CO2地质封存泄漏对浅层地下水影响的分析评价

CO2地质封存作为解决CO2排放问题的方法已经越来越受到重视。对于CO2长时间地质封存中可能出现的泄漏问题作为一个该方法的重要技术难题也逐渐被人们所关注,CO2地质封存中一旦出现泄漏问题可能会首先影响到浅层的地下水资源。本文通过总结封存中可能出现的泄漏途径及方式,结合国内外研究泄漏对地下水影响的野外试验和室内实验、数值模型等方法,提出了评价分析封存泄漏对地下水影响的框架和方法。介绍了目前评价的各种方法的缺陷,最后提出了评价中的场地评价、数值模拟、野外试验及室内实验未来的发展方向,三种方式的共同发展能够完善影响评价并且促进CCS工程未来的应用前景。     

二氧化碳地质封存工程防灾监测中瑞雷波敏感性初步分析

瑞雷波勘察技术常用于地震场地土评价,且长波微动观测可以获得深部地层的信息,但其在CO2地质封存工程防灾监测中应用的可行性探讨还未见深入研究报道。基于一典型CO2封存场地地层模型,通过数值模拟的方式,分析了瑞雷波波速对储层弹性参数改变的敏感性。模拟分析表明,CO2储层弹性参数变化对瑞雷波波速的影响随频厚积变化而变化;研究发现CO2储层横波波速改变相对于层厚、纵波或密度的改变对面波波速影响较大;研究还发现当CO2储层薄且埋深大时,面波频散特性对储层弹性参数改变不敏感。研究初步认为,当前常规的瑞雷波勘察技术用于深部CO2封存工程防灾监测具有一定的技术难度。     

中国 CO2地质封存及增强地热开采一体化的初步探讨

地热资源作为一种可再生清洁能源,具有较大的开发潜力。对CO2进行地质封存的同时,将CO2作为一种资源,增强地热开采是一种新技术。对2类不同地热资源开采(干热岩型、水热型)与CO2地质封存相结合的一体化技术进行讨论,并针对国内西北某典型咸水层CO2捕获与封存(CCS)示范项目特定地质条件,对比分析相同生产井/注入井条件下,CO2与水分别作为工质流体在井内流动的压力变化,以及二者在2类不同储层条件下各自的热提取率,并进行相应的碳封存量、安全性和经济性分析,发现采用CO2代替水作为工质流体开采地热资源具有显著的优势。数值模拟结果显示,在我国开展CO2地质封存与增强地热开采一体化技术具有较强的可行性。     

地质封存工程中CO2沿井筒渗漏影响因素分析

CO2地质封存作为现阶段温室气体减排的有效技术之一,在石油行业中具有许多优势,CO2沿井筒渗漏是地质封存过程中所面临的重要风险之一。为降低CO2渗漏对封存区域生态、环境和人员健康方面的不利影响,文章通过研究CO2地质封存背景和封存于地下的超临界CO2的性质,分析CO2沿井筒区域系统渗漏的潜在通道,并以此为基础开展CO2沿井筒区域系统渗漏主要影响因素的研究。     

咸水含水层中CO_2地质封存井口压力的确定及应用

CO2地质封存是减少二氧化碳排放的有效途径之一,井口压力的大小直接关系到封存项目的有效性和安全性。本文总结了井口压力求取的常规方法和漂移流模型解析法,并在实际封存场地进行了比较应用分析,结果发现漂移流模型解析法对井中流体运动刻画的更为准确,所得的结果与实际值更接近,而且井径大小对井口压力有一定程度的影响,其结果可为实际CO2地质封存项目的实施提供技术支持。     

浅谈挪威船级社CO2管道泄漏实验

管道输送作为所捕集的CO2与利用封存场地的纽带,在碳捕集、驱油与封存项目中起着重要的作用。鉴于我国CO2长输管道的设计标准和规范处于空白,文章对挪威船级社于2006年和2010年的管道泄漏实验进行归纳总结,介绍了工业规模泄放实验的研究目的、实验装置、恒压及泄压释放的操作流程、管道内对压力和温度的监测布点以及大气中对CO2浓度监测的布点方式等。这为我国研究人员开展CO2管道泄放的实验设计及研究方法提供了参考借鉴,有助于加快我国CO2管道输送安全性研究的步伐。     

