In this paper, uniaxial compression tests were carried out on a series of composite rock specimens with different dip angles, which were made from two types of rock-like material with different strength. The acoustic ...In this paper, uniaxial compression tests were carried out on a series of composite rock specimens with different dip angles, which were made from two types of rock-like material with different strength. The acoustic emission technique was used to monitor the acoustic signal characteristics of composite rock specimens during the entire loading process. At the same time, an optical non-contact 3 D digital image correlation technique was used to study the evolution of axial strain field and the maximal strain field before and after the peak strength at different stress levels during the loading process. The effect of bedding plane inclination on the deformation and strength during uniaxial loading was analyzed. The methods of solving the elastic constants of hard and weak rock were described. The damage evolution process, deformation and failure mechanism, and failure mode during uniaxial loading were fully determined. The experimental results show that the θ = 0?–45?specimens had obvious plastic deformation during loading, and the brittleness of the θ = 60?–90?specimens gradually increased during the loading process. When the anisotropic angle θincreased from 0?to 90?, the peak strength, peak strain,and apparent elastic modulus all decreased initially and then increased. The failure mode of the composite rock specimen during uniaxial loading can be divided into three categories:tensile fracture across the discontinuities(θ = 0?–30?), slid-ing failure along the discontinuities(θ = 45?–75?), and tensile-split along the discontinuities(θ = 90?). The axial strain of the weak and hard rock layers in the composite rock specimen during the loading process was significantly different from that of the θ = 0?–45?specimens and was almost the same as that of the θ = 60?–90?specimens. As for the strain localization highlighted in the maximum principal strain field, the θ = 0?–30?specimens appeared in the rock matrix approximately parallel to the loading direction,while in the θ = 45?–90?specimens it a展开更多
Aim To study dislocation elasticity theory in quasicrystals. Methods A dislocation was separated into pure edge part and pure screw part and their superposition was used to find the elastic field. Results and Conclu...Aim To study dislocation elasticity theory in quasicrystals. Methods A dislocation was separated into pure edge part and pure screw part and their superposition was used to find the elastic field. Results and Conclusion The elastic solution of a straight dislocation parallel to the quasiperiodic axis in 1D hexagonal quasicrystals was obtained and the generalized Peach Koehler force on a dislocation in quasicrystals was given.展开更多
Based on Kuo and Dai＇s vectorial wave-field extrapolation equations, we derive new Kirchhoff migration equations by introducing unit vectors which represent the ray directions at the imaging points of the reflected P...Based on Kuo and Dai＇s vectorial wave-field extrapolation equations, we derive new Kirchhoff migration equations by introducing unit vectors which represent the ray directions at the imaging points of the reflected P- and PS converted-waves. Furthermore, using the slope of the events on shot records and a ray racing procedure, mirror-image reflection points are found and the reflection data are smeared along the Fresnel zone. The migration method proposed in this paper solves two troublesome imaging problems caused by limited receiving aperture and migration artifacts resulting from wave propagation at the velocities of non original wave type. The migration method is applied successfully with model data, demonstrating that the new method is effective and correct.展开更多
Storage modulus and loss modulus is the main performance index of visco-elastic properties.In this paper the storage modulus and loss modulus of a new diverting acid and their influencing factors were systematically i...Storage modulus and loss modulus is the main performance index of visco-elastic properties.In this paper the storage modulus and loss modulus of a new diverting acid and their influencing factors were systematically investigated.Besides,the constitutive equations of the diverting acid at different temperatures were elicited from shearing experiments,which show that the visco-elastic surfactant(VES)acid system is a non-Newtonian power law fluid at low temperature and a Newtonian fluid at high temperature.The storage modulus and loss modulus at different temperatures,pH,and VES content in the acid are critical for the design of acid stimulation for oil well,especially when the VES acid is used in this field only on trial and the basic data are in urgent needed for the design and construction of the acidification stimulation.展开更多
