Analysis of core temperature variation and its influencing factors in deep rock in-situ temperature-preserved coring
Abstract view|103|times PDF download|66|times
Abstract
Deep rock in-situ temperature-preserved coring is important for the exploration and development of deep resources. In addition, understanding the temperature variation laws of the core during coring is fundamental to achieving temperature-preserved coring. In this study, under the coexistence of the core and strata water inside the coring tool, we explore the factors sensitive to the temperature variation of the core during coring and propose suggestions to reduce the unevenness of core temperature. The findings indicate that at a strata temperature of 150 ◦C and a core lifting speed of 2.5 m/s, during process of lifting the passively insulated core to the ground, natural convection occurs within the coring tool due to buoyancy, circulating in a counterclockwise direction. The temperature difference of the core in the axial and radial directions is 21 and 7.7 ◦C, respectively, with temperature variation rates of 21 and 308 ◦C/m per unit length, respectively. The greatest decrease in temperature is observed at the outer edge of the core bottom. The natural convection of strata water results in significant temperature differences along the axis of the core, exacerbating the unevenness of core temperature. To ensure uniform core temperature, efforts should be made to minimize the space between the core and the inner tube. In addition, the use of water-blocking mechanisms should be facilitated to reduce the ingress of strata water into the coring device. During the coring process, the frequency of active thermal insulation gradually increases as the ambient temperature decreases, thereby reducing the temperature difference between the inner and outer sides of the coring device to suppress the occurrence of natural convection. These research findings have practical implications for achieving deep rock in-situ temperature-preserved coring, providing theoretical and technical guidance for the development of deep resources such as coal, geothermal energy, and oil and gas.
Document Type: Original article
Cited as: Wei, Z., He, Z., Yang, J. Analysis of core temperature variation and its influencing factors in deep rock in-situ temperature-preserved coring. Advances in Geo-Energy Research, 2024, 14(3): 215-223. https://doi.org/10.46690/ager.2024.12.06
Keywords
Full Text:
PDFReferences
Abegg, F., Hohnberg, H. J., Pape, T., et al. Development and application of pressure-core-sampling systems for the investigation of gas- and gas-hydrate-bearing sediments. Deep-Sea Research Part I-Oceanographic Research Papers, 2008, 55(11): 1590-1599.
Feng, Q., Jin, J., Zhang, S., et al. Study on a damage model and uniaxial compression simulation method of frozenthawed rock. Rock Mechanics and Rock Engineering, 2022, 55(1): 187-211.
Guan, C., Liu, S., Li, C. W., et al. The temperature effect on the methane and CO2 adsorption capacities of Illinois coal. Fuel, 2018, 211: 241-250.
He, Z., Xie, H., Gao, M., et al. Design and verification of a deep rock corer with retaining the in situ temperature. Advances in Civil Engineering, 2020, 2020(1): 8894286.
He, Z., Xie, H., Gao, M., et al. The fracturing models of hard roofs and spatiotemporal law of mining-induced stress in a top coal caving face with an extra-thick coal seam. Geomech Geophys Geo-Energ Geo-Resources, 2021, 7(1): 1-15.
He, Z., Yang, Y., Yu, B., et al. Research on properties of hollow glass microspheres/epoxy resin composites applied in deep rock in-situ temperature-preserved coring. Petroleum Science, 2022, 19(2): 720-730.
Jia, L., Li, B., Li, J., et al. The effect of stress, pressure and temperature on CBM migration with elastic-plastic deformation. Geoenergy Science and Engineering, 2023, 221: 211405.
Li, S., Tian, F., Jiang, W., et al. Experimental investigation on coal desorption characteristics and spontaneous combustion properties evolution under the coupled effect of temperature and pressure. Fuel, 2023, 351: 128829.
Liu, H., Liu, L., Wang, X., et al. Research on the macroscopic and microscopic failure mechanisms and damage deterioration patterns of granite under unloading paths. International Journal of Geomechanics, 2024a, 24(11): 04024262.
Liu, S., Li, X., Wang, D., et al. Mechanical and acoustic emission characteristics of coal at temperature impact. Natural Resources Research, 2020, 29: 1755-1772.
Liu, Y., Zhang, J., Huang, H. Key technologies and development direction for deep and ultra-deep drilling and completion in China. Acta Petrolei Sinica, 2024b, 45(1): 312-324.
Qiu, J., Zhao, Z., Yang, J., et al. Theoretical characterization of the temperature-dependent mode I fracture toughness of rocks. Fatigue & Fracture of Engineering Materials & Structures, 2024, 47(3): 952-963.
Rabbani, A., Baychev, T. G., Ayatollahi, S., et al. Evolution of pore-scale morphology of oil shale during pyrolysis: a quantitative analysis. Transport in Porous Media, 2017, 119: 143-162.
