Lessons in carbon storage from geological analogues
Lessons in carbon storage from geological analogues
复制标题
从地质类似物中汲取碳储存的经验教训
DOI：
10.1130/focus0420132.1
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发表时间：
2013
期刊：
影响因子：
5.8
通讯作者：
Bickle M
中科院分区：
文献类型：
--
作者：
Bickle M
英国剑桥桥大学地球科学系，剑桥，CB 2 3EQ，英国526 www. gsapubs。org|四月2013|地质通过断层，区域水文驱动流量几米，每年向东南或南部的纳瓦霍砂岩。Kampman等人（2009）对喷发流体中的顺流地球化学梯度进行了建模，表明pH值的急剧下降反映了两个主要断层系统中CO2的增加，下游流体化学梯度允许计算流体-矿物反应及其速率。这些反应主要是CO2、斜长石、碱性长石、石膏和白云石的消耗，以及方解石、粘土矿物和石英的沉淀。关键的是，CO2注入点下游的反应速率降低，因为充CO2的盐水和硅酸盐矿物之间的热力学不平衡程度降低。那么，有多少CO2溶解在绿色河断层系统？横向距离为2 km（绿色河挖出的Entrada砂岩中CO2漂白区的宽度; Wigley等人，2012年）将从断层带输送约4000吨/年，是伯恩赛德等人估计的过去100千年泄漏率的20倍。至少有两个更深的含水层可能与纳瓦霍砂岩（温盖特和白色边缘砂岩）相当。如果溶解在每一个中的CO2的分数与纳瓦霍砂岩中的分数相当，则到达地表的CO2的分数将是注入断层系统的CO2的0.053或0.01%。显然，该系统中存在大量二氧化碳，因为向绿色河水晶间歇泉供水的钻孔在80年内一直以11 kt/年的速度泄漏，约为平均自然泄漏率的50倍。我们可以从Kampman等人的计算中对CO2封存到方解石中的净速率进行可比计算，（2009年）。这意味着约9%的溶解CO2（400吨/年）沉淀在方解石中。这只是溶解总量的一小部分，尽管比表面自然逸出的要多。然而，这是在最终流动路径的有限部分上的积分质量。自然系统不是简单的稳态过程，并且这些计算忽略了许多潜在的复杂性。Kampman等人（2012），使用伯恩赛德（2010）计算的U-Th年龄，结合微量元素和碳酸盐岩脉中的碳、氧和锶同位素比值，表明过去约135 ky的CO2脱气是幕式的，CO2泄漏的四个主要脉冲与间冰期变暖同期。他们假设，地下水补给率的变化，以及与大陆冰盖卸载和附近邦纳维尔湖相关排水有关的大陆应力的变化，引发了断层破坏区裂缝的扩张，从而促进了CO2的逃逸。此时，气相中的游离二氧化碳可能已经逸出到表面，并且钙华可能没有记录所有排放的二氧化碳。因此，模拟研究提供了一个重要的教训：我们可以限制控制地质储存库中CO2命运的过程的性质和速率。然而，要充分解释这些观测结果，需要了解环境的水文学，在涉及多相流的情况下，水文学总是很复杂。最重要的发现是，自由相CO2在地层盐水中迅速溶解，这一点得到了稀有气体浓度和同位素比（如CO2/3 He...
Mike Bickle and Niko Kampman Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK526 www. gsapubs. org| April 2013| GEOLOGY through the faults, and the regional hydrology drives flow rates of a few meters per year toward the southeast or south in the Navajo sandstones. Kampman et al.(2009) modeled the along-flow geochemical gradients in the erupted fluids to show that sharp drops in pH reflected the addition of CO2 at the two major fault systems, and gradients in fluid chemistry downstream allowed calculation of the fluid-mineral reactions and their rates. These reactions were primarily the consumption of CO2, plagioclase, and alkali feldspars, gypsum, and dolomite, and precipitation of calcite, clay minerals, and quartz. Critically, the reaction rates decreased downstream of the CO2 injection sites, because the magnitude of thermodynamic disequilibrium between the CO2-charged brines and silicate minerals decreased.So how much CO2 dissolves at the Green River fault systems? Flow rates of 2.5 m/yr in the~ 140-m-thick, 20% porosity Navajo sandstone over a lateral distance of 2 km (the width of the CO2 bleached zone in the exhumed Entrada sandstone at Green River; Wigley et al., 2012) would transport~ 4000 t/yr away from the fault zones, 20× the rate that Burnside et al. estimate has been leaking over the past 100 ky There are at least two deeper aquifers potentially comparable to the Navajo sandstone (the Wingate and White Rim sandstones). If the fraction of CO2 dissolved in each is comparable to that in the Navajo sandstone, the fraction of CO2 reaching the surface would be 0.053 or 0.01% of the CO2 injected into the fault system. Clearly, a large mass of CO2 is available in the system, since the borehole feeding Crystal Geyser at Green River has been leaking at a rate of 11 kt/yr for 80 yr,~ 50× the average natural leakage rate. We can make a comparable calculation of the net rate of CO2 sequestration into calcite from the calculations of Kampman et al.,(2009). These imply that~ 9% of the CO2 dissolved (400 t/yr) is precipitated in calcite. This is only a small part of the total amount dissolved, although more than is naturally escaping at the surface. This is, however, the integrated mass over a limited portion of the ultimate flow path. Natural systems are not simple steady-state processes, and these calculations ignore a number of potential complexities. Kampman et al.(2012), used the U-Th ages calculated by Burnside (2010) combined with trace element and carbon, oxygen, and strontium isotope ratios in the travertine veins, to show that the CO2 degassing was episodic over the past~ 135 ky, with four main pulses in CO2 leakage coeval with interglacial warming. They hypothesize that changes in groundwater recharge rates, and in the continental stresses related to unloading of the continental ice sheet and associated draining of nearby Lake Bonneville, triggered dilation of fractures in the fault damage zone, thus facilitating enhanced escape of CO2. At these times, free CO2 in the gas phase may have escaped to the surface, and the travertines may not have recorded all emitted CO2. The analogue studies thus teach an important lesson: we can constrain the nature and rates of the processes governing the fate of CO2 in geological storage reservoirs. Interpreting these observations fully, however, requires understanding the hydrology of the settings, invariably complex where multiphase flows are involved. The most important finding is that free-phase CO2 dissolves rapidly in formation brines, as supported by studies in which measurements of noble gas concentrations and isotope ratios (eg, CO2/3He …
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影响因子：
64.8
作者：
Gilfillan, Stuart M. V.;Lollar, Barbara Sherwood;Ballentine, Chris J.
通讯作者：
Ballentine, Chris J.
犹他州水晶间歇泉二氧化碳喷发的时间和预测
影响因子：
2.9
作者：
F. Gouveia;S. J. Friedmann
通讯作者：
S. J. Friedmann
科罗拉多高原石灰华的 U-Th 测年：对地质储存的二氧化碳泄漏的影响
DOI：
--
发表时间：
2010
期刊：
影响因子：
--
作者：
N. Burnside
通讯作者：
N. Burnside
犹他州水晶间歇泉二氧化碳排放量的航空测量和建模
DOI：
--
发表时间：
2005
期刊：
影响因子：
--
作者：
F. Gouveia;M. R. Johnson;R. Leif;S. J. Friedmann
通讯作者：
S. J. Friedmann