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中国东部CO2气田(藏)发育广泛,分布复杂。本文对中国东部松辽、渤海湾、苏北、三水、东海、珠江口、莺琼、北部湾等盆地和内蒙古商都地区以及部分现代构造岩浆活动区CO2气田(藏)和气苗中CO2的地球化学特征进行了分析和研究,探讨了中国东部CO2气的成因、来源及分布。中国东部CO2气的含量主要分布区间为0~10%,其次为90%~100%,呈现典型的U字型。δ13CCO2值则呈现典型的单峰式分布,峰值区间为-6‰~-4‰。CO2含量、δ13CCO2值和R/Ra值综合表明,中国东部高含CO2气以幔源无机成因为主,混有部分有机成因气和(或)壳源无机气。中国东部已发现的36个无机成因CO2气田(藏)在空间分布上与新近纪及第四纪北西西向玄武岩活动带展布一致,深大断裂和岩浆活动是无机成因CO2富集、运移和分布最重要、最直接的两大主控因素。 相似文献
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松辽盆地北部昌德东CO2气藏的“自生自储“成藏模式指成藏气体主要是无机成因的幔源火山岩吸附气，后期的构造运动使裂缝连通、天然气汇聚成藏。证据有：火山岩含有WB为0.429%~1.387%的吸附CO2，具有孔隙和缝隙相互组合的双孔介质，说明火山岩既可作为CO2气的源岩，亦可作为储层；昌德东CO2气藏中存在近距离不均一的CO2含量空间分布、下贫上富的储层CO2含量和上高下低的CH4-CO2平衡温度等特征。中国东部幔源—岩浆成因的CO2气藏地区均发育幔源火山岩，说明该成藏模式具有现实的可能性和普遍性。 相似文献
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腾冲新生代火山区温泉CO2气体排放通量研究 总被引：6，自引：6，他引：0
近期研究表明,不仅火山喷发期会向当时的大气圈输送大量的温室气体,火山间歇期同样会释放大量的温室气体。在火山活动间歇期,火山区主要以喷气孔、温(热)泉以及土壤微渗漏等形式向大气圈释放温室气体。腾冲是我国重要的新生代火山区,同时也是重要的水热活动区,那里出露大量的温泉,然而目前未见腾冲火山区温泉气体排放通量的研究报道。本文利用数字皂膜通量仪测量了腾冲新生代火山区温泉中CO2的排放通量。研究结果表明,腾冲新生代火山区温泉向当今大气圈输送的CO2通量达3.58×103 t·a-1,相当于意大利锡耶纳Bassoleto地热区温泉中CO2的排放规模。腾冲火山区温泉的CO2释放通量主要受深部岩浆囊、断裂分布、地下水循环、围岩成分等多方面因素的影响。本文根据温泉中CO2的排放特征,将腾冲温泉分为南北两区,南区温泉CO2通量远高于北区的温泉,热海地热区的通量为腾冲CO2通量的最大值。在北温泉区,CO2通量主要受控于断裂的分布;而在南温泉区,除受到断裂控制外,热海地热区底部的岩浆囊及其与围岩的相互作用成为CO2气体的重要物质来源,同时高温的岩浆囊为温泉及CO2的形成提供了重要热源。 相似文献
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沉积岩中无机CO2热模拟实验研究 总被引：4，自引：0，他引：4
结合三水盆地的地质特点，分析了无机CO2热模拟实验研究的可能性，进行了不同条件下的模拟试验和相关的分析测试，提出了无机CO2生成量和转化率的概念和计算方法。从实验结果来看：含有一定量碳酸盐矿物的沉积岩，在一定温度下可转化形成相当数量的无机CO2，无机CO2转化率越高，岩石中碳酸盐矿物越容易转化生成无机CO2；相同热成熟度条件下，Ⅱ型干酪根生成有机CO2的量较Ⅲ型的少；CO2中碳同位素与CO2的成因密切相关，随有机质热成熟度的增加，同种类型有机质生成的有机CO2相对富集13C；无机CO2较有机CO2的碳同位素明显富集13C，随水介质的pH值降低，无机CO2气含量、模拟温度及时间的增加，无机CO2相对富集13C。实验研究结果为CO2成因研究及其资源评价提供了实验依据。 相似文献
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云贵高原湖泊CO2的地球化学变化及其大气CO2源汇效应 总被引：3，自引：0，他引：3
湖泊是大气CO2的源还是汇,长期以来一直都存有争议。云贵高原地区的湖泊由于受流域碳酸盐岩风化作用的影响,使这一问题就显得更特殊,也更复杂。本次研究通过化学平衡计算和气相色谱测定两种方法得到了比较一致的湖水CO2浓度结果。研究发现,在夏季强烈的光合作用消耗了湖水CO2,致使湖水中CO2浓度降低。在贵州草海、百花湖以及云南的泸沽湖、杞麓湖,表层湖水CO2分压(为便于与大气CO2比较,文中湖水CO2用分压单位表示)小于200μatm,远低于大气CO2分压,湖泊正不断地从大气中吸收CO2,从而构成大气CO2的汇。 相似文献
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本文对目前开采天然气水合物的5种方法进行了归纳总结,重点分析了CO2置换开采以及固体开采法,并通过分析这2种开采方法的优劣势,提出了水射流冲蚀、破碎海洋天然气水合物储层联合CO2置换开采天然气水合物的新思路。水射流冲蚀、破坏水合物储层后形成的采空区能为CO2提供更好的储藏空间并提高其与储层的作用面积,提高置换效率;封存的CO2水合物也可以提高水合物储层的稳定性,具有良好的互补效应。实验结果表明,在整个置换过程中,含采空区储层CH4置换率为24.3%,CO2封存率为22.1%;完整储层CH4置换率为15.3%,CO2封存率为20.9%,置换率提升约59%,封存率提升约5.7%。采空区的作用主要体现在提升水合物置换介质的注入量上。 相似文献
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本文主要论述土壤热释CO2测量法在碳硅泥岩型铀矿床上的试验效果,实测结果表明,该法是有效的.文章还对CO2法找钻机制进行了初步探讨.有关取样技术、样品加工和分析测定方法也作了概述.最后认为土壤热释CO2 测量法可成为一种找铀的新方法. 相似文献
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大气CO2浓度增加对陆地化学侵蚀的影响小于酸雨的影响。水土流失可能促进大气CO2浓度的增高;植被破坏又影响大气CO2的固定。虽然大气CO2的较高浓度可能促成初级生产力的提高,但海洋光合作用速率增加于环境系统不利。尽管大气微量气体可能产生温室效应,但CO2与地表升温的对应关系不清楚、增温幅度与自然脉动的关系尚需客观评定。地质记录具全息性特征。加强地质记录和现代地质过程研究是揭示大气微量气体环境效应之谜的关键;从燃料和植被两个系列着手是维护全球环境的重要途径。 相似文献
