a MOE Key Laboratory of Deep Earth Science and Engineering, College of Architecture and Environment, Sichuan University, Chengdu, 610065, China
b Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization, Shenzhen University, Shenzhen,
518060, China
2024, 16(12): 5297-5324. doi:10.1016/j.jrmge.2024.02.020
Received: 2023-09-18 / Revised: 2023-12-28 / Accepted: 2024-02-29 / Available online: 2024-05-22
2024, 16(12): 5297-5324.
doi:10.1016/j.jrmge.2024.02.020
Received: 2023-09-18
Revised: 2023-12-28
Accepted: 2024-02-29
Available online: 2024-05-22
Rock fracture toughness is a critical parameter for optimizing reservoir stimulation during deep resource extraction. This index characterizes the in situ resistance of rocks to fracture and is affected by high temperature, in situ stress, thermal shock, and chemical corrosion, etc. This review comprehensively examines research on rock fracture properties in situ environments over the past 20 years, analyses the influences of various environmental factors on rock fracture, and draws the following conclusions: (i) Environmental factors can significantly affect rock fracture toughness through changing the internal microstructure and grain composition of rocks; (ii) While high temperature is believed to reduce the rock strength, several studies have observed an increase in rock fracture toughness with increasing temperature, particularly in the range between room temperature and 200 °C; (iii) In addition to a synergistic increase in fracture toughness induced by both high temperature and high in situ stress, there is still a competing effect between the increase induced by high in situ stress and the decrease induced by high temperature; (iv) Thermal shock from liquid nitrogen cooling, producing high temperature gradients, can surprisingly increase the fracture toughness of some rocks, especially at initial temperatures between room temperature and 200 °C; and (v) Deterioration of rock fracture toughness occurs more rapidly in acidic environments than that in alkaline environments. In addition, this review identified current research trends and suggested some potential directions to provide suggestions for deep subsurface resource extraction.
Keywords: Deep rock mechanics, Deep in situ geological conditions, Fracture toughness, Deep in situ rock fracture mechanics
Qin Zhou
Qin Zhou obtained her master degree (2019) from Sichuan University (SCU), China. She is currently a PhD candidate in Solid Mechanics at SCU, China. She research focuses on Deep Rock Fracture Mechanics and Deep Resource Exploitation.