本文選題：TTI介質(zhì) + 各向異性　； 參考：《地球物理學(xué)報(bào)》2016年03期

【摘要】：各向異性研究對(duì)地下介質(zhì)精確成像有著重要的意義,在當(dāng)前計(jì)算機(jī)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(zhì)的各向異性.逆時(shí)偏移是基于雙程波動(dòng)方程的較為精確的數(shù)值解的成像方法,所以相對(duì)于其他地震成像方法,它具有很大的優(yōu)勢(shì),譬如不受反射界面的傾角限制、偏移速度結(jié)構(gòu)合適時(shí)能夠使回轉(zhuǎn)波及多次波正確成像.在各向同性介質(zhì)中,可使用標(biāo)量波方程來(lái)模擬波場(chǎng).而在各向異性介質(zhì)中,P波和SV波是相互耦合的,即不存在單純的標(biāo)量波傳播,通常利用能代表耦合波場(chǎng)中P波分量運(yùn)動(dòng)學(xué)特征的擬聲波(qP波)進(jìn)行偏移成像.本文中,我們推導(dǎo)出了TTI介質(zhì)下qP波控制方程.該方程可采用顯式有限差分格式進(jìn)行求解.通過(guò)聲學(xué)近似,若沿對(duì)稱軸方向的剪切波速度為零,對(duì)于對(duì)稱軸方向不變且ε≥δ的模型來(lái)說(shuō),可得到穩(wěn)定的數(shù)值解.但對(duì)于TTI介質(zhì)來(lái)說(shuō),由于沿對(duì)稱軸方向各向異性參數(shù)是變化的,聲學(xué)近似會(huì)引起波場(chǎng)傳播及數(shù)值計(jì)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(wèn)題.最后,給出了Foothill模型的測(cè)試結(jié)果及某探區(qū)實(shí)際資料試算結(jié)果,展示了采用這個(gè)方程進(jìn)行復(fù)雜TTI模型正演和高質(zhì)量逆時(shí)偏移成像結(jié)果,證實(shí)了該方法的正確性和實(shí)際資料應(yīng)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(hào)：1848188