浅井高分辨率VSP技术

Shallow high-resolution VSP

本文详细讨论了浅井高分辨率VSP野外工作方法、室内资料处理方法以及资料效果分析。指出浅井高分辨率VSP与常规VSP相比具有许多特殊性，如选择小药量井炮激发比可控震源激发效果更好；管道波干扰对浅井VSP资料的影响极为严重，降低井中液面高度可有效地压制管道波等。提出了提高浅井高分辨率VSP资料的精度、分辨率以及信噪比的处理方法，获得的VSP资料主频可达140Hz，大大高于过井地面地震资料，这将对浅层高分辨地震资料的解释起重要作用，也为地面地震勘探提供了有益的经验。

Shallow high-resolution VSP is discusscd in detail on its field operation, in-house data processing and result analysis. Compared with conventional VSP, the shallow high-resolution VSP has some special properties, such as excitation with selected small charge is better than that using vibroseis, tube wave intcrferences are extremely serious to shallow VSP data but can be effetively suppressed by lowering liquid height in wells. A data processing method is presented here, which can increase accuracy, resolution and signal noise ratio of the shallow high-resolution VSP data. The obtained VSP data in this method have the main friquency of 140Hz, which is much higher than that of crosshole surfacc seismic data. This method is very useful to the interptetation of high-resolution shallow seismic data.