Affect of configuration parameters of geobody on regularization downward continuation imaging by successive layer optimization
WEN Bai-Hong1(), HU Qing-Hui2,3, ZHANG Lian-Qun1
1. PetroChina Institute of Petroleum Exploration and Development,Beijing 100083,China 2. No.4 Geological Team of Shandong Bureau of Geology and Mineral Resources,Weifang 261000,China 3. Key Laboratory of Coastal Zone Geological Environment Protection, Shandong Geology and Mineral Exploration and Development Bureau, Weifang 261000,China
Regularization downward continuation imaging by successive layer optimization (DCSLO) can be used to study the geometrical configuration and physical distribution of geological body(geobody). Due to possible similar features of potential fields for some bodies of different geometrical configurations, the downward continuation imaging is of no-uniqueness. From spectral study of 4 basic configurations of geological bodies and parameter selection for optimum downward continuation for the 35 gravity models of different configurations, a regressive formulas between configuration parameter and shape correction coefficient is obtained and consequently a configuration filter operator is proposed. With the configuration filter operator the DCSLO will enhance the imaging accuracy of geometrical center of complex geobody. A field example of DCSLO for gravity and magnetic data in FengSunChang area in Western Sichuan is given. With the configuration filter operator determined by the seismic structures and the regressive formulas, the DCSLO imaging is consistent with the main geometrical characteristics of the seismic deep structures and overall density logging data. This verified the applicability and effectiveness of the configuration filtering in DCSLO imaging.
Wang B H, Wang L. A new normalized method of downward extrapolation for potential field[J]. Computing Techniques for Geophysical and Geochemical Exploration, 1998, 20(1):30-35.
[7]
Fedi M, Florio G. A stable downward continuation by using the ISVD method[J]. Geophysical Journal International, 2002, 151:146-156.
doi: 10.1046/j.1365-246X.2002.01767.x
[8]
Cooper G. The stable downward continuation of potential field data[J]. Exploration Geophysics, 2004, 35, 260-265.
doi: 10.1071/EG04260
Zeng X N, Li X B, Han S Q, et al. A comparison of three iteration methods for downward continuation of potential fields[J]. Progress in Geophysics, 2011, 26(3):908-915.
[11]
Zeng X N, Li X H, Su J, et al. An adaptive iterative method for downward continuation of potential-field data from a horizontal plane[J]. Gephysics, 2013, 78(4):J43-J52.
Liu X G, Wang X T, Li Y C, et al. Optimal regularization parameter determination method in downward continuation of gravimetric and geomagnetic data[J]. Acta Geodaetica et Cartographica Sinica, 2014, 43(9):881-887.
Li X J, Wang Z L. A study on gravity field downward continuation using the regularized equivalent-layer method[J]. Chinese Journal of Geophysics, 2018, 61(7):3038-3036.
[14]
Naidu P. Spectrum of the potential field due to randomly distributed sources[J]. Geophysics, 1968, 33:337-345.
doi: 10.1190/1.1439933
[15]
Pawlowski R S. Green’s equivalent-layer concept in gravity band-pass filter design[J]. Geophysics, 1994, 59:69-76.
doi: 10.1190/1.1443535
[16]
Quarta T, Fedi M, Santis A. Source ambiguity from an estimation of the scaling exponent of potential field power spectra[J]. Geophys. J. Int., 2000, 140:311-323.
doi: 10.1046/j.1365-246x.2000.00021.x
Wang C, Zhang Y, Wen B H. The improved calculating method of downward continuation for gravity potential field[J]. Petroleum Geology and Oilfield Development in Daqing, 2018, 37(1):147-153.
Wen B H, Yang H, Zhang L Q. Deep physical structure prediction by gravity and magnetic optimized downward continuation imaging[C]// Collection of Chinese earth science integrated symposium: 6048-6051.
[19]
程方道, 黄国强. 重磁位场波谱理论及其应用[M]. 长沙: 中南工业大学出版社, 1987.
[19]
Cheng F D, Huang G Q. Spectral theory and its application of gravity and magnetic potential fields [M]. Changsha: Publishing Press of Central South University of Technology, 1987.
Wen B H, Cheng F D. A new interpolating cut method for identifying regional and local fields of magnetic anomaly[J]. Journal of Central South Mining and Metallurgy, 1990, 21(3):229-235.
Zhao W J, Zhao L, Yang Z J, et al. The improvement of the interpolation cutting potential field separation method and its application to data processing[J]. Geophysical and Geochemical Exploration, 2020, 44(4):886-893.
