Mechanical properties of sandstone under in-situ high-temperature and confinement conditions

Abstract

Low- to medium-maturity oil shale resources display substantial reserves, offering promising prospects for in-situ conversion in China. Investigating the evolution of the mechanical properties of the reservoir and caprock under in-situ high-temperature and confinement conditions is of considerable importance. Compared to conventional mechanical experiments on rock samples after high-temperature treatment, in-situ high-temperature experiments can more accurately characterize the behavior of rocks in practical engineering, thereby providing a more realistic reflection of their mechanical properties. In this study, an in-situ high-temperature triaxial compression testing machine is developed to conduct in-situ compression tests on sandstone at different temperatures (25, 200, 400, 500, and 650°C) and confining pressures (0, 10, and 20 MPa). Based on the experimental results, the temperature-dependent changes in compressive strength, peak strain, elastic modulus, Poisson’s ratio, cohesion, and internal friction angle are thoroughly analyzed and discussed. Results indicate that the mass of sandstone gradually decreases as the temperature increases. The thermal conductivity and thermal diffusivity of sandstone exhibit a linear relationship with temperature. Peak stress decreases as the temperature rises, while it increases with higher confining pressures. Notably, the influence of confining pressure on peak stress diminishes at higher temperatures. Additionally, as the temperature rises, the Poisson’s ratio of sandstone decreases. The internal friction angle also decreases with increasing temperature, with 400°C acting as the threshold temperature. Interestingly, under uniaxial conditions, the damage stress of sandstone is less affected by temperature. However, when the confining pressure is 10 or 20 MPa, the damage stress decreases as the temperature increases. This study enhances our understanding of the influence of in-situ high-temperature and confinement conditions on the mechanical properties of sandstone strata. The study also provides valuable references and experimental data that support the development of low- to medium-maturity oil shale resources.

Keywords

in-situ high temperature / mechanical property / thermal damage / thermomechanical coupling

References

[1] T. Ponomarenko, M. Nevskaya, and I. Jonek-Kowalska, Mineral resource depletion assessment: Alternatives, problems, results, Sustainability, 13(2021), No. 2, art. No. 862.

[2] SimoniMU, DrielsmaJA, EricssonM, et al.. Mass-balance-consistent geological stock accounting: A new approach toward sustainable management of mineral resources. Environ. Sci. Technol., 2024, 58(2): 971

[3] LiuLY, JiHG, LüXF, et al.. Mitigation of greenhouse gases released from mining activities: A review. Int. J. Miner. Metall. Mater., 2021, 28(4): 513

[4] Z.Q. Kang, Y.S. Zhao, and D. Yang, Review of oil shale in situ conversion technology, Appl. Energy, 269(2020), art. No. 115121.

[5] A. Zafar, Y. L. Su, W.D. Wang, M. Kashif, A. Mehmood, and S.G. Alam, Evaluation of the porosity and permeability of oil shale during in situ conversion process through numerical simulation and mathematical modeling, Oil Shale, 37(2020), No. 4, art. No. 319.

[6] LiuLY, ZhangL, JiHG. Mechanism analysis of rock damage and failure based on the relation between deep chamber axial variation and in situ stress fields. Chin. J. Eng., 2022, 44(4): 516

[7] WangT, YeWW, TongYM, JiangNS, LiuLY. Residual stress measurement and analysis of siliceous slate-containing quartz veins. Int. J. Miner. Metall. Mater., 2023, 30(12): 2310

[8] S. Vidana Pathiranagei, I. Gratchev, and P. Kong, Engineering properties of four different rocks after heat treatment, Geomech. Geophys. Geo Energy Geo Resour., 7(2021), No. 1, art. No. 16.

[9] P.Y. Guo, P. Zhang, M.H. Bu, H. Xing, and M.C. He, Impact of cooling rate on mechanical properties and failure mechanism of sandstone under thermal-mechanical coupling effect, Int. J. Coal Sci. Technol., 10(2023), No. 1, art. No. 26.

[10] ZhangH, SunQ, DongZH, GeZL, DaiJF, WangZY, CaoYP. Metamorphic response characteristics of yellow sandstone after heat treatment under 800–1250°C. J. Therm. Anal. Calorim., 2022, 147(20): 11107

[11] TianH, KempkaT, YuS, ZieglerM. Mechanical properties of sandstones exposed to high temperature. Rock Mech. Rock Eng., 2016, 49(1): 321

[12] Z.Z. Abdulagatova, S.N. Kallaev, Z.M. Omarov, A.G. Bakmaev, B.A. Grigor’ev, and I.M. Abdulagatov, Temperature effect on thermal-diffusivity and heat-capacity and derived values of thermal-conductivity of reservoir rock materials, Geomech. Geophys. Geo Energy Geo Resour., 6(2020), art. No. 8.

