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增强型地热系统(EGS)是采用人工形成地热储层的方法,从低渗透性岩体中经济地采出深层热能的人工地热系统。以CO2为载热流体的增强地热能系统(CO2-EGS)是实现CO2减排和深部地热资源开发的有效手段,系统运行时的水-岩-气相互作用对热储层孔渗特征有着重要影响,最终会影响储层的产热能力。笔者利用高温高压反应釜模拟CO2-EGS高温下的热储层-盐水-CO2的相互作用,通过对实验中反应液离子成分变化和岩样扫描电镜进行分析,结果表明:实验后的钾长石和方解石出现溶解现象,且方解石溶蚀剧烈;岩样表面出现极少量次生方解石和钠长石,并有新矿物析出,其主要组成元素为C、O、Si、Fe,为菱铁矿的中间产物。通过TOUGHREACT建立反应性溶质运移模型,模拟上述实验的化学反应过程,模拟结果和实验数据拟合较好。该研究可为CO2-EGS的水-岩-气作用机制提供地球化学数据。 相似文献
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《Applied Geochemistry》2005,20(11):2038-2048
Thermodynamic simulations of reactions among SO2-bearing CO2-dominated gas, water and mineral phases predict that FeIII in sediments should be converted almost entirely to dissolved FeII and siderite (FeCO3), and that SO2 should simultaneously be oxidized to dissolved sulfate. The reactions are however, subject to kinetic constraints which may result in deviation from equilibrium and the precipitation of other metastable mineral phases. To test the prediction, a laboratory experiment was carried out in a well stirred hydrothermal reactor at 150 °C and 300 bar with hematite, 1.0 m NaCl, 0.5 m NaOH, SO2 in quantity sufficient to reduce much of the iron, and excess CO2. The experiment produced stable siderite and metastable pyrite and elemental S. Changes in total dissolved Fe are consistent with nucleation of pyrite at ∼17 h, and nucleation of siderite at ∼600 h. Dissolution features present on elemental S at the conclusion of the experiment suggest nucleation early in the experiment. The experiment did not reach equilibrium after ∼1400 h, as indicated by coexistence of hematite with metastable pyrite and elemental sulfur. However, the results confirm that FeIII can be used to trap CO2 in siderite if partly oxidized S, as SO2, is present to reduce the Fe with CO2 in the gas phase. 相似文献
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地下水开采——重要的CO2排放源 总被引：5，自引：0，他引：5
运用水文地球化学模拟软件计算了大庆市齐家水源地地下水的CO2分压及地下水被抽出至地表与大气CO2达成平衡后CO2自水中的逸出量,结果表明,地下水p(CO2)=1.28×104 Pa,显著高出大气p(CO2);当地下水到达地表环境后将有11.15 mmol/kg 的CO2释放进入大气.进一步的讨论得知,各种岩性含水层的地下水都可以含有较高的p(CO2).因而,地下水的开采成为了一个不容忽视的CO2人为排放源.这应该引起有关学者的重视. 相似文献
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CO2驱煤层气中煤层膨胀对套管稳定性的影响 总被引：2，自引：0，他引：2
随着中国经济的快速发展,能源供需矛盾日益突出,由于过度依赖化石能源,大量排放CO2,致使面临的环境压力越来越大。CO2驱煤层气(CO2 enhanced coal-bed methane)技术可同时增产煤层气和大规模减排CO2,在我国具有良好应用前景,但应用该技术在注采生产过程中因煤层吸附CO2产生的膨胀效应对套管稳定性的影响尚未引起重视。通过建立考虑CO2煤岩吸附膨胀效应的套管-充填材料-煤岩平面应变模型计算的套管应力和变形理论解与ABAQUS数值模拟结果具有良好的一致性,并分析了CO2吸附膨胀条件下套管应力的影响因素。分析结果表明,膨胀对套管应力和变形具有显著影响。在给定CO2吸附浓度和套管内径条件下,套管和充填材料的壁厚、充填材料和煤岩的力学参数是影响套管应力的主要因素,可通过增加套管或（和）充填材料壁厚以及改变充填材料力学参数来降低套管应力。开发超低弹模和较大泊松比的充填材料是降低套管应力的有效途径。 相似文献
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二氧化碳沿井筒渗漏是二氧化碳地质埋存过程中所面临的重要风险之一.尤其是对于已经封堵的废弃井,由于获取井下的信息比较困难,因此评价废弃井的完整性是一个比较大的挑战.本文为评估二氧化碳沿废弃井渗漏提出了风险分析的方法.该方法包括了三个主要步骤:渗漏方案的制定,定量模拟及结果分析.所制定的渗漏方案将通过数值模拟进行定量分析及评价.本文将阐述该评价方法的第一步骤:渗漏方案的制定.该步骤为渗漏的定量模拟提供了理论基础.该方法被广泛接受并现场应用于德国某大型二氧化碳存储及提高天然气采收率项目中. 相似文献
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François Guyot Damien Daval Sébastien Dupraz Isabelle Martinez Bénédicte Ménez Olivier Sissmann 《Comptes Rendus Geoscience》2011,343(2-3):246-259
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. 相似文献
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A. Myrttinen V. Becker M. Nowak M. Zimmer P. Pilz J. A. C. Barth 《Environmental Earth Sciences》2012,67(2):473-479
