Study on coupling performance of tail vertebra-earth sweep frequency vibration of oil and gas exploration geophone

As the key equipment for collecting signals, the coupling performance of oil and gas exploration geophone and earth vibration affects the quality of collected signals and determines the exploration accuracy. In order to improve the exploration ability of the geophone, the structure of the tail vertebra of the geophone was taken as the research object. Based on the single-degree-of-freedom coupling vibration theory, a vibration model for the coupling of the tail vertebra of the geophone and the earth surface under the sweep frequency signal was proposed. The acceleration,velocity and displacement response of the received signal of the tail vertebra of the geophone under the sweep frequency were extracted and analyzed. The coupling degree evaluation index of the mean value of vibration displacement and the standard deviation of vibration acceleration was established, and the coupling degree response of the tail vertebra of the geophone and the earth was mastered. Through the geophone receiving test, the maximum error between the acceleration signal received by the geophone tail vertebra and the acceleration signal received by the test was less than 15%, which verified the correctness of the model and method. Finally, based on the response surface method, the key parameters of the length and radius of the tail vertebra under different shapes were optimized. The results show that the coupling degree of the tail vertebra under the triangular pyramid shape is the best. The coupling mean value of the displacement of the optimized ground-geophone tail vertebra is reduced by 7.94%, and the standard deviation of the acceleration is reduced by 6.42%, which effectively improve the ability of the geophone tail vertebra to receive signals.