Evidence of localised gas propagation pathways in a field-scale bentonite engineered barrier system; results from three gas injection tests in the large scale gas injection test (Lasgit)
Evidence of localised gas propagation pathways in a field-scale bentonite engineered barrier system; results from three gas injection tests in the large scale gas injection test (Lasgit)
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DOI：
10.1016/j.clay.2014.10.014
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发表时间：
2014-12-01
影响因子：
5.6
通讯作者：
Sellin, P.
中科院分区：
文献类型：
--
作者：
Cuss, R. J.;Harrington, J. F.;Sellin, P.
在瑞典Aspo硬岩实验室进行的大规模气体注入试验（Lasgit）期间，进行了三次气体注入试验。Lasgit是一个基于瑞典KBS-3储存库概念的全尺寸实验，研究控制高度水饱和致密缓冲膨润土中气体和水流动的过程。已经进行了三次初步注气试验。前两项检测在下部进样过滤器阵列（FL 903）中进行。这两项试验都显示出与实验室观察结果相一致的类似行为。第三次气体测试在上部阵列过滤器（FU 910）中进行，其在主要气体入口处给出了略微不同的响应，初始压降随后是二次气体峰值压力。Lasgit已经证实了在气田规模下，主要气体进入之前和之后的流动气体、应力和孔隙水压力之间的耦合。所有的观察结果表明，途径传播的机制，并占主导地位。在所有三种气体测试中，传播是通过倾向于利用铜罐和膨润土缓冲层之间的界面的局部特征。大量证据表明，存在一个高度动态的，曲折的网络压力诱导的路径，在粘土内的时间和地理空间的演变，打开和关闭可能是由于气体压力和或有效应力的局部变化的发展。(C)2014由Elsevier B. V.出版
Three gas injection tests have been conducted during a large scale gas injection test (Lasgit) performed at the Aspo Hard Rock Laboratory, Sweden. Lasgit is a full-scale experiment based on the Swedish KBS-3 repository concept, examining the processes controlling gas and water flow in highly water-saturated compact buffer bentonite. Three preliminary gas injection tests have been performed. The first two tests were conducted in the lower array of injection filters (FL903). Both of these tests showed similar behaviour that corresponded with laboratory observations. The third gas test was conducted in an upper array filter (FU910), which gave a subtly dissimilar response at major gas entry with an initial pressure drop followed by a secondary gas peak pressure. Lasgit has confirmed the coupling between gas, stress and pore-water pressure for flow before and after major gas entry at the field scale. All observations suggest mechanisms of pathway propagation and dilatancy predominate. In all three gas tests the propagation was through localised features that tended to exploit the interface between the copper canister and the bentonite buffer. Considerable evidence exists for the development of a highly-dynamic, tortuous network of pressure induced pathways which evolves both temporally and geospatially within the clay, opening and closing probably due to local changes in gas pressure and or effective stress. (C) 2014 Published by Elsevier B.V.