Abstract：A new algorithm for marine controlled-source electromagnetic (CSEM) fields of an arbitrary electric dipole over a layered anisotropic medium is presented in this paper. The algorithm is correct and accuracy based on the Maxwell equations, which is implemented by Hankel transform and double Fourier transform combined with vector potential. The fields of finite length wire source cannot be approximated as fields of a point dipole source, especially for the small source-receiver distance; but it can be synthesized by superposing point dipole fields and numerical integral method. We simulate the marine CSEM responses of canonical oil model over a layered anisotropic medium and analyze effects of anisotropy in over-burden layers and reservoir targets with different electric dipole sources. The results show that vertical anisotropy in both the reservoir target and the over-burden sediment affects considerably the marine CSEM fields, and contributes more to inline geometry electric field than to broadside geometry.
刘颖, 李予国. 层状各向异性介质中任意取向电偶源的海洋电磁响应[J]. 石油地球物理勘探, 2015, 50(4): 755-765.
Liu Ying, Li Yuguo. Marine controlled-source electromagnetic fields of an arbitrary electric dipole over a layered anisotropic medium. OGP, 2015, 50(4): 755-765.
Shen Jinsong and Chen Xiaohong. Development and enlightenment of controlled-source electromagnetic (CSEM) surveying method in marine oil/gas exploration. OGP, 2009, 44(1): 119-127.
[2]
Constable S, Srnka L J. An introduction to marinecontrolled source electromagnetic methods for hydrocarbon exploration. Geophysics, 2007, 72(2): WA3-WA12.
Wang Changxue, Zhou Chanchan, Chu Zhaotan et al. Modeling of electromagnetic responses in frequency domain to electrical anisotropic formations. Chinese Journal of Geophysics, 2006, 49(6): 1873-1883.
Sun Ya, He Zhanxiang, Liu Jianxin et al. Simulation study for long wire source frequency-domian electromagnetic sounding field source static displacement. OGP, 2011, 46(1): 149-154.
Cao Hui, Wang Xuben, He Zhanxiang et al. Calculation of borehole-to-surface electromagnetic responses on horizontal stratified earth medium. OGP, 2012, 47(2): 338-343.
[8]
Pal B P, Mukherjee K. Electrical potential due to a point current source over a layered conducting earth with dipping anisotropy. Geoexploration,1986,24(1):15-19.
[9]
Xiong Z. Electromagnetic fields of electric dipoles embedded in a stratified anisotropic earth. Geophy-sics, 1989, 54(12): 1643-1646.
[10]
Yin C, Maurer H M. Electromagnetic induction in a layered earth with arbitrary anisotropy. Geophysics, 2001, 66(5): 1405-1416.
[11]
Lseth L O, Ursin B. Electromagnetic fields in planarly layered anisotropic media. Geophysical Journal International, 2007, 170(1): 44-80.
[12]
Christensen N B, Dodds K. 1D inversion and resolution analysis of marine CSEM data. Geophysics, 2007,72(2):WA27-WA38.
[13]
刘长胜, Mark E Everett, 林君等. 海底电性源频率域CSEM勘探建模及水深影响分析. 地球物理学报, 2010, 53(8): 1940-1952] Liu Changsheng, Mark E Everett, Lin Jun et al. Modeling of seafloor exploration using electric-source frequency-domain CSEM and the analysis of water depth effect. Chinese Journal of Geophysics, 2010,53(8): 1940-1952.
Feng Xukui, Wang Kunpeng, Cao Hui et al. 1D forward modeling for marine borehole electromagnetic. OGP, 2014, 49(6): 1222-1227.
[15]
Nabighian M N. Electromagnetic methods in applied geophysics. SEG Technical Program Expanded Abstracts, 1988, 8:131-312.
[16]
William H. Press. Numerical Recipes Second Edi-tion: The Art of Scientific computing. Cambridge University Press, 1992, 147-161.
[17]
Yuguo Li and Shikun Dai. Finite element modeling of marine controlled-source electromagnetic response in two-dimensional dipping anisotropic conductivity structures. Geophysical Journal International, 2011, 185(): 622-636.
