大角度弹性波阻抗(英文)

Far Angle Elastic Impedance

弹性波阻抗及相关技术是以二项AVO方程和三项AVO方程为基础的,它的有效性在世界范围内的许多沉积盆地都得到了验证。在过去的几年中,大偏移距的数据采集使得入射角普遍大于30°,因此必须用三项AVO方程来解决储层流体和岩性识别问题。在入射角小于30°时,所有的线性弹性波阻抗方程都能给出可靠的结果,当入射角大于这一角度时,某些非线性弹性波阻抗方程也能给出理想的结果。然而,由非线性弹性波阻抗获得弹性参数并非易事,因为这需要进行一些复杂的数学变换。到目前为止,只有扩展弹性波阻抗能够适用于所有的入射角度,而在sin2θ域还没有一种能够用于大角度的线性弹性波阻抗。本文提出了另外一种线性弹性波阻抗——大角度弹性波阻抗(FEI)。理论模型和实际数据都证明FEI是大角度寻找油气的有力属性。

Fruit of either 2 - terms AV（） equation or 3 - terms AVO equation, elastic impedance and its associate technologies have shown its effectiveness in many sedimentary basins all over the word. In the last few years, the incidence angles superior to 30 °have become common in today＇s long - offset acquisition geometries and thus moving forward to three terms AVO equation to tackle reservoir fluid and lithology identification issues is evident. All linear elastic impedance equations give realistic results with angles less than 30° . Beyond this angle; certain nonlinear elastic impedance equations give appreciable results. However, obtaining elastic parameters from nonlinear elastic impedance is not an easy task, since it requires several and awkward mathematical transformations. This is a reason why explorationistes prefer to work with linear elastic impedance in order to derive elastic parameters. So far, except the extended elastic impedance which accepts main, there is not such 1 angles. In this paper we ang inear elastic impedance which can propose another formulation of all angles entries, but in sin2θ do be used at wide angles or ultra far linear elastic impedance called far e elastic impedance. In testing the new definition alternatively with synthetic elastic pa rameters models and real seismic data, it can be noticed that FEI is powerful attribute in highlighting hydrocarbon at far angles.