Research on Coal Thermo-Hydro-Mechanical Coupling Model and Influence Factors
In the coal cryogenic volume fracturing, the variations of temperature field, seepage field, and stress field of coal are the foundation to study fracture propagation in the condition of cryogenic injection. Taking 3# high-rank coal sample from Jincheng City of Shanxi Province as study object, based on coal mechanics tests and permeability tests in complete stress–strain process under cryogenic conditions, a thermo-hydro-mechanical coupling mode is introduced under the condition of low-temperature phase change and a THM coupling numerical model of high-rank coal is established. The effect of different treatment parameters, porosity, permeability, thermodynamic parameters, and coal cleat on temperature field, seepage field, and stress field during the cryogenic volume fracturing is simulated. The results show that the temperature field is mainly subjected to the influence of treatment parameters, porosity and permeability, and thermodynamic parameters of coal. As for the seepage field, it suffers the influence of both injection and mechanical parameters. In addition, the stress field is principally affected by treatment parameters, permeability, and modulus of elasticity. Additionally, cleat that exists is also able to substantially increase the influence area of cryogenic fluids on three fields mentioned above.
KeywordsTHM Temperature field Seepage field Stress field Influence factors
The financial support for this research was provided by the engineering technology research institute of Huabei oilfield, and is greatly appreciated. Also, the author would like to thank the input from Mr. Yu. Last, I give my most sincere love to my family, their company is the biggest encouragement for me.
- 1.Liu S (2007) Thermo-hydro-mechanical coupling model research in saturated rock mass. Hohai UniversityGoogle Scholar
- 5.Torike WS, Ali SM (1993) Reservoir simulation integrated with geomechanics. J Canadian Pet Technol 32(05)Google Scholar
- 7.Lai M, Wu Z, Zhu Y et al (1999) Nolinear analyses for the couple problem of temperature, seepage and stress fields in cold region tunnels. Chin J Geotech Eng 21(5):529–533Google Scholar
- 8.Zhang X, Wang C, Yu W et al (2005) Three-dimensional nonlinear analysis for coupled problem of heat transfer of surrounding rock and heat convection between air in Fenghuo Mountain tunnel and surrounding rock. Chin J Geotech Eng 27(12):1414–1420Google Scholar
- 9.Zhang X, Yu W, Liu Z (2006) Three-dimensional nonlinear analysis for coupled problem of seepage field and temperature field of cold regions tunnels. Chin J Geotech Eng 28(09):1095–1100Google Scholar
- 10.Xu G (2007) Study on mechanical characteristics and multiphysical coupling problems of rock at low temperatures. Chin J Rock Mechan Eng 26(05):1078Google Scholar
- 11.Chen Y, Zhou C, Tong F et al (2009) A numerical model for fully coupled THM processes with multiphase flow and code validation. Chin J Rock Mechan Eng 28(04):649–665Google Scholar
- 12.Zhang Y (2009) Coupled thermo-hydro-mechanical model and finite element analyses of dual-porosity fractured medium for ubiquitous-joint rock mass. Chin J Rock Mechan Eng 28(05):947–955Google Scholar
- 14.Rutqvist J, Tsang CF (2003) TOUGH-FLAC: a numerical simulator for analysis of coupled thermal-hydrologic-mechanical processes in fractured and porous geological media under multi-phase flow conditions. In: Proceedings of the TOUGH symposium. pp 12–14Google Scholar
- 16.Yang G, Zhang S (2006) Analysis for mechanism of rock microscopic damage and moisture-heat transfer under the frost and thaw condition. Shaanxi Science and Technology Press, Xian, pp 20–45Google Scholar
- 17.Tan X, Chen W, Jia S et al (2008) A coupled hydro-thermal model for low temperature rock including phase change. Chin J Rock Mechan Eng 27(07):1455–1461Google Scholar