An Analysis on mCSEM Responses for Sandstone Reservoirs with Respect to
Changes in Petrophysical Properties

doi:10.12972/ksmer.2014.51.5.641

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2014 Vol.51, Issue 5 Preview Page Next Page

Research Paper

An Analysis on mCSEM Responses for Sandstone Reservoirs with Respect to Changes in Petrophysical Properties 사암 저류층 특성 변화에 따른 해양전자탐사 반응 분석: 구본진 · 한누리 · 남명진
Bonjin Ku, Nuree Han, Myung Jin Nam

31 October 2014. pp. 641-652

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Abstract

This study makes an analysis on marine controlled-source electromagnetic method (mCSEM) responses for various petrophysical properties of sandstone reservoir. It is necessary to consider sensitivity of mCSEM data to petrophysical properties of the reservoir for valid interpretation of mCSEM field data. For computing reservoir resistivity that changes in accordance with reservoir porosity, water saturation and resistivity of formation water, we used Archie’s equation which is widely used for formation evaluation of sandstone reservoir. We obtain and analyze not only amplitude of electric field but also its normalized amplitude by using a three-dimensional mCSEM modeling algorithm. Furthermore, we study on relations between operation frequency and buried depth of hydrocarbon reservoir. The relative difference in mCSEM responses for a sand reservoir is more than 70% when the water saturation increases from 0.2 to 0.5.

Keywords

Marine CSEM

Petrophysical properties

Forward modeling

이 연구에서는 사암 저류층의 매개변수 값 변화에 따른 해양전자탐사 자료의 반응 변화를 분석하였다. 수포화도, 공극률, 지층수의 전기비저항과 같은 저류층의 특성에 따라 탐지하고자 하는 탄화수소층의 전기전도도가 달라지며 이는 전자기 반응에 영향을 미치게 된다. 따라서 해양전자탐사자료의 올바른 해석을 하기 위해서는 저류층 특성에 대한 연구가 필수적이다. 반응 변화 연구를 위하여 유한차분법에 기초한 3차원 순방향 모델링 알고리즘을 이용하였다. 순수사암 저류층 분석에 많이 이용되는 Archie 공식을 이용하여 순수 사암 저류층의 공극률과 수포화도 그리고 지층수의 전기비저항을 고려하여 저류층 전기비저항 값을 계산한다. 계산된 전기비저항을 저류층 수치 모델에 적용하여 반 무한매질에서 전기장의 진폭을 각각 비교 분석하였으며, 반무한 매질의 전기장 진폭으로 정규화한 결과로 반응 변화를 살펴본다. 또한 자료에 영향을 미칠 수 있는 탐사 변수인 주파수와 저류층의 매설 깊이의 영향도 분석하였다. 사암 저류층에서 수포화도가 0.2에서 0.5로 증가할 때 해양전자탐사의 반응은 70% 이상 변화하였다.

