The distribution of deep source rocks in the GS Sag: joint MT–gravity modeling and constrained inversion
Shi Yan-Ling1,3, Hu Zu-Zhi2,3, Huang Wen-Hui1, Wei Qiang3, Zhang Sheng3, Meng Cui-Xian3, and Ji Lian-Sheng3
1. School of Energy Resources, China University of Geosciences, Beijing 100083, China.
2. Institute of Geophysics & Geomatics, China University of Geosciences, Wuhan 430074, China.
3. BGP, CNPC, Zhuozhou 072751, China.
Abstract：
The coal-bearing strata of the deep Upper Paleozoic in the GS Sag have high hydrocarbon potential. Because of the absence of seismic data, we use electromagnetic (MT) and gravity data jointly to delineate the distribution of deep targets based on well logging and geological data. First, a preliminary geological model is established by using three-dimensional (3D) MT inversion results. Second, using the formation density and gravity anomalies, the preliminary geological model is modified by interactive inversion of the gravity data. Then, we conduct MT-constrained inversion based on the modified model to obtain an optimal geological model until the deviations at all stations are minimized. Finally, the geological model and a seismic profile in the middle of the sag is analysed. We determine that the deep reflections of the seismic profile correspond to the Upper Paleozoic that reaches thickness up to 800 m. The processing of field data suggests that the joint MT–gravity modeling and constrained inversion can reduce the multiple solutions for single geophysical data and thus improve the recognition of deep formations. The MT-constrained inversion is consistent with the geological features in the seismic section. This suggests that the joint MT and gravity modeling and constrained inversion can be used to delineate deep targets in similar basins.
. The distribution of deep source rocks in the GS Sag: joint MT–gravity modeling and constrained inversion[J]. APPLIED GEOPHYSICS, 2016, 13(3): 469-479.
[1]
Adetunji, A., Ferguson, I. J., and Jones, A.G., 2015, Imaging the mantle lithosphere of the Precambrian Grenville Province: large-scale electrical resistivity structures: Geophysical Journal International, 201, 1038-1059.
[2]
Chen, H. G., Li, J. X., Wu, J. S., and Yu, P., 2012, Study on simulated-annealing MT-gravity joint inversion: Chinese J. Geophys. (in Chinese), 55(2), 663-670.
[3]
Christiansen, A. V., and Auken, E., 2004, Optimizing a layered and laterally constrained 2D inversion of resistivity data using Broyden’s update and 1D derivatives: J. Appl. Geophys., 56, 247-261.
[4]
Colombo, D., and De Stefano, M., 2007, Geophysical modeling via simultaneous joint inversion of seiemic, gravity, and electromagnetic data: Application to prestack depth imaging: The Leading Edge, 26(3), 326-331.
[5]
Dell'Aversana, P., Colombo, S., Ciurlo, B., Leutscher, J., and Seldal, J., 2012, CSEM data interpretation constrained by seismic and gravity data: An application in a complex geological setting: First Break, 30(11), 43-52.
[6]
de Stefano, M., Andreasi, F. G., Re, S., Virgilioet, M., and Snyder, F. F., 2011, Multiple-domain, simultaneous jointinversion of geophysical data with application to subsalt imaging: Geophysics, 76(3), R69-R80.
[7]
Feng, S. L., Ye, J. P., and Zhang, S. A., 2002, Coalbed methane resources in the Ordos Basin and its development potential: Geological Bulletin of China (in Chinese), 21(10), 658-662.
[8]
Fregoso, E., and Gallardo, L. A., 2009, Cross-gradients joint 3D inversion with applications to gravity and magnetic data: Geophysics, 74(4), L31-L42.
[9]
Gallardo, L. A., 2007, Multiple cross-gradient joint inversion for geospectral imaging: Geophys. Res. Lett., 34(19), L19301.
[10]
Gallardo, L. A., Fontes, S. L., Meju, M. A., Buonora, M. P., and de Lugao, P. P., 2012, Robust geophysical integration through structure-coupled joint inversion and multispectral fusion of seismic reflection, magnetotelluric, magnetic and gravity images: example from Santos Basin, offshore Brazil: Geophysics, 77(5), B237-B251.
