Influence of Temperature on the Structure of Pore–Fracture of Sandstone

Excerpt

Sandstone is a kind of sedimentary rock with extensive distribution, which is involved in a variety of high-temperature rock engineering applications, such as underground coal gasification (Akbarzadeh and Chalaturnyk 2014), in situ heat-injection exploitation of coal (Niu et al. 2014; Shao et al. 2016), geological disposal of radioactive wastes (Gibb 1999), enhanced oil recovery (Thomas 2007) and deep geothermal energy extraction (Zimmermann et al. 2010). As a kind of natural porous material, there are numerous irregular and multi-size pores in its interior. When subjected to high temperature, significant changes would occur to the internal micro-scale pore structure of sandstone, which is strongly related to its physical, mechanical and hydraulic/transport properties (Ranjith et al. 2012; Tian et al. 2012, 2016; Liu et al. 2016; Feng et al. 2017, 2018; Sirdesai et al. 2017a, b; Yang et al. 2017b; Zhang et al. 2017c ). Therefore, exploring the pore–fracture microstructure response of sandstone to temperature will benefit not only our knowledge of the rock failure mechanism in high-temperature sandstone underground formations, but also our understanding of fluid transport characteristics in heated sandstone cap formations or reservoirs. …