Poroelastic property analysis of seismic low-frequency shadows associated with gas reservoirs
Poroelastic property analysis of seismic low-frequency shadows associated with gas reservoirs
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DOI：
10.1093/jge/gxaa005
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发表时间：
2020-03
影响因子：
1.4
通讯作者：
Shengjie Li;Y. Rao
中科院分区：
文献类型：
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作者：
Shengjie Li;Y. Rao
地震低频振幅阴影已被广泛用作油气指示。研究了储层性质和地震波模态转换对含气储层低频振幅阴影特征的影响。目标气藏一般与致密砂岩岩性有关，非均质性强。储层内孔隙流体在垂向和水平方向上呈斑状饱和，这种斑状饱和容易在含气储层下方形成低频阴影。利用孔隙弹性模拟方法对这些低频阴影进行了验证。基于现场实例的研究结果表明，孔隙流体性质、储层厚度和非均质性是低频阴影产生的关键因素。结果还表明，通过直接验证地震资料中存在的低频阴影现象，孔隙弹性模拟方法可以有效地预测含气储层的空间分布。
Seismic low-frequency amplitude shadows have been widely used as a hydrocarbon indicator. This study investigates the effect of reservoir properties and seismic wave mode conversion on the characteristics of the low-frequency amplitude shadows in gas-bearing reservoirs. The target gas reservoirs are typically related to the lithology of tight sandstone with strong heterogeneity. Pore-fluid distribution within the reservoirs presents patchy saturation in the vertical and horizontal directions, and this patchy saturation easily induces low-frequency shadows beneath gas-bearing reservoirs. These low-frequency shadows are validated by using a poroelastic simulation method. The results of our field case-based study indicate that pore-fluid property, plus the thickness and heterogeneity of reservoirs are the key elements in the generation of low-frequency shadows. The results also indicate that the poroelastic simulation method can be used to effectively predict the spatial distribution of gas-bearing reservoirs, by directly verifying the low-frequency shadow phenomenon existing in the seismic data.