Frequency‐ and angle‐dependent poroelastic seismic analysis for highly attenuating reservoirs |
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| Authors: | Luanxiao Zhao Qiuliang Yao De‐hua Han Rui Zhou Jianhua Geng Hui Li |
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| Affiliation: | 1. State Key Laboratory of Marine Geology, Tongji University, Shanghai, China;2. Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX, USA;3. Halliburton Consulting and Project Management, Houston, TX, USA;4. The school of electronic and information engineering, Xi'an Jiaotong University, Xi'an, China |
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| Abstract: | We extend the frequency‐ and angle‐dependent poroelastic reflectivity to systematically analyse the characteristic of seismic waveforms for highly attenuating reservoir rocks. It is found that the mesoscopic fluid pressure diffusion can significantly affect the root‐mean‐square amplitude, frequency content, and phase signatures of seismic waveforms. We loosely group the seismic amplitude‐versus‐angle and ‐frequency characteristics into three classes under different geological circumstances: (i) for Class‐I amplitude‐versus‐angle and ‐frequency, which corresponds to well‐compacted reservoirs having Class‐I amplitude‐versus‐offset characteristic, the root‐mean‐square amplitude at near offset is boosted at high frequency, whereas seismic energy at far offset is concentrated at low frequency; (ii) for Class‐II amplitude‐versus‐angle and ‐frequency, which corresponds to moderately compacted reservoirs having Class‐II amplitude‐versus‐offset characteristic, the weak seismic amplitude might exhibit a phase‐reversal trend, hence distorting both the seismic waveform and energy distribution; (iii) for Class‐III amplitude‐versus‐angle and ‐frequency, which corresponds to unconsolidated reservoir having Class‐III amplitude‐versus‐offset characteristic, the mesoscopic fluid flow does not exercise an appreciable effect on the seismic waveforms, but there exists a non‐negligible amplitude decay compared with the elastic seismic responses based on the Zoeppritz equation. |
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| Keywords: | Poroelastic Attenuation Dispersion Amplitude‐versus‐offset Waveform |
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