Baseline monitoring at the proposed enhanced gas recovery site in Altmark (Germany) was carried out in combination with theoretical and laboratory investigations to describe and predict the principles of expected stable carbon isotope and dissolved inorganic carbon (DIC) trends during CO2 injection in reservoirs. This provides fundamental data for site-specific characterisation for monitoring purposes. Baseline ??13C values at the Altmark site ranged between ?1.8 and ?11.5??? and DIC values were about 2?mmol?L?1. These baseline values form the basis for a theoretical study on the influences of the ambient reservoir conditions on the state of geochemical and isotope equilibrium of the reservoir fluids. Transferring this theoretical study to the Altmark site enables predictions on geochemical trends during potential injection. Assuming that CO2 would be injected at the Altmark site to pCO2?=?100?bar and with a ??13C of ?30???, at isotopic and geochemical equilibrium, ??13CDIC values would approach this end-member, and DIC concentrations of 1,000?mmol L?1 would be expected. Laboratory experiments were conducted at low pCO2 levels (4?C35?bars) to mimic the approach of a CO2 plume at a monitoring well. These results support field investigations from other sites: that ??13CDIC is a sensitive tool for monitoring CO2 migration in the subsurface and simultaneously allows quantification of geochemical trapping of CO2. 相似文献
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S. Bauer H. Class M. Ebert V. Feeser H. G?tze A. Holzheid O. Kolditz Sabine Rosenbaum W. Rabbel D. Sch?fer A. Dahmke 《Environmental Earth Sciences》2012,67(2):351-367
Capture and geological sequestration of CO2 from large industrial sources is considered a measure for reducing anthropogenic emissions of CO2 and thus mitigating climate change. One of the main storage options proposed are deep saline formations, as they provide the largest potential storage capacities among the geologic options. A thorough assessment of this type of storage site therefore is required. The CO2-MoPa project aims at contributing to the dimensioning of CO2 storage projects and to evaluating monitoring methods for CO2 injection by an integrated approach. For this, virtual, but realistic test sites are designed geometrically and fully parameterized. Numerical process models are developed and then used to simulate the effects of a CO2 injection into the virtual test sites. Because the parameterization of the virtual sites is known completely, investigation as well as monitoring methods can be closely examined and evaluated by comparing the virtual monitoring result with the simulation. To this end, the monitoring or investigation method is also simulated, and the (virtual) measurements are recorded and evaluated like real data. Application to a synthetic site typical for the north German basin showed that pressure response has to be evaluated taking into account the layered structure of the storage system. Microgravimetric measurements are found to be promising for detecting the CO2 phase distribution. A combination of seismic and geoelectric measurements can be used to constrain the CO2 phase distribution for the anticline system used in the synthetic site. 相似文献
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当温度和压力分别达到31．10℃、7．38 MPa及以上时,CO2成为超临界状态,超临界CO2具有类似于液体的密度,而其粘度又比空气和氮气大,可以驱动井下动力钻具旋转破岩,并携带岩屑,形成超临界CO2钻井技术。超临界CO2钻井具备破岩速度快、油气层保护好、驱替效率高等优势,对于非常规油气藏开发具有明显优势。超临界CO2钻井与连续管钻井技术相结合,应用于压力欠平衡钻井和压力衰竭地层前景广阔。介绍了超临界CO2物理特征、超临界CO2钻井技术流程及其技术优势,最后阐述了超临界CO2钻井技术的研究进展及发展趋势。 相似文献
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大气CO2汇:硅酸盐风化还是碳酸盐风化的贡献? 总被引：1，自引：0，他引：1
至今人们仍普遍认为:是硅酸盐的化学风化碳汇作用在控制着长时间尺度的气候变化,而碳酸盐的化学风化作用不具有这一功能,因为碳酸盐溶解过程中消耗的所有CO<,2>又通过海洋中相对快速的碳酸盐沉积而返回大气.本研究发现,碳酸盐溶解的快速动力学特性(比硅酸盐快100倍以上)以及硅酸盐流域中少量碳酸盐矿物在控制流域溶解无机碳(DI... 相似文献
