Modeling of Antenna for Deep Target Hydrocarbon Exploration

Noorhana Yahya, Nadeem Nasir, Majid Niaz Akhtar, Muhammad Kashif, Hasnah Mohd Zaid, Afza Shafie

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DOI: 10.4236/jemaa.2012.41005                

Abstract

Nowadays control source electromagnetic method is used for offshore hydrocarbon exploration. Hydrocarbon detection in sea bed logging (SBL) is a very challenging task for deep target hydrocarbon reservoir. Response of electromagnetic (EM) field from marine environment is very low and it is very difficult to predict deep target reservoir below 2 km from the sea floor. This work premise deals with modeling of new antenna for deep water deep target hydrocarbon exploration. Conventional and new EM antennas at 0.125 Hz frequency are used in modeling for the detection of deep target hydrocarbon reservoir. The proposed area of the seabed model (40 km ′ 40 km) was simulated by using CST (computer simulation technology) EM studio based on Finite Integration Method (FIM). Electromagnetic field components were compared at 500 m target depth and it was concluded that Ex and Hz components shows better resistivity contrast. Comparison of conventional and new antenna for different target depths was done in our proposed model. From the results, it was observed that conventional antenna at 0.125 Hz shows 70%, 86% resistivity contrast at target depth of 1000 m where as new antenna showed 329%, 355% resistivity contrast at the same target depth for Ex and Hz field respectively. It was also investigated that at frequency of 0.125 Hz, new antenna gave 46% better delineation of hydrocarbon at 4000 m target depth. This is due to focusing of electromagnetic waves by using new antenna. New antenna design gave 125% more extra depth than straight antenna for deep target hydrocarbon detection. Numerical modeling for straight and new antenna was also done to know general equation for electromagnetic field behavior with target depth. From this numerical model it was speculated that this new antenna can detect up to 4.5 km target depth. This new EM antenna may open new frontiers for oil and gas industry for the detection of deep target hydrocarbon reservoir (HC).