키워드

해양 전자탐사

저류층 암석물리 특성

순방향 모델링

References

Abubakar, A., Habashy, T.M., Druskin, V.L., Knizhnerman, L. and Alumbaugh, D., 2008, “2.5D forward and inverse modeling for interpreting low-frequency electromagnetic measurements,” Geophysics, Vol. 73, No. 4, pp. F165-F177.
Archie, G.E., 1942, “The Electrical Resistivity Log as and Aid in Determining some Reservoir Characteristics,” Trans. AIME, Vol. 146, pp. 54-62.
Chave, A.D., 2009, “Marine CSEM: Evolution of a technology,” Oilfield Review, Spring 2009, Schlumberger, p. 1.
Commer, M. and Newman, G.A., 2008, “New advances in three-dimensional controlled-source electromagnetic inversion,” Geophysical Journal International, Vol. 172, pp. 513-535.
Constable, S. and Weiss, C., 2006, “Mapping thin resistors and hydrocarbons with marine EM methods: Insights from 1D modeling,” Geophysics, Vol. 71, No. 2, pp. G43-G51.
Constable, S. and Srnka, L.J., 2007, “An introduction to marine controlled-source electromagnetic methods for hydrocarbon exploration,” Geophysics, Vol. 72, No. 2, pp. WA3-WA12.
Constable, S., 2010, “Ten years of marine CSEM for hydrocarbon exploration,” Geophysics, Vol. 75, No. 5, pp. 75A67-75A81.
Cox, C.S., 1981, “On the electrical conductivity of the oceanic lithosphere,” Physics of the Earth and Planetary Interiors, Vol. 25, Issue 3, pp. 196-201.
Ellingsrud, S., Eidesmo, T., Johansen, S., Sinha, M.C., MacGregor, L.M. and Constable, S., 2002, “Remote sensing of hydrocarbon layers by seabed logging SBL: Results from a cruise offshore Angola,” The Leading Edge, Vol. 21, pp. 972-982.
Glover, P.W.J., 2000, Petrophysics, Department of Geology and Petroleum Geology University of Aberdeen, UK, p. 17.
Han, N., Nam, M.J., Ku, B., and Kim, H.J., 2012, “Three- dimensional Modeling of Marine Controlled-source Electromagnetic Surveys Based on Finite Difference Method”, Jigu-Mulli-wa-Mulli-Tamsa, Vol. 15, No. 2, pp. 66-74.
Hoversten, M.G., Newman, G.A., Geier, N. and Flanagan, G., 2006, “3D modeling of a deepwater EM exploration survey,” Geophysics, Vol. 71, No. 5, pp. G239-G248.
Johansen, S.E., Amundsen, H.E.F., Rosten, T., Ellingsrud, S., Eidesmo, T. and Bhuyian, A.H., 2005, “Subsurface hydrocarbons detected by electromagnetic sounding,” First Break, Vol. 23.
Key, K., 2009, “1D inversion of multicomponent, multifrequency marine CSEM data: Methodology and synthetic studies for resolving thin resistive layers,” Geophysics, Vol. 74, No. 2, pp. F9-F20.
Li, Y. and Constable, S., 2007, “2D marine controlled-source electromagnetic modeling: Part 2 – The effect of bathymetry,” Geophysics, Vol. 72, No. 2, pp. WA63-WA71.
MacGregor, L., Andeis, D., Tomlinson, T. and Barker, N., 2006, “Controlled-source electromagnetic imaging of the Nuggets-1 reservoir,” vThe Leading Edge, Vol. 25, pp. 984-992.
Newman, G.A., Commer, M. and Carazzone, J.J., 2010, “Imaging CSEM data in the presence of electrical anisotropy,” Geophysics, Vol. 75, No. 2, pp. F51-F61.
Thirud, Å., 2002, “EMGS article,” Scandinavian Oil-Gas Magazine, Issue 3/4, pp. 8-9.
Tompkins, M., 2005, “The role of vertical anisotropy in interpreting marine controlled-source electromagnetic data,” Expanded Abstracts of the 75th Annual International Meeting, SEG, Houston, Texas, USA, Nov. 6-11, pp. 514-517.
Sasaki, Y. and Meju, M.A., 2009, “Useful characteristics of shallow and deep marine CSEM responses inferred from 3D finite-difference modeling,” Geophysics, Vol. 74, No. 5, pp. F67-F76.
Shahin, A., Key, K., Stoffa, P. and Tatham, R., 2012, “Petro- electric modeling for CSEM reservoir characterization and monitoring,” Geophysics, Vol. 77, No. 1, pp. E9-E20.
Smith, J.T., 1996, “Conservative modeling of 3-D electromagnetic fields, Part II: Biconjugate gradient solution and an accelerator,” Geophysics, Vol. 61, pp. 1319-1324.
Srnka, L.J., Carazzone, J.J., Ephron, M.S. and Eriksen, E.A., 2006, “Remote reservoir resistivity mapping,” The Leading Edge, Vol. 25, pp. 972-975.
Um, E.S. and Alumbaugh, D.L., 2007, “On the physics of the marine controlled-source electromagnetic method,” Geophysics, Vol. 72, No. 2, pp. WA13-WA26.
Yee, K.S., 1966, “Numerical solution of initial boundary value problems involving Maxwell’s equation in isotropic media,” IEEE Trans. Anten. Prop., Vol. 14, No. 3, pp. 302-307.

Information

Publisher :The Korean Society of Mineral and Energy Resources Engineers
Publisher(Ko) :한국자원공학회
Journal Title :Journal of the Korean Society of Mineral and Energy Resources Engineers
Journal Title(Ko) :한국자원공학회지
Volume : 51
No :5
Pages :641-652
DOI :https://doi.org/10.12972/ksmer.2014.51.5.641

[1] Abubakar, A., Habashy, T.M., Druskin, V.L., Knizhnerman, L. and Alumbaugh, D., 2008, “2.5D forward and inverse modeling for interpreting low-frequency electromagnetic measurements,” Geophysics, Vol. 73, No. 4, pp. F165-F177.

[2] Archie, G.E., 1942, “The Electrical Resistivity Log as and Aid in Determining some Reservoir Characteristics,” Trans. AIME, Vol. 146, pp. 54-62.

[3] Chave, A.D., 2009, “Marine CSEM: Evolution of a technology,” Oilfield Review, Spring 2009, Schlumberger, p. 1.

[4] Commer, M. and Newman, G.A., 2008, “New advances in three-dimensional controlled-source electromagnetic inversion,” Geophysical Journal International, Vol. 172, pp. 513-535.

