世界二氧化碳埋存技术现状与展望

埋存CO2是避免气候变暖的主要方法之一,经过十几年的探索,CO2埋存技术取得了很大进步,欧美等世界典型埋存盆地和公司都取得了不错的CO2埋存成果。当前可行的埋存方式有三种:地下埋存、海洋埋存、森林和陆地生态埋存。地下埋存主要选择枯竭的油气藏、深部的盐水储集层、不能开采的煤层及深海埋存等方式。中国在CO2埋存方面具有广阔的前景。CO2埋存前景十分乐观,这一技术的推广和应用必将对全球CO2减排起到举足轻重的作用。     

世界二氧化碳减排政策与储层地质埋存展望

阐述了因温室气体排放所引起的全球气候变暖和环境问题,介绍了国际社会的各种二氧化碳减排政策,提出了利用二氧化碳埋存提高石油采收率的技术,分析了二氧化碳埋存方式及世界二氧化碳埋存量的评估值。     

CO2在盐水层中的扩散和运移泄漏风险评价模型

温室效应和空气污染是21世纪人类面临的严重问题,而CO2埋存是解决温室效应的最有效方法。在CO2地下地质埋存中,盐水层埋存因其地质储量巨大受到了极大关注,同时也存在很多潜在的风险,因此建立CO2注入到盐水层后的扩散运移泄露风险评价模型将为人类安全埋存CO2提供理论支持。首先,考虑到CO2在联通水层中因浓度差泄漏,以菲克定律为理论基础,结合惠尔凯公式,建立了CO2扩散泄漏风险评价模型;其次,考虑到CO2在联通水层中因压力差泄漏,以达西定律为基础,利用气体平面径向稳定渗流公式和垂直管流相关公式等建立了CO2运移泄露风险评价模型;最后,考虑到CO2从盖层逃逸,以毛细管压力为基础建立了CO2通过盖层泄漏风险评价模型。结果表明,扩散系数越大,泄漏时间越短;扩散和运移泄漏时间相差很大,计算运移泄漏时可忽略扩散作用的影响;当埋存的CO2剩余压力小于盖层的突破毛细管压力时,气体以扩散方式泄漏,否则在压力差的作用下以渗流运移方式泄漏。     

超临界CO_2的携热优势及在地热开发中的应用潜力分析

利用超临界CO2作为工作介质,循环携带地热或驱替地下热水,是一种新颖的地热开发技术。文章在介绍超临界CO2携热优势的基础上,评价了不同类型地热储层注CO2开采地热的应用潜力。超临界CO2采热能力强,对岩石矿物溶解度小,还可与地质埋存技术相结合,适用于干热岩以及沉积岩地热资源的开发。干热岩开发主要考虑采用超临界CO2作为携热介质,沉积岩地热资源储量丰富、孔隙表面积大、地质条件安全,应是注CO2开采地热和地质埋存的首选。     

二氧化碳在深部盐水层中溶解封存规律的研究进展

将二氧化碳埋存到深部盐水层中是目前缓解温室效应的可行性对策之一,在评价储层理论埋存量时,溶解封存量在总埋存量中占有很大的比例。本文通过对相关文献的调研,计算对比了Duan&Sun模型模拟数据与前人实验数据的误差,根据前人实验与本文模拟数据分析了二氧化碳在盐水层中溶解的动力过程和热力过程,二氧化碳通过扩散作用溶解到盐水中,引起盐水层密度的变化,计算系统瑞利数满足对流运动发生的基本条件后,系统产生对流,这有利于二氧化碳的溶解。分析了温度、压力和矿化度对二氧化碳溶解的影响。在前几百年内溶解缓慢易导致泄漏,低温高压、低矿化度下二氧化碳溶解度较高,小二氧化碳水滴更有利于二氧化碳封存。     