地层倾角对CO2地质封存的影响研究—以鄂尔多斯CCS工程为例

CO2地质储存是减少CO2向大气排放的有效手段。CO2在储层中的运移受地层的物理属性和空间展布形态的影响,本文以鄂尔多斯CO2地质封存示范场地石千峰组为研究对象,研究了地层产状倾斜对CO2地质储存的影响。结果表明,在定压注入时,地层倾角对CO2的空间分布、CO2的注入速率、CO2的空间运移距离、以及CO2的封存量等均呈现出规律性的影响;地层倾角越大,注入速率越小、横向运移距离越远,而其封存量小;地层倾角的增大不利于CO2地质封存。     

二氧化碳封存和强化采油

人为产生的CO2排入大气造成温室效应,引发全球变暖。CO2地质封存是一种极具发展潜力减少CO2排入大气中的方法。本文介绍了C02封存技术的各个组成部分以及CO2封存和强化采油联合的应用情况,分析了影响CO2封存和强化采油实施的三个因素。     

TOUGH2软件的发展及应用

TOUGH2是一套功能强大、应用广泛的模拟孔隙或裂隙介质中多相流的系列程序。本文概略地回顾了TOUGH2软件的开发背景和升级历史。系统地介绍了TOUGH2软件的结构组成、特点和基本原理以及该软件的应用现状。     

深部非采煤层CO2封存稳定性模糊综合评判

为实现对深部非采煤层CO2封存稳定性问题的多因素量化评价,采用模糊数学理论提出基于二级评判模型的深部非采煤层CO2封存稳定性模糊综合评判方法,基于科学性、合理性、可操作性、代表性的原则确立8个一级因素指标和4个二级因素指标,建立综合评判体系,综合采用模糊统计法和专家评分法对各个因素指标按4个稳定性等级进行量化分级,分析各因素指标隶属函数的构造,采用层次分析法合理分配各因素指标的权重,结合我国山西沁水盆地CO2-ECBM项目地质勘查资料进行工程实际评判验证,取得与工程实际相一致的评判结果,由此表明:采用模糊综合评判的方法评价深部非采煤层封存CO2的稳定性具有合理性和可操作性,为CO2煤层封存的场地选址提供理论支持。     

The sequestration switch: removing industrial CO2 by direct ocean absorption

This review paper considers direct injection of industrial CO2 emissions into the mid-water oceanic column below 500 m depth. Such a process is a potential candidate for switching atmospheric carbon emissions directly to long term sequestration, thereby relieving the intermediate atmospheric burden. Given sufficient research justification, the argument is that harmful impact in both the Atmosphere and the biologically rich upper marine layer could be reduced. The paper aims to estimate the role that active intervention, through direct ocean CO2 storage, could play and to outline further research and assessment for the strategy to be a viable option for climate change mitigation. The attractiveness of direct ocean injection lies in its bypassing of the Atmosphere and upper marine region, its relative permanence, its practicability using existing technologies and its quantification. The difficulties relate to the uncertainty of some fundamental scientific issues, such as plume dynamics, lowered pH of the exposed waters and associated ecological impact, the significant energy penalty associated with the necessary engineering plant and the uncertain costs. Moreover, there are considerable uncertainties regarding related international marine law. Development of the process would require acceptance of the evidence for climate change, strict requirements for large industrial consumers of fossil fuel to reduce CO2 emissions into the Atmosphere and scientific evidence for the overall beneficial impact of ocean sequestration.     

