【作者】 宋传星；

【导师】 宋延杰； 黄宝华；

【作者基本信息】 大庆石油学院 ， 地球探测与信息技术， 2005， 硕士

【摘要】 随着油气勘探和开发程度逐渐入深,迫切需要解决薄层划分和厚层细分问题,重新评价老井测井资料,寻找漏失掉的油气层。因此,有必要进行测井曲线的高分辨率处理,以提高薄层解释精度。交叉偶极子阵列声波测井是目前各油田已推广使用的测井项目,现有的处理方法追求时差计算的精度,忽视了时差的纵向分辨率。另外,目前常规声波时差曲线的高分辨率处理方法虽然取得了一定的实际效果,但其建模困难,实际应用效果还不十分令人满意。本文针对目前声波测井高分辨率处理中的实际情况,基于地球物理方法学和数字信号处理学理论,提出了最大熵与互功率谱相位法结合多炮点的处理方法。最大熵与互功率谱相位法就是首先求出组分波的波至点。对于偶极波形采用波形长短时窗能量比值与波形信号能量包络的平方乘积检测横波波至。用相关对比法粗略求取两个接收器时差,然后用最大熵谱估计法求出远近波形的主频值,取其二者均值作为该组分波的主频,用互功率谱法求得相位差做剩余时差校正,从而获得最短子阵列(0.152 米)时差值。最后,将跨同一深度地层的所有最短共发射子阵列和共接收子阵列时差值平均,获得最终高分辨率处理声波时差值。应用该方法处理大庆地区实际测井资料,并将其处理的结果与eXpress 系统处理的结果对比,表明该方法具有较高的纵向分辨率,同时也保证了时差的计算精度。更多还原

【Abstract】 With the gradual development of exploration and exploitation for oil and gas, it is pressing solving the problem of distinguishing thin bed, reevaluating old well logs and seeking neglected oil beds. Therefore, well log must be high resolution processed so as to enhance the accuracy of evaluating thin bed. Cross-dipole array acoustic logging has been applied widely by oil fields at present. Existing array waveforms processing techniques pursue accuracy of each wave component’s slowness calculated, while neglect its vertical resolution. In addition, Since it is difficult to build model, the applied effect of existing high resolution processing methods for conventional sonic log is not completely satisfactory though it has acquired some effects. Based on the theory of geophysics and digital signals processing, the high resolution processing method of maximum entropy and cross power spectrum phase combined with multiple-shot method has been presented for the wavesonic well logging. The arrival of components must been picked for the method of maximum entropy and cross power spectrum phase. For the dipole waveform, it calculates the product of multiplying energy ratio between the long window and the short window by the square of the amplitude envelope of waveforms to pick the S-Wave arrival. First, it calculates the slowness between the near recerver and the far recerver by using of the STC method. Then, it calculates the main frequencies of the near waveform and the far waveform by using of the maxium entropy method, and regards the average the main frequencies of the near waveform and the far waveform as the main frequency of the component, and using the surplus phase processed by use of cross power spectrum phase method compensates the slowness calculated by using of the STC method, also obtains the slowness of the shortest subarrays (0.152m). At last, it averages all the slowness of the same depth interval formation spanned by the shortest common-source subarrays and common-receiver subarrays and obtains the higher resolution slowness Apply the technique to array acoustic logging data in Daqing Oil Field, and compare its results with the results precessed by express. It shows that the method has the higher resolution, also ensures the accuracy of the slowness.更多还原