Amplitude-versus-offset variations in gas sands
Amplitude-versus-offset variations in gas sands
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DOI：
10.1190/1.1442696
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发表时间：
1989-06
期刊：
影响因子：
3.3
通讯作者：
S. Rutherford;Robert H. Williams
中科院分区：
文献类型：
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作者：
S. Rutherford;Robert H. Williams
含气砂岩的地震反射波具有广泛的振幅随炮检距变化（AVO）特征。决定气砂反射AVO特性的两个最重要的因素是垂直入射反射系数R0和反射体处泊松比的对比度。在这两个因素中，R0受到的约束最小。根据其AVO特征，气砂反射体可分为三类，以气砂顶部的R0定义。1类气砂具有比包裹页岩更高的阻抗，R0具有相对大的正值。2类气砂具有与包裹页岩几乎相同的阻抗，并且特征在于接近零的R0值。3级砂的阻抗低于包裹页岩，R0为负且幅值较大。这些砂类中的每一种都具有不同的AVO特征。文中给出了这三种类型中每种类型的气砂的一个例子。Class 1示例涉及Hartshorn通道s.
Seismic reflections from gas sands exhibit a wide range of amplitude‐versus‐offset (AVO) characteristics. The two factors that most strongly determine the AVO behavior of a gas‐sand reflection are the normal incidence reflection coefficient R0 and the contrast in Poisson’s ratio at the reflector. Of these two factors, R0 is the least constrained. Based on their AVO characteristics, gas‐sand reflectors can be grouped into three classes defined in terms of R0 at the top of the gas sand. Class 1 gas sands have higher impedance than the encasing shale with relatively large positive values for R0. Class 2 gas sands have nearly the same impedance as the encasing shale and are characterized by values of R0 near zero. Class 3 sands have lower impedance than the encasing shale with negative, large magnitude values for R0. Each of these sand classes has a distinct AVO characteristic. An example of a gas sand from each of the three classes is presented in the paper. The Class 1 example involves a Hartshorn channel s...