Karsts-caved Carbonate Reservoir Heterogeneity Study by AVO/AVA Inversion Using a Physical Modeling Data

The storage spaces of Karsts carbonate reservoir in Tarim basin are mostly secondary dissolution caves and characterized as strong heterogeneity. One of the key technical problems is how to calculate the volume of these caves. Due to low signal to noise ratio, AVA inversion using partially stacked data is often used to characterize the carbonate reservoir. Compared to AVO inversion using single trace, AVA inversion suffers from losing lateral resolution when characterizing heterogeneity. Considering the question mentioned above, a physical model is used to analyze influence of AVO/AVA inversion on heterogeneity. On the one hand, the difference in lateral resolution is quantitatively studied. On the other hand, the influence of noise on the lateral resolution in AVO/AVA inversion is discussed by adding random noise of different degree. The results demonstrate that the signal to noise ratio can be improved by AVA inversion while the lateral resolution is reduced subsequently. Additionally, random noise influences the lateral resolution, that is, the inverted volume of heterogeneity become smaller as the noise increased.