Analysis of factors affecting the performance of air gun source under shallow water conditions: Insights from the non-ideal gas air gun wavelet model

Abstract

Optimized design of high-resolution air gun sources is crucial with the exploration of oil and gas resources moving toward the middle-deep reservoir in the Bohai Sea. To this end, the absorption and attenuation law of seismic waves in the stratum of the Bohai Sea was analyzed. It was clarified that expanding the low frequency based on retaining the high frequency was the focus of optimized design of air gun array. Then the air gun wavelets in the shallow sea environment were simulated based on the non-ideal gas air gun wavelet model. The emphasis is put on several key aspects: the influence law of array sinking depth, towed-streamer sinking depth, single air gun spacing, subarray spacing, and air gun volume on the performance of wavelets. Finally, array parameters for shallow sea environments were optimized based on simulation results. The resulting optimized array wavelet in this work is able to provide significant improvements in energy, spectrum quality, and directional response. Moreover, the imaging effect of the acquired data can be improved to a large degree using the optimized array wavelet, which indicates that an optimized array with the consideration of multiple factors is more suitable for the exploration of the middle-deep reservoir.