北美石油工业二氧化碳提高采收率现状研究

环境保护受到高度关注,由于温室气体大量排放而引起的全球气候变暖问题日趋严峻,必须采取积极有效措施。应用CO2提高采收率是埋存CO2的重要途径,美国拥有应用二氧化碳提高采收率的成熟技术。CO2提高采收率包括混相驱油和非混相驱油2种方式,实现了最大CO2的埋存和提高原油产量有机结合,改善开发效果。北美提高采收率的机理和应用思路研究,必将为全球生态保护,石油资源的高水平、高效益开发和可持续发展提供理论及实践依据。     

典型高温地热系统——羊八井热田基本特征

羊八井热田是属于陆陆碰撞板缘非火山型高温地热田。热田是由3个不同的热储层构成，即浅层、深部第一和第二热储层，实质上它们属同一个水力系统，是一个完整的地热系统的不同部位。浅层热储由第四系松散沉积物及部分基岩风化壳构成，其埋深在地表以下180—280m，热储温度130—173℃，水质类型为Cl^--HCO3^-～Na^ 型水，属深部热流体与冷水混合的产物，流体以液相为主。深部热储由变质杂岩体申的滑离断层系构造空间构成，属基岩裂隙型脉状或带状热储，其中深部第一热储层埋深为950—1350m，最高温度259．6℃；深部第二热储层位于180m深，热储最高温度可达329．8℃，深部热流体水质类型均属Cl^--Na^ 型，气体组份中CO2占主导地位。     

世界气候变暖形势严峻 二氧化碳减排工作势在必行

温室气体大量排放而引起的全球气候变暖问题日趋严峻,由此导致的空气污染和温室效应正在严重地威胁着人类赖以生存的环境。为减缓气候变化,就要减少温室气体排放和增加温室气体的吸收,各个国家相继采取积极有效措施。地质埋存CO2是避免气候变化的有效途径,结合气候变暖存在问题,中国政府批准国家973项目——开展温室气体提高石油采收率的资源化利用及地下埋存研究,提出二氧化碳减排发展对策,必将为全球资源和环境的高水平、高效益开发和可持续发展提供理论及实践依据。     

二氧化碳封存和资源化利用研究进展

以CO2为主的温室气体的大量排放,造成近年全球平均温度急剧升高,减排CO2已成为当务之急。CO2封存被认为是CO2减排最具潜力的选择。CO2封存包括海洋封存和地质封存。介绍CO2封存的一些影响因素和研究进展,并对CO2资源化利用存在的孔喉分布、润湿性和表面张力等影响因素做了综述。     

二氧化碳羽流地热系统中储层物性参数对热提取率的影响

二氧化碳羽流地热是以超临界CO2作为地热系统的载热流体,利用天然孔隙介质,在进行CO2地质储存的同时实现深部地热资源的提取。CO2在注入地下储层后呈羽状扩散和分布,因此称这种地热开发系统为CO2羽流地热系统。在CO2羽流地热系统中,砂岩储层分布广泛,物性各异,对热提取率的影响较大。文章以松辽盆地中心凹陷区泉头组三、四段为地热储层,建立平面二维羽流地热模型,采用TOUGH2-MP软件进行数值模拟,定量评价储层物性对热提取率的影响。结果表明,温度对热提取率的影响最大,初始盐度的影响最小,故应按照"低压、低盐度、高温、高渗透、高比热"的标准选取储层,其中高温和高渗透率是应重点考虑的因素。     

Preliminary assessment of underground hydrogen storage sites in Ontario,Canada

The replacement of coal-fired power plants with increasing proportions of renewable and nuclear energies in the province of Ontario highlights the need to balance seasonal energy demands. This can be achieved through power-to-gas technology, where excess energy is used to generate hydrogen gas through electrolysis, and the generation is coupled with underground hydrogen storage. This article presents a preliminary assessment regarding the potential for underground hydrogen storage in geological formations including salt and hard rock caverns, depleted oil and gas fields, and saline aquifers in Ontario, highlighting potential locations where future storage could be feasible. Southern Ontario presents many potential storage options, including Silurian bedded salts, depleted Ordovician natural gas reservoirs, saline aquifers in Cambrian sandstone and hard rock caverns in argillaceous limestones. Hard rock caverns in Precambrian crystalline rocks of the Canadian Shield are also discussed, in addition to the potential for the use of lined rock caverns. This work aims to provide a basis for further research regarding the appropriate location of underground hydrogen gas storage facilities in Ontario.     