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This paper reviews various coal seam gas (CSG) models that have been developed for the Sydney Basin, and provides an alternative interpretation for gas composition layering and deep-seated CO2 origins. Open file CSG wells, supplemented by mine-scale information, were used to examine trends in gas content and composition at locations from the margin to the centre of the basin. Regionally available hydrochemistry data and interpretations of hydrodynamics were incorporated with conventional petroleum well data on porosity and permeability. The synthesised gas and groundwater model presented in this paper suggests that meteoric water flow under hydrostatic pressure transports methanogenic consortia into the subsurface and that water chemistry evolves during migration from calcium-rich freshwaters in inland recharge areas towards sodium-rich brackish water down-gradient and with depth. Groundwater chemistry changes result in the dissolution and precipitation of minerals as well as affecting the behaviour of dissolved gases such as CO2. Mixing of carbonate-rich waters with waters of significantly different chemistries at depth causes the liberation of CO2 gas from the solution that is adsorbed into the coal matrix in hydrodynamically closed terrains. In more open systems, excess CO2 in the groundwater (carried as bicarbonate) may lead to precipitation of calcite in the host strata. As a result, areas in the central and eastern parts of the basin do not host spatially extensive CO2 gas accumulations but experience more widespread calcite mineralisation, with gas compositions dominated by hydrocarbons, including wet gases. Basin boundary areas (commonly topographic and/or structural highs) in the northern, western and southern parts of the basin commonly contain CO2-rich gases at depth. This deep-seated CO2-rich gas is generally thought to derive from local to continental scale magmatic intrusions, but could also be the product of carbonate dissolution or acetate fermentation. 相似文献
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结合CO_2地质利用与封存技术机理,在国际权威潜力评估公式的基础上,系统地提出了适合中国地质背景的次盆地尺度CO_2封存潜力评估方法及关键参数取值。同时,以四川盆地为例,依次开展了枯竭油田地质封存与CO_2强化石油开采、枯竭气田与CO_2强化采气、不可采煤层地质封存与CO_2驱替煤层气,以及咸水层地质封存技术的CO_2地质封存潜力。结果表明,四川盆地利用深部咸水层与枯竭天然气田CO_2地质封存潜力最大,期望值分别达154.20×10~8t和53.73×10~8t。其中,枯竭天然气田因成藏条件好、勘探程度高、基础建设完善,为四川盆地及其周边利用枯竭气田CO_2地质封存技术实现低碳减排提供了早期示范机会。CO_2地质利用与封存潜力评估方法,对进一步开展全国次盆地尺度理论封存潜力评估与工程规划具有重要意义。 相似文献
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S. Mazumder P. van Hemert A. Busch K-H.A.A. Wolf P. Tejera-Cuesta 《International Journal of Coal Geology》2006,67(4):267-279
Presently many research projects focus on the reduction of anthropogenic CO2 emissions. It is intended to apply underground storage techniques such as flue gas injection in unminable coal seams. In this context, an experimental study has been performed on the adsorption of pure CO2 and preferential sorption behavior of flue gas. A coal sample from the Silesian Basin in Poland (0.68% V Rr), measured in the dry and wet state at 353 K has been chosen for this approach. The flue gas used was a custom class