Signal Detection Of The Drill Bit Seismic Wave While Drilling

Seismic while drilling (SWD) is a combination of exploration geophysics andpetroleum engineering. It takes the working drill-bit vibration as seismic source,acquiring the reflected wave propagating through the formation. It is useful toevaluate the formation ahead of the drill-bit, predict abnormal pressure and formationinterface, and reduce the drilling risk.Based on the analysis of the development of SWD technique, we put forward anew SWD scenario, in which the highly sensitive and three-component portableseismometer is used to monitor the working drill-bit vibration signal continuously.The primary field tests show that it is feasible. We made the theoretical analysis andnumerical simulation on SWD source characteristics and seismic wave field, and theexploration research on the field observation technique and SWD data processing,obtained some basic understanding of the space and the polarization characteristics ofthe drill-bit wave field. A great deal of original test data has been collected. A set ofinstrument parameters was suggested for SWD new instrument development.According to the principle of the Winner filter, we built a deconvolution processingprocedure of the reference signal and got some frequency repair to the referencesignal. A set of processing procedure on the cross-correlation and the polarizationfilter was built to extract the effective signal from the multi-channel data.This research focuses on the development of the new SWD technique differentfrom the traditional methods, which introduces the highly sensitive and three-component portable seismometer to engineering and three-component data analysis.This new technique have strong detection ability and easy to use.