Abstract
Understanding the mechanical properties of the reservoir rock under different temperatures after rapid thermal cooling is necessary for safe and effective deep geoengineering applications, including deep mining projects, deep geological disposal of nuclear waste, and geothermal energy extraction. This paper is devoted to investigating the effect of rapid cooling on the mechanical behavior of the granite rock. At first, high-temperature heating was conducted. The 24 samples were divided into six groups and were heated at 100, 200, 300, 400, 500, and 600°C, and once they had reached the chosen temperature, they were immediately cooled with a cold water container, and the temperature of water in the pan was 25°C. After the thermal treatment, the samples were measured using ultrasonic wave velocities, and then they were deformed under uniaxial and triaxial compression tests. The P -wave velocity, damage characteristics, stress-strain curves, compressive strength, and Young’s modulus of the samples were presented considering different thermal temperatures. The results confirmed that the P -wave velocities of the samples generally decrease with temperature. P-wave velocity can indirectly reflect the damage of the rock structure. These changes represent a negative exponential relationship between P -wave velocity and hold temperature following cooling. As the samples experienced greater temperatures, the peak strength and elastic characteristics also significantly reduced. This is mainly due to thermally induced damage in the form of both intergranular and intragranular cracks. The stress-strain response revealed that the failure mode can change from brittle to quasi-brittle fracturing following treatment at increasingly greater temperatures.
Highlights
Understanding the mechanical properties of the reservoir rock under different temperatures after rapid thermal cooling is necessary for safe and effective deep geoengineering applications, including deep mining projects, deep geological disposal of nuclear waste, and geothermal energy extraction. is paper is devoted to investigating the effect of rapid cooling on the mechanical behavior of the granite rock
The construction of artificial reservoirs by using hydraulic fracturing technology is complex fracture dynamic thermal cracking in rock mass, and the fracture propagation direction is affected by rock thermal fracture propagation. ese are related to the mechanical behavior of granite after water is cooled under high temperature, so it is necessary to have a clear understanding of the mechanical properties of high-temperature granite after water cooling
Many scholars have conducted a lot of research studies on the physical and mechanical properties of granite under high temperature and have made many valuable research results. e physical and mechanical properties in granite rocks will change with high temperature such as elastic modulus reduction [5], permeability enhancement [7], and mechanical strength decrease [8]. e stress-strain characteristics of granite under normal temperature and high temperature were analyzed, and the phase characteristics of the heating treatment of different temperatures were analyzed. e results of the mechanical test and the results of the diffraction experiment were compared and analyzed [9]
Summary
Understanding the mechanical properties of the reservoir rock under different temperatures after rapid thermal cooling is necessary for safe and effective deep geoengineering applications, including deep mining projects, deep geological disposal of nuclear waste, and geothermal energy extraction. is paper is devoted to investigating the effect of rapid cooling on the mechanical behavior of the granite rock. To exploit HDR geothermal energy, we need a great amount of drilling in granite, especially deep boreholes that are used to form an artificial reservoir, mainly through hydraulic fracturing technologies [3] In this process, a lot of cold water is injected and circulated through the artificial fractures in the geothermal reservoirs and eventually pumped back to the surface as steam [4]. Rough the real-time temperature after loading and high-temperature and SEM fracture tests under the uniaxial compression of two kinds of situations, the mechanical properties of granite under different temperatures were studied, and two kinds of uniaxial compressive strength, elastic modulus, and longitudinal wave velocity were analyzed [10]. Using the high-precision micro-CT experiment system, the granite crystal grain size is 100 to 300 μm irregular spatial structures [12]. e mechanical properties of watercooled granite samples under high temperatures within 600°C and the degradation mechanism of thermal cracking of watercooled granite were discussed [13]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
