Research On Active Vibration Isolation Technology Of Vibroseis Model

Vibroseis is one of the important equipment which is widely used in exploration of oil and gas field.Compared with traditional seismic source,substantial progress has been made in improved exploration accuracy,lowered operation cost,environmental protection etc.The vibration isolation part of vibroseis is passive vibration isolation system which is usually constituted by parallel connection of air springs.It is used for isolating the vibrating disturbance generated by engine and hydraulic system.Influenced by its own structure and operating characteristic of vibroseis,when the energizing signal is at medium-high frequency,the isolation efficiency of the passive vibration isolation system is yet able to meet the need of exploration.However,when the energizing signal is at low-frequency(less than 6Hz),passive vibration isolation system shall be impacted by factors like its own frequency,which makes it difficult to achieve effective isolation interference and then affect the final quality of exploration operation.Since low-frequency signal has the biggest advantage of strong penetrating power over the stratum once applied to the exploration of oil and gas field,to make use of this advantage,it is of crying need to design a combined vibration isolation system involving correlated active&passive vibration isolation that is applied to vibroseis,so as to effectively reduce the vibrating disturbance caused by signals of each frequency,especially the vibrating disturbance caused by low-frequency signals,and further enhance the seismic exploration quality of vibroseis.To achieve the said target,this paper accomplishes the following work:First,based on the important technical parameters of KZ-28 vibroseis,it analyzes the vibration performance of the vibroseis with detail and builds the mathematic model of KZ-28 vibroseis via a series of theoretical calculation.It confirms the respective working frequency range of passive vibration isolation&active vibration isolation involved in the combined vibration isolation system studied by this paper and conducts the preliminary design of experimental model.Second,on the ground of the preliminary research results,it sets up the passive vibration isolation&active vibration isolation simulation model of the KZ-28 vibroseis in the development environment of Lab VIEW 2013 by using the control design and simulation module package and confirms the classical PID controller is used for the algorithm of active vibration isolation.The simulation results have verified the feasibility of the combined vibration isolation system designed by this paper and have verified that theoretical calculation done in the earlier stage is accurate.Third,to make it easy to conduct further research in the Lab,and verify the rationalization of the simulation results,it sets about designing and machining the physical model that basically conforms to features of KZ-28 vibroseis and confirming links of excitation signal generation,vibration signal acquisition,control signal output and execution etc.The experiment platform was established based on the above-mentioned links and development of all software was done in Lab VIEW 2013.Fourth,we did a series of shock excitation and vibration experiments on the experimental model,recorded and compared the experimental data and all has achieved desired efficiency of vibration isolation.The experimental result shows that the combined vibration isolation system designed can meet the vibration isolation need of KZ-28 vibroseis.Fifth,it raises the hypothesis of forming semi-active vibration isolation based on negative stiffness spring and eddy current damper.The preliminary design of semi-active vibration isolation system based on KZ-28 vibroseis is completed via theoretical calculation.The vibration isolation simulation is done in Lab VIEW,the specific feasibility is subject to further demonstration.