Investigating subsurface structures of Gachsaran oil field in Iran using 2D inversion of magnetotelluric data
Mohamadhasan Mohamadian Sarvandani 1 4 Ali Nejati Kalateh 1 Reza Ghaedrahmati 2 Abbas Majidi 3
+ Author Affiliations
- Author Affiliations
1 Faculty of Mining, Petroleum and Geophysics Engineering, Shahrood University of Technology, Shahrood 3619995161, Iran.
2 Faculty of Engineering, Lorestan University, Khorramabad 6815144316, Iran.
3 National Iranian Oil Company, Tehran 1994814695, Iran.
4 Corresponding author. Email: mohamadian.sarvandani@gmail.com
Exploration Geophysics 49(2) 148-162 https://doi.org/10.1071/EG16057
Submitted: 24 May 2016 Accepted: 21 November 2016 Published: 23 December 2016
Abstract
The magnetotelluric method is most often considered in hydrocarbon exploration in cases which are difficult for seismic imaging. In 2012, the National Iranian Oil Co. (NIOC) conducted an electromagnetic survey which included magnetotelluric and time domain electromagnetic (TEM) methods in the Gachsaran oil field in the south-west of Iran to delineate the reservoir formation of the region. Magnetotelluric data were collected at 5215 sites and a regular site spacing of 200 m was utilised. We chose a 16.5 km profile perpendicular to the main geological strike direction in the study area. The Bahr’s skew and Mohr diagrams were used to perform the dimensionality analysis of the magnetotelluric (MT) data and indicated that the subsurface structures are one dimensional or two dimensional at shallow depths, whereas they are mainly three dimensional at lower depths. The phase tensor showed that the dominant geoelectrical strike in the survey area is in the NW–SE direction. Two dimensional inversion was utilised to acquire a realistic resistivity model that was compromise between the spatial smoothness of the inversion model and the MT data fit. Apparent resistivity and phase data were modelled using the smoothness-constrained least-squares method. Models obtained of the TM, TE and TM+TE mode data were examined to have the best possible interpretation. The resulting 2D model revealed the main anticline and overthrust zone in the region. The near surface layer in the model which has a low resistivity, was identified as the cover rock of the region. The formation of the top of the reservoir in the region is estimated to be located at the depth of 1400–1900 m below sea level. The resistivity model is in good correlation with the geological features and the results of well drilling.
Key words: 2D inversion, Asmari Formation, Gachsaran oil field, magnetotelluric, MT2DInvMatlab.
References
Abdul Azeez, K. K., Satish Kumar, T., Basava, S., Harinarayana, T., and Dayal, A. M., 2011, Hydrocarbon prospects across Narmada–Tapti rift in Deccan trap, central India: Inferences from integrated interpretation of magnetotelluric and geochemical prospecting studies: Marine and Petroleum Geology, 28, 1073–1082| Hydrocarbon prospects across Narmada–Tapti rift in Deccan trap, central India: Inferences from integrated interpretation of magnetotelluric and geochemical prospecting studies:Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXjsFCqu7w%3D&md5=09670e2efe3733f8a59bcd39e8a7f19eCAS |
Agard, P., Omrani, J., Jolivet, L., and Mouthereau, F., 2005, Convergence history across Zagros Iran; constraints from collisional and earlier deformation: International Journal of Earth Sciences, 94, 401–419
| Convergence history across Zagros Iran; constraints from collisional and earlier deformation:Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXlslOgt7g%3D&md5=af99e636b3c83628ef15759042a45b7aCAS |
Alborzian, Sh., Nejati, A., Moradzadeh, A., Ayoubi, M., and Ghaedrahmati, R., 2015, 1D and 2D interpretation of MT data for detection of hydrocarbon structures in the Gachsaran region: Academic Research Journal of Exploration and Production Oil and Gas, 122, 40–45
