An amplitude-preserved adaptive focused beam seismic migration method

• Published in: Petroleum science Vol. 12; no. 3; pp. 417 - 427
• Main Authors: Yang, Ji-Dong, Huang, Jian-Ping, Wang, Xin, Li, Zhen-Chun
• Format: Journal Article
• Language: English
• Published: Beijing China University of Petroleum (Beijing) 01.08.2015; School of Geoscience, China University of Petroleum, Qingdao 266580, Shandong, China
• Subjects: Accuracy; Beams (radiation); Earth and Environmental Science; Earth Sciences; Economics and Management; Energy Policy; Geology; Imaging; Industrial and Production Engineering; Industrial Chemistry/Chemical Engineering; Mathematical models; Migration; Mineral Resources; Original Paper; Spreads; Wave equations; 叠前深度偏移方法; 地震; 成像方法; 成像质量; 振幅; 波动方程偏移; 波束域; 自适应聚焦; Adaptive focused beam; Gaussian beam; Amplitude-preserved migration; Depth imaging
• ISSN: 1672-5107; 1995-8226
• DOI: 10.1007/s12182-015-0044-7

Gaussian beam migration （GBM） is an effec- tive and robust depth seismic imaging method, which overcomes the disadvantage of Kirchhoff migration in imaging multiple arrivals and has no steep-dip limitation of one-way wave equation migration. However, its imaging quality depends on the initial beam parameters, which can make the beam width increase and wave-front spread with the propagation of the central ray, resulting in poor migration accuracy at depth, especially for exploration areas with complex geological structures. To address this problem, we present an adaptive focused beam method for shot-domain prestack depth migration. Using the infor- mation of the input smooth velocity field, we first derive an adaptive focused parameter, which makes a seismic beam focused along the whole central ray to enhance the wave- field construction accuracy in both the shallow and deep regions. Then we introduce this parameter into the GBM, which not only improves imaging quality of deep reflectors but also makes the shallow small-scale geological struc- tures well-defined. As well, using the amplitude-preserved extrapolation operator and deconvolution imaging condi- tion, the concept of amplitude-preserved imaging has been included in our method. Typical numerical examples and the field data processing results demonstrate the validity and adaptability of our method.