Noise suppression with box-wave in Tuolamu-Shenggen area, Qiangtang Basin
Li Zhongxiong1, Shi Dai2, Lei Yang2, Yu Wenke2, Ma Long1
1. Chengdu Center of Geological Survey, CGS, Chengdu, Sichuan 610081, China;
2. The Second Geophysical Services Company, Southwest Bureau of Petroleum, SINOPEC, Deyang, Sichuan 618000, China
Abstract：This paper discusses noise investigation by box wave method in Tuolamu-Shenggen area, Qiangtang Basin. Different kinds of noises can be found on Common receiver gathers. Using time slice and radar image scanning analysis, noise velocity, its propagation direction and its relative energy on the raw records can be obtained along with signal-noise ratio. Apart from ambient noise, we have found also four kinds of ground rolls, two kinds of linear noise, multi-refraction and refraction wave in this area. Meantime the results of suppressing noises by different geophone array lengths are analyzed and compared on the basis of areal analysis of box wave. The following conclusions can be drawn: A.The noises cannot be suppressed when geophone array length is zero; B.The ambient noises can be partly suppressed when geophone array length is 40 meters; C.The ground rolls can be primarily suppressed when geophone array length is 120 meters; D.Both the ambient noises and ground rolls can be suppressed much better when geophone array length is 160 meters; E.But for linear noise, multi-refraction and refraction wave, good suppressed results cannot be obtained even when geophone array length is 160 meters.