Archie, G. E., 1942, The electric resistivity log as an aid in determining some reservoir characteristics: Transactions of the American Institute of Mining, Metallurgical and Petroleum Engineers, 146, 54–62
Arnason, K., Eysteinsson, H., and Hersir, G. P., 2010, Joint 1D inversion of TEM and MT data and 3D inversion of MT data in the Hengill area, SW Iceland: Geothermics, 39, 13–34
| Joint 1D inversion of TEM and MT data and 3D inversion of MT data in the Hengill area, SW Iceland:Crossref | GoogleScholarGoogle Scholar |
Avdeev, D., and Avdeeva, A., 2009, 3D magnetotelluric inversion using a limited-memory quasi-Newton optimization: Geophysics, 74, F45–F57
| 3D magnetotelluric inversion using a limited-memory quasi-Newton optimization:Crossref | GoogleScholarGoogle Scholar |
Bahr, K., 1991, Geological noise in magnetotelluric data: a classification of distortion types: Physics of the Earth and Planetary Interiors, 66, 24–38
| Geological noise in magnetotelluric data: a classification of distortion types:Crossref | GoogleScholarGoogle Scholar |
Berdichevsky, M. N., Bubnov, V., Aleksanova, E., Alekseev, D., Yakovlev, A., and Yakovlev, D., 2015, Magnetotelluric studies in Russia: regional scale surveys and hydrocarbon exploration, in V. V. Spichak, ed., Electromagnetic sounding of the earth’s interior: theory, modeling, practice (2nd edition): Elsevier, 379–401.
Caldwell, T. G., Bibby, H. M., and Caldwell, C., 2004, The magnetotelluric phase tensor: Geophysics, 158, 457–469
| 1:CAS:528:DC%2BD2cXotVGrsbw%3D&md5=f2e1184b072b1e3675db406d016675aaCAS |
Christopherson, K. R., 1991, Applications of magnetotelluric to petroleum exploration in Papua New Guinea: a model for frontier areas: The Leading Edge, 10, 21–27
| Applications of magnetotelluric to petroleum exploration in Papua New Guinea: a model for frontier areas:Crossref | GoogleScholarGoogle Scholar |
Degroot-Hedlin, C., and Constable, S., 1993, Occam’s inversion and the North American Central Plains electrical anomaly: Journal of Geomagnetism and Geoelectricity, 45, 985–999
| Occam’s inversion and the North American Central Plains electrical anomaly:Crossref | GoogleScholarGoogle Scholar |
Dobrin, M. D., and Savit, C. H., 1988, Introduction to geophysical prospecting (6th edition): McGraw-Hill.
Han, N., Nam, M. J., Kim, H. J., Lee, T. J., Song, Y., and Suh, J. H., 2008, Efficient three-dimensional inversion of magnetotelluric data using approximate sensitivities: Geophysical Journal International, 175, 477–485
| Efficient three-dimensional inversion of magnetotelluric data using approximate sensitivities:Crossref | GoogleScholarGoogle Scholar |
Hubert, J., 2012, From 2D to 3D models of electrical conductivity based upon magnetotelluric data: experiences from two case studies: Ph.D. thesis, Uppsala University, Sweden.
Jiracek, G. R., 1990, Near-surface and topographic distortions in electromagnetic induction: Surveys in Geophysics, 11, 163–203
| Near-surface and topographic distortions in electromagnetic induction:Crossref | GoogleScholarGoogle Scholar |
Jones, A. G., 1988, Static shift of magnetotelluric data and its removal in sedimentary basin environment: Geophysics, 53, 967–978
| Static shift of magnetotelluric data and its removal in sedimentary basin environment:Crossref | GoogleScholarGoogle Scholar |
Lee, S. K., Kim, H. J., Song, Y., and Lee, C., 2009, MT2DInvMatlab - a program in MATLAB and FORTRAN for two-dimensional magnetotelluric inversion: Computers & Geosciences, 35, 1722–1734
| MT2DInvMatlab - a program in MATLAB and FORTRAN for two-dimensional magnetotelluric inversion:Crossref | GoogleScholarGoogle Scholar |
Lemma, Y., 2007, Magnetotelluric and transient electromagnetic methods in geothermal exploration, with an example from Tendaho geothermal field, Ethiopia: United Nations University – Geothermal Training Programme, Reykavik, Iceland, 225–256.
