摘要
Abstract
The surface of karst topography in Guizhong mountainous area is characterized by strong heterogeneity, so the quality of common-shot record and common-receiving record of different lithology sections in one single line varies largely, and the stack of single line cannot well solve the problem. Therefore, we carried out three-line &. Three-shot wide line seismic acquisition experiment, to analyze the common-shot record and common-receiving record of the sum of three single lines, as well as the S/N and frequency of single-line and wide line stack profiles. The results show that when the variation of the S/N curves from the three lines is uniform, the S/N cannot be largely improved by single-line stack or wide line,so the advantage of wide line is not obvious;if the variation trend is severe, wide line means is optimal. However, multi-line receiving in wide line means will inevitably decrease the frequency component of the seismic data. Aiming at the problem, we proposed the method for computing the improvement ratio of S/N and the reduction ratio of dominant frequency by using lowest value of S/N and highest value of dominant frequency of single line. Meanwhile, we discussed the approximate reciprocal relationship between the S/N and dominant frequency with wide line means and obtained the approximate fitting formula. In terms of the achievements, we selected three-line &. Two-shot wide line geometry for the seismic acquisition of Guizhong mountainous area.关键词
喀斯特地区/共炮点记录/共接收点记录/宽线观测系统/信噪比提高率/主频降低率Key words
karst areas common-shot records common-receiving record/wide line geometry improvement ratio of S/N/reduction ratio of dominant frequency分类
天文与地球科学
