutrophic water and their superior feeding value following ensiling.
Ecogeographic Assessment Of Mediterranean Environments For Targeting Legume Collections, S J. Bennett
Ecogeographic Assessment Of Mediterranean Environments For Targeting Legume Collections, S J. Bennett
IGC Proceedings (1977-2023)
The mediterranean area is the centre of diversity for many of the legume species of agricultural importance and their wild relatives. Ecogeographical assessments are a method of determining the areas within the mediterranean that are homologous with a particular area within southern Australia. Using Geographical Information Systems the distribution of legume species are mapped and related to other climatic and edaphic factors. Using this data it is possible to show which areas of the mediterranean have been well collected and where the edaphic requirements of a species can be found and therefore where to collect it. The detail of an …
Genetic Diversity As Affected By Selection Methodology In Native Grass Species, A T. Phan, S R. Smith
Genetic Diversity As Affected By Selection Methodology In Native Grass Species, A T. Phan, S R. Smith
IGC Proceedings (1977-2023)
The utilization of native grasses for widespread plantings is limited by availability and cost of adapted seed sources. The objectives of this study were to assess the genetic diversity of locally collected blue grama (Bouteloua gracilis) and little bluestem (Schyzachyrium scoparium) populations and to examine potential shifts in genetic diversity using two selection methodologies. The ecovar method involved selection of the 20% highest seed yielding genotypes with equal representation from all populations while the ‘cultivar’ method involved selecting the highest 5% based on overall rank. Phenotypic variability was observed for morphological and reproductive traits between collected …
Physiological And Chemical Characteristics Of Five Cultivars Of Cynodon, C C.C. Gomide, L.R. De A. Rodrigues, T.De J.D. Rodrigues, R A. Reis, D A. Banzatto
Physiological And Chemical Characteristics Of Five Cultivars Of Cynodon, C C.C. Gomide, L.R. De A. Rodrigues, T.De J.D. Rodrigues, R A. Reis, D A. Banzatto
IGC Proceedings (1977-2023)
The experiment was carried out at UNESP, Brazil, to evaluate five Cynodon cultivars: (Cynodon nlemfuensis Vanderyst cv “Tifton 68”, Cynodon spp. cv “Tifton 85”, Cynodon dactylon cv “Florakirk”, Cynodon nlemfuensis Vanderyst var. nlemfuensis cv “Florico” e Cynodon nlemfuensis Vanderyst var. nlemfuensis cv “Florona”). Plants were sampled once a week from 14 to 84 days of growth to study physiological characteristics and at 14-day intervals to study chemical characteristics. The following variables were studied: DM production, leaf/stem ratio, leaf weight/total dry matter ratio, relative growth rate, chlorophyll contents, leaf area, specific leaf area, LAI, and the contents of CP, NDF, …
Pasture Yield And Animal Performance From Aeschynomene Americana Cultivars Glenn And Lee, H G. Bishop, T B. Hilder, J J. Bushell
Pasture Yield And Animal Performance From Aeschynomene Americana Cultivars Glenn And Lee, H G. Bishop, T B. Hilder, J J. Bushell
IGC Proceedings (1977-2023)
An on farm demonstration site was used to promote and compare the performance of the tropical legumes Glenn American jointvetch and Lee American jointvetch (Aeschynomene americana). Both legumes are widely sown in tropical Australia and are being increasingly sown in South-East Asian pasture projects. Glenn and Lee both grew well and persisted in grass/legume pastures over a 5 year period. Liveweight gain of steers, at a stocking rate of 1.5/ha, slightly favoured the Glenn pasture and gains of 0.49 kg/day for a 595 day period were achieved. Soil seed reserves were much higher under the annual Glenn than …
Diversity And Sustainability Of The Pek Savannas Of The Lao Pdr, V Phengvichith, J B. Hacker
Diversity And Sustainability Of The Pek Savannas Of The Lao Pdr, V Phengvichith, J B. Hacker
IGC Proceedings (1977-2023)
The pek savannas of the Lao PDR occur in the southern half of the country and are relatively undeveloped. They are disjunct upland communities characterised by an understorey dominated by three species of Arundinaria, known locally as pek. The canopy varies from open forest to woodland. In relatively undisturbed communities, pek grows to c. 1.5 m tall, and is generally 99% pure, with tall growing grasses occurring infrequently. Higher levels of disturbance lead to invasion of shrub species and ingress of some lower-growing grasses and occasional legumes, some of which are palatable to livestock. Pek is palatable to livestock …
