An improved relative refraction statics technique
Pan Hongxun,Fang Wubao,Wu Yongshan,Sun Jianguo (Institute of Geophysical Prospecting, SINOPEC Research Institute of Petroleum Exploration and Production, Nanjing 210014, China)
Conventional refraction statics techniques such as delay time method and reciprocal method suffer from pickup of accurate first break of refraction waves and tracing of a common high velocity refractor which are hard to obtain in complex area. To cope with these problems, relative refraction statics method was developed. However conventional relative refraction statics methods fail to yield desired results when S/N ratio is low and the energy of first break changes rapidly. This paper presents an improved relative refraction statics (IRRS) technique. Based on the correlation characteristics of refracted waves on adjacent traces, the method calculates the relative time shift between adjacent traces by correlation coefficient method and double time windows, and estimates an unique relative time shift for each stake on statistic optimization basis. Tests on synthetic and real data show that the method is of high precision, applicability, and automation. The method can yield the static quantity of short and long wavelength.