关键词: 各向异性, 非均质介质, 正常时差, 校正

Abstract: Velocity anisotropy can be widely seen in low-relief structures and carbonate fractures of Tarim basin. It is difficult for both conventional normal moveout (NMO) and multi-term Taylor series expansion to eliminate nonhyperbolic traveltime caused by anisotropy, which will affect following stack imaging and research of reservoir rocks. Compared with NMO based on assumption of isotropy, the technique of higher-order traveltime correction based on theory of anisotropy is more approximate to the real formation media. By using this technique, a methos for velocity analysis in anisotropic media is proposed, and a typical seismic procession flow for anisotropic parameter ηis given. The study shows that the technique of higher-order traveltime correction combined with NMO can solve efficiently the problem of velocity anisotropy and meet the need of accurate imaging in low-relief structures.

Key words: anisotropy, heterogeneous media, normal moveout (NMO), correction