Research Programme To Improve The Utilization Of Home-Grown Forages In The Netherlands, A.M. Van Vuuren, A H. Bosma, G J. Kaspers, J.J. M.H. Ketelaars, E.N. Van Loo, H J.P. Marvin, H Valk, G.W.J. Van De Ven
Research Programme To Improve The Utilization Of Home-Grown Forages In The Netherlands, A.M. Van Vuuren, A H. Bosma, G J. Kaspers, J.J. M.H. Ketelaars, E.N. Van Loo, H J.P. Marvin, H Valk, G.W.J. Van De Ven
IGC Proceedings (1977-2023)
In The Netherlands a research programme has been initiated by the Ministry of Agriculture, Nature Management and Fisheries to increase the proportion of high-quality home-grown forage in rations for dairy cows. This should result in a more sustainable dairy husbandry by improving the efficiency of utilization of nitrogen and phosphorus from home-grown forages (mainly grass and maize) on farm level. Research disciplines involved are plant breeding, forage harvesting and conservation and nutrition.
The European Ryegrass Core Collection: A Tool To Improve The Use Of Genetic Resources, N R. Sackville Hamilton, I D. Thomas, P Marum, L Ostrem, M Sevcíková, E Willner, F Balfourier, B Boller, V F. Chapurin, V Connolly, G Dologa, H Fritzen, T Van Hintum, L Horváth, W Majtkowski, V Negri, A Oliveira Prendes, D Reheul, D Shamov1, T Vaitsis
The European Ryegrass Core Collection: A Tool To Improve The Use Of Genetic Resources, N R. Sackville Hamilton, I D. Thomas, P Marum, L Ostrem, M Sevcíková, E Willner, F Balfourier, B Boller, V F. Chapurin, V Connolly, G Dologa, H Fritzen, T Van Hintum, L Horváth, W Majtkowski, V Negri, A Oliveira Prendes, D Reheul, D Shamov1, T Vaitsis
IGC Proceedings (1977-2023)
A core collection of 162 populations of ryegrass (Lolium perenne) native to 18 European countries, is being evaluated across Europe in a multi-country trial. Each participating country contributed the lesser of 10% or 25 accessions from its collection of native populations. The accessions are being grown at 18 sites in 17 countries. Quick, cheap protocols were developed for evaluation. Preliminary results are presented for performance during the first winter. Populations of northern origin showed uniformly low winter damage and low winter growth at all evaluation sites. Populations of Mediterranean origin were more affected by the environment used for …
Differences Between Adapted Populations Of Dactylis Glomerata L. In Argentina, A Andres, M Barufaldi
Differences Between Adapted Populations Of Dactylis Glomerata L. In Argentina, A Andres, M Barufaldi
IGC Proceedings (1977-2023)
Nine adapted populations of orchardgrass (Dactylis glomerata L.) were collected from different grassland environments of Buenos Aires Province, Argentina, in order to investigate genetic differences between and within populations. Fifty plants per population were clonally propagated and transplanted as spaced-plant trial in a randomized design with three replicates. The results indicated large differences between and within populations for most attributes measured. Attributes related with the expression of foliar diseases and seed yield had the highest broad-sense heritability values. The results suggest that the genetic variation found in the adapted populations of orchardgrass has been mainly determined by the environmental …
The Plants Database: Providing Basic Plant Information, J S. Peterson, J F. Henson, W Oaks, J T. Kartesz
The Plants Database: Providing Basic Plant Information, J S. Peterson, J F. Henson, W Oaks, J T. Kartesz
IGC Proceedings (1977-2023)
The PLANTS database provides basic plant information to the United States Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), its clients, cooperators, and the general public via the World Wide Web (Fig. 1). The foundation of PLANTS is a taxonomic backbone (checklist) of the vascular and nonvascular plants of North America (north of Mexico) and United States territories in the Caribbean and Pacific regions. Attribute data are appended to this backbone pertaining to distribution, vegetative specifications, nativity, federal and state status, crop data, growth form, growth parameters, species abstracts, and images.