Saif, T., Lin, Q., Bijeljic, B., et al. Microstructural imaging and characterization of oil shale before and after pyrolysis. Fuel, 2017, 197: 562-574.
Sakurovs, R., Day, S., Weir, S., et al. Temperature dependence of sorption of gases by coals and charcoals. International Journal of Coal Geology, 2008, 73(3-4): 250-258.
Sun, J., Liu, W., Wang, Q., et al. Challenges and development prospects of oil and gas drilling and completion in myriametric deep formation in China. Drilling & Production Technology, 2024, 47(2): 1-9. (in Chinese)
Su, X., Feng, Z., Cai, T., et al. Coal permeability variation during the heating process considering thermal expansion and desorption shrinkage. Adsorption Science & Technology, 2022, 2022(4): 1-13.
Wang, C., He, M., Zhang, X., et al. Temperature influence on macro-mechanics parameter of intact coal sample containing original gas from Baijiao Coal Mine in China. International Journal of Mining Science and Technology, 2013, 23(4): 597-602.
Wang, C., Li, X., Cheng, L., et al. Mechanical properties and acoustic emission characteristics of deep hard coal after segmented high-temperature treatment. Scientific Reports, 2023, 13(1): 1134.
Wei, Z., Li, C., Yu, B., et al. Study on heat transfer model theory and numerical simulation used in deep rock in-situ temperature-preserved coring. Thermal Science, 2023, 27(1 Part B): 639-646.
Xie, H., Gao, F., Ju, Y. Research and development of rock mechanics in deep ground engineering. Chinese Journal of Rock Mechanics and Engineering, 2015, 34(11): 2161-2178. (in Chinese)
Xie, H., Gao, M., Zhang, R., et al. Study on concept and progress of in situ fidelity coring of deep rocks. Chi nese Journal of Rock Mechanics and Engineering, 2020, 39(5): 865-876. (in Chinese)
Xie, H., Gao, M., Zhang, R., et al. Application prospects of deep in-situ condition-preserved coring and testing systems. Advances in Geo-Energy Research, 2024, 14(1): 12-24.
Xie, J., Meng, T., Jin, T., et al. Mesoscopic mechanism of permeability of coal rock mass with increasing temperature in the range of room temperature to 350 ◦C. Advances in Materials Science and Engineering, 2022, 2022(1): 2097959.
Yang, M., Li, J., Gao, M., et al. Experimental study on nonlinear mechanical behavior and sampling damage characteristics of rocks from depths of 4900-6830 m in Well Songke-2. Journal of Central South University, 2023, 30(4): 1296-1310.
Yin, G., Jiang, C., Wang, J., et al. Combined effect of stress, pore pressure and temperature on methane permeability in anthracite coal: An experimental study. Transport in Porous Media, 2013, 100: 1-16.
Zhang, H., Shen, J., Li, K., et al. Precise distinction of mechanical behavior stages of coal under temperature-pressure constraints and its permeability and energy consumption characteristics. Fuel, 2022, 325: 124826.
Zhao, J., Yang, D., Kang, Z., et al. A micro-CT study of changes in the internal structure of Daqing and Yan’an oil shales at high temperatures. Oil Shale, 2012, 29(4): 357-367.
Zhao, J., Zhang, H., Wang, H., et al. Key technical challenges and prospects of drilling and completion in ultra-deep reservoirs, Sinopec. Drilling & Production Technology, 2024a, 47()2): 28-34. (in Chinese)
Zhao, L, Peng, R, Hao, P, et al. Effects of pore pressure on coring-induced damage based on simulation by mesoscale stress-flow coupling numerical model. Advances in Geo-Energy Research, 2024b, 14(3): 170-186.
Zheng, C., Yao, Q., Li, X., et al. Experimental investigation of mechanical characteristics of coal samples at different drying temperatures. Drying Technology, 2022, 40(16): 3483-3495.
Zhou, X., Pang, X., Li, Q., et al. Advances and problems in hydrocarbon exploration in the Tazhong area, Tarim Basin. Petroleum Science, 2010, 7: 164-178.
Zhu, H., Liu, Q., Deng, J., et al. Pressure and temperature preservation techniques for gas-hydrate-bearing sediments sampling. Energy, 2011, 36(7): 4542-4551.
Zou, J., Jiao, Y., Rathnaweera, T. D., et al. Experimental study on the influence of temperature cycle on low-rank coal permeability. Science China-Technological Sciences, 2020, 63(6): 1055-1065.
DOI: https://doi.org/10.46690/ager.2024.12.06
Refbacks
- There are currently no refbacks.
Copyright (c) 2024 The Author(s)
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.