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The vibration of oil well sucker rod is one of the main reasons that cause breaking and disengaging to the pumping well. According to vibration mechanics theory and nonlinear theory, building the vibration mechanics model of the subsurface rod system, combined with finite element theory, using spatial beam element to establish the finite element of the rod. And according to the interface ingenerating conditions, adopt augmented Lagrange multiplier method to embed it into the finite element equations, tracing the contact friction state of the rod and tubing, to obtain the rod vibration characteristics and the contact state with the tubing during work process, to analyze the change law and influencing factors, providing the theoretical support to the vibration control of the rod.

Widespread problem in hydraulic fracturing of low-permeability reservoir is difficulty of crack initiation of fracturing, high initiation pressure of fracturing put forward higher requirements of fracturing equipment. Low-permeability reservoir for the study, in the fluid-solid coupling conditions, established a low-permeability reservoir perforation mechanical model of stress, using numerical solution techniques, consider the dynamic effects, we can achieve the stress distribution at different stages: drilling, well cementation, perforation and fracturing in low-permeability reservoir. With rock tensile fracture criterion can determine the initiation location and initiation pressure. The results show that the lower the degree of pollution in perforating hole, the smaller the pressure from the crack initiation as well as the higher the degree of pollution in perforating hole, the larger the pressure from the crack initiation. Orientation, diameter and depth of perforating hole effect on crack initiation and extension are more significant.

Fatigue failure of sucker rod can occur under the effect of alternating load, and results in failure of sucker rod. In this paper, the damage mechanics theory is applied to the fatigue damage of sucker rod on the study, establish the fatigue damage evolution equation of sucker rod, and the damage mechanics-finite element method is adopted to solve fatigue damage of sucker rod, obtain change law of stress field, strain field and fatigue damage field of sucker rod, and carry out fatigue damage cycles of sucker rod. The study has a certain theoretical significance and practical significance on the rational use of sucker rod, the decrease of sucker rod fracture accident and the improvement of overall economic benefits in oilfield development.

Propagation characteristics of crack cross different elastic material interface is important to hydrodynamic fracture of control technology .It makes the specimens of rock and similar materials including interfacial layer to do theItype crack through three-point bending experiments. The text shows that the crack occurred deflection through the interface. Based on damage mechanics, establish the plasticity damage model to describe the sand-mudstone damage behavior. Using the numerical solution technology to simulate the loading cracking process, the experimental and numerical simulation results are in good agreement. The main reason causing the fracture deflection is that the difference of sand-mudstone mechanics of materials property results in interface shear stress increasing, and result in the Itype crack expand transform to the I-IImixed type mode crack. TheII type shear crack makes the crack lateral spreading on the interface. Finally, leading to fracture deflection, the extent of deflection is associated with materials properties of mudstone, Shale content is more low, the deflection is more weak, and vice versa. It is important significance to controlling hydro-fracturing fracture extension.