[11]
Haber, E., and Oldenburg, D., 1997, Joint inversion: A structural approach: Inverse Problems, 13(1), 63-77.
[12]
Han, H. Y., Zhang, Y., and Yuan, Z. X., 2005, The formation and evolution of W basin and the movement of the fault blocks: Earthquake Rresearch (in Chinese), 25(4), 362-368.
[13]
He, Z. X., Hu, W. B., and Dong, W. B., 2010a, Petroleum EM prospecting advances and case studies in China: Surveys in Geophysics, 31(2), 207-224.
[14]
He, Z. X., Hu, Z. Z., Gao, Y., He, L. F., Meng, C. X., and Yang, L. K., 2015, Field test of monitoring gas reservoir development using timelapse continuous electromagnetic profile method: Geophysics, 80(2), WA127-WA134.
[15]
He, Z. X., Hu, Z. Z., Luo, W. F., and Wang, C. F., 2010b, Mapping reservoirs based on induced polarization and Resistivity anomaly of continuous 3D electromagnetic profiling: Case study from Qaidam Basin, China: Geophysics, 75(1) , 25-33.
[16]
Hu, Z. Z., He, Z. X., Wang, Y. T., and Sun, W. B., 2010, MT parallel simulated annealing constrained inversion and its application: 80th Annual International Meeting, SEG Expanded Abstracts, 895-899.
[17]
Hu, Z. Z., He, Z. X., Yang, W. C., and Hu, X. Y., 2015, Constrained inversion of magnetotelluric data with the artificial fish swarm optimization method: Chinese J. Geophys. (in Chinese), 58(7), 2578-2587.
[18]
Hu, Z. Z., Hu, X. Y., and He, Z. X., 2006, Pseudo-Three-Dimensional magneto-telluric inversion using nonlinear conjugate gradients: Chinese J. Geophys, 49, 1226-1234.
[19]
Li, D. C., Yang, S. J., and Hu, Z. Z., Zhao, Z., Li, Y., Zhong, D. K., Sun, W. B., and Ji, L. S., 2012, Joint interpretation of 3D Gravity-magnetic and seismic data: Oil Geophysical Prospecting (in Chinese), 47(2), 353-359.
[20]
Li, S. C., Nie, L. C., Liu, B., Song, J., Liu, Z. Y., Su, M. X., Xu, L., and Sun, H. F., 2015, 3D electrical resistivity inversion using prior spatial shape constraints: Applied Geophysics, 10(4), 361-372.
[21]
Li, Y. H., Li, J. C., Li, J. C., Chen, G. C., Wei, X. Y., and Xu, H. H., 2011, Genetic and significance of natural gas in W basin: Journal of Xi’an Shiyou University (in Chinese), 26(5), 11-18.
[22]
Lin, C. H., Tan, H. D., Shu, Q., Tong, T., and Zhang, Y. M., 2012, Three-dimensional interpretation of sparse survey line MT data: synthetic examples: Applied Geophysics, 9(1), 9-18.
[23]
Lin, C. H., Tan, H. D., and Tong, T., 2011, Three-dimensional conjugate gradient inversion of magnetotelluric full information data: Applied Geophysics, 8(1), 1-10.
[24]
Liu, J. C., Liu, L. T., Liang, X. H., and Ye, Z. R., 2015, 3D density inversion of gravity gradient data using the extrapolated Tikhonov regularization: Applied Geophysics, 12(2), 137-146.
[25]
Liu, T. Y., Yang, Y. S., and Li, Y. Y., 2005, Deciding on the distribution of deep reservoir by the joint inversion method of gravity and seismic data-taking the carboniferous in Xilin sag as an example: Natural Gas Industry (in Chinese), 25(5), 34-36.
[26]
Liu, Y. X., 2013, Application of a three-dimensional gravity inversion method constrained with density in complex areas: 83rd Annual International Meeting, SEG Expanded Abstracts, 1156-1160.
[27]
Lu, J. C., Wei, X. X., and Li, Y. H., 2005, Preliminary study about genesis and pool formation conditions of rich-helium type natural gas: Northwest Geology (in Chinese), 38(3), 82-86.
[28]
Mackie, R. L., and Madden, T. R., 1993, Three-dimensional magnetotelluric inversion using conjugate gradients: Geophysical Journal International, 115, 215-229.
