Quantitative computation and comparison of S/N ratio in seismic data
Zhang Jun-hua1, Zang Sheng-tao1, Zhou Zhen-xiao1, Wang Jing1, Shan Lian-yu2, Xu Hui2, Fu Jin-rong2, Yu Hai-cheng2, Bu Chang-cheng2
1. College of Earth Resource and Information,China University of Petroleum (East China),Dongying City,Shandong Province,257061,China;
2. GRI of Shengli Oilfield,Dongying City,Shandong Province,257022,China
Abstract：The paper systematically introduced and discussed five methods of S/N ratio evaluation:superposition of energy,frequency-spectrum evaluation method,power-spectrum evaluation method,correlation method and eigenvalue method. Model tests were used to correlate the influence of noise,time window,trace number,frequency band and structural attitude on the results of 5 methods. The results showed that the spectrum methods (both frequency spectrum and power spectrum) have higher computational precision for the low-quality data; the size of time window has less influences on S/N ratio calculation and influence of size of time window on power spectrum method is minimum; there are also the issues of lateral resolution and precision for the S/N ratio and it greatly reduces the computational precision of superposition of energy and eigenvalue method for the incline and curved formation; the frequency band of data is not main factor affecting the computational results of S/N ratio; the eigenvalue method is decomposition and combination of horizontal signal intrinsically,which is appropriate for flatter formulation. The study pointed out that it should choose correlation method when S/N ratio is selected for singularity detection of lateral prediction attribute of reservoir (fracture,fault,buried-hill structure etc).