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Seal or cap-rock integrity is a safety issue during geological carbon dioxide capture and storage (CCS). Industrial impurities such as SO2, O2, and NOx, may be present in CO2 streams from coal combustion sources. SO2 and O2 have been shown recently to influence rock reactivity when dissolved in formation water. Buoyant water-saturated supercritical CO2 fluid may also come into contact with the base of cap-rock after CO2 injection. Supercritical fluid-rock reactions have the potential to result in corrosion of reactive minerals in rock, with impurity gases additionally present there is the potential for enhanced reactivity but also favourable mineral precipitation.The first observation of mineral dissolution and precipitation on phyllosilicates and CO2 storage cap-rock (siliciclastic reservoir) core during water-saturated supercritical CO2 reactions with industrial impurities SO2 and O2 at simulated reservoir conditions is presented. Phyllosilicates (biotite, phlogopite and muscovite) were reacted in contact with a water-saturated supercritical CO2 containing SO2, or SO2 and O2, and were also immersed in the gas-saturated bulk water. Secondary precipitated sulfate minerals were formed on mineral surfaces concentrated at sheet edges. SO2 dissolution and oxidation resulted in solution pH decreasing to 0.74 through sulfuric acid formation. Phyllosilicate dissolution released elements to solution with ∼50% Fe mobilized. Geochemical modelling was in good agreement with experimental water chemistry. New minerals nontronite (smectite), hematite, jarosite and goethite were saturated in models. A cap-rock core siltstone sample from the Surat Basin, Australia, was also reacted in water-saturated supercritical CO2 containing SO2 or in pure supercritical CO2. In the presence of SO2, siderite and ankerite were corroded, and Fe-chlorite altered by the leaching of mainly Fe and Al. Corrosion of micas in the cap-rock was however not observed as the pH was buffered by carbonate dissolution. Ca-sulfate, and Fe-bearing precipitates were observed post SO2-CO2 reaction, mainly centered on surface cracks and an illite rich illite-smectite precipitate quantified. Water saturated impure supercritical CO2 was observed to have reactivity to rock-forming biotite, muscovite and phlogopite mineral separates. In the cap-rock core however carbonates and chlorite were the main reacting minerals showing the importance of assessing actual whole core. 相似文献
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Summary In previous work,Gunter et al. (1993), suggested water-rock reactions in deep aquifers in sedimentary basins could sequester injected-CO2-waste from industry, thereby reducing greenhouse gas emissions. Experiments, carried out at 105°C and 90 bars CO2 pressure, to test the validity of this mineral-trapping of CO2 were unsuccessful due to sluggish kinetics of reaction. The most significant change recorded by the reaction products from these experiments was a large increase in alkalinity, which was attributed to very small amounts of water-mineral reaction. A computer model, PATHARC.94, was used to interpret this change in alkalinity and to predict the path and time necessary to reach equilibrium. Substantial trapping of CO2 by formation of siderite, calcite and aqueous bicarbonate ions was predicted to occur in 6 to 40 years.Potential errors as high as two orders of magnitude were estimated based on a thorough examination of the kinetic data used in the modelling. In order to achieve reasonable time estimates, reactive surface areas were approximated by 100 micron spherical grains in the computer model. This represents a smaller cumulative surface area than actually present in the experiment. When these results are extrapolated to the field, where the aquifers are at lower temperatures,Perkins andGunter (1995a), concluded that CO2-trapping reactions are expected to take 100s of years to complete. This is sufficient time for the trapping to occur as the residence time of a packet of fluid in a deep low-permeability aquifer in a sedimentary basin is measured in 10,000s to 100,000s of years.
