Seismic Spectral Attributes of Apparent Attenuation: Part 1 - Methodology

Abstract

Ideally, accurate seismic attenuation estimation is extremely useful for reservoir characterization, subtle geological structure identification, and seismic signal compensation. However, seismic attenuation not only distorts their amplitudes but also disperses seismic waves, which gives rise to a number of issues and renders the accurate attenuation estimation impossible. As the measurement of attenuation, the absolute value of quality factor Q does not interest us in seismic interpretation, and the relative value is more important. Instead of struggling to characterize the accurate Q value, we propose a package of seismic spectrum characterization based attenuation attributes to evaluate apparent attenuation effects. The proposed attributes assume the seismic wave is propagating through the earth as a Richer wavelet. Based on this, the attributes' validities are proved analytically in this paper (Part 1: Methodology). Using field data results (presented in the following paper, see Part 2), it is shown that the proposed seismic attenuation attributes are effective and robust for seismic interpretation compared to previous Q estimation results.

Assessment of spectral attributes in identifying gas hydrates in seismic data from the Pegasus Basin, offshore New Zealand

“…A lower peak frequency, as demonstrated by Li et al (2015) is expected to present as positive kurtosis. Positive kurtosis may also be thought of in relationship to bandwidth; a narrower bandwidth from attenuated frequencies should therefore exhibit positive kurtosis.…”

“…Gas hydrates are shown to attenuate seismic waves from numerous seismic or well studies Chand and Minshull, 2004;Dvorkin and Uden, 2004;Sahoo et al, 2019, and others), and this effect is even observed in synthetic seismic data created from realworld, hydrate-bearing well log data . To quantify the attenuation response for hydrocarbon accumulations, Li et al (2015 and proposed skewness and kurtosis, two statistical measures, in combination with five other attenuation-related attributes, to measure attenuation in hydrocarbon-filled sediments in both conventional and unconventional reservoirs.…”

Seismic attenuation attributes with applications on conventional and unconventional reservoirs

“…Seismic interpreters are not usually interested in the absolute attenuation value, but they are usually more interested in the relative attenuation effects between an area and its surroundings. Li et al (2015b) propose a suite of seismic attenuation attributes that quantify the spectral changes between a shallower reference and a deeper target horizon to detect anomalous spectral energy loss. The sketches in Figure 1 summarize these seismic attenuation attributes.…”