oa Improvement of Data Quality in Seismic While Drilling

Seismic while drilling (SWD) is a seismic survey technology using a working drill-bit as an energy source. We can specify bit location on the existing seismic time section and can predict a drilling hazard ahead of the bit, ‘while drilling’, by using SWD technology. Vertical Seismic Profiling (VSP) also can be used for the same purpose. In comparison with VSP, advantages of SWD are its survey cost and quick availability of the survey result, such as T-D (Time-Depth) information. However, a serious disadvantage exists in the data quality due to contamination by noise generated from the working rig. Furthermore, there is a limitation to applicability on the SWD technology currently in use, when drilling with a PDC (Polycrystal-line Diamond Compact) bit or drilling in unconsolidated rocks. In this paper, we proposed a data acquisition method, a data processing method and a new energy source system for improving the quality of the SWD data. Efficacy of those methods and the system were demonstrated by field experiments.