Karmaşık jeolojik ortamlarda gelişen hidrokarbon kapan türlerinin patlayan yansıtıcı yöntemi ile modellenmesi

Karmaşık jeolojik ortamlarda gelişen yapısal ve stratigrafik hidrokarbon (petrol, gaz) kapanları, tektonik deformasyona maruz kalan bölgelerde veya yanal yönde geçirimsiz kayaçların bulunduğu yerlerde oluşurlar ve önemli miktarlarda hidrokarbon biriktirirler. Bu tür kapanların olduğu ortamlarda, yansımalar oldukça karmaşık davranış gösterirler. Dolayısıyla, bu tür karmaşık jeolojik ortamlarda sismik dalga yayılımını anlamak, yorumlama aşamasında önemli katkılar sağlar. Bu çalışmada, yapısal ve stratigrafik hidrokarbon kapanlarının modellemesi patlayan yansıtıcı (PY) tekniği ile gerçekleştirilmiştir. Yöntemin en önemli avantajları sismik kaynağın yansıtıcı ara yüzeylerine konulması ve tek yol seyahat zamanı ile yüzeydeki alıcılarda kaydedilmesidir. Dolayısıyla, hesaplama sonucunda doğrudan sıfır ofset kesitler elde edilmiştir. Kaynaktan yayılan sismik dalgalarının sayısal hesaplaması isteğe bağlı farklı özelliklerde giriş modelleri seçebilme yeteneği ve dalga yayılım problemlerine doğrudan çözüm sağlaması nedeniyle oldukça kullanışlı olan sonlu farklar yöntemi (SFY) ile yapılmıştır. Böylece, patlayan yansıtıcı tekniğine dayalı olarak SFY ile tam dalga alanın çözümü sayesinde hidrokarbon araştırmalarında sıklıkla karşılaşılan kanal, antiklinal, senklinal, normal fay tipi kapanların sismik modelleri kolay ve hızlı bir şekilde hesaplanmıştır. Sonuç olarak, PY tekniği ile sıfır ofset kesitlerinin (yığma kesitleri) elde edilmesi, pratik olarak gerçek sismik verilerin yorumlanmasında yorumcuya önemli katkılar sağlayacağı gösterilmiştir.

Anahtar Kelimeler:

Hidrokarbon kapanı, Patlayan yansıtıcı, Sismik modelleme, Sonlu farklar yöntemi

Modeling of hydrocarbon trap types developing in complex geological environments by exploding reflector method

Structural and stratigraphic hydrocarbon (oil, gas) traps that develop in complex geological environments are formed in regions subjected to tectonically deformation or where there are impermeable rocks in the lateral direction and accumulate significant amounts of hydrocarbons. Reflections from the subsurface media including such traps indicate highly complex behaviour. Therefore, understanding seismic wave propagation in such environments provide important contributions to the interpretation stage. In this study, the modeling of structural and stratigraphic hydrocarbon traps was carried out with exploding reflector (ER) technique. The most important advantages of the method is that the seismic source is located at the reflective interfaces and recorded by the receivers at the surface with the one way travel time. Therefore, as a result of the calculation, directly zero offset sections could be obtained. Numerical calculation of the seismic waves propagated from the source was made by the finite difference method (FDM) which is very useful due to the ability to choose arbitrary input models with different features and provide direct solutions to wave propagation problems. Thus, seismic models of channel, anticline, syncline, normal fault type traps which are frequently encountered in hydrocarbon explorations were calculated easily and quickly by means of the solution of the full wave field with FDM based on the exploding reflector technique. As a result, it has been shown that obtaining zero offset sections (stacked sections) with the ER technique will practically make important contributions to the interpreter during the interpretation of real seismic data.