Forage Production Potential Of Poa Arachnifera Torr In Semi-Arid Climates, J C. Read, M A. Sanderson, G W. Evers, P W. Voigt, J A. Reinert
Forage Production Potential Of Poa Arachnifera Torr In Semi-Arid Climates, J C. Read, M A. Sanderson, G W. Evers, P W. Voigt, J A. Reinert
IGC Proceedings (1977-2023)
This study was undertaken to determine the forage potential of Texas bluegrass (Poa arachnifera Torr). Texas bluegrass is a perennial coolseason grass native to Kansas, Oklahoma, western Arkansas, and the central region of Texas, USA (Gould, 1975). Thirteen different accessions were established in 1988 at the Texas A&M University Centers at Dallas and Stephenville and tested for 2 years. Mean yields at Stephenville and Dallas were 3610 and 6022 kg ha-1. Two synthetic varieties (Syn-1 and Syn-2) were tested from 1990 to 1995 at four locations in Texas. Yields of Syn-1 was greater than Syn-2 whereas Syn- 2 provided …
More Aeschynomene Pasture Legumes For The Tropics And Sub-Tropics, H G. Bishop, B G. Cook, B H. English, J J. Bushell, T B. Hilder
More Aeschynomene Pasture Legumes For The Tropics And Sub-Tropics, H G. Bishop, B G. Cook, B H. English, J J. Bushell, T B. Hilder
IGC Proceedings (1977-2023)
Two cultivars of Aeschynomene villosa were released in Queensland in 1995. Cultivars ‘Reid’ (previously CPI 91209) and ‘Kretschmer’ (previously CPI 93621) are both native to Mexico and are the first cultivars of A. villosa to be released as pasture legumes. They will complement the three Aeschynomene cultivars already in use in tropical and sub-tropical northern and eastern Australia, namely cultivars ‘Glenn’ and ‘Lee’ (A. americana) and ‘Bargoo’ (A. falcata). Characteristics of Reid and Kretschmer jointvetch include, early seeding perennials within high seed yields, prostrate to semi-erect growth habit, adaptation to a wide range of soil types …
Lotic-Sipco2: Adaptation Of An Open-Source Co2 Sensor System And Examination Of Associated Emission Uncertainties Across A Range Of Stream Sizes And Land Uses, Andrew L. Robison, Lauren E. Koenig, Jody D. Potter, Lisle E. Snyder, Christopher W. Hunt, William H. Mcdowell, Wilfred M. Wollheim
Lotic-Sipco2: Adaptation Of An Open-Source Co2 Sensor System And Examination Of Associated Emission Uncertainties Across A Range Of Stream Sizes And Land Uses, Andrew L. Robison, Lauren E. Koenig, Jody D. Potter, Lisle E. Snyder, Christopher W. Hunt, William H. Mcdowell, Wilfred M. Wollheim
Faculty Publications
River networks play a crucial role in the global carbon cycle, as relevant sources of carbon dioxide (CO2) to the atmosphere. Advancements in high-frequency monitoring in aquatic environments have enabled measurement of dissolved CO2 concentration at temporal resolutions essential for studying carbon variability and evasion from these dynamic ecosystems. Here, we describe the adaptation, deployment, and validation of an open-source and relatively low-cost in situ pCO2 sensor system for lotic ecosystems, the lotic-SIPCO2. We tested the lotic-SIPCO2 in 10 streams that spanned a range of land cover and basin size. Key system adaptations for lotic environments included prevention of biofouling, …
Table Of Contents, The Editors
Deep Coalbed Methane Production Technology For The Eastern Margin Of The Ordos Basin: Advances And Their Implications, Zeng Wenting, Xu Fengyin, Zhang Lei, Sun Weiwei, Wang Qian, Liu Yinhua, Yu Lizhu, Ji Liang, Zeng Quanshu, Zhang Kang
Deep Coalbed Methane Production Technology For The Eastern Margin Of The Ordos Basin: Advances And Their Implications, Zeng Wenting, Xu Fengyin, Zhang Lei, Sun Weiwei, Wang Qian, Liu Yinhua, Yu Lizhu, Ji Liang, Zeng Quanshu, Zhang Kang
