我国沉积盆地CO2地质储存的地热条件适宜性评价

CO2地质储存是减少人类活动产生的CO2向大气排放的有效措施之一。目前CO2地质储存适宜性评价中仅把地热条件作为单一因子进行考虑,难以准确评价地热条件对CO2地质储存的影响,评价精度较差。为此本文采用加权法将地热条件三因素(大地热流、地温梯度与地表年均气温)进行CO2地质储存适宜性评价,提高了精度。表明:我国总体上较适宜CO2地质储存,储存空间大。2.1%(8.5×104km2)沉积盆地适宜CO2地质储存,68.6%(274.0×104km2)较适宜,24.6%(98.4×104km2)一般适宜,4.7%较不适宜(18.7×104km2),无不适宜区。     

松辽盆地CO2地质储存适宜性评价

为缓解全球气候变暖趋势,CO2地质储存成为目前减少向大气排放CO2量的有效方法之一.区域CO2地质储存适宜性评价是筛选CO2地质储存目标区和工程建设的基础,合理的评价指标体系和指标权重对评价结果有重要影响.本次研究结合松辽盆地地质条件,建立包括地质储存规模、储存经济性、储存条件和储存安全性4个方面、20个指标、5个指标...     

深部咸水层CO2地质储存适宜性评价方法研究

随着温室效应的加剧,CO₂地质储存已成为减缓全球气候变暖的有效方法之一. 可用于CO₂ 地下储存的场地主要有枯竭的油气田、深部咸水层和深部不可开采的煤层等,我国深部咸水层CO₂地质储存潜力占总潜力的98%以上. 在全面分析CO₂ 地质储存适宜性影响因素的基础上,建立了适宜于沉积盆地深部咸水层CO₂ 地质储存的适宜性评价体系,主要包括地质安全性、储存规模、社会环境风险和经济适宜性4大指标层,共计28个评价指标,评价方法以层次分析法及指标叠加法为主. 以西宁盆地为研究实例,通过基于排除法的地质条件综合分析与层次分析法的定量评价相互验证,表明该指标体系和评价方法具有广泛的应用价值. 结果表明,西宁盆地一级构造单元中双树坳陷最适宜CO₂地质储存,可作为CO₂地质储存的优先选区.     

我国碳酸盐岩储层CO2地质储存潜力与适宜性

文章系统收集并分析了我国各盆地地层、大地构造、油田地质、水文地质数据,研究了我国各盆地碳酸盐岩地层空间分布和孔隙度特性,做出了《全国盆地碳酸盐岩分布面积分级图》、《全国盆地碳酸盐岩厚度分级图》、《全国盆地碳酸盐岩孔隙度分级图》、《全国盆地碳酸盐岩二氧化碳地质储存潜力分级图》。逐一对全国各沉积盆地内800～5 000 m深度区间各地质时代形成的碳酸盐岩储层的CO2储存能力进行了计算。通过层次分析法确定各评价指标权重,制做出全国盆地E级碳酸盐岩储层CO2地质储存适宜性评价结果表,绘制出《全国盆地碳酸盐岩储层CO2储存适应性评价图》。对全国盆地CO2储存进行了适宜性评价,剔除了不适宜CO2地质储存的沉积盆地,选出适宜的沉积盆地以供下一阶段继续研究。      

CO_2地质储存潜力与适宜性评价编图方法研究

借鉴国外CO2地质储存潜力与适宜性调查评价工作程序,将我国CO2地质储存潜力与适宜性评价工作划分为五个阶段。影响盆地评价阶段CO2地质储存适宜性的因素很多,本文分别从盆地本身物理条件、数据源和资源潜力、地壳稳定性、温度以及经济适宜性五个影响方面形成单因子图,此五类单因子图件的编图基础为中国1∶500万地质图,利用图层属性的加权计算、叠加的成图方法,综合单因子图件形成我国CO2地质储存远景区划图件。     

CO_2地质储存潜力与适宜性评价方法及初步评价

借鉴国外CO2地质储存潜力与适宜性调查评价工作程序,在充分考虑我国复杂的地质背景、CO2地质储存研究现状等因素的基础上,将我国CO2地质储存潜力与适宜性评价工作划分国家级潜力评价阶段、盆地级潜力评价阶段、目标区级潜力评价阶段、场地级评价阶段、灌注、监测运行期评价阶段,按评价精度由低到高,分称为CO2地质储存潜力与适宜性评价E、D、C、B、A级;并对我国CO2地质储存潜力与适宜性进行了E级评价,即运用层次分析-模糊指数法对我国陆相沉积盆地进行了初步筛选,并对其储量进行了计算,认为我国陆上沉积盆地深部咸水含水层是最主要的CO2地质储量场所。     

