JpGU-AGU Joint Meeting 2017

Presentation information

[EJ] Oral

S (Solid Earth Sciences) » S-SS Seismology

[S-SS11] [EJ] Seismic wave propagation: Theory and Application

Thu. May 25, 2017 1:45 PM - 3:15 PM A08 (Tokyo Bay Makuhari Hall)

convener:Kiwamu Nishida(Earthquake Research Institute, University of Tokyo), Hisashi Nakahara(Solid Earth Physics Laboratory, Department of Geophysics, Graduate School of Science, Tohoku University), Kazuya Shiraishi(Japan Agency for Marine-Earth Science and Technology), Jun Matsushima(School of Engineering, The University of Tokyo), Chairperson:Kazuya Shiraishi(Japan Agency for Marine-Earth Science and Technology), Chairperson:Nori Nakata(University of Oklahoma)

2:30 PM - 2:45 PM

[SSS11-15] Application of full waveform inversion and pre-stack imaging to 2D land seismic data in a complex terrain

*Takao Nibe1, Shogo Masaya2, Susumu Abe3, Shinji Matsuura2, Hiroshi Sato4, Tatsuya Ishiyama4 (1.JGI, Inc., 2.INPEX, 3.JAPEX, 4.ERI)

Keywords:Full Waveform Inversion, Velocity estimation, Reflection seismic exploration

Imaging deep structures using land data acquired in complex terrains of Japan often faces problems such as irregularity of topography and variable shallow structures, variation of reflection points caused by crooked-line geometry, irregular shot interval and low signal to noise ratio. Recently, acquisition of long-offset high density data using combination of cable and cable-free systems in complex terrain is standardized in domestic land acquisition. First Arrival Travel-Time Tomography is applied to such data to estimate subsurface velocity structure where conventional velocity analysis is difficult because of the above mentioned problems.

Although Tomography is able to estimate velocity structure accurately, limited resolution is one of the problems in this method. Full Waveform Inversion (FWI) is a method to estimate high resolution velocity structures compared to tomography since the method uses more information in the inversion process where tomography uses only first arrival time. Recently, a lot of applications are reported widely.

We tried FWI on 2D land data acquired in Japan. First, a synthetic study was done using a similar situation of domestic land data including different source wavelets, irregular sampling, etc. Next, the real data case study is done. We finally applied Pre-stack Depth Migration using FWI result as input and verified their capability of imaging deep structures in the complex terrain.