Coal Geology & Exploration
Contrasting with shallow to moderately deep coalbed methane (CBM) reservoirs, deep CBM reservoirs exhibit favorable coal structures, high formation pressure, high free gas ratios, and high contents of total dissolved solids (TDS) and CO2. Extensive fracturing allows for CBM flowing at the initial stage, while the production parameters vary significantly throughout the CBM production. This requires wide technological boundaries of the main production technologies. Compared to shale gas and tight gas, deep CBM manifests different production mechanisms and relatively low free gas ratios, which lead to short flowing cycles of CBM. This necessitates timely water withdrawal for CBM …
Differences In Geological Conditions Of Deep And Shallow Coalbed Methane And Their Formation Mechanisms, Xu Hao, Tang Dazhen, Tao Shu, Li Song, Tang Shuling, Chen Shida, Zong Peng, Dong Yu
Differences In Geological Conditions Of Deep And Shallow Coalbed Methane And Their Formation Mechanisms, Xu Hao, Tang Dazhen, Tao Shu, Li Song, Tang Shuling, Chen Shida, Zong Peng, Dong Yu
Coal Geology & Exploration
Deep coalbed methane (CBM) boasts abundant resources and great potential for exploitation. However, there is a lack of in-depth studies on the internal connections between deep and shallow CBM. This study investigated the Upper Paleozoic coalbed in the Ordos Basin. From the perspective of coalbed formation and evolution, it obtained three burial depth evolution modes of coalbed through summaries: both the maximum and present burial depths exceeding 2000 m, the maximum burial depth over 2000 m while the present burial depth less than 2000 m, and both the maximum and present burial depths less than 2000 m. This study systematically …
Occurrence Mechanism, Environment And Dynamic Evolution Of Gas And Water In Deep Coal Seams, Li Yong, Xu Lifu, Liu Yu, Wang Ziwei, Gao Shuang, Ren Ci
Occurrence Mechanism, Environment And Dynamic Evolution Of Gas And Water In Deep Coal Seams, Li Yong, Xu Lifu, Liu Yu, Wang Ziwei, Gao Shuang, Ren Ci
Coal Geology & Exploration
Accurately understanding of the occurrence states, relative content, and distribution characteristics of gas - water under deep conditions has important guiding significance for efficient exploration and development of coalbed methane (CBM). Based on the theoretical model, molecular simulation and systematic analysis of gas-water, the occurrence states of gas-water in coal seam is clarified, and the boundary and dynamic evolution process of gas-water dynamic migration and accumulation are revealed. Considering the coal - water interface interaction, the mobility and occurrence states of water, the coalbed water can be divided into movable water (gravity water and capillary water), bound water (adsorbed water, …
Effects Of Depth On Gas-Bearing Properties Of Coal Reservoirs And Their Coupling Relationships With Coalbed Methane Accumulation, Chen Shida, Hou Wei, Tang Dazhen, Li Xiang, Xu Hao, Tao Shu, Li Song, Tang Shuling
Effects Of Depth On Gas-Bearing Properties Of Coal Reservoirs And Their Coupling Relationships With Coalbed Methane Accumulation, Chen Shida, Hou Wei, Tang Dazhen, Li Xiang, Xu Hao, Tao Shu, Li Song, Tang Shuling
Coal Geology & Exploration