典型电厂海洋CO2地质储存场地选址适宜性评估

我国华东和东部沿海地区分布有大量的火电、水泥和炼油等CO₂排放源,但由于距离陆域大中型沉积盆地较远,限制了规模化的深部咸水层CO₂地质储存工程选址。本文以华能玉环电厂为实例,开展了东海陆架盆地瓯江凹陷场地选址适宜性评估。通过瓯江凹陷CO₂地质储存地质条件分析,初步圈定出了发育有利储盖层的目标靶区,并依次开展了地质安全性和经济适宜性分析。利用碳封存领导人论坛潜力评估公式,计算了目标靶区推荐储层的单位面积储存潜力;并在构建综合储集条件、地质安全性条件和经济适宜性条件的指标体系基础上,开展了GIS多源信息叠加评估,在丽水西次凹内筛选出两处较好的场地。研究对开展该区海域CO₂地质储存选址具有一定的探索意义。     

全国二氧化碳地质储存适宜性评价编图技术方法研究

将全国CO2地质储存潜力与适宜性评价工作划分为5个阶段,依次为区域级预测潜力(E级)评价、盆地级推定潜力(D级)评价、目标区级控制潜力(C级)评价、场地级基础储存量(B级)评价和灌注级工程储存量(A级)评价阶段.第一阶段编制的成果图件主要为全国1∶500万CO2地质储存成果图系;第二、三阶段主要编制沉积盆地CO2地质储存成果图集;第四、五阶段主要编制CO2地质储存示范工程成果图册.提出中国CO2地质储存潜力与适宜性评价和编图是一项有步骤、分阶段逐步完成的工程,评价及编图方法有待通过潜力与适宜性评价和编图的实践不断完善.     

国外 CO2地质储存现状与展望

温室气体CO2的大量排放给全球气候和环境带来的巨大影响,受到了世界各国的关注.实现CO2的深度减排是人类可持续发展的必由之路.CO2地质储存是缓解碳排放行之有效的方法之一.本文通过以下几方面论述了国外CO2地质储存的现状以及对未来的展望:1)CO2捕集机理,2)CO2地质储存,3)CO2地质储存项目现状与未来预测,4) CO2地质储存场地储量评估,5)CO2地质储存监测技术,6)CO2地质储存模拟工具,7)CO2地质存储经费等.     

国外CO2地质储存现状与展望

温室气体CO2的大量排放给全球气候和环境带来的巨大影响,受到了世界各国的关注。实现CO2的深度减排是人类可持续发展的必由之路。CO2地质储存是缓解碳排放行之有效的方法之一。本文通过以下几方面论述了国外CO2地质储存的现状以及对未来的展望：1）CO2捕集机理,2）CO2地质储存,3）CO2地质储存项目现状与未来预测,4）CO2地质储存场地储量评估,5）CO2地质储存监测技术,6）CO2地质储存模拟工具,7）CO2地质存储经费等。     

深部咸水层CO2地质储存地质安全性评价方法研究

CO2地质储存工程属于环保型工程项目,地质安全性是影响CO2长期封存的首要因素。深部咸水层CO2地质储存地质安全性影响因素主要包括盖层适宜性、场地地震安全性、水文地质条件、地面场地地质条件四个方面,其中盖层适宜性是CO2安全储存的最关键因素,场地地震安全性和水文地质条件次之,而地面场地地质条件也是影响工程施工的重要因素。本文基于CO2地质储存的地质安全性影响因素分析,建立了层次分析结构的地质安全性评价指标体系,并初步计算了评价指标的权重;提出可以利用模糊综合评价方法进行深部咸水层CO2地质储存地质安全性综合评价,为中国深部咸水层CO2地质储存的地质安全性评价方法和安全选址指明了方向。     

Hydrogeochemical and isotopic evidence for trans-formational flow in a sedimentary basin: Implications for CO2 storage

Deep saline aquifers are considered as the most promising option for geologic disposal of CO₂. One of the main concerns, however, is the integrity of the caprocks between and above the storage formations. Here, a hydrogeochemical and isotopic investigation is presented, using ionic chemistry, stable isotopes (δ¹⁸O, δ²H and ⁸⁷Sr/⁸⁶Sr) and radiocarbon dating, on five saline aquifers on a regional scale, namely: Neogene Minghuazhen, Guantao, Ordivician, Cambrian and Precambrian, all found in the Bohai Bay Basin (BBB) in North China. Groundwater recharge, flow pattern, age and mixing processes in the saline aquifers show that the Neogene Guantao Formation (Ng) in the Jizhong and Huanghua Depressions on both of the west and east sides of the Cangxian Uplift is a prospective reservoir for CO₂ sequestration, with a well confined regional seal above, which is the clayey layers in the Neogene Minghuazhen Formation (Nm). However, this is not the case in the Cangxian Uplift, where the Ng is missing where structural high and fault zones are developed, creating strong hydraulic connections and trans-formational flow to the Nm aquifer. Comparing storage capacity and long-term security between the various hydrogeologic units, the depressions are better candidate sites for CO₂ sequestration in the BBB.     