industrial flue gas with 10.9% of CO2, 0.01% of CO, 9% of H2, 3.01% of CH4, 3.0% of O2, 0.106% of SO2 and nitrogen as balance.Adsorption isotherms of CO2 and flue gas were measured upto a maximum of 11 MPa using a volumetric method. Total excess sorption capacities for CO2 on dry and wet Silesia coal ranged between 1.9 and 1.3 mmol/g, respectively. Flue gas sorption capacities on dry and wet Silesia coal were much lower and ranged between 0.45 and 0.2 mmol/g, respectively, at pressures of 8 MPa. The low sorption capacity of wet coal has resulted from water occupying some of the more active adsorption sites and hence reducing the heterogeneity of adsorption sites relative to that of dry coal. Desorption tests with flue gas were conducted to study the degree of preferential sorption of the individual components. These experiments indicate that CO2 is by far the prefered sorbing component under both wet and dry conditions. This is followed by CH4. N2 adsorbs very little on the coal in the presence of CO2 and CH4. It is also observed that the adsorption of CO2 onto coal is not significantly hindered by the addition of other gases, other than dilution effect of the pressure.In addition to the sorption experiments, the density of the flue gas mixture has been determined up to 18 MPa at 318 K. A very good precision of these measurements were documented by volumetric methods. 相似文献
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Interpretation of carbon dioxide diffusion behavior in coals 总被引：3，自引：1，他引：3
Nikolai Siemons Karl-Heinz A.A. Wolf Johannes Bruining 《International Journal of Coal Geology》2007,72(3-4):315-324
Storage of carbon dioxide in geological formations is for many countries one of the options to reduce greenhouse gas emissions and thus to satisfy the Kyoto agreements. The CO2 storage in unminable coal seams has the advantage that it stores CO2 emissions from industrial processes and can be used to enhance coalbed methane recovery (CO2-ECBM). For this purpose, the storage capacity of coal is an important reservoir parameter. While the amount of CO2 sorption data on various natural coals has increased in recent years, only few measurements have been performed to estimate the rate of CO2 sorption under reservoir conditions. An understanding of gas transport is crucial for processes associated with CO2 injection, storage and enhanced coalbed methane (ECBM) production.A volumetric experimental set-up has been used to determine the rate of sorption of carbon dioxide in coal particles at various pressures and various grain size fractions. The pressure history during each pressure step was measured. The measurements are interpreted in terms of temperature relaxation and transport/sorption processes within the coal particles. The characteristic times of sorption increase with increasing pressure. No clear dependence of the characteristic time with respect to the particle size was found. At low pressures (below 1 MPa) fast gas diffusion is the prevailing mechanism for sorption, whereas at higher pressures, the slow diffusion process controls the gas uptake by the coal. 相似文献