The potential of hydrogen storage in depleted unconventional gas reservoirs: A multiscale modeling study

Subsurface energy storage in depleted petroleum reservoirs is a promising technique to balance and optimize the utilization of energy resources. In this work, we numerically explore the possibility of storing excessive hydrogen gas in depleted unconventional gas reservoirs. Our study is a multiscale analysis. From the molecular (pore) scale, we investigate the thermodynamics and transport mechanism of the hydrogen gas in the nanopores of the unconventional reservoirs. Then based on the results of the pore scale, we conduct reservoir-scale simulations to quantitatively investigate the preferred cycling pressure, the effective fraction of cushion gas and the amount of storage capacity of unconventional reservoirs. We have discovered that, compared to conventional gas reservoirs, hydrogen stored in unconventional reservoirs maintains higher purity because of the differential adsorption effect of the nanopores. This feature makes depleted unconventional gas reservoirs appealing candidates for underground storage of the hydrogen gas.     

鄂尔多斯盆地CO_2地质封存潜力分析

鄂尔多斯盆地是中国大型能源化工基地,本文以此为研究对象,在已有可公开地质资料的基础上,讨论分析了在鄂尔多斯盆地实施CO2地质封存的潜力,提出了盆地内的潜在封存地层,包括油气储层、煤层和盐/咸水层,初步预测出CO2的封存容量大约有数百亿吨,本文还对鄂尔多斯盆地的封存方式提出了初步看法,对存在的问题提出了建议。     

Salt domes in Poland – Potential sites for hydrogen storage in caverns

Salt bearing formations have world-wide distribution. The geological structures of Permian salt bearing deposits in Poland are similar to those in the other parts of the Central European salt basin, to which they belong as its SE part. There is a notable trend to use salt domes as sites for underground storage of various gases, fuels and other substances, including hydrogen. Possibilities of using salt domes in Poland for underground hydrogen storage are presented with the focus on the option of using the underground space for energy storage. Usefulness of the 27 hitherto studied salt domes in the Polish Lowlands for underground hydrogen storage in caverns is evaluated using analytical methods of the geology of mineral deposits.Seven not yet developed salt domes are selected as the most promising ones, taking into account geological and reservoir criteria: Rogó?no, Damas?awek, Lubień, ?ani?ta, Goleniów, Izbica Kujawska and D?bina. Initial experience in underground hydrogen storage in salt caverns is presented. Geological conditions favourable for hydrogen storage in underground caverns leached in salt domes are outlined. Their advantage relative to underground storage sites in porous rocks (depleted hydrocarbon deposits and deep aquifers) is discussed.     

Underground hydrogen storage in Australia: A review on the feasibility of geological sites

Hydrogen has attracted attention worldwide with its favourable inherent properties to contribute towards a carbon-free green energy future. Australia aims to make hydrogen as its next major export component to economize the growing global demand for hydrogen. Cost-effective and safe large-scale hydrogen storage in subsurface geology can assist Australia in meeting the projected domestic and export targets. This article discusses the available subsurface storage options in detail by first presenting the projected demand for hydrogen storage. Australia has many subsurface formations, such as depleted gas fields, salt caverns, aquifers, coal seams and abandoned underground mines, which can contribute to underground hydrogen storage. The article presents basin-wide geological information on the storage structures, the technical challenges, and the factors to consider during site selection. With the experience and knowledge Australia has in utilizing depleted reservoirs for gas storage and carbon capture and sequestration, Australia can benefit from the depleted gas reservoirs in developing hydrogen energy infrastructure. The lack of experience and knowledge associated with other geostructures favours the utilization of underground gas storage sites for the storage of hydrogen during the initial stages of the shift towards hydrogen energy. The article also provides future directions to address the identified important knowledge gaps to utilize the subsurface geology for hydrogen storage successfully.     