Burial depth serves as a comprehensive factor influencing coalbed methane (CBM) accumulation. Understanding the effects of depth on gas-bearing properties is critical for ascertaining the occurrence states and accumulation mechanisms of deep/shallow CBM. Based on the present situation of CBM exploration and the dissection of data from CBM exploration wells on the eastern margin of the Ordos Basin, this study explored the effects of burial depth on the gas content, saturated adsorbed gas capacity, and gas saturation of coal seams, as well as their coupling relationship with accumulation processes, using conventional and unconventional petroleum accumulation. The results indicate that CBM …
Deep Coalbed Methane Resources In The Shenmu-Jiaxian Block, Ordos Basin, China: Geological Characteristics And Potential For Exploration And Exploitation, Li Guoyong, Yao Yanbin, Wang Hui, Meng Lingjian, Li Peijie, Zhang Yongchao, Wang Jianwei, Ma Limin
Deep Coalbed Methane Resources In The Shenmu-Jiaxian Block, Ordos Basin, China: Geological Characteristics And Potential For Exploration And Exploitation, Li Guoyong, Yao Yanbin, Wang Hui, Meng Lingjian, Li Peijie, Zhang Yongchao, Wang Jianwei, Ma Limin
Coal Geology & Exploration
China boasts abundant coalbed methane (CBM) resources in deep layers (burial depths: greater than 2000 m), with considerable potential for CBM exploration and development. Compared to medium and shallow CBM, deep CBM differs significantly in enrichment and accumulation patterns and exploitation means. Therefore, there is an urgent need to dissect key CBM blocks. The Shenmu-Jiaxian block, situated in the northeastern Ordos Basin, is currently in the early stages of deep CBM exploration, with enrichment characteristics and exploration potential remaining undefined. Based on recently obtained seismic data, logging data from over 300 wells, and analytical results from four cored wells, this …
Potential For The Production Of Deep To Ultradeep Coalbed Methane Resources In The Upper Permian Longtan Formation, Sichuan Basin, Ming Ying, Sun Haofei, Tang Dazhen, Xu Liang, Zhang Benjian, Chen Xiao, Xu Chang, Wang Jiaxian, Chen Shida
Potential For The Production Of Deep To Ultradeep Coalbed Methane Resources In The Upper Permian Longtan Formation, Sichuan Basin, Ming Ying, Sun Haofei, Tang Dazhen, Xu Liang, Zhang Benjian, Chen Xiao, Xu Chang, Wang Jiaxian, Chen Shida
Coal Geology & Exploration
Breakthroughs have been achieved in the high-yield gas flow of coalbed methane (CBM) wells with burial depths ranging from 1000 to 2500 m in the Cainan area of the Junggar Basin and the Daning-Jixian and southern Yanchuan blocks on the eastern margin of the Ordos Basin, signifying the enormous potential for the production of deep CBM. In the Sichuan Basin, the thin to moderately thick coal seam groups (7‒15 layers) in the Upper Permian Longtan Formation primarily exhibit burial depths ranging between 2000 and 4500 m. In the central Sichuan Basin, characterized by north-dipping monoclines and local low-amplitude uplifts, deep …
Geological Characteristics And Favorable Area Evaluation Of Deep Coalbed Methane In Wangfu Fault Depression, Southern Songliao Basin, Shen Xia, Gong Haitao, Shao Mingli, Yang Minfang, Huo Wanguo
Geological Characteristics And Favorable Area Evaluation Of Deep Coalbed Methane In Wangfu Fault Depression, Southern Songliao Basin, Shen Xia, Gong Haitao, Shao Mingli, Yang Minfang, Huo Wanguo
Coal Geology & Exploration
The Wangfu fault depression in the southern Songliao Basin is rich in coalbed methane (CBM) resources. However, CBM exploration in this area has been restricted by the low-level exploration of deep CBM and a lack of systematic studies on the geological characteristics of CBM, primary factors controlling CBM enrichment and accumulation, and the selection of favorable targets. Therefore, based on the systematical analysis of the geological characteristics of coal-bearing strata, this study identified the major factors controlling deep CBM accumulation, established the index system for favorable area selection, and predicted the favorable areas of CBM enrichment. The results show that: …
