Abstract:Secondary positioning technique is one of key techniques of seismic exploration in neritic transitional zone. Currently used secondary positioning methods mainly include sonic secondary positioning and first breaks secondary positioning methods. In practice, the former has disadvantage of lower data recovery rate that seriously affects the production efficiency, therefore, in recent years, the first breaks secondary positioning method has been used mostly in international scope. By now, we don't have a set of first breaks secondary positioning software to be better used at home. According to the technical requirement of UNOCAL project and using first breaks secondary positioning software developed by ENSOCO Co., the paper systematically analyzed the principle and major application links of the software, and summed up a set of concrete application methods in combination with realacquired data in the project. It is shown by the practice that, using sonic positioning and first breaks secondary positioning respectively for each geophone in a 2D seismic line, the positioning errors for two methods were all within 5m.