基金supported by the National Basic Research 973 Program of China (Grant 2014CB046905)the Natural Science Foundation of Jiangsu Province for Distinguished Young Scholars (Grant BK20150005)+1 种基金the Fundamental Research Funds for the Central Universities (China University of Mining and Technology) (Grant 2014XT03)the innovation research project for academic graduate of Jiangsu Province (Grant KYLX16_0536)
文摘In this paper, uniaxial compression tests were carried out on a series of composite rock specimens with different dip angles, which were made from two types of rock-like material with different strength. The acoustic emission technique was used to monitor the acoustic signal characteristics of composite rock specimens during the entire loading process. At the same time, an optical non-contact 3 D digital image correlation technique was used to study the evolution of axial strain field and the maximal strain field before and after the peak strength at different stress levels during the loading process. The effect of bedding plane inclination on the deformation and strength during uniaxial loading was analyzed. The methods of solving the elastic constants of hard and weak rock were described. The damage evolution process, deformation and failure mechanism, and failure mode during uniaxial loading were fully determined. The experimental results show that the θ = 0?–45?specimens had obvious plastic deformation during loading, and the brittleness of the θ = 60?–90?specimens gradually increased during the loading process. When the anisotropic angle θincreased from 0?to 90?, the peak strength, peak strain,and apparent elastic modulus all decreased initially and then increased. The failure mode of the composite rock specimen during uniaxial loading can be divided into three categories:tensile fracture across the discontinuities(θ = 0?–30?), slid-ing failure along the discontinuities(θ = 45?–75?), and tensile-split along the discontinuities(θ = 90?). The axial strain of the weak and hard rock layers in the composite rock specimen during the loading process was significantly different from that of the θ = 0?–45?specimens and was almost the same as that of the θ = 60?–90?specimens. As for the strain localization highlighted in the maximum principal strain field, the θ = 0?–30?specimens appeared in the rock matrix approximately parallel to the loading direction,while in the θ = 45?–90?specimens it a
文摘Aim To study dislocation elasticity theory in quasicrystals. Methods A dislocation was separated into pure edge part and pure screw part and their superposition was used to find the elastic field. Results and Conclusion The elastic solution of a straight dislocation parallel to the quasiperiodic axis in 1D hexagonal quasicrystals was obtained and the generalized Peach Koehler force on a dislocation in quasicrystals was given.
基金supported by National High-Tech Research and Development Program of China (Grant No. 2006AA06Z202)Open Fund of the Key Laboratory of Geophysical Exploration of CNPC (Grant No. GPKL0802)+2 种基金CNPC Young Innovation Fund (Grant No. 05E7028) graduate student Innovation Fund of China University of Petroleum(East China) (Grant No. S2008-1)the Program for New Century Excellent Talents in University (Grant No. NCET-07-0845).
文摘Based on Kuo and Dai＇s vectorial wave-field extrapolation equations, we derive new Kirchhoff migration equations by introducing unit vectors which represent the ray directions at the imaging points of the reflected P- and PS converted-waves. Furthermore, using the slope of the events on shot records and a ray racing procedure, mirror-image reflection points are found and the reflection data are smeared along the Fresnel zone. The migration method proposed in this paper solves two troublesome imaging problems caused by limited receiving aperture and migration artifacts resulting from wave propagation at the velocities of non original wave type. The migration method is applied successfully with model data, demonstrating that the new method is effective and correct.
基金Supported by the Acidification for Heterogeneous Carbonate Reservoirs Program of Petro China Company Limited
文摘Storage modulus and loss modulus is the main performance index of visco-elastic properties.In this paper the storage modulus and loss modulus of a new diverting acid and their influencing factors were systematically investigated.Besides,the constitutive equations of the diverting acid at different temperatures were elicited from shearing experiments,which show that the visco-elastic surfactant(VES)acid system is a non-Newtonian power law fluid at low temperature and a Newtonian fluid at high temperature.The storage modulus and loss modulus at different temperatures,pH,and VES content in the acid are critical for the design of acid stimulation for oil well,especially when the VES acid is used in this field only on trial and the basic data are in urgent needed for the design and construction of the acidification stimulation.
