宽频立体枪阵优化设计

Optimization design of the broadband stereo gun array

在海洋油气勘探这一过程中,震源设计是关键环节,其性能的优劣直接影响采集信号的质量。气枪以其质量可靠、组合灵活、安全环保等优势成为海洋勘探领域应用最广泛的激发震源,然而,随着勘探环境的复杂化,平面阵列的激发子波难以满足高分辨率勘探需求。因此,在立体阵列的基础上,分析不同容量气枪子波信号与时间关系,通过优化沉放深度,使不同容量单枪激发产生的振幅在接收时同相叠加,达到拓宽频带和压制陷波效应,进而改进震源的性能。将优化的立体阵列与常规阵列进行属性对比,证明宽频立体气枪阵列拥有更强的振幅能量和更宽的有效频带,可明显压制陷波效应,对复杂地质目标有较好的识别效果。

In offshore oil and gas exploration,seismic source design is the key to ensure good pickup of signals,for which air gun has become the most widely used excitation source in marine exploration due to its reliable quality,flexible combination,safety,and environmental protection.However,with the complexity of exploration environment,conventional excited wavelet of planar array is no longer to satisfy high-resolution exploration.Therefore,based on the stereoscopic array,we analyzed the relationship between wavelet signals and time of gas guns with different capacities.By optimizing the sinking depth,the amplitudes generated by the excitation of single gun with different capacities are superimposed in the same phase during receiving to broaden the frequency band and suppress the notch effect and improve the seismic source performance.By comparing the properties of the optimized stereoscopic array with the conventional array,it was proved that the broadband stereo air gun array had stronger amplitude energy and wider effective frequency band,which could suppress the notch effect obviously,and achieved better recognition results at complex geological targets.