[13] HolmbergB, CuiL. Multiphysics processes in the interfacial transition zone of fiber-reinforced cementitious composites under induced curing pressure and implications for mine backfill materials: A critical review. Int. J. Miner. Metall. Mater., 2023, 30(8): 1474

[14] XieBS, MaH, LiCC, ChenJ. Enhanced properties of stone coal-based composite phase change materials for thermal energy storage. Int. J. Miner. Metall. Mater., 2024, 31(1): 206

[15] WangT, YeWW, LiuLY, LiuK, JiangNS, FengXH. Disturbance failure mechanism of highly stressed rock in deep excavation: Current status and prospects. Int. J. Miner. Metall. Mater., 2024, 31(4): 611

[16] X.P. Wang, L.H. Wang, B.Y. Zhao, Y.J. Wu, J.S. Yang, and J.C. Sun, Experimental study on mechanical properties of gas storage sandstone and its damage under temperature and pressure, Front. Earth Sci., 10(2022), art. No. 905642.

[17] X.S. Li, J. Peng, Y.L. Xie, Q.H. Li, T. Zhou, J.W. Wang, and W.B. Zheng, Influence of high-temperature treatment on strength and failure behaviors of a quartz-rich sandstone under true triaxial condition, Lithosphere, 2022(2022), No. Special 10, art. No. 3086647.

[18] Y.Z. Li, Y. Wu, W.G. Qiao, S. Zhang, and X.G. Li, The permeability evolution of sandstones with different pore structures under high confining pressures, high pore water pressures and high temperatures, Appl. Sci., 13(2023), No. 3, art. No. 1771.

[19] L.F. Fan, H. Li, and Y. Xi, Evaluation of the effects of three different cooling methods on the dynamic mechanical properties of thermal-treated sandstone, Bull. Eng. Geol. Environ., 81(2022), No. 4, art. No. 154.

[20] M. Vigroux, J. Eslami, A.L. Beaucour, A. Bourges, and A. Noumowé, High temperature behaviour of various natural building stones, Constr. Build. Mater., 272(2021), art. No. 121629.

[21] C. Zhang, F.Z. Wang, L.B. Hu, F. Jiang, and G.Q. Huang, Experimental investigation on the mechanical behavior and fracture mechanism of sandstone after heat treatment, Bull. Eng. Geol. Environ., 83(2024), No. 6, art. No. 220.

[22] X. Li, S. Huang, T.B. Yin, et al., Dynamic properties of thermal shock treated sandstone subjected to coupled dynamic and static loads, Minerals, 11(2021), No. 8, art. No. 889.

[23] GautamPK, VermaAK, SharmaP, SinghTN. Evolution of thermal damage threshold of jalore granite. Rock Mech. Rock Eng., 2018, 51(9): 2949

[24] LuoSY, DouB, TianH, ChenJ, XiaoP, ZhangST. Comparative experimental study on physical and mechanical properties of granite after natural cooling and under real-time high temperature. Earth Sci. Front., 2020, 27(1): 178

[25] KumariWGP, PanjithPG, PereraMSA, et al.. Mechanical behaviour of Australian Strathbogie granite under in situ stress and temperature conditions: An application to geothermal energy extraction. Geothermics, 2017, 65: 44

[26] AkdagS, KarakusM, TaheriA, NguyenG, HeMC. Effects of thermal damage on strain burst mechanism for brittle rocks under true-triaxial loading conditions. Rock Mech. Rock Eng., 2018, 51(6): 1657

[27] VorobievOY, MorrisJP. Modeling dynamic fracture in granite under in situ conditions at high temperatures and pressures. Int. J. Rock Mech. Min. Sci., 2019, 113: 241

[28] L.Y. Liu, Z. Zhang, T. Wang, S. Zhi, and J. Wang, Evolution characteristics of fracture volume and acoustic emission entropy of monzogranite under cyclic loading, Geomech. Geophys. Geo Energy Geo Resour., 10(2024), No. 1, art. No. 16.

[29] MohamadiM, WanPG. Strength and post-peak response of Colorado shale at high pressure and temperature. Int. J. Rock Mech. Min. Sci., 2016, 84: 34

[30] YangSQ, PanjithPG, JingHW, TianWL, JuY. An experimental investigation on thermal damage and failure mechanical behavior of granite after exposure to different high temperature treatments. Geothermics, 2017, 65: 180

[31] HeZQ, YangY, YuB, et al.. Pesearch on properties of hollow glass microspheres/epoxy resin composites applied in deep rock in situ temperature-preserved coring. Pet. Sci., 2022, 19(2): 720

[32] HeskethJ, HaynesH, PeddyB, et al.. Carbon steel corrosion in a bentonite buffer: A comparison between in situ exposure and lab-based experiments. Mater. Corros., 2023, 74(11–12): 1728

[33] L.Y. Liu, H.G. Ji, D. Elsworth, S. Zhi, X.F. Lv, and T. Wang, Dual-damage constitutive model to define thermal damage in rock, Int. J. Rock Mech. Min. Sci., 126(2020), art. No. 104185.

[34] J. Jin, J.D. Liu, W.X. Chen, et al., The impact of high temperature on mechanical properties and behaviors of sandstone, Front. Earth Sci., 12(2024), art. No. 1322495.

[35] SunQ, ChenSE, GaoQ, ZhangWQ, GengJS, ZhangYL. Analyses of the factors influencing sandstone thermal conductivity. Acta Geodyn. Geomater, 2017, 14(2): 173

RIGHTS & PERMISSIONS

University of Science and Technology Beijing