A comprehensive literature review on the challenges associated with underground hydrogen storage

The current rate of global warming is greatly increasing greenhouse gas emissions which is only set to worsen the planet's environmental condition. In ensuring a sustainable future, it has become necessary to move away from fossil fuels and adopt renewable energy sources as the primary source of energy generation. Dependency of renewable energy sources on the environment, however, has entailed storing the excess generated energy in bulk for times of need. Hydrogen storage in subsurface porous media has contended to be the buffer for energy storage. Still in infancy, there is little known about the consequences associated with storing hydrogen in naturally existing (depleted oil and gas reservoirs, and saline aquifers) as well as artificially intervened (salt caverns) subsurface geological media. This review article aims to define, characterize, and summarize the different types of subsurface geological media currently considered viable for underground hydrogen storage. Present in this article is also an elaboration of hydrogen's physiochemical properties and the resulting potential interactions that may occur, prospects that need to be addressed and challenges that need to be overcome in ensuring hydrogen's large scale geological storage.     

CO2 sequestration in depleted methane hydrate deposits with excess water

The recent increase in atmospheric CO₂ concentration makes it necessary to investigate new ways to reduce CO₂ emissions. Simultaneously, natural gas hydrate mining technology is developing rapidly. The use of depleted methane hydrate (MH) deposits as potential sites for CO₂ storage is relatively safe and economical. This method can alleviate the shortage of hydrate displacement gas with CO₂. The purpose of this study was to investigate CO₂ hydrate formation characteristics during the seepage process—in reservoirs with excess water—and their effect on CO₂ storage. The experimental process can be divided into 5 parts: MH formation, water injection, MH dissociation, CO₂ hydrate formation, and CO₂ hydrate dissociation. Magnetic resonance imaging was employed to monitor the distribution of liquid water, and the effects of different parameters on the formation and dissociation of CO₂ hydrates were analyzed. It was found that a state of initial water saturation can effectively control hydrate saturation in artificial MH reservoirs for hydrate reservoirs with excess gas. In the process of CO₂ flow, initial water saturation was not the main controlling factor for CO₂ hydrate formation. Increasing the flow pressure and reducing the flow rate were beneficial for CO₂ hydrate formation. This study is of great significance for advancing the science of CO₂ geological storage in the form of deep‐sea hydrates.     

Toward underground hydrogen storage in porous media: Reservoir engineering insights

Subsurface hydrogen storage in depleted hydrocarbon reservoirs and saline formations is a potential option for storing hydrogen at large scales. These subsurface formations need to store sufficient hydrogen efficiently and securely, and the hydrogen must be withdrawn in adequate quantities on demand. In this study, we investigate the reservoir, geological, and operational controls that enable large-scale hydrogen storage and maximize hydrogen injection and withdrawal from depleted natural gas reservoirs. Hydrogen injection, storage, and withdrawal scenarios were computed using a reservoir simulator. Sensitivity analyses exposed the crucial parameters to achieve the goal of optimum storage and withdrawal of hydrogen. We determined that reservoirs with smaller pressures at the start of storage operations are suitable for hydrogen storage if wellhead pressure constraints permit. Steeply dipping reservoirs enable better hydrogen withdrawal if the reservoirs have good permeability (greater than 100 mD) and the injection/withdrawal well is placed updip within the reservoir. Permeable reservoirs and reservoirs with sufficient thickness increase hydrogen withdrawal rates. These findings and the results of the sensitivity analyses are used to propose site selection criteria for underground storage of hydrogen in depleted gas reservoirs.