Frequency‐ and angle‐dependent poroelastic seismic analysis for highly attenuating reservoirs
Frequency‐ and angle‐dependent poroelastic seismic analysis for highly attenuating reservoirs
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DOI：
10.1111/1365-2478.12492
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发表时间：
2017-11
影响因子：
2.6
通讯作者：
Luanxiao Zhao;Qiuliang Yao;De‐hua Han;Rui Zhou;J. Geng;Hui Li
中科院分区：
文献类型：
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作者：
Luanxiao Zhao;Qiuliang Yao;De‐hua Han;Rui Zhou;J. Geng;Hui Li
我们扩展了频率和角度相关的孔隙弹性反射率，系统地分析了高衰减储层岩石的地震波形特征。研究发现，介观流体压力扩散可以显著影响地震波形的均方根振幅、频率成分和相位特征。我们将不同地质条件下的地震波振幅-角度-频率特性粗略地分为三类：（i）对于I类振幅-角度-频率特性，对应于具有I类振幅-炮检距特性的致密储层，近炮检距处的均方根振幅在高频处增大，而远炮检距处的地震能量集中在低频处;（ii）对于II类振幅对角度和频率，即对应于具有II类振幅对炮检距特性的中等压实储层，弱地震振幅可能表现出相位反转趋势，从而扭曲地震波形和能量分布;（iii）对于III类振幅-角度和频率，对应于具有III类振幅-偏移距特性的未固结储层，介观流体流动对地震波形没有明显影响，但与基于Zoeppritz方程的弹性地震响应相比，存在不可忽略的振幅衰减。
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.