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A. Saghafi 《Australian Journal of Earth Sciences》2014,61(3):453-462
A new site-specific (Tier 3) method has been developed to determine greenhouse gas emissions from open coal mining. The Tier 3 method presented here is based on extensive measurement of gas emissions from open-cut coal mines and the physics of gas desorption from coal. It was adopted by Australian National Greenhouse and Energy Reporting in 2009 and since 2012 formed the scientific basis for the Australian Government guidelines on calculating greenhouse gas emissions from open cut mines. The main strength of this method is its site-specific nature and accuracy, as well as its ability to be integrated with routine coal exploration programs. New concepts were produced for the model: a coal mine is regarded as a ‘gas reservoir,’ with coal seam gas being emitted from a ‘gas release zone’ that consists of sedimentary geological units (emission layers) above and below the base of the mine. The primary data required for the method are the in situ gas content and gas composition of the coal and carbonaceous rocks contained within the gas-release zone. These data are obtained through direct measurement of gas desorption from bore cores. To reduce gas drilling, a mine lease is compartmentalised into ‘gas zones’ of similar gas content and reservoir properties. The outputs of the method are emission density (the potential volume of gas emitted from mining site per unit area of the ground surface) and emission factor (the gas volume emitted per tonne of raw coal extracted). Owing to spatial variability and errors of measurement, the estimate of emissions is associated with uncertainty. A simple method of calculating uncertainty of emissions is presented in this work. 相似文献
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地震活动断裂带能够向大气释放大量的温室气体、放射性气体和有毒气体(CO_2、CH_4、Rn和Hg),并对大气环境的影响产生复杂的影响。利用静态暗箱法,对汶川M_s8.0地震破裂带CO_2、Rn和Hg脱气强度进行实地测量,并计算了CO_2和Hg脱气对大气的年贡献量。结果表明:(1)破裂带土壤气中CO_2、CH_4、Rn和Hg异常浓度最大值分别可以达到7.98%、2.38%、524.30k Bq/m~3和161.00ng/m~3;破裂带CO_2、Rn和Hg脱气平均通量是34.95g·m~(-2)d~(-1)、36.11m Bq·m~(-2)s~(-1)和26.56ng·m~(-2)h~(-1),最大值分别达到259.23g·m~(-2)d~(-1)、580.35m Bq·m~(-2)s~(-1)和387.67ng·m~(-2)h~(-1);(2)汶川Ms8.0地震破裂带向大气脱气的CO_2年贡献量是0.95Mt,Hg的年贡献量是15.94kg。汶川Ms8.0地震破裂带破裂CO_2、CH_4、Rn和Hg等的脱气强度,不仅与破裂带渗透率有关,还与断裂带浅部存在的气藏、煤层以及磷矿层等气体源有重要的联系。 相似文献
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松辽盆地含CO_2火山岩气藏的形成和分布 总被引：2，自引：0，他引：2
松辽盆地特有的深部构造背景和裂谷演化特征,造成盆地内含CO_2火山岩气藏的形成和富集。松辽裂谷盆地中新生代火山岩浆活动发育,总体上具有多期喷发、分布广泛和储集条件良好的特点。火山活动以中心式喷发为主,主要发育中基性-酸性火山岩,发育流纹岩、凝灰岩等多种岩石类型,爆发相和溢流相2种火山岩相。中生代火山岩在盆地内分布广泛,营域组构成深层有利储层,新生代火山岩在盆地外围出露较多,而在盆内出露较少。盆地高含量的二氧化碳为无机幔源成因,由青山口期和新生代幔源岩浆脱气形成。含CO_2火山岩气藏的形成主要受深部构造背景、深大断裂和中新生代火山岩控制。已发现含CO_2火山岩气藏主要分布于古中央隆起带及其两侧断陷的营城组火山岩中,具有点状、带状分布,局部富集的特点。根据主控因素分析,预测了5个CO_2富集区带。 相似文献
