纳米压痕技术在页岩力学性质表征中的应用进展

Review on the application of nanoindentation to study of shale mechanical property

王建丰 杨超 柳宇柯 熊永强

Jianfeng Wang Chao Yang Yuke Liu Yongqiang Xiong

近年来，随着力学测试技术的不断发展，微观材料科学研究中广泛应用的纳米压痕技术被引入到页岩研究领域，成为测试页岩表面微观力学性质的重要手段。从微观视角去研究页岩的力学性能已成为当下的研究热点之一。为此，梳理了页岩样品的制备方法和压痕试验制度对测试结果的影响，详细论述了纳米压痕技术在页岩中微观力学和蠕变性能表征方面的应用现状，对其应用的优势和存在的问题进行了分析和讨论，并对发展趋势进行了展望。研究结果表明：①纳米压痕技术可以精确表征页岩整体以及基质组成相的力学性能；②通过研究保载阶段的位移-时间曲线可以获得页岩微观尺度的蠕变特征，深入理解微观下页岩蠕变变形机制；③测试流体/页岩相互作用下力学性能的演变特征，可以为实际页岩水力压裂或超临界二氧化碳压裂提供基础的实验数据。该技术实现了对页岩更精细化的观测，有助于从根本上认识页岩的力学行为，为页岩气勘探开发提供更可靠的理论依据。

With the development of mechanical testing technology in recent years， the nanoindentation， a technique wildly recognized in micro-fabrication materials research， has been introduced into shale study， and become an important tool to test the micro-mechanical properties of shale. At present， it has been one of the hot research topics to study the mechanical properties of shale from the microscopic perspective. In this study， we summarize the influences of shale sample preparation methods and nanoindentation test system on test results， elaborate the application of nanoindentation technique in micro-mechanical and creep rupture characterization of shale. The advantages and existing problems of this technique are thereby analyzed and discussed， while looking to its development trend. The results are shown as follows. First， the technique can serve for precisely characterizing the mechanical properties of the bulk shale and its matrix phases. Second， the micro-creep rupture behavior of shale can be obtained by studying the displacement-time curve during the loading stage， which is of significance to having an in-depth understanding on the creep rupture deformation mechanism of shale in micro view. Third， testing the evolution characteristics of micro mechanical properties of fluid/shale interactions can provide basic experimental data for actual hydraulic fracturing or supercritical carbon dioxide fracturing of shale. In all， the nanoindentation technique serves to get an even finer understanding of shale in micro level， which is conducive to analyzing the mechanical behavior of shale in essence， and provide theoretical basis more reliable for the exploration and development of shale gas.

10.11743/ogg20220219