Lilley, F. E. M., 1993a, Three-dimensionality of the BC87 magnetotelluric data set studied using Mohr circles: Journal of Geomagnetism and Geoelectricity, 45, 1107–1113
| Three-dimensionality of the BC87 magnetotelluric data set studied using Mohr circles:Crossref | GoogleScholarGoogle Scholar |
Lilley, F. E. M., 1993b, Magnetotelluric analysis using Mohr circle: Geophysics, 58, 1498–1506
| Magnetotelluric analysis using Mohr circle:Crossref | GoogleScholarGoogle Scholar |
Lilley, F. E. M., 1998, Magnetotelluric tensor decomposition: Part I, theory for a basic procedure: Geophysics, 63, 1885–1897
| Magnetotelluric tensor decomposition: Part I, theory for a basic procedure:Crossref | GoogleScholarGoogle Scholar |
Lin, C. H., Tan, H. D., and Tong, T., 2008, Three dimensional conjugate gradient inversion of magnetotelluric sounding data: Applied Geophysics, 5, 314–321
| Three dimensional conjugate gradient inversion of magnetotelluric sounding data:Crossref | GoogleScholarGoogle Scholar |
Mackie, R. L., and Madden, T. R., 1993, Three-dimensional magnetotelluric inversion using conjugate gradients: Geophysical Journal International, 115, 215–229
| Three-dimensional magnetotelluric inversion using conjugate gradients:Crossref | GoogleScholarGoogle Scholar |
Mansoori, I., Oskooi, B., and Pedersen, L. B., 2015, Magnetotelluric signature of anticlines in Iran’s Sehqanat oil field: Tectonophysics, 654, 101–112
| Magnetotelluric signature of anticlines in Iran’s Sehqanat oil field:Crossref | GoogleScholarGoogle Scholar |
Marti, A., 2006, A magnetotelluric investigation of geoelectrical dimensionality and study of the Central Betic crustal structure: Ph.D. thesis, University of Barcelona.
Matsuo, K., and Negi, T., 1999, Oil exploration in difficult Minami-Noshiro area, part 2: magnetotelluric survey: The Leading Edge, 18, 1411–1413
| Oil exploration in difficult Minami-Noshiro area, part 2: magnetotelluric survey:Crossref | GoogleScholarGoogle Scholar |
Meju, M. A., 1996, Joint inversion of TEM and distorted MT soundings: some effective practical considerations: Geophysics, 61, 56–65
| Joint inversion of TEM and distorted MT soundings: some effective practical considerations:Crossref | GoogleScholarGoogle Scholar |
Miensopust, M. P., 2010, A 2D case study and a 3D approach to simultaneously invert for resistivity structure and distortion parameters: Ph.D. thesis, Dublin Institute for Advanced Studies.
Mitsuhata, Y., Matsuo, K., and Minegishi, M., 1999, Magnetotelluric survey for exploration of a volcanic-rock reservoir in the Yurihara oil and gas field, Japan: Geophysical Prospecting, 47, 195–218
| Magnetotelluric survey for exploration of a volcanic-rock reservoir in the Yurihara oil and gas field, Japan:Crossref | GoogleScholarGoogle Scholar |
Mohamadian Sarvandani, M., Nejati, A., and Ghaedrahmati, R., 2016, Comparison of various dimensionality methods on the Sabalan magnetotelluric data: Journal of Applied Geophysics, 128, 179–190
| Comparison of various dimensionality methods on the Sabalan magnetotelluric data:Crossref | GoogleScholarGoogle Scholar |
Mostafaee, R., Mohammadinia, M., and Mirzaee Tabesh, F., 2011, A case study to evaluate the role of basiluses in producing biosurfactant and the feasibility of MEOR: Journal of Petroleum Science and Technology, 1, 60–67
Motiei, H., 1995, Geology of Iran, petroleum geology of Zagros: Geological Survey of Iran, Tehran.
Naidu, G. D., 2012, Deep crustal structure of the Son-Narmada-Tapti Lineament, Central India: Springer.