二氧化碳封存技术研究进展

CO₂作为最重要的温室气体越来越受关注,而CCS技术因在大规模减少温室气体排放方面的潜力也受到广泛重视。在广泛搜集国内外有关CCS技术相关资料的基础上,详细介绍了最新的CCS技术现状,列出了国内外最新CCS工程案例,讨论了地质封存、CO₂-EOR、CO₂-ECBM技术的内涵及研究进展,对深部咸水层、枯竭油(气)田、玄武岩含水层、CO₂-EOR及CO₂-ECBM封存技术选型、CO₂泄露、储存容量和可注入性、试验与模拟技术以及选址与风险评估等研究现状进行了讨论并指出了下一步的研究重点。最后,对中国的CCS技术发展进行了展望。     

Integrating Forest Carbon Sequestration Into a Cap-and-Trade Program to Reduce Net CO2 Emissions

Problem: Most research on planning to mitigate climate change has focused on reducing CO2 emissions from coal-f?red power plants or the transportation sector. The contribution of forests to lowering net CO2 emissions has largely been overlooked. U.S. forests already offset about one eighth of the nation's annual CO2 emissions and have the potential to offset more, all at a relatively low cost. It will not be easy to integrate forest carbon sequestration into a cap-and-trade program to reduce net CO2 emissions, however.

Purpose: I explore what forest land use planning, forestry management practices, and land preservation strategies would be required to integrate forest carbon seques-tration into a cap-and- trade program, and explain the role planning and planners can play in promoting forest carbon seques-tration.

Methods: The Regional Greenhouse Gas Initiative is a 10-state cap-and-trade program to reduce greenhouse gas emissions from coal-f?red power plants in the northeastern United States. It provides a case study of how forest carbon sequestration can be included in a cap-and-trade program. Meanwhile, California has devised certif?able carbon credits from forestland. I analyze both approaches and generalize from them.

Results and conclusions: To promote forest carbon sequestration through a cap-and-trade program will require ensuring the permanence of CO2 reductions, minimizing leakage from forestland conversion, and obtaining prices for carbon offsets that are high enough to induce forestland owners to participate in the program and offer them for sale. The capital needed to purchase and monitor permanent forest conservation easements as well as to provide a stream of annual income for timberland owners may require a national system of carbon credits. Ideally, the easements would be set up in advance through investments by govern-ment or nonprof?ts, so that landowners will be ready to sell credits when they are demanded.

Takeaway for practice: A cap-and-trade system could be a cost-effective way to lower net CO2 emissions if it included certif?able, tradable credits from forestland preservation and management, and if the price of carbon credits were high enough to induce forest landowners to offer credits. To promote forest carbon sequestration, planners in rural areas should work with the local, state, and federal governments and nonprof?t land trusts to zone forestland at low densities, to preserve forest land through acquiring conservation ease ments, and to fashion forest management plans that ensure long cycles of timber harvesting. Planners in metropolitan areas should promote tree planting and tree retention ordinances to protect, expand, and manage urban forests to absorb greenhouse gases.

Research support: None.     

Effects of in situ stress measurement uncertainties on assessment of predicted seismic activity and risk associated with a hypothetical industrial-scale geologic CO_2 sequestration operation

Carbon capture and storage(CCS) in geologic formations has been recognized as a promising option for reducing carbon dioxide(CO_2) emissions from large stationary sources.However,the pressure buildup inside the storage formation can potentially induce slip along preexisting faults,which could lead to felt seismic ground motion and also provide pathways for brine/CO_2 leakage into shallow drinking water aquifers.To assess the geomechanical stability of faults,it is of crucial importance to know the in situ state of stress.In situ stress measurements can provide some information on the stresses acting on faults but with considerable uncertainties.In this paper,we investigate how such uncertainties,as defined by the variation of stress measurements obtained within the study area,could influence the assessment of the geomechanical stability of faults and the characteristics of potential injection-induced seismic events.Our modeling study is based on a hypothetical industrial-scale carbon sequestration project assumed to be located in the Southern San Joaquin Basin in California,USA.We assess the stability on the major(25 km long) fault that bounds the sequestration site and is subjected to significant reservoir pressure changes as a result of 50 years of CO_2 injection.We present a series of geomechanical simulations in which the resolved stresses on the fault were varied over ranges of values corresponding to various stress measurements performed around the study area.The simulation results are analyzed by a statistical approach.Our main results are that the variations in resolved stresses as defined by the range of stress measurements had a negligible effect on the prediction of the seismic risk(maximum magnitude),but an important effect on the timing,the seismicity rate(number of seismic events) and the location of seismic activity.     