[5] Constable, S. and Weiss, C., 2006, “Mapping thin resistors and hydrocarbons with marine EM methods: Insights from 1D modeling,” Geophysics, Vol. 71, No. 2, pp. G43-G51.

[6] Constable, S. and Srnka, L.J., 2007, “An introduction to marine controlled-source electromagnetic methods for hydrocarbon exploration,” Geophysics, Vol. 72, No. 2, pp. WA3-WA12.

[7] Constable, S., 2010, “Ten years of marine CSEM for hydrocarbon exploration,” Geophysics, Vol. 75, No. 5, pp. 75A67-75A81.

[8] Cox, C.S., 1981, “On the electrical conductivity of the oceanic lithosphere,” Physics of the Earth and Planetary Interiors, Vol. 25, Issue 3, pp. 196-201.

[9] Ellingsrud, S., Eidesmo, T., Johansen, S., Sinha, M.C., MacGregor, L.M. and Constable, S., 2002, “Remote sensing of hydrocarbon layers by seabed logging SBL: Results from a cruise offshore Angola,” The Leading Edge, Vol. 21, pp. 972-982.

[10] Glover, P.W.J., 2000, Petrophysics, Department of Geology and Petroleum Geology University of Aberdeen, UK, p. 17.

[11] Han, N., Nam, M.J., Ku, B., and Kim, H.J., 2012, “Three- dimensional Modeling of Marine Controlled-source Electromagnetic Surveys Based on Finite Difference Method”, Jigu-Mulli-wa-Mulli-Tamsa, Vol. 15, No. 2, pp. 66-74.

[12] Hoversten, M.G., Newman, G.A., Geier, N. and Flanagan, G., 2006, “3D modeling of a deepwater EM exploration survey,” Geophysics, Vol. 71, No. 5, pp. G239-G248.

[13] Johansen, S.E., Amundsen, H.E.F., Rosten, T., Ellingsrud, S., Eidesmo, T. and Bhuyian, A.H., 2005, “Subsurface hydrocarbons detected by electromagnetic sounding,” First Break, Vol. 23.

[14] Key, K., 2009, “1D inversion of multicomponent, multifrequency marine CSEM data: Methodology and synthetic studies for resolving thin resistive layers,” Geophysics, Vol. 74, No. 2, pp. F9-F20.

[15] Li, Y. and Constable, S., 2007, “2D marine controlled-source electromagnetic modeling: Part 2 – The effect of bathymetry,” Geophysics, Vol. 72, No. 2, pp. WA63-WA71.

[16] MacGregor, L., Andeis, D., Tomlinson, T. and Barker, N., 2006, “Controlled-source electromagnetic imaging of the Nuggets-1 reservoir,” vThe Leading Edge, Vol. 25, pp. 984-992.

[17] Newman, G.A., Commer, M. and Carazzone, J.J., 2010, “Imaging CSEM data in the presence of electrical anisotropy,” Geophysics, Vol. 75, No. 2, pp. F51-F61.

[18] Thirud, Å., 2002, “EMGS article,” Scandinavian Oil-Gas Magazine, Issue 3/4, pp. 8-9.

[19] Tompkins, M., 2005, “The role of vertical anisotropy in interpreting marine controlled-source electromagnetic data,” Expanded Abstracts of the 75th Annual International Meeting, SEG, Houston, Texas, USA, Nov. 6-11, pp. 514-517.

[20] Sasaki, Y. and Meju, M.A., 2009, “Useful characteristics of shallow and deep marine CSEM responses inferred from 3D finite-difference modeling,” Geophysics, Vol. 74, No. 5, pp. F67-F76.

[21] Shahin, A., Key, K., Stoffa, P. and Tatham, R., 2012, “Petro- electric modeling for CSEM reservoir characterization and monitoring,” Geophysics, Vol. 77, No. 1, pp. E9-E20.

[22] Smith, J.T., 1996, “Conservative modeling of 3-D electromagnetic fields, Part II: Biconjugate gradient solution and an accelerator,” Geophysics, Vol. 61, pp. 1319-1324.

[23] Srnka, L.J., Carazzone, J.J., Ephron, M.S. and Eriksen, E.A., 2006, “Remote reservoir resistivity mapping,” The Leading Edge, Vol. 25, pp. 972-975.

[24] Um, E.S. and Alumbaugh, D.L., 2007, “On the physics of the marine controlled-source electromagnetic method,” Geophysics, Vol. 72, No. 2, pp. WA13-WA26.

[25] Yee, K.S., 1966, “Numerical solution of initial boundary value problems involving Maxwell’s equation in isotropic media,” IEEE Trans. Anten. Prop., Vol. 14, No. 3, pp. 302-307.

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