Hydraulic fracturing is accompanied by a change in pore fluid pressure. As a result,this may be conveniently represented as inflated dislocation moving within a semi-infinite medium. Theory is developed to describe th...Hydraulic fracturing is accompanied by a change in pore fluid pressure. As a result,this may be conveniently represented as inflated dislocation moving within a semi-infinite medium. Theory is developed to describe the pore pressures that build up around an inflated volumetric dislocation migrating within a saturated porous-elastic semi-infinite medium as analog to hydraulic fracturing emplacement. The solution is capable of evaluating the system behavior of both constant fluid pressure and zero flux surface conditions through application of a superposition. Characterization of horizontal moving dislocation processes is conducted as an application of these techniques. Where the mechanical and hydraulic parameters are defined,a priori,type curve matching of responses may be used to evaluate emplacement location uniquely. Pore pressure response elicited at a dilation,subject to pressure control is of interest in representing hydraulic fracturing where leak-off is an important component. The effect of hydraulic fracturing on fracture fluid pressure is evaluated in a poroelastic hydraulic fracture model utilizing dislocation theory. A minimum set of dimensionless parameters are defined that describe the system. Pore fluid pressures recorded during hydraulic fracturing of a well in the San Joaquin Valley of Central California is examined using the proposed model. The estimated geometry of the hydraulic fracture is matched with reasonable fidelity with the measured data.展开更多
Focused upon the dynamic changing regularity and tendency of overburden movement and bed separation developing during the strip mining and stoping under rail- ways were simulated by ANSYS model.The results show that m...Focused upon the dynamic changing regularity and tendency of overburden movement and bed separation developing during the strip mining and stoping under rail- ways were simulated by ANSYS model.The results show that movement and rheology developing of key strata is one of the main reasons to cause surface subsidence and to further induce deformation of surface railways.It provids a basis for taking efficient meas- ures to control the deformation of surface railways.展开更多
Based on the theory of nonlinear dynamic finite element,the control equation ofcoal and water jet was acquired in the coal breaking process under a water jet.The calculationmodel of coal breaking under a water jet was...Based on the theory of nonlinear dynamic finite element,the control equation ofcoal and water jet was acquired in the coal breaking process under a water jet.The calculationmodel of coal breaking under a water jet was established;the fluid-structure couplingof water jet and coal was implemented by penalty function and convection calculation.The dynamic process of coal breaking under a water jet was simulated and analyzed bycombining the united fracture criteria of the maximum tensile strain and the maximal shearstrain in the two cases of damage to coal and damage failure to coal.展开更多
According to the geological and mining conditions of deep high gas coal seam,this paper established the mechanical model of stope surrounding rock,and analyzed the stress distribution and deformation failure mechanism...According to the geological and mining conditions of deep high gas coal seam,this paper established the mechanical model of stope surrounding rock,and analyzed the stress distribution and deformation failure mechanism of working face and coal pillar.The research determined the arrangement mode that adjacent working faces retain wide pillar,and the reasonable support method of roadway that the combined support of roof and grouting combined together.The reasonable time of reinforced roadway was determined.Through analyzing the mechanical model of the ways of roadway supporting,this research drew the conclusions as follows:the combined support of roof and working slope improved the support strength and range of surrounding rock,optimized the support by adjusting the angle of anchor,and reached the support requirements by using cement grouting in working slope and chemical grout in roof.The technology was applied in 15104 working face of Baoan Mine,and obtained good results.展开更多
基金Projects PRF-25922-AC2 supported by the American Chemical SocietyMSS-9218547 by the US National Science Foundation
文摘Hydraulic fracturing is accompanied by a change in pore fluid pressure. As a result,this may be conveniently represented as inflated dislocation moving within a semi-infinite medium. Theory is developed to describe the pore pressures that build up around an inflated volumetric dislocation migrating within a saturated porous-elastic semi-infinite medium as analog to hydraulic fracturing emplacement. The solution is capable of evaluating the system behavior of both constant fluid pressure and zero flux surface conditions through application of a superposition. Characterization of horizontal moving dislocation processes is conducted as an application of these techniques. Where the mechanical and hydraulic parameters are defined,a priori,type curve matching of responses may be used to evaluate emplacement location uniquely. Pore pressure response elicited at a dilation,subject to pressure control is of interest in representing hydraulic fracturing where leak-off is an important component. The effect of hydraulic fracturing on fracture fluid pressure is evaluated in a poroelastic hydraulic fracture model utilizing dislocation theory. A minimum set of dimensionless parameters are defined that describe the system. Pore fluid pressures recorded during hydraulic fracturing of a well in the San Joaquin Valley of Central California is examined using the proposed model. The estimated geometry of the hydraulic fracture is matched with reasonable fidelity with the measured data.
基金the National Natural Science Funds Committee(50174035)
文摘Focused upon the dynamic changing regularity and tendency of overburden movement and bed separation developing during the strip mining and stoping under rail- ways were simulated by ANSYS model.The results show that movement and rheology developing of key strata is one of the main reasons to cause surface subsidence and to further induce deformation of surface railways.It provids a basis for taking efficient meas- ures to control the deformation of surface railways.
基金Supported by the National Basic Research Program of China(973 Program)(2005CB221504)the National Natural Science Foundation of China(50534080)the National Science and Technology Supporting Program of China(the 11th Five-Year Program)(2006BAK03B03)
文摘Based on the theory of nonlinear dynamic finite element,the control equation ofcoal and water jet was acquired in the coal breaking process under a water jet.The calculationmodel of coal breaking under a water jet was established;the fluid-structure couplingof water jet and coal was implemented by penalty function and convection calculation.The dynamic process of coal breaking under a water jet was simulated and analyzed bycombining the united fracture criteria of the maximum tensile strain and the maximal shearstrain in the two cases of damage to coal and damage failure to coal.
基金support by the State Key Basic Program of China(No.2011CB201206)
文摘According to the geological and mining conditions of deep high gas coal seam,this paper established the mechanical model of stope surrounding rock,and analyzed the stress distribution and deformation failure mechanism of working face and coal pillar.The research determined the arrangement mode that adjacent working faces retain wide pillar,and the reasonable support method of roadway that the combined support of roof and grouting combined together.The reasonable time of reinforced roadway was determined.Through analyzing the mechanical model of the ways of roadway supporting,this research drew the conclusions as follows:the combined support of roof and working slope improved the support strength and range of surrounding rock,optimized the support by adjusting the angle of anchor,and reached the support requirements by using cement grouting in working slope and chemical grout in roof.The technology was applied in 15104 working face of Baoan Mine,and obtained good results.