[29]
Moorkamp, M., Heincke, B., Jegen, M., Roberts, A. W., and Hobbs, R. W., 2011, A framework for 3-D joint inversion of MT, gravity andseismic refraction data: Geophysical Journal International, 184(1), 477-493.
[30]
Nelson, K.D., Zhao, W. J., Brown, L. D., et al., 1996, Partially molten middle crust beneath southern Tibet: an initial synthesis of Project INDEPTH results: Science, 274, 1684-1688.
[31]
Newman, G. A. and Alumbaugh, D. L., 2000, Three-dimensional magnetotelluric inversion using non-linear conjugate gradients: Geophysical Journal International, 140, 410-424.
[32]
Nieuwenhuis, G., Unsworth, M. J., Pana, D., Craven, J., and Bertrand, E., 2014, Three-dimensional resistivity structure of Southern Alberta, Canada: implications for Precambrian tectonics: Geophysical Journal International, 197, 838-859
[33]
Oldenburg, D. W., 1974, The inversion and interpretation of gravity anomalies: Geophysics, 39(4), 526-536.
[34]
Parker, R. L., 1973, The rapid calculation of potential anomalies: Geophysical Journal of the Royal Astronomical Society, 31(4), 447-455.
[35]
Parker, R. L., 1974, Best bounds on density and depth from gravity data: Geophysics, 39(5), 644-649.
[36]
Quan, X. C., 2005, Study on fracture structure of W Basin: China Coal geology (in Chinese), 17(3), 1-5.
[37]
Siripunvaraporn, W., Uyeshima, M., and Egbert, G., 2004, Three-dimensional inversion for network-magnetotelluric data: Earth Planets Space, 56(9), 893-902.
[38]
Sun, W. B., Deng, Y. Y., Wang, C. F., Hu, Z. Z., and Lin, C. G., 2007, Deep structure study in complex area by 3D MT Data: 77th Annual International Meeting, SEG Expanded Abstracts, 684-687.
[39]
Tournerie, B., and Chouteau, M., 2005, Three-dimensional magnetotelluric survey to image structure and stratigraphy of a sedimentary basin in Hungary: Physics of the Earth and Planetary Interiors, 150, 197-212.
[40]
Unsworth, M. J., Malin, P., Egbert, G. D., and Booker, J. R., 1997, Internal structure of the San Andreas fault at Parkfield, California: Geology, 25, 359-362.
[41]
Wang, J. M., 1984, A study on the tectonics of the Weihe river graben: Geological Review (in Chinese), 30(3), 217-223.
[42]
Xia,Y., 2007, The relationship between the sedimentary characteristics of the Cenozoic and structure in W basin: Master's thesis, Chang'an University, Xi'an.
[43]
Yan, J. P., 2011, Sedimentary-tectonic evolution and gas-potential exploration of Late Paleozoic in Southern Ordos Basin: PhD Thesis, Northwest University, Xi'an.
[44]
Yang, H., Dai, S. K., and Mu, Y. G., 2004, Joint layer-stripped inversion of 3-D gravity and seismic data: Oil Geophysical Prospecting (in Chinese), 39(4), 468-471.
[45]
Yang, W. C., Xu, Y. X., Zhang, L. L., Yu, C. Q., Yu, P., Zhang, B. Z., and Yang, B., 2015, Magnetotellruic investigation and 3D lithospheric structures in the Tarim terrane: Acta Geologica Sinica (in Chinese), 89(7), 1151-1161.
[46]
Yu, P., Zhang, L. L., Wang, J. L., and Wu, J. S., 2008, Determination of physical property parameters structure in middle Guizhou uplift by joint inversion of magnetotelluric, seismic, gravity and magnetic data: Journal of Tongji University (Nature Science) (in Chinese), 36(3), 406-412.
[47]
Zhang, G. W., Zhang, B. R., Yuan, X. C., et al., 2001, Qinling Orogenic belt and continental dynamics: Science Press, Beijing.
[48]
Zhdanov, M. S., Gribenko, A., and Wilson, G., 2012, Generalized joint inversion of multimodal geophysical data using Gramian constraints: Geophys. Res. Lett., 39, L09301.
2016, Vol. 13 
