Design And Noise Control For Portable Vibroseis System

Shale gas is a kind of unconventional and clean energy,which is an important supplement to our country's natural gas energy.The southern marine shale gas is the focus of China's shale gas exploration.The actual situation of the deep burial,complex formation information,the undulating surface and vegetation cover demands a specific exploration technology to improve the efficiency of shale gas exploration.Based on the analysis of the present situation of the shale gas exploration method,and in view of the characteristics of the southern marine shale gas exploration in China,a portable vibroseis system is put forward and designed in detail,as well as the noise control method is studied.The main conclusions are as follows:(1)A portable vibroseis system is proposed,on the base of fully analysis of the KZ hydraulic vibroseis and the characteristics of the southern marine shale gas exploration.The vibroseis system is designed in modules instead of the integrated structure.The three main modules include vehicle,vibrator,and control system.In this case,the design of vehicle is carried out by refitting of forklift;the structure of the vibrator is optimized by changing the position of the hydraulic oil channels.(2)The structure of the vehicle and its typical piston vibrator is optimized,according to the design scheme.The 3D model of the vehicle,vibrator and their critical parts are established.Finally,the fork and the baseplate are analyzed by ANSYS workbench to verify the reliability of the system.(3)For the noise problem in the vibroseis exploration,noise control study was carried out from the structure of the vibrator and the data processing.The structure of typical piston vibrator is studied and the mechanism of noise is analyzed.The output force of typical vibrator and improved vibrator are compared by SimulationX vibration experiment,and the results verify that the noise is reduced.In addition,the wavelet threshold algorithm is improved.Finally,the optimal parameters of the algorithm are obtained through the simulation experiment of the Heavy sine signal,and then applied to the synthetic seismogram and the actual seismic data denoising to verify the denoising effect of the improved algorithm.