Seismic odd and even component amplitudes for estimating porosity in tight dolomite reservoirs

Zhou, Jian (Hohai University and University of Houston) | Ba, Jing (Hohai University) | Castagna, John P. (University of Houston) | Yu, Cun (Hohai University) | Jiang, Ren (RIPED-Langfang) | Ge, Qiang (RIPED-Langfang)


Seismic amplitude analysis could provide valuable information regarding physical properties of reservoir rocks that is related to seismic reflection characteristics, e.g. porosity. However, for thin-layer reservoirs, limited seismic resolution and related wavelet tuning often hinders accurate interpretation of seismic amplitudes. We show that for generalized simple layer, i.e. without the same magnitudetop and base reflections, amplitude of composite top-base reflection signal is affected by both perturbations to thinlayer reservoir and overburden rocks. The complex tuning behavior can be simplified using the fact that any arbitrary seismic signal can be uniquely decomposed using the Fourier transform into odd and even components that have distinct sensitivities to variation in thin-layer and overburdenproperties. Numerical analysis based on true log parameters in a tight-dolomite reservoir in the Sichuan Basin, China show that amplitude at peak frequency of the seismic data odd part (OAPF) is more sensitive to thin-reservoir porosity change compared to that of original signal (total waveform, TAPF) and even part of the waveform (EAPF). When applied in analyzing real seismic data, conventional TAPF is not obviously correlated to porosity variations. However, the OAPF attribute responds well to the porosity measured in boreholes, and also relates to apparent seismic attenuation. These results suggest that, for thin layers, amplitude-based interpretation and inversion may benefit from isolation of even and odd amplitude attributes.

Presentation Date: Monday, October 15, 2018

Start Time: 1:50:00 PM

Location: 209A (Anaheim Convention Center)

Presentation Type: Oral