| 摘要: |
| 为满足各向异性储层精细勘探的需求,基于各向异性介质拟声波一阶速度-应力方程,首先推导适用于反演成像的偏移成像算子及线性正演算子,进而构建出泛函梯度及散射波场;其次从最小二乘反演框架出发,发展各向异性介质拟声波最小二乘逆时偏移成像方法;为了提高反演效率,进一步引入平面波编码技术,并结合预条件、正则化及GPU加速等措施,最终发展一种稳定高效的各向异性介质平面波最小二乘反演成像多级优化策略,并进行典型模型反演成像测试。结果表明:该方法能够对逆掩断层、高陡倾构造、崎岖浅表层等复杂构造进行相对保幅成像,成像效率较高,且迭代过程中自动压制交叉干扰和偏移噪音,进而提升剖面的整体成像质量。 |
| 关键词: 各向异性介质 一阶速度-应力方程 线性正演算子 平面波编码 平面波最小二乘偏移 |
| DOI：10.3969/j.issn.1673-5005.2019.06.006 |
| 分类号::P 631.4 |
| 文献标识码:A |
| 基金项目:国家科技重大专项(2016ZX05024-003-011)；国家重点基础研究发展计划(2014CB239006)；国家自然科学基金项目(41774133)；中央高校科研业务费专项(R1401005A)；贵州大学引进人才科研项目(贵大人基合字(2018)27号)；贵州省人才基地项目(RCJD2018-21) |
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| Plane-wave least-squares reverse time migration based on the first-order velocity-stress equation in anisotropic media |
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ZHOU Donghong1, HUANG Jinqiang2, LI Zhenchun3, LÜ Dingyou1
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(1.Bohai Petroleum Research Institute, Tianjin Branch, CNOOC, Tianjin 300452, China;2.School of Resources and Environment Engineering, Guizhou University, Guiyang 550025, China;3.School of Geosciences in China University of Petroleum(East China), Qingdao 266580, China)
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| Abstract: |
| High-precision imaging of anisotropic media has always been a research hotspot but remains a difficulty in the field of seismic exploration,in which the computational efficiency is one of the key factors restricting the application of inversion imaging method. In order to meet the demand of precise exploration for anisotropic reservoir,this paper first derives the imaging operator and linearized forward modeling operator suitable for inversion imaging based on the first-order velocity-stress pseudo-acoustic-wave equation of anisotropic media. The gradient of functional and scattered wavefields is then constructed. In the least square inversion framework,an anisotropic media pseudo-acoustic-wave least-squares reverse time migration method was developed afterwards.In order to improve the inversion efficiency,plane-wave coding technique,precondition,regularization,and GPU acceleration were introduced, and a stable and efficient plane-wave least-square inversion imaging optimization strategy for anisotropic media was developed. Tests on typical models show that this approach can perform with high imaging efficiency amplitude-preserving imaging on complex structures such as overthrust, high-steep-dip structure, rugged shallow surface layer and so on, and also can automatically suppress crosstalk and migration noise with the iteration to improve the overall imaging quality. |
| Key words: anisotropic media first-order velocity-stress equation linearized modeling operator plane-wave coding plane-wave least-squares reverse time migration |