Feasibility study of CO2 geological storage in China

It has been proved to be one effective means to reduce emissions of CO2 to mitigate the worsening global climate change through lots of projects and tests about CO2 geological storage. The sites that are suitable for CO2 geological storage include coal seams that can not be mined, deep saline aquifers, oil fields, and depleted gas fields. The emission of CO2 from fuel combustion is about 3.54 Gt in China in 2003, which is the second biggest in the world. Because the energy consumption in China mainly depends on fossil fuels for a long time in the future, China will become a country with the biggest emission of CO2 in the world, which will make China have to reduce the emissions of CO2 by some methods including geological storage. Based on lots of information about the reserves of coal seam methane and the rank of coal in the 68 coal basins in China, the total CO2 storage capacity in these coal basins was estimated according to the recovery coefficient and exchange ratio of CO2 to CHa.The total storage capacity in deep saline aquifers can be regarded as the total quantity of CO2 that can be dissolved in the saline aquifers at the depth from 1000m to 3000m under ground. The quantity can be estimated by multiplying the solubility of CO2 in the saline water and the volume of the appropriate aquifers. According to the reserve and quality of crude oil in 46 main oil basins in China, the CO2 storage capacity and the quantity of enhanced oil were calculated. The storage capacity of depleted gas fields can be derived from the reserve and depth of the gas fields. The total CO2 geological storage capacity is about 196.2 Gt CO2 that is as against 55.4 times the CO2 emission from fuel combustion in China in 2003. According to the results of the finished projects and tests about CO2-EOR and CO2-ECBM, the CO2 geological storage capacities in coal seams, deep saline aquifers, oil fields and depleted gas fields will be estimated.     

安徽省地质环境承载能力评价

通过分析安徽省地质环境特点,选取其中8个地质环境因子建立了地质环境评价指标体系,采用专家打分法确定权重,利用层次分析法进行了地质环境承载能力综合评价。结果显示,安徽省地质环境承载能力总体较强;仅大别山区、黄山市、池州市-铜陵市-芜湖市等矿山集中开采区承载能力较弱,面积占比4.78%。根据安徽省地质环境承载能力特征,提出了针对对大别山区、皖南山区开展地质环境保护和针对安徽省地下水超采区进行修复的建议,为国土空间开发提供科学参考。     

CO2 geological storage: The environmental mineralogy perspective

Geological storage of carbon dioxide (CO₂) is one of the options envisaged for mitigating the environmental consequences of anthropogenic CO₂ increases in the atmosphere. The general principle is to capture carbon dioxide at the exhaust of power plants and then to inject the compressed fluid into deep geological formations. Before implementation over large scales, it is necessary to assess the efficiency of the process and its environmental consequences. The goal of this paper is to discuss some environmental mineralogy research perspectives raised by CO₂ geological storage.     

On the risk of hydraulic fracturing in CO2 geological storage

We present a contribution on the risk of hydraulic fracturing in CO₂ geological storage using an analytical model of hydraulic fracturing in weak formations. The work is based on a Mohr–Coulomb dislocation model that is extended to account for material with fracture toughness. The complete slip process that is distributed around the crack tip is replaced by superdislocations that are placed in the effective centers. The analytical model enables the identification of a dominant parameter, which defines the regimes of brittle to ductile propagation and the limit at which a mode‐1 fracture cannot advance. We examine also how the corrosive effect of CO₂ on rock strength may affect hydraulic fracture propagation. We found that a hydraulically induced vertical fracture from CO₂ injection is more likely to propagate horizontally than vertically, remaining contained in the storage zone. The horizontal fracture propagation will have a positive effect on the injectivity and storage capacity of the formation. The containment in the vertical direction will mitigate the risk of fracturing and migration of CO₂ to upper layers and back to the atmosphere. Although the corrosive effect of CO₂ is expected to decrease the rock toughness and the resistance to fracturing, the overall decrease of rock strength promotes ductile behavior with the energy dissipated in plastic deformation and hence mitigates the mode‐1 fracture propagation. Copyright © 2016 John Wiley & Sons, Ltd.     

渗透率的非均质性对CO_2地质封存的影响

CO2地质封存可以减少化石燃料燃烧排放的CO2量,有效减缓温室效应。储层渗透率可以决定CO2通道的形成,进而改变其在储层中的运移规律,因而是影响CO2地质封存的重要因素。根据研究区基本地质数据、三维地震勘探结果和统计规律确定了渗透率的分布情况,运用储层多相流模拟软件TOUGH2-MP分析了渗透率的非均质性对CO2地质封存的影响。结果表明:(1)渗透率的分布情况对CO2储存量和注入压力的影响很大,相比于均值模型,CO2的注入总量明显减少,到达最大允许压力积聚所需的时间要比均质模型短;(2)在保证注入速率和压力积聚不超过允许最大值的双重要求下,定压和定量两种注入方案都有待改进,建议考虑如人工压裂等工程措施;(3)渗透率的非均质性使得CO2晕呈现出不规则扩散,经过20年的注入,其最大扩散距离约800m,比均质情况下小150m,须做好相应的监测工作。