Keywords

Electromagnetic; Hydrocarbon; SBL; Antenna; CST

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	L. MacGregor and M. Sinha, “Use of Marine Controlled- Source Electromagnetic Sounding for Sub-Basalt Exploration,” Geophysical Prospecting, Vol. 48, No. 6, 2000, pp. 1091-1106. doi:10.1046/j.1365-2478.2000.00227.x
[2]	B. Tossman, D. Thayer and W. Swartz, “An Underwater Towed Electromagnetic Source for Geophysical Exploration,” IEEE Journal of Oceanic Engineering, Vol. 4, No. 3, 1979, pp. 84-89. doi:10.1109/JOE.1979.1145427
[3]	S. Johansen, et al., “Subsurface Hydrocarbons Detected by Electromagnetic Sounding,” First Break, Vol. 23, No. 3, 2005, pp. 31-36.
[4]	N. Yahya, M. N. Akhtar, N. Nasir, A. Shafie, M .S. Jabeli, and K. Koziol, “CNT Fibres/Aluminium-NiZnFe2O4 Based EM Transmitter for Improved Magnitude vs. Offset (MVO) in a Scaled Marine Environment,” Journal of Nanoscience and Nanotechnology, 2011, in press.
[5]	N. Yahya, M. N. Akhtar, N. Nasir, H. Daud and M. Narahari, “Forward Modeling of Seabed Logging by Finite Integration (FI) and Finite Element (FE) Methods,” DSL, 2011, in press.
[6]	N. Yahya, M. Kashif, H. Daud, H. M. Zaid, A. Shafie, N. Nasir and A. See, “Fabrication and Characterization of Y3.0-XLaXFe5O12—PVA Composite as EM Waves Detector,” International Journal of Basic & Applied Sciences, Vol. 9, No. 9, 2009, pp. 131-134.
[7]	N. Nasir, N. Yahya, M. N. Akhtar, M. Kashif, A. Shafie, H. Daud and H. M. Zaid, “Magnitude Verses Offset Study with EM Transmitter in Different Resistive Medium,” Journal of Applied Sciences, Vol. 11, No. 7, 2011, pp. 1309-1314.
[8]	M. N. Akhtar, N. Yahya, H. Daud, A. Shafie, H. M. Zaid, M. Kashif and N. Nasir, “Development of EM Wave Guide Amplifier Potentially Used for Seabed Logging,” Journal of Applied Sciences, Vol. 11, No. 7, 2011, pp. 1361-1365.
[9]	M. Unsworth, “New Developments in Conventional Hydrocarbon Exploration with Electromagnetic Methods,” CSEG Recorder, 2005, pp. 34-38. http://www.ualberta.ca/~unsworth/papers/2005-CSEG-recorder-unsworth-apr05_07.pdf
[10]	P. Clemmow, “The Theory of Electromagnetic Waves in a Simple Vanisotropic Medium,” Proceedings of the Institution of Electrical Engineers, Vol. 110, No. 1, 1963, pp. 101-106.
[11]	F. N. Kong., H. Weterdahl, S. Ellingsrud, T. Eidesmo and S. Johansen, “A Possible Direct Hydrocarbon Indicator for Deep Sea Prospects Using EM Energy,” Oil and Gas Journal, Vol. 100, No. 19, 2002, pp. 30-38.
[12]	C. S. Cox, S. C. Constable, A. D. Chave and S. C. Webb, “Controlled Source Electromagnetic Sounding of the Oceanic Lithosphere,” Nature, Vol. 320, 1986, pp. 52-54. doi:10.1038/320052a0
[13]	M. C. Sinha, P. D. Patel, M. J. Unsworth, T. R. E. Owen and M. G. R. MacCormack, “An Active Source Electromagnetic Sounding System for Marine Use,” Marine Geophysical Research, Vol. 12, No. 1-2, 1990, pp. 59-68. doi:10.1007/BF00310563
[14]	P. D. Young and C. S. Cox, “Electromagnetic Active Source Sounding Near the East Pacific Rise,” Geophysical Research Letters, Vol. 8, No. 10, 1981, pp. 1043-1046. doi:10.1029/GL008i010p01043
[15]	E. Um and D. Alumbaugh, “On the Physics of the Marine Controlled-Source Electromagnetic Method,” Geophysics, Vol. 72, No. 2, 2007, pp. WA13-WA26.
[16]	S. C. Webb, S. C. Constable, C. S. Cox and T. K. Deaton, “A Seafloor Electric Field Instrument,” Journal of Geomagnetism and Geoelectricity, Vol. 37, No. 12, 1985, pp. 1115-1129. doi:10.5636/jgg.37.1115
[17]	A. D. Chave, S. C. Constable and R. N. Edwards, “Electrical Exploration Methods for the Seafloor Electromagnetic Methods in Applied Geophysics,” Electromagnetic Methods in Applied Geophysics, Vol. 2, 1992, pp. 931- 966.
[18]	T. Eidesmo, S. Ellingsrud, L. M. MacGregor, S. C. Constable, M. C. Sinha, S. Johansen, F. N. Kong and H. Westerdahl, “SeaBed Logging (SBL), a New Method for Remote and Direct Identification of Hydrocarbon Filled Layers in Deepwater Areas Using Controlled Source Electromagnetic Sounding,” First Break, Vol. 20, No. 3, 2002, pp. 144-152.
[19]	G. M. Hoversten, G. A. Newman, N. Geier and G. Flanagan, “3D Modeling of a Deepwater EM Exploration Survey,” Geophysics, Vol. 71, No. 5, 2009, pp. G239- G248.
[20]	P. D. Aversana and M. Vivier, “Expanding the Frequency Spectrum in Marine CSEM Applications,” Geophysical Prospecting, Vol. 57, No. 4, 2008, pp. 573-590.
[21]	B. Niels, L. Christensen and K. Dodds, “Special Section —Marine Controlled Source Electromagnetic Methods1D Inversion and Resolution Analysis of Marine CSEM Data,” Geophysics, Vol. 72, No. 2, 2007, pp. WA73- WA84. doi:10.2529/PIERS060822070325
[22]	L. Gelius, “Multi-Component Processing of Sea Bed Lo- gging Data,” Progress in Electromagnetic Research On- line, Vol. 2, No. 6, 2006, pp. 589-593.
[23]	A. Shaw, A. I. Al-Shamma’a, S. R. Wylie and D. Toal, “Experimental Investigations of Electromagnetic Wave Propagation in Seawater,” Proceedings of the 36th European Microwave Conference, Manchester, 10-15 September 2006, pp. 572-575.
[24]	Y. Li and K. Key, “2D Marine Controlled Electromagnetic Modeling: An Adaptive Finite Element Algorithem,” Geophysics, Vol. 72, No. 2, 2007, pp. 51-62.