SEISMIC WAVE VELOCITY MONITORING OF CO_2 MIGRATION IN POROUS SANDSTONES SATURATED WITH WATER

Abstract Laboratory experiments were conducted to measure the compressional wave velocities under hydrostaticpressure in Shirahama and Tako sandstones with a porosity of 12% and 24%, respectively In dry samples, the pressuredependence of velocity is ascribed to the difference in pore structures. Velocities were also measurd to map themovement of the injected CO_2 within water-satutaled samples during CO_2 injection. In the water-saturated samples,velocity changes caused by the CO_2 injection are typically on the order of 10%. A series of seismic tomography     

建筑材料全寿命期CO2 排放量计算方法

建筑材料CO2 减排是我国整体CO2 减量计划的重要方面,建筑材料CO2 排放量的计算是发展低碳建材、推进建筑节能减排的前提和基础,为此需要确立建筑材料CO2 排放量的计算方法。通过CO2 排放活动分析,从全寿命期和CO2 排放源角度,确定了建筑材料CO2 排放构成;并对六种建筑材料CO2 排放量的计算方法进行了比较分析,选择碳排放系数法作为计算我国建筑材料CO2 排放量的方法;构建了建筑材料全寿命期CO2 排放三阶段计算模型,并提出了建筑材料生产、运输以及处置阶段CO2 排放因子的确定方法。应用实例显示,该方法可较方便地测算出建筑材料全寿命期CO2 排放量。     

利用弹性波检测多孔质饱和砂岩中的二氧化碳流动状态

Laboratory experiments were conducted to measure the compressional wave velocities under hydrostatic pressure in Shirahama Tako sandstones with a porosity of 12% and 24%,respectively.In dry samples,the pressure dependence of velocity is ascribed to the difference in pore structures.Velocities were also measured to map the movement of the injected CO2 within water-saturated samples during CO2 injection.In the water-saturated samples,velocity changes caused by the CO2 injection are typically on the order of 10%.A series of seismic tomography experiments are conducted on porous sandstone samples to demonstrate the use of cross-well seismic profiling for monitoring the migration of CO2 in geological sequestration projects.     

吸附不同气体对煤岩渗透特性的影响

注CO2或者CO2/N2混合气强化煤层气开采以及进行CO2封存时,气体的吸附/解吸会影响煤岩的渗透特性。采用自行研制的煤岩三轴渗流装置进行恒定有效应力、不同气体压力条件下,煤岩吸附纯CO2,CH4,N2以及不同配比的CO2/N2混合气体对渗透特性影响的试验研究,以探讨煤岩在气体压力以及吸附作用下渗透特性的变化规律。结果表明:(1)气体组分固定的条件下,煤样渗透率随气体压力的增加呈负指数减小。(2)相同气体压力条件下,煤样吸附气体后渗透率都有不同程度的下降,且下降幅度跟吸附气体的组分有关,吸附纯CO2下降的幅度最大,吸附CH4次之,吸附N2最小;吸附CO2/N2混合气时,其中CO2组分浓度越高,煤样渗透率越低,但当N2量达到一定比例时,煤样渗透率会得到改善。(3)气体压力加卸载过程得到的煤岩渗透率–气体压力关系曲线存在滞后现象,这与气体在煤岩中的吸附/解吸曲线滞后有关,因此煤岩渗透率跟压力路径有关。试验结果对于煤矿瓦斯抽采以及CO2或烟道气注入煤层后的储层渗透率的预测与控制具有重要指导意义。     

碳中和背景下城市碳汇功能及提升策略——以沈阳核心区为例

城市是碳排放产生的主要地域空间,是进行"碳中和"核算与政策制定的主体.除了减少固定能源与交通碳排放外,增加城市碳汇也是实现"碳中和"的重要手段.通过分析沈阳三环区域城市碳汇(植被、土壤、水系、建筑物)不同组成部分的碳汇能力,估算出城市碳汇固碳量为430.93万t,能够抵消沈阳市年能源消耗产生CO2的7.34％.在明晰城...