三维反射纵波旅行时检测裂隙

Fracture detection using the travel time of 3-D reflected compressional wave

本文从垂直走向裂隙地面纵波反射旅行时的方位差别出发，推导出了利用多条任意方位测线计算裂隙走向的方法，并证明了一般情况下裂隙介质都有2ε-δ＞0，从而确定反演出的裂隙走向值是唯一的。裂隙介质模型的两组正交测线和四条互不正文测线反射纵波旅行时的反演结果验证了本文方法的正确性。

In view of the fact that the travel time of reflected compressional wave passing through vertical fracture medium varys azimuthally, a new method is developed which derives fracture strike from the compressional wave data of some seismic lines having different azimuths. In general circumstances, fracture medium has expression 2ε--δ＞0, so that fracture strike estimated by inversion is an unique solution. Correctness of this method has been proved by the inversion results of travel times of reflected compressional waves in both two group of orthogonal seismic lines and four oblique seismic lines of a fracture medium model.