基于对比折射法的三维静校正技术及其应用

在地形起伏剧烈、速度和厚度横向变化大的地区，折射静校正技术的应用受到诸多限制，主要表现在不能准确地识别和拾取来自于地下连续地质界面的折射波，使得精确求取的长波长静校正量困难。为此，提出了一种基于对比折射法的三维静校正技术。介绍了这种静校正技术的方法原理和特点，基于对比折射法的折射波至拾取实质上是一个折射层的对比分析解释过程，因此能准确地拾取折射波至，精确地求解低速带的绝对延迟时；然后利用延迟时和近地表速度模型（等效，时深，空变）反演表层模型，最终一次性完成基准面静校正（包含低速带校正和高程校正）。在黄土塬、沙漠以及沙漠和山地的接合部等地区，利用基于对比折射法的三维静校正技术进行静校正处理，使资料的品质得到了明显改善，反射同相轴连续性好，信噪比和分辨率高，构造形态清晰可靠，提高了勘探精度。

Application of 3-D static correction technology based on correlation refractionmethod.

Since it is unreliable to identify and pick refraction wave from underground continuous layers in those areas with drastic variation of topography as well as lateral variation of velocity and thickness, refraction static correction technology is limited in calculating static correction value of long wavelength with high precision. A 3-D static correction technology based on Correlation Refraction Method is proposed to pick first break and calculate absolute delay time precisely, eventually refraction static correction is performed by delay time and near-surface model. Result from real data processing shows that this approach can substantially improve the quality of seismic stack sections in areas with complex near surface conditions such as loess table land, desert and the commissure between desert and mountainous region.