The impact of CO2 on the electrical properties of water bearing porous media – laboratory experiments with respect to carbon capture and storage
The impact of CO2 on the electrical properties of water bearing porous media – laboratory experiments with respect to carbon capture and storage
复制标题
DOI：
10.1111/j.1365-2478.2012.01129.x
复制
发表时间：
2013-06
影响因子：
2.6
通讯作者：
J. Börner;V. Herdegen;J. Repke;K. Spitzer
中科院分区：
文献类型：
--
作者：
J. Börner;V. Herdegen;J. Repke;K. Spitzer
我们进行了详细的实验研究的效果CO2注入含水多孔介质的电导率，需要一个改进的地球物理监测的CO2储存水库。因此，我们开发了一种实验装置，可以研究注入过程的电气特性以及溶解的CO2对孔隙水电导率的影响。我们发现，气体，流体和超临界纯CO2相在高达13 MPa的压力和高达50° C的温度下没有相关的电导率。当CO2溶解在孔隙水中时，压力相关的解离过程可以使孔隙水电导率加倍，这可以用于泄漏检测。这是量化的适应阿尔奇定律。经验的适应性和实验数据的证实，结合地球化学-地电模型。此外，在压力高达13 MPa和温度高达40° C的条件下，研究了CO2置换孔隙水时的水饱和砂样品。测量到电导率降低高达33倍，对应于14- 19%的残余水饱和度。在超临界条件下，也证明了质量降低。作为一个综合的解释，在CO2封存的岩石电性的概念模型。
We conducted a detailed experimental investigation of the effect of CO2 injection on the electrical conductivity of water bearing porous media, needed for an improved geophysical monitoring of CO2 storage reservoirs. Therefore, we developed an experimental set‐up that allows to investigate electrical characteristics of the injection process as well as the impact of dissolved CO2 on pore water conductivity. We found that a gaseous, fluid and supercritical pure CO2 phase bears no relevant conductivity at pressures up to 13 MPa and temperatures up to 50° C. When CO2 dissolves in pore water, pressure‐dependent dissociation processes can double the pore water conductivity, that can be used in leakage detection. This is quantified by an adaptation of Archie’s law. The empirical adaptation and the experimental data are confirmed by combined geochemical‐geoelectrical modelling. Furthermore, water‐saturated sand samples were investigated while CO2 displaced the pore water at pressures up to 13 MPa and temperatures up to 40° C. A decrease in electrical conductivity by a factor of up to 33 was measured, corresponding to a residual water saturation of 14–19%. Qualitatively, a decrease was also demonstrated under supercritical conditions. As an integrative interpretation, a conceptual model of electrical rock properties during CO2 sequestration is presented.