Einlagerung von CO2-Treibhaus-Gasen in einem Aquifer: Erweiterung des Zeitmaßstabes von Experimenten von CO2-Aufnahme-Reaktionen durch geochemische Modellierung
Zusammenfassung In früheren Arbeiten habenGunter et al. (1993) Wasser-Gesteinsreaktionen in tiefen Aquiferen in Sedimentbecken vorgeschlagen, die injiziertes CO2 aus industriellen Abgasen aufnehmen, und damit die Treibhausgasemissionen reduzieren könnten. Experimente wurden bei 105°C und 90 bar CO2-Druck durchgeführt, um die Anwendbarkeit dieser mineralischen Fallen für CO2 zu testen; wegen der langsamen Reaktions-Kinetik waren diese nicht erfolgreich. Die markanteste Änderung, die diese Experimente in den Reaktionsprodukten hervorriefen, war eine beträchtliche Zunahme der Alkalinität, die auf geringfügige Wasser-Mineralreaktionen zurückgehen dürfte. Ein Computermodell, PATHARC 94, wurde benützt, um diese Änderungen der Alkalinität zu interpretieren und die erforderlichen Zeiten und Pfade vorherzusagen, die notwendig sind, um Gleichgewicht zu erreichen. Signifikanter Einbau von CO2 durch Bildung von Siderit, Calcit und Bikarbonat-tonen sollte dementsprechend in 6 bis 40 Jahren stattfinden.Mögliche Fehler, die bis in zwei Größenordnungen gehen können, wurden aufgrund einer sorgfältigen Überprüfung der kinetischen Daten, die hier benützt wurden, ermittelt. Um sinnvolle Zeitmaßstäbe zu erreichen, wurden im Computermodell reaktive Ober flächen durch 100 Mikron große kugelförmige Körner repräsentiert. Dies stellt eine kleinere Gesamtoberfläche dar, als die, die tatsächlich im Experiment vorhanden ist. Wenn diese Ergebnisse ins Gelände extrapoliert werden, wo die Aquifere niedrigere Temperaturen aufweisen, kommenPerkins undGunter (1995a) zu dem Schluß, daß ein vollständiger Einbau von CO2 hunderte von Jahre benötigen würde. Diese Zeiträume sind ausreichend, da die Verweildauer einer Fluid-Menge in einem tief gelegenen Aquifer mit niedriger Permeabilität in einem sedimentären Becken in Größenordnungen von 10.000 bis 100.000 von Jahren gemessen wird.相似文献
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Carbon dioxide capture and storage (CCS) in sub-seabed geological formations is currently being studied as a potential option to mitigate the accumulation of anthropogenic CO2 in the atmosphere. To investigate the validity of CO2 storage in the sub-seafloor, development of techniques to detect and monitor CO2 leaked from the seafloor is vital. Seafloor-based acoustic tomography is a technique that can be used to observe emissions of liquid CO2 or CO2 gas bubbles from the seafloor. By deploying a number of acoustic tomography units in a seabed area used for CCS, CO2 leakage from the seafloor can be monitored. In addition, an in situ pH/pCO2 sensor can take rapid and high-precision measurements in seawater, and is, therefore, able to detect pH and pCO2 changes due to the leaked CO2. The pH sensor uses a solid-state pH electrode and reference electrode instead of a glass electrode, and is sealed within a gas permeable membrane filled with an inner solution. Thus, by installing a pH/pCO2 sensor onto an autonomous underwater vehicle (AUV), an automated observation technology is realized that can detect and monitor CO2 leakage