Acoustic Characteristic Research On Towed Solid Fiber Streamer

Towed seismic detection is an important method for submarine geological exploration,which can flexibly and efficiently detect large scale seabed structure,oil and gas storage,and submarine mineral distribution.When the arrays are towed in the sea,it will be affected by the ship vibration and current fluctuation.The received signal quality will be reduced and the system noise will be decreased.Thus the vibration will reduce the depth and precision of the towed exploration system.Optimize the structure and filling properties of the detection array can effectively inhibit the system noise.In this paper,the acoustic propagation performance and vibration transmissibility of towed array are studied.The sample streamers are filled with oil,gel and solid polyurethane.This is of great significance to the noise and vibration reduction of the detection array.The main points and the innovation of the paper are as followed.(1)The dynamic model of towed detection streamer section is established by using COMSOL,a nd the acoustic characteristics and vibration characteristics of the streamer are simulated and analyzed.In the uniform pressure field,the more Young's modulus and Poisson's ratio of material,the better the transmission performance.For the axial and transverse vibrations,the response of the detector to the cable vibration increases with the increase of Young's modulus and Poisson's ratio of the filling material.(2)The streamers with different filling materials were fabricated,and the acoustic response and vibration response characteristics of the solid and liquid streamers were tested.The test results show that the solid state detection streamer has a certain sound attenuation of acoustic signal,attenuation increases with the increasing of the thickness.The liquid detection streamer attenuation is relatively small.The vibration response of the solid streamer is bigger than liquid streamer,consistent with the theoretical analysis.(3)The acoustic characteristics of the different filling materials are compared.The acoustic propagation and vibration reducing performance of the detection streamer increased with the decrease of thickness.This peculiarity can be used as reference for selection of fixed array.