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AVO分析的基础是反射振幅随着震源和检波器之间的距离增加而增加。已经证实,AVO异常在利用地震资料确定天然气方面具有重要意义。已经开发的一种特定的反演技术是根据AVO异常估计泊松比。这项技术以Shuey(1985)的公式为基础并且参考Marquardt(1963)的简化线性反演方法。这项技术高整迭代过程的收敛,从有用的观察资料中确定未知的参数。一旦获得了泊松比的值,便可以估计S波速度及推导出储层岩石的弹性属性。例如杨氏模量。在Java盆地西北部应用这项技术研究Cicauh灰岩储层获得杨氏模量数值为23392MPa左右。根据这个数值推导的孔隙度为36.6％,与井资料非常接近。根据Wren(1984)的图件,含流体的砂岩储集层相对应的P波速度是2700—3550m/s。实际上,根据井资料,应该是含天然气的灰岩。因此,开发一种特殊的图件,表明P波速度和泊松比之间的关系,对于钻探之前确定储层流体应该是有用的。
The basis of the AVO analysis is that the reflection amplitude increases as the distance between the source and the detector increases. It has been confirmed that AVO anomaly is of great significance in the use of seismic data to determine natural gas. A specific inversion technique that has been developed is to estimate Poisson’s ratio based on AVO anomalies. This technique is based on the formula of Shuey (1985) and refers to the simplified linear inversion method of Marquardt (1963). The convergence of the high-iteration process of this technique determines unknown parameters from useful observations. Once the Poisson’s ratio is obtained, the S-wave velocity can be estimated and the elastic properties of the reservoir rock can be derived. For example, Young’s modulus. Applying this technique to study the Cicauh limestone reservoir in northwestern Java basin, the Young’s modulus value is about 23392MPa. The porosity derived from this value is 36.6%, very close to well data. According to Wren (1984), the P-wave velocities corresponding to fluid-bearing sandstone reservoirs are 2700-3550 m / s. In fact, according to well data, it should be a limestone with natural gas. Therefore, developing a special map showing the relationship between P-wave velocity and Poisson’s ratio should be useful for determining reservoir fluids prior to drilling.