Research On Optimization Design Method Of Three-dimensional Delay Air Gun Array

With the continuous development of China's economic construction and industrial level,our demand for oil is increasing.However The extraction of onshore oil resources has stabilized and it is no longer possible to increase the extraction volume significantly.Therefore,exploration and development of offshore oil and gas resources has become China's strategic development direction.Marine oil and gas exploration mainly uses seismic exploration methods,and the source selection is mainly using air gun source.There are many types of air guns and design methods for air gun seismic sources.Different air gun arrays need to be designed for different sea areas,so that the seismic signal quality used for exploration is the best.Because a single air gun seismic source has serious defects in actual production,the air gun array has been generally selected for signal excitation.This paper selects four air gun types of Bolt gun and G gun,and compares and analyzes through single air gun simulation and air gun array simulation.The main purpose is to obtain a stereo delay air gun array that can effectively suppress the virtual reflection.The main research contents include the following:(1)When performing single air gun simulation,set the same excitation parameters,including working pressure,capacity,seawater temperature,etc.By comparing the far-field wavelet and spectrogram of a single air gun,the characteristics,differences,advantages and disadvantages of the four gun types are analyzed.(2)In the process of planar air gun array simulation,set the same number of air guns,placement method,air gun capacity,working pressure and other parameters,The planar air gun array simulation is mainly used as a reference experiment for comparison with the stereo.(3)Three-dimensional delay air gun array simulation.The planar array cannot effectively suppress the virtual reflection,so it is necessary to design a three-dimensional delay air gun array.The three-dimensional delay air gun array mainly uses two hanging methods of side hanging type and rear drag type.In the simulation of the side-hanging type,the entire air gun array is divided into four sub-arrays.Through different combinations of two pairs,six combinations are obtained,and the sub-array sinking depth of each combination is changed,so that different depth differences appear between the sub-arrays,and different simulation results appear.In the process of researching the trailing air gun array,it is divided into four combinations: ladder type,stairs type,inverted ladder type and interlaced type.By changing the depth of sub-array sinking,different simulation experiment results are obtained,the spectrum charts between the four combinations are compared,the advantages and disadvantages are analyzed,and the optimal solution is finally selected.This paper designs a large number of different stereo delay air gun arrays,and conducts a large number of simulation experiments.Through simulation experiment analysis and comparative analysis between the arrays,the three-dimensional delay air gun arrays required in actual production are selected.This kind of simulation experiment can select the specific sea area quickly and accurately,and the optimal solution of the air gun array required for different production tasks.