Keywords:

Hydrocarbon trap, Exploding reflector, Seismic modelling, Finite difference method,

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Baysal, E., Koslof, D.D., & Sherwood, J.W.C. (1984). A two-way nonreflecting wave equation. Geophysics, 49(2), 132-141. https://doi.org/10.1190/1.4441644.
Carcione, J.M., Böhm, G., & Marchetti, A. (1994). Simulation of a CMP seismic section. Journal of Seismic Exploration, 3, 381-396.
Carcione, J. M., Feliciangeli, L. P., & Zamparo, M. (2002). The exploding-reflector concept for ground-penetrating-radar modeling. Annals of Geophysics, 45(3-4). https://doi.org/10.4401/ag-3526.
Claerbout, J.F. (1985). Imaging the earth’s interior. Blackwell Scientific Publications, 86(1), 217-219. https://doi.org/10.1111/j.1365-246X.1986.tb01086.
Cooper, J. K., Lawton, D.C., & Margrave, G. F. (2010). The wedge model revisited: A physical modeling experiment. Geophysics, 75(2). https://doi.org/10.1190/1.3309641.
Fagin, S.W. (1991). Seismic modeling of geologic structures. Society of Exploration Geophysicists. Geophysical Development series (2).
Franco, R., Petracchini L., Scrocca D., Caielli, G., & Montegrossi, G. (2018). Synthetic seismic reflection modelling in a supercritical geothermal system: an ımage of the k-horizon in the Larderello Field (Italy). Hindawi Geofluids (2019). https://doi.org/10.1155/2019/8492453.
Hardman, R. F. P., & Booth, J.E. (1991). The significance of normal fault in the exploration and production of North Sea hydrocarbons. Special Publications, 56(1). http://dx.doi.org/10.1144/GSL.SP.1991.056.01.01.
Kelly, K.R., Ward, R.W., Treitel S., & Alford, R.M. (1976). Synthetic seismograms: A Finite-Difference Approach. Geophysics, 41 (1), 2-27. https://doi.org/10.1190/1.1440605.
Kjartansson, E., & Rocca, F. (1979). The exploding reflector model and laterally variable media. Stanford Exploration Project Report No. 16, Stanford University.
Kosloff, D. D., & Baysal, E. (1982). Forward modeling by a fourier method. Society of Exploration Geophysicists, 47(10), 1402-1412.
Loewenthal, D., Lu, L., Roberson, R., & Sherwood, J. (1976). The wave equation applied to migration. Geophysical Prospecting, 24(2), 380–399. https://doi.org/10.1111/j.1365-2478.1976.tb00934.x
Loewenthal, D. (1996). Huygens principle versus exploding reflector-theoretical and numerical aspects. Exploration Geophysics, 27(4), 183-186. https://doi.org/10.1071/EG996183.
Marfurt, K. J. (1984). Accuracy of finite‐difference and finite‐element modeling of the scalar and elastic wave equations. Geophysics, 49 (5), 533-549. https://doi.org/10.1190/1.1441689.
Margrave, G. (2003). Numerical methods of exploration seismology with algorithms in Matlab. Erişim adresi http://www.crewes.org/ResearchLinks/FreeSoftware/.
Moczo, P., Robertsson, O. J. A., & Eisner, L. (2007). The finite-difference time-domain method for modeling of seismic wave propagation. Advances in Geophysics, 48, 421-516. https://doi.org/10.1016/S0065-2687(06)48008-0.
Mohebian, R., Mohammad, A. R., & Yousefi, O. (2018). Detection of channel by seismic texture analysis using Grey Level Co-occurrence Matrix based attributes. Journal of Geophysics and Engineering, 15, 1953–1962. https://doi.org/10.1088/1742-2140/aac099.
Nejati, M,, & Hashemi, H. (2012). Migrated Exploding Reflectors in Evaluation of Finite Difference Solution for Inhomogeneous Seismic Models. Engineering, (4), 950-957. https://doi.org/10.4236/Eng.2012.412A120.
Sefünç, A. (2017). Petrol aramacılığında sismik yoruma giriş, (1). Poyraz Ofset Matbaacılık.
Shuxin, P., Huaqing, L., Carlos, Z., Caiyan, L., Sujuan, L., Qingshi, Z., & Zhongfeng, B. (2017). Sublacustrine hyperpycnal channel-fan system in a large depression basin: A case study of Nen 1 Member, Cretaceous Nenjiang Formation in the Songliao Basin, NE China. Petroleum Exploration and Development, 44(6), 911–922. https://doi:org/10.4236/eng.2012.412A120.
Zhu, W., & Huang, Q. (2015). Application of reverse time migration on GPR data for detecting internal structures in a sand dune. Society of Exploration Geophysicists, 2269–74. https://doi.org/10.1190/segam2015-5833237.1.
Yee, K. (1966). Numerical solution of initial boundary value problems involving Maxwell’s equations in isotropic media. IEEE Transactions on Antennas Propagation 14 (3), 302–7.