Attenuation (1/Q) estimation in reflection seismic records
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Date
2013
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Publisher
Institute of Physics publishing
Abstract
Despite its numerous potential applications, the lack of a reliable method for determining
attenuation (1/Q) in seismic data is an issue when utilizing attenuation for hydrocarbon
exploration. In this paper, a new method for measuring attenuation in reflection seismic data is
presented. The inversion process involves two key stages: computation of the centroid
frequency for the individual signal using a variable window length and fast Fourier transform;
and estimation of the difference in the centroid frequency and travel time for paired incident
and transmitted signals. The new method introduces a shape factor and a constant which
allows several spectral shapes to be used to represent a real seismic signal without altering the
mathematical model. Application of the new method to synthetic data shows that it can
provide reliable estimates of Q using any of the spectral shapes commonly assumed for real
seismic signals. Tested against two published methods of Q measurement, the new method
shows less sensitivity to interference from noise and change of frequency bandwidth. The
method is also applied to a 3D data set from the Gullfaks field, North Sea, Norway. The trace
length is divided into four intervals: AB, BC, CD, and DE. Results show that interval AB has
the lowest 1/Q value, and that interval BC has the highest 1/Q value. The values of 1/Q
measured in the CDP stack using the new method are consistent with those measured using the
classical spectral ratio method.
Description
Keywords
Centroid frequency, Attenuation measurement, Rock quality factor
Citation
Raji, W. O. and Rietbrock, A. (2013): Attenuation (1/Q) estimation in Reflection Seismic Data, Journal of Geophysics and Engineering Vol. 10(4) 1-8 (045012), (Q2) Institute of Physics Publishing, Bristol, UK. Link to the table of content https://academic.oup.com/jge/issue/10/4?login=false full paper at: https://academic.oup.com/jge/article/10/4/045013/5110347