from the seafloor. Furthermore, by towing a multi-layer monitoring system (a number of pH/pCO2 sensors and transponders) behind the AUV, the dispersion of leaked CO2 in a CCS area can also be observed. Finally, an automatic elevator can observe the time-series dispersion of leaked CO2. The seafloor-mounted automatic elevator consists of a buoy equipped with pH/pCO2 and depth sensors, and uses an Eulerian method to collect spatially continuous data as it ascends and descends.Hence, CO2 leakage from the seafloor is detected and monitored as follows. Step 1: monitor CO2 leakage by seafloor-based acoustic tomography. Step 2: conduct mapping survey of the leakage point by using the pH/pCO2 sensor installed in the AUV. Step 3: observe the impacted area by using a remotely operated underwater vehicle or the automatic elevator, or by towing the multi-layer monitoring system. 相似文献
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Anita Peter Hendrik Lamert Matthias Beyer G?tz Hornbruch Ben Heinrich Alexandra Schulz Helmut Geistlinger Ben Schreiber Peter Dietrich Ulrike Werban Carsten Vogt Hans-Hermann Richnow Jochen Gro?mann Andreas Dahmke 《Environmental Earth Sciences》2012,67(2):335-349
A small scale and temporally limited CO2 injection test was performed in a shallow aquifer to investigate the geochemical impact of CO2 upon such aquifers and to apply and verify different monitoring methods. Detailed site investigation coupled with multiphase simulations were necessary to design the injection experiment and to set up the monitoring network, before CO2 was injected over a ten-day period at three injection wells, at a depth of 18?m below surface level into a quaternary sand aquifer located close to the town of Wittstock in Northeast Germany. Monitoring methods comprised groundwater sampling and standard analyses, as well as trace element analyses and isotope analyses; geoelectrical borehole monitoring; passive samplers to analyse temporally integrated for cations and multi-parameter probes that can measure continuously for dissolved CO2, pH and electrical conductivity. Due to CO2 injection, total inorganic carbon concentrations increased and pH decreased down to a level of 5.1. Associated reactions comprised the release of major cations and trace elements. Geoelectrical monitoring, as well as isotope analyses and multi-parameter probes proved to be suitable methods for monitoring injected CO2 and/or the alteration of groundwater. 相似文献
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Nicole Le Breton 《Contributions to Mineralogy and Petrology》1989,103(3):387-396
CO2 molecules were introduced experimentally into the structural channels of synthetic well ordered Mgcordierite (Mg2
[VI][(Al4Si5)[IV]O18]) at temperatures of 600 and 800° C, and pressures of 7, 8, 10, 12, and 25 kbar. Powder infrared spectra of the run products show five absorption bands in the region of the asymmetric stretching mode of CO2. Two of them, strong and sharp, occurring at 2353 cm–1 {2} and 2348 cm–1 {3}, are related to two different types of CO2 molecules. The relative intensity of the band {2} (type I) increases with the cell parameter co whereas the relative intensity of the band {3} (type II) increases with the parameter a0 of the crystal. It is concluded that CO2 molecules of type I may be oriented with their elongation parallel to the c-axis of the crystal, while CO2 molecules of type II lie with their O-C-O vector parallel to the a-axis. Analytical data indicate that the intensity ratio Z of these two bands ({2}/{3}) is a linear function of the CO2 content of cordierite. This ratio depends also on the temperature and, to a less extent, on the pressure under which cordierite entrapped CO2 molecules. It is proposed to combine this infrared parameter Z together with an estimate of the P-T conditions of the incorporation of CO2 into the channels, in order to determine the CO2 content of natural cordierites. The samples do not need to be of high purity and only small amounts (<5 mg) are necessary. This semi-empirical analytical method, which does not require complicated data treatments, is suitable for CO2-rich cordierites of granulite facies rocks. 相似文献
