VTI介質(zhì)FFD疊前深度偏移成像方法
發(fā)布時(shí)間:2018-06-09 12:50
本文選題:各向異性VTI介質(zhì) + 頻散關(guān)系 ; 參考:《石油地球物理勘探》2017年03期
【摘要】:從波動(dòng)方程出發(fā),借助聲學(xué)近似假設(shè)得到VTI介質(zhì)中qP波的頻散關(guān)系方程并進(jìn)行有理化近似,推導(dǎo)出不同精度的FFD(Fourier finite-difference)波場(chǎng)延拓算子(由頻率—波數(shù)域的相移項(xiàng)、頻率—空間域的時(shí)移項(xiàng)及有限差分補(bǔ)償項(xiàng)三部分組成),基于互相關(guān)成像條件實(shí)現(xiàn)了VTI介質(zhì)FFD疊前深度偏移成像。該偏移方法具有單程波偏移的高效性,適用于介質(zhì)強(qiáng)橫向變速情形,且考慮了介質(zhì)各向異性對(duì)地震波傳播的影響。在實(shí)現(xiàn)上述算法的基礎(chǔ)上,通過誤差分析、脈沖響應(yīng)和SEG/EAGE巖丘模型成像測(cè)試驗(yàn)證了方法的有效性,其成像精度也比常規(guī)各向同性成像方法有明顯提高。
[Abstract]:Based on the wave equation and acoustic approximation assumption, the dispersion equation of QP wave in VTI medium is obtained and the physical and chemical approximation is carried out. The wave field continuation operator (FFDF Fourier finite-difference) operator with different precision is derived (from the phase shift term in frequency-wavenumber domain). The time-shift term and the finite-difference compensation term in frequency-space domain consist of three parts. Based on the cross-correlation imaging condition, the FFD prestack depth migration imaging of VTI medium is realized. This migration method has the high efficiency of one-way wave migration, and is suitable for the case of strong lateral velocity change in the medium, and the influence of anisotropy on seismic wave propagation is taken into account. On the basis of the above algorithm, the validity of the method is verified by error analysis, impulse response and SEG / Eage dome model imaging test, and its imaging accuracy is obviously improved compared with the conventional isotropic imaging method.
【作者單位】: 中國石油大學(xué)(華東)地球科學(xué)與技術(shù)學(xué)院地球物理系;
【基金】:國家“973”計(jì)劃課題(2014CB239006) 國家油氣重大專項(xiàng)(2016ZX05002-005-07HZ,2016ZX05014-001-008HZ) 國家自然基金課題(41274124)聯(lián)合資助
【分類號(hào)】:P631.4
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本文編號(hào):1999784
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