The Excitation Effect Of The Transverse Wave Controllable Vibrator And The Design Of The Plate Tooth Structure

In the process of oil and gas exploration and development,seismic exploration needs high quality seismic signal excitation source,vibroseis is a kind of non-explosive source which can excite controlled seismic wave signal.As the key equipment of modern seismic exploration industry,vibroseis has the advantages of controllable excitation signal,high seismic operation efficiency,green environmental protection and so on.At present,the research on P-wave vibroseis at home and abroad has become mature.However,the study of shear wave source is still in the stage of preliminary exploration.Compared with P-wave vibroseis,shear waves have many advantages,such as high sensitivity of underground media,strong recognition ability of small targets,higher resolution and stronger anti-interference ability.Therefore,shear wave exploration plays a good role in natural gas exploration.At present,the current state of the country's oil and gas resources is grim industry status and environmental protection situation,Chinese President Xi Jinping put forward the new development concept of "Green Water Mountain is Jinshan Yinshan".To speed up the exploration and development of natural gas is the most urgent requirement of the country to the oil and gas equipment,and the important new field of oil and gas equipment,that is,S-wave vibroseis enters people's line of sight.The core component of the shear wave controllable source is a vibrator,and the plate teeth of the vibrator are used as a medium for transmitting signals between the vibrator and the ground.The optimization and design of flat-plate teeth is the key to improve the performance of the whole vehicle.Through the study of shear wave vibroseis vibrator plate teeth,the propagation reason and mechanism of shear wave are analyzed qualitatively,and the evaluation index of shear wave excitation effect is established.A plate tooth structure suitable for shear wave vibroseis with good comprehensive performance is proposed to enhance the excitation energy of shear wave so as to lay a theoretical foundation for the accuracy and high efficiency of shear wave exploration.The specific work and conclusions are as follows:(1)In this paper,the structure and working principle of shear wave vibroseis are analyzed,and the force model of vibrator is studied on the basis of the analysis of the structure and working principle of vibroseis.Horizontal reciprocating motion of shear wave vibroseis vibrator under static and dynamic loads.The hydraulic pressure generated by the motion is transmitted to the plate through the piston rod,so that the signal generated by the vibrator is transmitted down to the earth and the seismic wave signal is excited.(2)The finite element simulation analysis is carried out by establishing the plate-earth coupling dynamic model of the vibrator.According to the propagation of shear wave in the surface,stratum section and three-dimensional space,it is found that the transference of shear wave is actually the interaction and vibration between the earth particles and the earth particles.The motion of the wave is essentially the motion of the particle,and the microscopic view is the effective motion of the particle in the Z direction.On the basis of the propagation mechanism of shear wave,the evaluation index of shear wave excitation effect is put forward:the motion intensity and down-propagation energy of the earth particles in Z direction.It provides the basis for constructing the evaluation system of shear wave excitation effect.(3)On the basis of triangular tooth plate structure,two different plate tooth structures,conical tooth and tetrahedral tooth,are designed.The evaluation system of shear wave excitation effect is constructed,which takes the motion intensity and downward energy of particles in Z direction as the evaluation index,and the evaluation and analysis of the effect of vibrator excitation shear wave are carried out.The comprehensive results show that the geodetic particles excited by tetrahedral tooth plate have the highest Z direction motion intensity and the highest downward energy,and the tetrahedral tooth plate has better excitation effect.(4)Based on the established evaluation system of shear wave excitation effect,the analysis and research of full size flat plate shear wave excitation effect are carried out.According to the simulated displacement cloud picture and chart data,the structural optimization scheme of plate and tooth is put forward.1)the size design of the outermost tooth is a little smaller than that of the middle row of teeth,which makes the force of each tooth more uniform and improves the service life of the flat tooth.2)in order to alleviate the energy loss and harmonic interference caused by the vortex field in the original plate spacing,the tooth arrangement design is carried out by combining the four plates into a whole plate,which is beneficial to the reduction of energy loss and harmonic interference caused by the vortex field.