Viscoacoustic least-squares migration with a blockwise Hessian matrix: an effective Q approach

Song, Mingpeng1,2,3; Zhang, Jianfeng4; Zhang, Jiangjie1,2,3

2020-08

10.1093/jge/gxaa017

Journal of Geophysics and Engineering   影响因子和分区

1742-2132

We present an explicit inverse approach using a Hessian matrix for least-squares migration (LSM) with Q compensation. The scheme is developed by incorporating an effective Q-based solution of the viscoacoustic wave equation into a blockwise approximation to the Hessian in LSM, which is implemented after the so-called deabsorption prestack time migration (PSTM). The effective Q model used fully accounts for frequency-dependent traveltime and amplitude at the same imaging location. We can extract the effective Q parameters by scanning during previous deabsorption PSTM. This avoids the challenging task of building the Q model. The blockwise Hessian matrix approach decomposes the full Hessian matrix into a series of computationally tractable small-sized matrices using a localised approach. We derive the explicit formula of the offset-dependent Hessian matrix using an analytical Green's function obtained from deabsorption PSTM. In this way, we can approximate a reflectivity imaging for the targeted zone by a spatial deconvolution of the migrated result with an explicit inverse. The resulting scheme broadens the frequency-band of imaging by deabsorption, and improves the subsurface illumination and spatial resolution through the inverse Hessian. A high-resolution, true-amplitude migrated gather can then be obtained. Synthetic and field data sets demonstrate the proposed blockwise LS-QPSTM.

high-resolution imaging least-squares migration effective Q seismic attenuation Hessian matrix

SCI

英语

通讯

National Natural Science Foundation of China[41604120] ; National Major Project of China[2017ZX05008-007]

Geochemistry & Geophysics

Geochemistry & Geophysics

WOS:000591576700005

OXFORD UNIV PRESS

Web of Science

1.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Petr Resources Res, Beijing 100029, Peoples R China
2.Chinese Acad Sci, Innovat Acad Earth Sci, Beijing 100029, Peoples R China
3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China
4.Southern Univ Sci & Technol, Dept Earth & Space Sci, Shenzhen 518055, Peoples R China

Song, Mingpeng,Zhang, Jianfeng,Zhang, Jiangjie. Viscoacoustic least-squares migration with a blockwise Hessian matrix: an effective Q approach[J]. Journal of Geophysics and Engineering,2020,17(4):618-634.

Song, Mingpeng,Zhang, Jianfeng,&Zhang, Jiangjie.(2020).Viscoacoustic least-squares migration with a blockwise Hessian matrix: an effective Q approach.Journal of Geophysics and Engineering,17(4),618-634.

Song, Mingpeng,et al."Viscoacoustic least-squares migration with a blockwise Hessian matrix: an effective Q approach".Journal of Geophysics and Engineering 17.4(2020):618-634.