Newman, G. A., and Alumbaugh, D. L., 2000, Three dimensional magnetotelluric inversion using non-linear conjugate gradients: Geophysical Journal International, 140, 410–424
| Three dimensional magnetotelluric inversion using non-linear conjugate gradients:Crossref | GoogleScholarGoogle Scholar |
NIOC, 2012, Gachsaran, Iran, MT exploration result report.
NISOC (National Iranian South Oil Company), 2001, Final reports of wells in the Gachsaran region.
Ogawa, Y., 2002, On two-dimensional modeling of magnetotelluric field data: Surveys in Geophysics, 23, 251–273
| On two-dimensional modeling of magnetotelluric field data:Crossref | GoogleScholarGoogle Scholar |
Ogawa, Y., and Uchida, T., 1996, A two-dimensional magnetotelluric inversion assuming Gaussian static shift: Geophysical Journal International, 126, 69–76
| A two-dimensional magnetotelluric inversion assuming Gaussian static shift:Crossref | GoogleScholarGoogle Scholar |
Oskooi, B., and Darijani, M., 2014, 2D inversion of the magnetotelluric data from Mahallat geothermal field in Iran using finite element approach: Arabian Journal of Geosciences, 7, 2749–2759
| 2D inversion of the magnetotelluric data from Mahallat geothermal field in Iran using finite element approach:Crossref | GoogleScholarGoogle Scholar |
Patro, P. K., Abdul Azeez, K. K., Veeraswamy, K., Sarma, S. V. S., and Sen, M. K., 2015, Sub-basalt sediment imaging – the efficacy of magnetotellurics: Journal of Applied Geophysics, 121, 106–115
| Sub-basalt sediment imaging – the efficacy of magnetotellurics:Crossref | GoogleScholarGoogle Scholar |
Pellerin, L., and Hohmann, W. G., 1990, Transient electromagnetic inversion: a remedy for magnetotelluric static shifts: Geophysics, 55, 1242–1250
| Transient electromagnetic inversion: a remedy for magnetotelluric static shifts:Crossref | GoogleScholarGoogle Scholar |
Rodi, W. L., 1976, A technique for improving the accuracy of finite element solutions for magnetotelluric data: Geophysical Journal of the Royal Astronomical Society, 44, 483–506
| A technique for improving the accuracy of finite element solutions for magnetotelluric data:Crossref | GoogleScholarGoogle Scholar |
Rodi, W. L., and Mackie, R. L., 2001, Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion: Geophysics, 66, 174–187
| Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion:Crossref | GoogleScholarGoogle Scholar |
Sasaki, Y., 2001, Full 3D inversion of electromagnetic data on PC: Journal of Applied Geophysics, 46, 45–54
| Full 3D inversion of electromagnetic data on PC:Crossref | GoogleScholarGoogle Scholar |
Sasaki, Y., 2004, Three-dimensional inversion of static-shifted magnetotelluric data: Earth, Planets, and Space, 56, 239–248
| Three-dimensional inversion of static-shifted magnetotelluric data:Crossref | GoogleScholarGoogle Scholar |
Siripunvaraporn, W., and Egbert, G., 2000, An efficient data-subspace inversion method for 2-D magnetotelluric data: Geophysics, 65, 791–803
| An efficient data-subspace inversion method for 2-D magnetotelluric data:Crossref | GoogleScholarGoogle Scholar |
Siripunvaraporn, W., and Egbert, G., 2007, Data space conjugate gradient inversion for 2-D magnetotelluric data: Geophysical Journal International, 170, 986–994
| Data space conjugate gradient inversion for 2-D magnetotelluric data:Crossref | GoogleScholarGoogle Scholar |
Siripunvaraporn, W., Egbert, G., Lenbury, Y., and Uyeshima, M., 2005, Three dimensional magnetotelluric inversion: data-space method: Physics of the Earth and Planetary Interiors, 150, 3–14
| Three dimensional magnetotelluric inversion: data-space method:Crossref | GoogleScholarGoogle Scholar |
Smith, T., and Booker, J. R., 1991, Rapid relaxation inversion of two-and three dimensional magnetotelluric data: Journal of Geophysical Research, 96, 3905–3922
| Rapid relaxation inversion of two-and three dimensional magnetotelluric data:Crossref | GoogleScholarGoogle Scholar |
Sternberg, K. B., Washburne, C. J., and Pellerin, L., 1988, Correction for the static shift in magnetotellurics using transient electromagnetic soundings: Geophysics, 53, 1459–1468
| Correction for the static shift in magnetotellurics using transient electromagnetic soundings:Crossref | GoogleScholarGoogle Scholar |
Swift, C. M., 1967, A magnetotelluric investigation of an electrical conductivity anomaly in the south-western United States: Ph. D. thesis, Massachusetts Institute of Technology.
