广义S域Q值估计方法及其在油气检测中的应用

发布时间：2018-08-03 17:41

【摘要】：时—频分析方法的实质是加窗傅里叶变换,即地震数据与窗函数相乘后再进行傅里叶变换。因此,在时—频谱上包含了窗函数的频率响应,对子波傅里叶谱造成了污染,使经典谱比法中对数谱比与频率之间表现为非线性关系。为此,推导了新的广义S域谱比法Q值估计公式,该公式中对数谱比与一个新定义的参数γ为线性关系,该参数中包含了控制窗口形态的参数λ和p,计算过程中利用对数谱比值与参数γ进行线性拟合,拟合直线斜率值的倒数即为Q值。合成数据试算及实际数据处理结果表明:(1)广义S域时—频瞬时振幅谱与传统傅里叶谱存在一定差异,由于高斯窗函数在高频端振幅强,造成瞬时振幅谱在高频端发生畸变;(2)利用广义S域时—频瞬时振幅谱计算的对数谱比与频率之间为明显的非线性关系,与经典Futterman衰减机制不符,而对数谱比与定义的参数γ之间具有良好的线性关系;(3)利用本文方法对南海某盆地生物礁储层的含油气异常进行了检测,Q值低异常指示了含油储层的存在。
[Abstract]:The essence of the time-frequency analysis method is the windowed Fourier transform, that is, the Fourier transform is carried out after the seismic data is multiplied with the window function. Therefore, the frequency response of the window function is included in the time-frequency spectrum, which pollutes the wavelet Fourier spectrum and makes the logarithmic spectral ratio and frequency in the classical spectral ratio method appear to be nonlinear. For this reason, a new formula for estimating the Q value of the generalized S-domain spectral ratio method is derived, in which the logarithmic spectral ratio is linearly related to a newly defined parameter 纬. The parameters 位 and p of controlling window shape are included in this parameter. The logarithmic spectrum ratio and parameter 纬 are used for linear fitting in the process of calculation, and the reciprocal value of the fitted straight line slope is Q value. The experimental results of synthetic data and actual data processing show that: (1) the time-frequency instantaneous amplitude spectrum in generalized S domain is different from the traditional Fourier spectrum, because of the strong amplitude of Gao Si window function at the high frequency end. The instantaneous amplitude spectrum is distorted at the high frequency end. (2) the logarithmic spectrum ratio calculated by the generalized S-domain instantaneous amplitude spectrum is obviously nonlinear to the frequency, which is inconsistent with the classical Futterman attenuation mechanism. There is a good linear relationship between logarithmic spectrum ratio and defined parameter 纬. (3) the low Q value anomaly of oil and gas in a reef reservoir in a basin in the South China Sea is detected by using this method which indicates the existence of oil-bearing reservoir.
【作者单位】：中国石油大学(北京)非常规天然气研究院;油气资源与探测国家重点实验室(中国石油大学(北京));油气藏地质及开发工程国家重点实验室(成都理工大学);中国石油华北油田分公司第一采油厂;
【基金】：国家自然科学基金项目(41674139)资助
【分类号】：P618.13;P631.4

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