The analysis of frequency-dependent characteristics for fluid detection: a physical model experiment*
Chen Shuang-Quan1,2,♦, Li Xiang-Yang1,2,3, and Wang Shang-Xu1,2
1. State Key Laboratory of Petroleum Resources and Prospecting, China University of Petroleum, Beijing, 102249, China.
2. CNPC Key Laboratory of Geophysical Prospecting, China University of Petroleum, Beijing 102249, China.
3. British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA, U. K.
Abstract According to the Chapman multi-scale rock physical model, the seismic response characteristics vary for different fluid-saturated reservoirs. For class I AVO reservoirs and gas-saturation, the seismic response is a high-frequency bright spot as the amplitude energy shifts. However, it is a low-frequency shadow for the Class III AVO reservoirs saturated with hydrocarbons. In this paper, we verified the high-frequency bright spot results of Chapman for the Class I AVO response using the frequency-dependent analysis of a physical model dataset. The physical model is designed as inter-bedded thin sand and shale based on real field geology parameters. We observed two datasets using fixed offset and 2D geometry with different fluid saturated conditions. Spectral and time-frequency analyses methods are applied to the seismic datasets to describe the response characteristics for gas-, water-, and oil-saturation. The results of physical model dataset processing and analysis indicate that reflection wave tuning and fluid-related dispersion are the main seismic response characteristic mechanisms. Additionally, the gas saturation model can be distinguished from water and oil saturation for Class IAVO utilizing the frequency-dependent abnormal characteristic. The frequency-dependent characteristic analysis of the physical model dataset verified the different spectral response characteristics corresponding to the different fluid-saturated models. Therefore, by careful analysis of real field seismic data, we can obtain the abnormal spectral characteristics induced by the fluid variation and implement fl uid detection using seismic data directly.
This work is also partially supported by the National Science and Technology Major Project (No. 2011ZX05019-008),the National Natural Science Foundation of China (No. 41074080), and the Science Foundation of China University of Petroleum, Beijing (No. KYJJ2012-05-11).
Cite this article:
CHEN Shuang-Quan,LI Xiang-Yang,WANG Shang-Xu. The analysis of frequency-dependent characteristics for fluid detection: a physical model experiment*[J]. APPLIED GEOPHYSICS, 2012, 9(2): 195-206.
2012, Vol. 9 
