Estimation of net-pay thickness, using seismic reflectivity and band-limited impedance approaches, Central Nile Delta, Egypt

Fawzy, Aly; El Rawy, Azaa; Lala, Amir

doi:10.21608/jag.2022.284846

Estimation of net-pay thickness, using seismic reflectivity and band-limited impedance approaches, Central Nile Delta, Egypt

Document Type : Original Article

Authors

¹ Senior Geophysicist, Belayim Petroleum Co. (Petrobel), Cairo, Egypt.

² Assistant Professor of Geophysics, Ain Shams University, Cairo, Egypt.

³ Professor of Geophysics, Ain Shams University, Cairo, Egypt.

10.21608/jag.2022.284846

Abstract

It is well-known that, the seismic amplitude scaling techniques are used to remove the tuning effect on seismic amplitude maps. Nonetheless, they are useful to predict the net-pay thickness in low-impedance hydrocarbon-bearing sands. The aim of this paper is to address the prediction of the net-pay from seismic reflectivity compared to the band-limited impedance inversion techniques. The first step for the net-pay prediction from reflectivity consists in plotting the amplitude extracted between the top and bottom of the reservoir against the apparent thickness. Another approach to predict net-pay thickness is through colored inversion. Connolly and co-authors utilized the band-limited impedance of the coloured inversion data rather than the conventional seismic amplitude. Connolly’s method uses the average band-limited impedance and the apparent thickness values extracted between the zero-crossing picks. The results show that the Connolly's band-limited impedance technique showed a significant improvement over Brown's reflectivity-based techniques.

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