In order to analyze the impact of rock plasticity on crack closure during production, an elastic-plastic crack closure model was established using the Drucker Prager yield criterion based on the Herz contact model. The effects of different in-situ stresses and rock plasticity parameters on the crack closure behavior were analyzed. The results indicate that the elastic modulus, hardening parameters, and cohesion are key factors affecting the plastic crack closure. The greater the cohesion, the greater the initial yield stress. The larger the ratio of hardening parameters to the elastic modulus is the greater the subsequent yield stress, and the weaker the plastic effect of crack closure. In addition, the in-situ stress also has a significant impact on crack closure. The higher the normal stress in the normal direction of the crack surface, the higher the plastic effect coefficient of crack closure.
[5] ZHANG P, MISHRA B, HEASLEY K A. Experimental Investigation on the Influence of High Pressure and High Temperature on the Mechanical Properties of Deep Reservoir Rocks[J]. Rock Mechanics and Rock Engineering,2015,48(6):2197-2211.
[6] ZHAO Y S, WAN Z J, FENG Z J, et al. Evolution of Mechanical Properties of Granite at High Temperature and High Pressure[J]. Geomechanics and Geophysics for Geo-energy and Geo-resources,2017,3(2):199-210.
[7] LIU S, XU J. An Experimental Study on the Physico-mechanical Properties of Two Post-high-temperature rocks[J]. Engineering Geology,2015,185:63-70.
[11] THIAGARAJAN G, HUANG Y, HSIA K J.Fracture Simulation Using an Elasto-Viscoplastic Virtual Internal Bond Model with Finite Elements[J].Journal of Applied Mechanics,2004,71:796-804.
[12] GAO H, KLEIN P. Numerical Simulation of Crack Growth in an Isotropic Solid with Randomized Internal Cohesive Bonds[J]. Journal of the Mechanics and Phy-sics of Solids,1998,46(2):187-218.
[14] WEI X, ZHAO B, JI C, et al.Elastoplastic Augmented Virtual Internal Bond Modeling for Rock:A Fracture-plasticity Combined Constitutive Model[J].International Journal for Numerical and Analytical Methods in Geomechanics,2023,47(8):1331-1348.
[15] ZHANG Z, GAO H. Simulating Fracture Propagation in Rock and Concrete by an Augmented Virtual Internal Bond Method[J].International Journal for Numerical and Analytical Methods in Geomechanics,2012,36(4):459-482.