Three‐Dimensional Propagation Simulation and Parameter Analysis of Rock Joint with Displacement Discontinuity Method

Abstract

Displacement discontinuities method (DDM) is convenient for and efficient at dealing with discontinuity problems such as fracture and fault. However, the known method of ease iteration is not available for nonlinear joint surface problems. This paper introduces Barton-Bandis nonlinear joint deformation failure criterion, figures out the propagation model of joint through the maximum energy release rate theory of rock fracture mechanics, and establishes three-dimensional nonlinear displacement discontinuity model for rock joint. This paper gives results of the joint propagation pattern and its distribution law under tension and compression with different parameters and side pressure coefficients via compiled program.

Numerical Simulation Investigation on Fracture Propagation of Fracturing for Crossing Coal Seam Roof

“…The Newton-Raphson method is used to solve Equation (16), and the solution of Equation ( 16) is iterated with the fluid-solid coupling Equation (14) and Equation (15) to calculate the flow rate of each cluster. The fluid-solid coupling equations are stiff.…”

“…Some theoretical and field experimental studies on fracturing or penetration fracturing through a coal seam roof have been carried out. To date, the related research focuses on the effects of fracturing parameters and perforation parameters on crossing layer fracture propagation [12][13][14][15], optimization of development technology of horizontal wells in a coal seam roof [16,17], fracture initiation pressure of a coal seam or coal seam roof [18,19], properties of different roof rocks of a coal seam [20], fracture characteristics of rock mass during mining [21][22][23], and the effects of coal mechanical parameters on proppant embedding [24,25]. However, few studies on favorable geological conditions suitable for fracturing through horizontal wells in a coal seam roof have been reported.…”

A Planar-3D Mathematical Model for Studying the Effect of Heterogeneity of Rock Fracture Toughness on Hydraulic Fracture Propagation: Early-Time Solution including the Stage before Propagation

“…At present, algorithms for two-dimensional (2D) models with consideration of heterogeneous factors (the anisotropic elastic properties [12,13], non-uniform in situ stress [14], an inhomogeneous permeability [15]) are relatively mature. For planar-3D or 3D models, although many algorithms and simulators [16][17][18][19][20] have been proposed for studying the effects of different parameters on hydraulic fracture propagation, the rock's heterogeneity is generally ignored in these algorithms and simulators.…”