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《Gondwana Research》2013,23(3-4):799-809
Externally derived, pure CO2 that mixes with a carbon-(under)saturated C-O-H fluid in lower crustal granulites may result in graphite precipitation if the host-rock oxygen fugacity (fO2rock) is below the upper fO2 limit of graphite. The maximum relative amount of graphite that can precipitate varies between a few mol% up to more than 25 mol%, depending on pressure, temperature, and host-rock redox state. The maximum relative amount of graphite that can precipitate from an infiltrating CO2 fluid into a dry granulite (CO fluid system) varies between zero and a few mol%. Thermodynamic evaluation of the graphite precipitation process shows that CO2 infiltration into lower crustal rocks does not always result in a carbon (super)saturated fluid. In that case, graphite precipitation is only possible if carbon saturation can be reached as a result of the reaction CO2 → CO + ½ O2. Graphite that has been precipitated during granulite facies metamorphic conditions can subsequently be absorbed by a COH fluid during retrograde metamorphism. It is also possible, however, that significant amounts of graphite precipitate from a COH fluid during retrograde metamorphism. This study shows that interpreting the presence or absence of graphite in granulites with respect to CO2 infiltration requires detailed information on the P–T–fO2rock conditions, the relative amount of CO2 that infiltrates into the rock, and whether H2O is present or not. 相似文献
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Gas adsorption isotherms of Akabira coals were established for pure carbon dioxide (CO2), methane (CH4), and nitrogen (N2). Experimental data fit well into the Langmuir model. The ratio of sorption capacity of CO2, CH4, and N2 is 8.5:3.5:1 at a lower pressure (1.2 MPa) regime and becomes 5.5:2:1 when gas pressure increases to 6.0 MPa. The difference in sorption capacity of these three gases is explained by differences in the density of the three gases with increasing pressure. A coal–methane system partially saturated with CH4 at 2.4 MPa adsorption pressure was experimentally studied. Desorption behavior of CH4 by injecting pure CO2 (at 3.0, 4.0, 5.0, and 6.0 MPa), and by injecting the CO2–N2 mixture and pure N2 (at 3.0 and 6.0 MPa) were evaluated. Results indicate that the preferential sorption property of coal for CO2 is significantly higher than that for CH4 or N2. CO2 injection can displace almost all of the CH4 adsorbed on coal. When modeling the CH4–CO2 binary and CH2–CO2–N2 ternary adsorption system by using the extended Langmuir (EL) equation, the EL model always over-predicted the sorbed CO2 value with a lower error, while under-predicting the sorbed CH4 with a higher error. A part of CO2 may dissolve into the solid organic structure of coal, besides its competitive adsorption with other gases. According to this explanation, the EL coefficients of CO2 in EL equation were revised. The revised EL model proved to be very accurate in predicting sorbed ratio of multi-component gases on coals. 相似文献