RESEARCH

研究兴趣 | Research Interests

以“岩石圈与含油气盆地地震成像”作为研究方向,结合地震学、地质学、岩石物理学理论以及人工智能(如深度学习)与大数据分析方法,考虑地球介质的弹性非均匀性、各向异性和地震频带内的衰减性质,聚焦主动源和被动源地震信号重构、偏移成像与波形反演新方法,提升对岩石圈、俯冲带、沉积盆地和油气储层的高分辨率探测能力。
My team focuses on seismic imaging of the lithosphere and petroleum basin using the theories and approaches of seismology, geology and rock physics. Taking into account elastic heterogeneity and anisotropy of the Earth’s media as well as intrinsic attenuation within seismic frequency-band; Taking the advantage of artificial intelligence (e.g., deep learning) approaches for characterizing the complex nonlinear systems, we make efforts for developing data reconstruction, imaging and waveform inversion techniques for active- and passive-source seismic data. The objectives include promoting the capability to characterize the lithosphere, subduction belts, sedimentary basin and petroleum reservoirs with high-resolution.

1)弹性体波模式分解及全波成像与反演应用 Elastic body-wave mode decomposition and its applications for full wave imaging and inversion

  • Novel description of wave propagation in anisotropic media
  • P/S separation of multicomponent seismograms on free-surface or at ocean bottom
  • Elastic body-wave mode decomposition in isotropic and anisotropic media
  • Mode decomposition-based (least-squares) elastic reverse time migration (E-RTM/E-LSRTM)
  • Mode decomposition-based elastic wave-equation migration velocity analysis (E-WEMVA)
  • Mode decomposition-based elastic full waveform inversion (E-FWI)
  • Mode decomposition-based elastic reflection waveform/traveltime inversion (E-RWI/E-RTI)
  • P/S separation of the multicomponent seismograms using deep learning
  • Seismic inverison based on deep learning

2)油气储层局部角度域全方位地震成像 Full-azimuth local angle-domain seismic imaging of petroleum reservoirs

  • Azimuth-preserved local angle-domain prestack time migration for 3D anisotropic media
  • Ray-theory-based angle-domain (Kirchhoff, Gaussian Beam) prestack depth migration and tomography
  • Wave-equation-based angle-domain prestack depth migration and tomography
  • Azimuthal anisotropy and fracture/stress characterization
  • Basin-scale velocity-model building using geologic and rock physics constraints

3)被动源地震与岩石圈成像Passive-source seismic and imaging of lithospheric imaging

  • Earthquake/microseismic source location and mechanism
  • Imaging of lithoshphere using regional and teleseismic signals
  • Anisotropy investigation using shear wave splitting in sbuduction zones

4)人工智能地震学应用Seismological applications of artificial intelligence

  • Reconstruction of seismic data based on deep-learning
  • P- and S-wave mode decomposition based on deep-learning
  • Seismic inversion based on deep-learning

主要学术贡献 | Representative Academic Contribution

以现代宽方位、多分量地震观测为基础,以地震体波P/S模式解耦与全波成像为突破口,面向地球介质弹性非均质性和各向异性的高分辨率刻画,开展一系列基础性研究,取得如下创新成果:

    1)创建各向异性体波模式解耦的两种数学物理模型,夯实了多分量地震全波成像的理论基础:一方面以弹性波方程“解耦”为目标,建立以伪纯模式波动方程为核心的“标量各向异性”传播模型,摆脱了当前普遍采用的拟声波理论对横波的歧视。另一方面以全波矢量成像为目标,建立纵横波矢量分解的广义傅立叶积分方程及其高效算法,较系统地解决了各向异性体波模式解耦计算昂贵、传统弹性波成像受模式泄漏与转换波极性反转问题困扰等阻碍地震全波成像走向应用的一系列瓶颈问题。同行评价参见Pollitz,2019 JGR Solid Earth; Gao & Huang,2019 Geophysics;Song, Fomel & Ying, 2013 GJI; Djebbi & Alkhalifah, 2014 SEG; Casasanta et al.2015 EAGE; Stanton & Sacchi, 2017 Geophysics; Sripanich & Fomel,2017, Geophysical Prospecting; Wang, McMechan & Duquet, 2018 Geophysics; Masmoudi & Alkhalifah, 2018 Geophysics等会议和期刊论文;

      2)提出以体波模式解耦为核心的弹性参数宽谱反演方法,显著提升深部地层弹性非均匀性地震刻画的分辨率:针对弹性波反演非线性强、多参数trade-off以及地震成像分辨率(中波数)缺口等理论难题,在敏感核与分辨率矩阵中引入模式解耦分析获得重要物理启示,提出的模式解耦预条件反演方法成为国际上解决上述难题的代表性方案;在模式解耦基础上分级拟合标量场反射走时、矢量场反射与全波形数据的多尺度反演方法,显著提升深层介质弹性非均匀性高分辨率地震刻画的可行性。同行评价参见Pan, Innanen & Geng, 2018 GJI; Wang, Hua, McMechan & Williamson,2019 Geophysics等期刊论文;

        3)发明面向非均质和各向异性储层的局部角度域方位保真成像技术,推动岩性油气藏勘探开发的技术进步:在国际上率先提出适应各向异性介质的叠前时间偏移局部角度域方位保真成像方法,建立了包括各向异性介质角度域高斯束叠前深度偏移、角度域弹性波逆时偏移以及角度域双差反射层析在内的技术系列;与产业界联合在塔里木和四川盆地开展应用,极大地提高了礁滩/溶岩/断溶型碳酸盐岩、裂缝型致密砂岩和页岩等岩性储层的地震刻画能力。同行评价参见Sun et al. 2014 The leading Edge; Sun & Sun, 2015 Geophysics; Hao, Stovas & Alkhalifah,2016 Geophysics;Decker et al.2017 Geophysics等期刊论文;

          上述研究突破了宽方位、多分量地震勘探的多个关键的理论或技术瓶颈,促进了面向复杂岩性油气藏的宽方位地震勘探技术进步,对各向异性弹性全波成像理论方法研究起到了一定的引领作用。此外,也曾在广角单程波传播算子、双平方根单程波叠前深度偏移、起伏地表波动方程叠前深度偏移以及角度域振幅保真成像等方面做出了有新意的工作。