本文選題：TTI介質 + 各向異性　； 參考：《地球物理學報》2016年03期

【摘要】：各向異性研究對地下介質精確成像有著重要的意義,在當前計算機硬件迅速發(fā)展及寬方位地震數(shù)據(jù)采集日益普遍的情況下,成像必須考慮介質的各向異性.逆時偏移是基于雙程波動方程的較為精確的數(shù)值解的成像方法,所以相對于其他地震成像方法,它具有很大的優(yōu)勢,譬如不受反射界面的傾角限制、偏移速度結構合適時能夠使回轉波及多次波正確成像.在各向同性介質中,可使用標量波方程來模擬波場.而在各向異性介質中,P波和SV波是相互耦合的,即不存在單純的標量波傳播,通常利用能代表耦合波場中P波分量運動學特征的擬聲波(qP波)進行偏移成像.本文中,我們推導出了TTI介質下qP波控制方程.該方程可采用顯式有限差分格式進行求解.通過聲學近似,若沿對稱軸方向的剪切波速度為零,對于對稱軸方向不變且ε≥δ的模型來說,可得到穩(wěn)定的數(shù)值解.但對于TTI介質來說,由于沿對稱軸方向各向異性參數(shù)是變化的,聲學近似會引起波場傳播及數(shù)值計算的不穩(wěn)定.因此,我們提出了正則化有限橫波的方法,很好地解決了這一問題.最后,給出了Foothill模型的測試結果及某探區(qū)實際資料試算結果,展示了采用這個方程進行復雜TTI模型正演和高質量逆時偏移成像結果,證實了該方法的正確性和實際資料應用中的有效性.
[Abstract]:The study of anisotropy plays an important role in accurate imaging of underground media. With the rapid development of computer hardware and the increasing popularity of seismic data acquisition in wide azimuth, anisotropy of medium must be considered in imaging. Inverse time migration is an imaging method based on a more accurate numerical solution of two-way wave equation, so it has great advantages over other seismic imaging methods, for example, it is not restricted by the dip angle of the reflection interface. When the migration velocity structure is suitable, the rotation and multiple waves can be correctly imaged. Scalar wave equation can be used to simulate the wave field in isotropic media. However, in anisotropic media, the P wave and SV wave are coupled, that is, there is no simple scalar wave propagation, and usually the pseudo acoustic wave QP, which can represent the kinematic characteristics of the P wave component in the coupled wave field, is used for migration imaging. In this paper, we derive the QP wave control equation in TTI medium. The equation can be solved by explicit finite difference scheme. By acoustic approximation, if the velocity of shear wave along the symmetry axis is zero, the stable numerical solution can be obtained for the model with constant symmetry axis and 蔚 鈮，

本文編號：1848188