Features of drill string vibration signal and multiples imaging
钻柱振动信号特征及多次波成像

Drill string is the medium connecting the formation and ground. Its vibration stimulated by the rotary bit contains a lot of useful information. It is possible to get the drill tools’ working condition and information of the formation that is drilled and will be drilled by analyzing the drill-bit vibration propagating in the drill string. Because different units of drill string have different cross section areas, the drill-bit vibration signal is reflected on the interface of changing cross section areas. By processing the drill string vibration signal with one-side deconvolved autocorrelation method, drill string image and drill string wave velocity are obtained. They match with the theoretical result very well. This provides a valid basis for the future drill string vibration logging and seismic while drilling (SWD) technology.