Moderately Deep Coalbed Methane Reservoirs In The Southern Qinshui Basin: Characteristics And Technical Strategies For Exploitation, Zhang Cong, Li Mengxi, Hu Qiujia, Jia Huimin, Li Kexin, Wang Qi, Yang Ruiqiang
Moderately Deep Coalbed Methane Reservoirs In The Southern Qinshui Basin: Characteristics And Technical Strategies For Exploitation, Zhang Cong, Li Mengxi, Hu Qiujia, Jia Huimin, Li Kexin, Wang Qi, Yang Ruiqiang
Coal Geology & Exploration
This study investigated the northern Zhengzhuang-western Qinnan block for the purpose of achieving effective exploitation of moderately deep coalbed methane (CBM) reservoirs in the southern Qinshui Basin. Based on results from the analyses and tests of parametric wells, including core analysis and tests, injection/falloff tests, and in situ stress cyclic tests, as well as a large amount of dynamic and static data, this study expounded on the characteristics of moderately deep CBM reservoirs in the study area by comparison with shallow counterparts. Then, it explored the technical improvements in fracturing through vertical wells and staged fracturing through horizontal wells for …
A Calculation Model Of Free Gas Saturation In Deep Coalbed Methane Reservoirs And Its Application, Shi Juntai, Cao Jingtian, Xu Fengyin, Xiong Xianyue, Huang Hongxing, Sun Zheng, Jia Yanran, Ma Shurui, Zheng Haohang, Deng Ting, Li Jing, Li Xiangfang
A Calculation Model Of Free Gas Saturation In Deep Coalbed Methane Reservoirs And Its Application, Shi Juntai, Cao Jingtian, Xu Fengyin, Xiong Xianyue, Huang Hongxing, Sun Zheng, Jia Yanran, Ma Shurui, Zheng Haohang, Deng Ting, Li Jing, Li Xiangfang
Coal Geology & Exploration
In recent years, breakthroughs have been achieved in the exploration of deep coalbed methane (CBM) in China based on fine-scale geological research and techniques such as multistage hydraulic fracturing using proppants in a horizontal well. As a result, some wells yielded daily gas production of up to 100000 m3, inspiring confidence again in the CBM industry. However, since deep coal reservoirs occur in a complex geological environment characterized by high in-situ stress, high geotemperature, high pore pressure, and low permeability, there is an urgent need to reveal the typical parameters of coal reservoirs at different depths and the …
Mechanisms And Technological Parameter Optimization Of Near-Wellbore Laser Thermal Fracturing For Deep Coal Seams, Zhao Haifeng, Yang Ziyi, Liang Wei, Zhong Junbing
Mechanisms And Technological Parameter Optimization Of Near-Wellbore Laser Thermal Fracturing For Deep Coal Seams, Zhao Haifeng, Yang Ziyi, Liang Wei, Zhong Junbing
Coal Geology & Exploration
China boasts abundant deep coalbed methane (CBM) resources, which play a significant role in further CBM production. However, deep coal seams exhibit low porosities and ultra-low permeabilities due to intricate geological conditions. In the drilling process, drilling fluids enter the reservoirs, prone to cause near-wellbore contamination. Although conventional hydraulic fracturing technology tends to create fractures in the direction of the maximum horizontal principal stress, it is challenging for this technology to achieve blockage removing throughout the whole borehole. Laser thermal fracturing technology can break rocks in a short time. Furthermore, it allows for the laser irradiation angle to change freely …