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To stabilize the atmospheric concentration of greenhouse gases (GHG), a huge reduction of carbon dioxide (CO2) emissions is required. Although some people believe that this necessitates a considerable reduction in the use of fossil fuels or fuel switching, other options are available that allow the use of fossil fuels and reduce atmospheric emissions of CO2. Sequestration of CO2 from fossil fuel combustion in the subsurface could prevent the CO2 from reaching the surface for millions of years. Geological sequestration of CO2 in deep aquifers or in depleted oil and gas reservoirs is a mature technology. Despite the huge quantities of CO2 that can be sequestered in this way, this approach does not provide any economic benefit. This paper discusses a third option, which consists of injecting CO2 in deep coal seams to sequester the carbon and enhance the recovery of coalbed methane (CBM). Waste CO2 from CBM-fueled power plants could be injected into CBM reservoirs to produce more methane (CH4) for the power plant. The 2:1 coal-sorption selectivity for CO2 over CH4 supports the feasibility of operating fossil-fueled power plants without atmospheric CO2 emissions. Other CO2 sequestration technologies, such as ocean disposal and biofixation, are briefly discussed and the suitability of these approaches is evaluated for use in Alberta, Canada. 相似文献
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A large suite of natural gases (93) from the North West Shelf and Gippsland and Otway Basins in Australia have been characterised chemically and isotopically resulting in the elucidation of two types of gases. About 26% of these gases have anomalous stable carbon isotope compositions in the C1–C4 hydrocarbons and CO2 components, and are interpreted to have a secondary biogenic history. The characteristics include unusually large isotopic separations between successive n-alkane homologues (up to +29‰ PDB) and isotopically heavy CO2 (up to +19.5‰ PDB). Irrespective of geographic location, these anomalous gases are from the shallower accumulations (600–1700 m) where temperatures are lower than 75°C. The secondary biogenic gases are readily distinguishable from thermogenic gases (74% of this sample suite), which should assist in the appraisal of hydrocarbons during exploration where hydrocarbon accumulations are under 2000 m. While dissolution effects may have contributed to the high 13C enrichment of the CO2 component in the secondary biogenic gases, the primary signature of this CO2 is attributed to biochemical fractionation associated with anaerobic degradation and methanogenesis. Correlation between biodegraded oils and biodegraded “dry” gas supports the concept that gas is formed from the bacterial destruction of oil, resulting in “secondary biogenic gas”. Furthermore, the prominence of methanogenic CO2 in these types of accumulations along with some isotopically-depleted methane provides evidence that the processes of methanogenesis and oil biodegradation are linked. It is further proposed that biodegradation of oil proceeds via a complex anaerobic coupling that is integral to and supports methanogenesis. 相似文献