Schepp Laura L, Ahrens Benedikt, Balcewicz Martin, Duda Mandy, Nehler Mathias, Osorno Maria, Uribe David, Steeb Holger, Nigon Benoit, Stöckhert Ferdinand, Swanson Donald A, Siegert Mirko, Gurris Marcel, Saenger Erik H
Fraunhofer IEG, Institution for Energy Infrastructures and Geothermal Systems, Bochum, 44801, Germany.
Bochum University of Applied Sciences, Department of Civil and Environmental Engineering, Bochum, 44801, Germany.
Sci Rep. 2020 Apr 3;10(1):5840. doi: 10.1038/s41598-020-62741-1.
Digital rock physics combines microtomographic imaging with advanced numerical simulations of effective material properties. It is used to complement laboratory investigations with the aim to gain a deeper understanding of relevant physical processes related to transport and effective mechanical properties. We apply digital rock physics to reticulite, a natural mineral with a strong analogy to synthetic open-cell foams. We consider reticulite an end-member for high-porosity materials with a high stiffness and brittleness. For this specific material, hydro-mechanical experiments are very difficult to perform. Reticulite is a pyroclastic rock formed during intense Hawaiian fountaining events. The honeycombed network of bubbles is supported by glassy threads and forms a structure with a porosity of more than 80%. Comparing experimental with numerical results and theoretical estimates, we demonstrate the high potential of in situ characterization with respect to the investigation of effective material properties. We show that a digital rock physics workflow, so far applied to conventional rocks, yields reasonable results for high-porosity rocks and can be adopted for fabricated foam-like materials with similar properties. Numerically determined porosities, effective elastic properties, thermal conductivities and permeabilities of reticulite show a fair agreement to experimental results that required exeptionally high experimental efforts.
数字岩石物理将微观断层扫描成像与有效材料属性的先进数值模拟相结合。它用于补充实验室研究，旨在更深入地理解与输运和有效力学性能相关的物理过程。我们将数字岩石物理应用于网纹岩，一种与合成开孔泡沫有很强相似性的天然矿物。我们认为网纹岩是具有高刚度和脆性的高孔隙率材料的端元。对于这种特定材料，水力-力学实验很难进行。网纹岩是在强烈的夏威夷喷泉活动期间形成的火山碎屑岩。蜂窝状气泡网络由玻璃状细丝支撑，形成孔隙率超过80%的结构。通过将实验结果与数值结果及理论估计进行比较，我们证明了原位表征在有效材料属性研究方面的巨大潜力。我们表明，迄今为止应用于传统岩石的数字岩石物理工作流程，对于高孔隙率岩石能产生合理结果，并且可用于具有相似属性的人造泡沫状材料。通过数值确定的网纹岩孔隙率、有效弹性属性、热导率和渗透率与实验结果相当吻合，而这些实验需要付出极高的努力。
