Chen Hui, Chen Yuanchun, Sun Shaotong, Hu Ying, Feng Jun
Geomathematics Key Laboratory of Sichuan Province, Chengdu University of Technology, Chengdu 610059, China.
State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China.
Entropy (Basel). 2018 Jun 3;20(6):428. doi: 10.3390/e20060428.
According to the fact that high frequency will be abnormally attenuated when seismic signals travel across reservoirs, a new method, which is named high-precision time-frequency entropy based on synchrosqueezing generalized S-transform, is proposed for hydrocarbon reservoir detection in this paper. First, the proposed method obtains the time-frequency spectra by synchrosqueezing generalized S-transform (SSGST), which are concentrated around the real instantaneous frequency of the signals. Then, considering the characteristics and effects of noises, we give a frequency constraint condition to calculate the entropy based on time-frequency spectra. The synthetic example verifies that the entropy will be abnormally high when seismic signals have an abnormal attenuation. Besides, comparing with the GST time-frequency entropy and the original SSGST time-frequency entropy in field data, the results of the proposed method show higher precision. Moreover, the proposed method can not only accurately detect and locate hydrocarbon reservoirs, but also effectively suppress the impact of random noises.
根据地震信号穿过储层时高频会异常衰减这一事实,本文提出了一种基于同步挤压广义S变换的高精度时频熵方法用于油气储层检测。首先,该方法通过同步挤压广义S变换(SSGST)获得时频谱,这些时频谱集中在信号的实际瞬时频率附近。然后,考虑噪声的特性和影响,给出了基于时频谱计算熵的频率约束条件。合成实例验证了当地震信号存在异常衰减时熵会异常高。此外,在实际资料中与GST时频熵和原始SSGST时频熵进行比较,该方法的结果显示出更高的精度。而且,该方法不仅能准确检测和定位油气储层,还能有效抑制随机噪声的影响。