Research On The Mechanism And Suppression Of Vibrator Disturbance Caused By Heavy Hammer Oil

Extending the exploration of oil and gas is the inevitable way to face the challenge of resource shortage in China.With the development of oil and gas exploration.the equipment for exploring has entered a stage of precision.With the advantages of controllable excitation,high efficiency,safety and environmental protection,vibroseis has been widely applied to explore oil and gas.However,the signal distortion coming from the vibrator disturbance hinders the vibroseis exploration toward high precision and quality.Through analyzing the vibrator,it is found that the reaction mass passageway is a main reason of the vibrator disturbance.At present,there are few reports about the research on the vibrator disturbance,let alone the passageway on the vibrator disturbance generating.The flied tests show that the passageway is a key factor to improve the quality of vibrator excitation signal,promote the performance of vibroseis exploration,and realize the precise exploration.Based on the above background,study on generating mechanism and measures of suppressing vibrator disturbance is carried out.The main contents and conclusions of this paper are as follows:(1)The cause of vibrator disturbance was carried out.The force analysis of reaction mass shows that because the reaction mass is subject to the radial force of piston and the deflecting moment of reaction mass in horizontal direction,the movement trajectory of reaction mass changes from a vertical line to a curve,which leads to the vibrator disturbance.(2)Generating mechanism of the reaction mass passageway on the vibrator disturbance was studied.Results indicate that,in the reaction mass passageway,the horizontal deformation of piston and rotating of the reaction mass around piston form the horizontal interferences due to the radial force of piston,the circumferential hydraulic pressure of upper and lower cavities and the deflecting moment of reaction mass.At the same time,the horizontal interferences influence the vertical movement of reaction mass,which causes the movement of reaction mass deviating from its theoretic moving trajectory and leads to vibrator disturbance.(3)To solve the problem of the reaction mass passageway causing the vibrator disturbance,the piston passageway for suppressing the vibrator disturbance was researched by improvement of the structure of the vibrator and adoption of the piston oil passageway.Results demonstrate that,because there are no the radial force of piston and the deflecting moment of reaction mass,the deformation of the piston is obviously reduced and the reaction mass is no longer deflected with piston passageway.New structure suppresses the horizontal interferences effectively,reduces the interference of the reaction mass vertical movement greatly.And the movement of reaction mass is closed to its theoretic moving trajectory,thus the vibrator disturbance is improved obviously.(4)The vibrator disturbance with different piton passageway angle was compared and analyzed.Results show that with the increasing of passageway angel the piston deformation first increases,then decreases.And the 0° passageway piston deformation is minimal.The research provides the basis for the further improvement of piston passageway.(5)Experiments of vibrator disturbance with different passageways were conducted.The vibrator disturbance was analyzed according to the curve of reaction mass disturbance.Experimental results show that the disturbance of the reaction mass at x and y directions is large with the passageway inside the reaction mass,which means the reaction mass is subjected to the horizontal interferences,while the x and y direction disturbance of the reaction mass reduces by 73.943%and 54.232%respectively after using the piston passageway.The motion of the reaction mass subjecting to the horizontal interference is suppressed and the vibrator disturbance decreases with piston passageway.