Szarka, L., and Menvielle, M., 1997, Analysis of rotational invariants of the magnetotelluric impedance tensor: Geophysics, 129, 133–142
Takin, M., 1972, Iranian geology and continental drift in the Middle East: Nature, 235, 147–150
| Iranian geology and continental drift in the Middle East:Crossref | GoogleScholarGoogle Scholar |
Tikhonov, A. N., and Arsenin, V. Y., 1977, Solution of ill-posed problems: Wiley.
Tournerie, B., Chouteau, M., and Marcotte, D., 2007, Magnetotelluric static shift: estimation and removal using the cokriging method: Geophysics, 72, F25–F34
| Magnetotelluric static shift: estimation and removal using the cokriging method:Crossref | GoogleScholarGoogle Scholar |
Uchida, T., 1993, Smooth 2-D inversion for magnetotelluric data based on statistical criterion ABIC: Journal of Geomagnetism and Geoelectricity, 45, 841–858
| Smooth 2-D inversion for magnetotelluric data based on statistical criterion ABIC:Crossref | GoogleScholarGoogle Scholar |
Unsworth, M., 2005, New developments in conventional hydrocarbon exploration with electromagnetic methods: Recorder, 30, 34–38
Vozoff, K., 1991, The magnetotelluric method, in J. D. Corbett, ed., Electromagnetic method in applied geophysics — Applications, part A and part B: Society of Exploration Geophysicists, 641 –711.
Watts, M. D., and Pince, A., 1998, Petroleum exploration in overthrust areas using magnetotelluric and seismic data: SEG Technical Program Expanded Abstracts, 429–431.
Xiao, W., and Unsworth, M., 2006, Structural imaging in the Rocky Mountain Foothills (Alberta) using magnetotelluric exploration: AAPG Bulletin, 90, 321–333
| Structural imaging in the Rocky Mountain Foothills (Alberta) using magnetotelluric exploration:Crossref | GoogleScholarGoogle Scholar |
Yi, M. J., Kim, J. H., and Chung, S. H., 2003, Enhancing the resolving power of least squares inversion with active constraint balancing: Geophysics, 68, 931–941
| Enhancing the resolving power of least squares inversion with active constraint balancing:Crossref | GoogleScholarGoogle Scholar |
Zhang, K., Wei, W., Lu, Q., Dong, H., and Li, Y., 2014, Theoretical assessment of 3D magnetotelluric method for oil and gas exploration: synthetic examples: Journal of Applied Geophysics, 106, 23–36
| Theoretical assessment of 3D magnetotelluric method for oil and gas exploration: synthetic examples:Crossref | GoogleScholarGoogle Scholar |
Zhdanov, M. S., 2002, Geophysical inverse theory and regularization problems: Elsevier.
Zhdanov, M. S., Fang, S., and Hursan, G., 2000, Electromagnetic inversion using quasi-linear approximation: Geophysics, 65, 1501–1513
| Electromagnetic inversion using quasi-linear approximation:Crossref | GoogleScholarGoogle Scholar |
Zhdanov, M. S., Wan, L., Gribenko, A., Čuma, M., Key, K., and Constable, S., 2011, Large-scale 3D inversion of marine magnetotelluric data: case study from the Gemini prospect, Gulf of Mexico: Geophysics, 76, F77–F87
| Large-scale 3D inversion of marine magnetotelluric data: case study from the Gemini prospect, Gulf of Mexico:Crossref | GoogleScholarGoogle Scholar |