A model study of residual oil distribution jointly using crosswell and borehole-surface electric potential methods
Tóm tắt
Although high resolution can be provided by electrical logging, the measured electrical log range is narrow and is limited to near the well. Borehole-surface electric potential measurements are able to detect a wide enough range but its resolution is limited, particularly for reservoirs with complex oil and water distribution or complicated structure. In this study, we attempt to accurately locate the 3-D reservoir water and oil distribution by combining borehole-surface and crosswell electric potentials. First, the distributions of oil and water in both vertical and horizontal directions are detected by the borehole-surface and crosswell electric potential methods, respectively, and then the measured crosswell potential result is used to calibrate the measured borehole-surface electric potential data to improve vertical resolution so that the residual oil distribution is determined in a lower half-space with three dimensions. The evaluation of residual oil distribution is obtained by investigation of differences between the simulation results of the reservoir with and without water flooding. The finite difference numerical simulation results prove that the spatial residual oil distribution can be effectively determined by combining the crosswell and borehole-surface electric potentials.
Tài liệu tham khảo
Archie, G. E., 1942, The electrical resistivity log as an aid in determining some reservoir characteristics: Trans. Am. Inst. Mech. Eng., 146, 54–61.
Dey, A., and Morrison, H. F., 1979, Resistivity modeling for arbitrarily shaped three-dimensional Structures: Geophysics, 44(4), 753–780.
He, F., 2009, Application of test technique of crosswell electrical potential in Daqing oilfield: Petroleum Instruments (in Chinese), 23(3), 63–68.
He, Z. X., Liu, X. J., and Qiu, W. T., 2004, Mapping reservoir boundary by using borehole-surface TFEM Technique: Two case studies: 74th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 10–15.
Kershaw, D. S., 1978, The Incomplete Cholesky-Conjugate Gradient method for the iterative solution of systems of linear equations: J. Comp. Phys., 26, 43–65.
Liu, H., Wang, Z. G., and He, Z. X., 2008, Frequency — domain 3D borehole — surface electromagnetic modeling by the volume integral equation method: 70th EAGE Conference and Exhibition, Expanded Abstracts, 9–12.
Marsala, A. F., Al-Buali, M., Ali, Z., et al. 2011, First borehole to surface electromagnetic survey in KSA: Reservoir mapping and monitoring at a New Scale: SPE Paper 146348, SPE Annual Technical Conference and Exhibition.
Parasnis, D. S., 1967, Three-dimensional electric mise-à-la-masse survey of an irregular lead — zinc — copper deposit in central Sweden: Geophys. Prospect. 15(3), 407–437.
Sill, W. R., and Wards, S. H, 1978, Electrical energizing of well casing: Final Report: Univ. of Utah Dept of Geology and Geophysics, 77–78.
Stierman, D. J., 1984, Electrical methods of detec ing contaminated groundwater at the String Fellow waste disposal site, Riverside County, California: Environ. Geol. Water Sci. 6(1), 1–20.
Su, J. J., 2004, Research on the principle and method of crosswell e1ectromagnetic 1ogging and the rule of the influence of casing on cross-we11 e1ectromagnetic logging: PhD thesis, Ocean University of China.
Tuma, J., 1979, Engineering mathematics handbook, 2th edition: McGraw-Hill Book Company, New York.
Ushijima, K., Mizunaga, H., and Tanaka, T., 1999, Reservoir monitoring by a 4 — D electrical technique: The Leading Edge, 18(12), 1422–1424.
Wang, Z. G., He, Z. X., Liu, Y., and Deng, M., 2005, The three dimensional physical model experiment research of borehole-ground electric method: Oil Geophysical Prospecting (in Chinese), 40(5), 594–597.
Wang, Z. G., He, Z. X., and Liu, Y., 2006, Research of three-dimensional modeling and anomalous rule on borehole-ground DC method: Chinese Journal of Engineering Geophysics (in Chinese), 3(2), 87–92.
Wang, W. M., and Li, C. X., 1999, Electromagnetic field theory: JLU Press, Changchun, China, 1999.
Xu, S. Z., Liu, B., and Ruan, B. Y, 1994, The finite element method for solving anomalous potential for resistivity surveys: Chinese Journal Geophysics (in Chinese), 37(S2), 511–515.