Experimental study on mechanical properties and porosity and permeability of rock in high temperature environment

Abstract

In order to explore the mechanical characteristics and porosity and permeability parameter of three kinds of rock (sandstone, granite and limestone) in high temperature environment, conventional triaxial compression experiments and porosity and permeability tests were conducted on three kinds of rocks under 25°C, 300°C and 500°C. The experimental results show that the high temperature environment increases the development degree of microcracks and pore structures in sandstone and limestone. As the temperature rises, the interpenetration length of triaxial compression shear crack of sandstone decreases gradually, and the angle between shear crack and horizontal direction increases gradually. Change of damage mode from single shear damage to tension shear damage (shear-dominated) in granite and limestone. The three rocks’ permeability and porosity increase as ambient temperature rises, and the permeability exhibits clear pressure-constricting sensitivity in a range of temperature settings. The results provide a reference for understanding and predicting the mechanical properties and porosity and permeability characteristics of rocks in high temperature environment.