The estimation of elastic properties of thin-bed formations from sonic logging is challenging. Standard slowness processing of sonic logging waveforms typically yields an average slowness log profile over the span of the receiver array, obscuring thin-layer features smaller than the array aperture. In order to enhance vertical resolution of the slowness logs, the subarray processing techniques have been developed. However, for the subarrays with smaller aperture, the semblance from subarray waveforms becomes susceptible to noise, which results in a low signal-to-noise (S/N) ratio for the processing slowness logs. To overcome the above drawbacks, we propose a slowness estimation method with the enhanced resolution ranging from the conventional array aperture resolution to the inter-receiver spacing based on the reconstruction of neighboring virtual traces (RNVTs). The method utilizes super-virtual interferometry to reconstruct a large number of waveforms for slowness extraction using redundant information from overlapping receiver subarrays. We validate the feasibility and effectiveness of the proposed method using synthetic numerical experiments. By adding different levels of noise to synthetic data, we conclude that the new method has better noise robustness. Finally, we apply this method to field data, and the estimated high-resolution slowness logs show good agreement in interbedded sand-shale sequences. Both numerical tests and examples of field data show that, the slowness logs estimated by the new method can be obtained with a high resolution as well as with a high S/N ratio, providing an effective method for assessing slowness properties from a borehole.

通过声波测井估计薄层地层的弹性特性具有挑战性。声波测井波形的标准慢度处理通常会在接收器阵列的跨度上产生平均慢度测井剖面，从而模糊小于阵列孔径的薄层特征。为了提高慢度测井的垂直分辨率，开发了子阵处理技术。然而，对于孔径较小的子阵列，子阵列波形的相似性变得容易受到噪声的影响，这导致处理慢度日志的信噪比较低。为了克服上述缺点，我们提出了一种慢度估计方法，其分辨率范围从传统的阵列孔径分辨率到基于相邻虚拟迹线（RNVT）重建的接收器间距。该方法利用超虚拟干涉测量法来重建大量波形，以使用来自重叠接收器子阵列的冗余信息来提取慢度。我们通过综合数值实验验证了所提出方法的可行性和有效性。通过向合成数据添加不同级别的噪声，我们得出结论，新方法具有更好的噪声鲁棒性。最后，我们将该方法应用于现场数据，估计的高分辨率慢度测井在互层砂页岩序列中表现出良好的一致性。数值试验和现场数据实例表明，新方法估算的慢度测井可以获得高分辨率、高信噪比，为评估钻孔慢度特性提供了一种有效方法。