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提高地震资料的分辨率是地震数据处理流程中的重要环节,对后续的精细构造解释起到重要作用。传统的提高分辨率方法大都假设地震资料是稳态的并且噪声水平不随空间发生变化,而实际情况不满足这一假设,导致提高分辨率处理后的效果达不到预期要求。针对这一问题,本文提出了一种基于时频二次谱的提高地震资料分辨率方法。首先,文中提出了基于S变换的时频二次谱,并结合模型论述了时变子波和反射系数在时频二次谱中的特征及其可分离性;其次,依据时变子波和反射系数在时频二次谱中的特征差异,构建了二维滤波器在地震记录的时频二次谱中提取时变子波的振幅谱;再次,文中研究了噪声环境中时变提高分辨率算子设计方法,并提出了依据时频谱能量强弱相对关系自适应确定频带拓宽范围的时变提高分辨率算子设计,进行提高分辨率处理;最后,文中对该方法进行了模型和实际数据的试处理,并与传统谱模拟方法和Q补偿方法的处理结果进行了对比分析,对比结果表明:本方法不需要估计Q值,提高分辨率能力不受震源子波频带的限制,在兼顾信噪比的前提下能够充分提高不同时间局部的地震数据的分辨率。
Increasing the resolution of seismic data is an important part of the seismic data processing flow and plays an important role in the subsequent interpretation of fine structures. Most of the traditional methods for improving resolution assume that the seismic data is steady-state and the noise level does not change with space. However, the actual situation does not satisfy this assumption, which leads to the effect of improving the resolution not meeting the expectation. In response to this problem, this paper presents a method based on time-frequency quadratic spectrum to improve seismic data resolution. Firstly, the time-frequency quadratic spectrum based on S transform is proposed in this paper, and the characteristics and separability of time-varying wavelets and reflection coefficients in time-frequency quadratic spectrum are discussed. Secondly, The characteristic difference of the reflection coefficient in the time-frequency quadratic spectrum was analyzed. A two-dimensional filter was constructed to extract the amplitude spectrum of the time-varying wavelet in the time-frequency quadratic spectrum of the seismic record. Thirdly, Rate operator design method is proposed and the design of time-varying resolution enhancing operator which can adaptively determine the broadening range of frequency band based on the relative relationship between the strength and weakness of time-frequency spectrum energy is proposed to improve the resolution. Finally, the paper makes a detailed analysis of the model and the actual The experimental results show that this method does not need to estimate the Q value and the resolution ability is not limited by the frequency band of the source wavelet. Under the premise of signal-to-noise ratio, the resolution of local seismic data at different time can be improved sufficiently.