Application of Seismic Coherency Attributes For Characterization of Reservoir Faults and Fractures

Varasteh, Alireza; Siahkoohi, Hamidreza; Khamehchi, Ehsan; Norouzi, Siavash

doi:10.22078/pr.2013.101

Application of Seismic Coherency Attributes For Characterization of Reservoir Faults and Fractures

Document Type : Research Paper

Authors

¹ Department of Petroleum Engineering, Science and Research Branch, Islamic Azad University

² Institute of Geophysics, University of Tehran,

³ Faculty of Petroleum Engineering, Amirkabir University of Technology

⁴ 4. Petroleum Engineering and Development Company (PEDEC)

10.22078/pr.2013.101

Abstract

It is very important to recognize faults and fractures in order to enhance oil recovery and to develop oil fields. Seismic coherency attribute is one of the common techniques in discontinuity characterization. Seismic coherency defines continuity of seismic events using the measurement of lateral changes in seismic responses. The rate of seismic continuity is a sign of geological continuity. In areas where are changed by faults and fractures, seismic traces have a low similarity with their neighboring traces. In this study, coherency attributes were determined using two algorithms based on cross correlation and semblance. These algorithms applied on a 3D seismic data cube from one of the Iranian oil fields in Persian Gulf. The performance of algorithms was evaluated to detect faults and fractures at lower member of Fahliyan reservoir. The results show that the semblance based algorithm provides a better coherency cube than the cross-correlation algorithm. The quality of the recognized discontinuities, especially fractures, was further increased by applying appropriate filters on stacked data cube and using reflectors dip and azimuth information. According to the results, the main orientation of faults and fractures at Fahliyan reservoir is NW-SE. This orientation is in accordance with the orientation detected by FMI log at the same depth from nearby well.

Keywords

20.1001.1.23452900.1391.22.69.6.7

References

مراجع

[1] Taner M.T., “Seismic attributes”, Canadian Society of Exploration Geophysicists Recorder., 26, pp. 48–56, 2001.

[2] Bahorich M.S., and Farmer S.L., “3-D seismic discontinuity for faults and stratigraphic features the coherence cube”, The Leading Edge., 14, pp. 1053–1058, 1995.

[3] Mai H.T., Marfurt K.J., and Chavez-Perez S., “Coherence and volumetric curvatures and their spatial relationship to faults and folds”, anexample from Chicontepec basin, Mexico, SEG International Exposition and Annual Meeting., Houston, USA, pp. 1063–1067, 2009.

[4] Marfurt K.J., Kirlin R.L., Farmer S.H., and Bahorich M.S., “3D seismic attributes using a semblance-based coherency algorithm”, Geophysics., Vol. 63, No. 4, pp. 1150–1165, 1998.

[5] Gersztenkorn A., and Marfurt K.J., Coherency computations with eigenstructure, 58th Internat. Mtg., Eur. Assn. Geoscientist and Engineers, Extended Abstracts., x031, 1996.

[6] Marfurt K.J., Sudhakar V., Gersztenkorn A., Crawford K.D., and Nissen S.E., “Coherency calculations in the presence of structural dip, Geophysics”, Vol. 64, No. 1, pp. 104–111, 1999.

[7] Chopra S., and Marfurt K.J., Seismic attributes for prospect identification and reservoir characterization, SEG geophysical developments., No. 11, 2007.

[8] Marfurt K.J., and Kirlin R.L., “3D broadband estimates of reﬂector dip and amplitude”, Geophysics., Vol. 65, No. 1, pp. 304–320, 2000.

[9] Technical Reports of Petroleum Engineering and Development Company (PEDEC).