Method and device for determining a vertical seismic profiling by the measurement of the vibrations coming from a borehole

摘要

Seismic measurements are taken during drilling operations by an array of seismometers placed on the earth's surface about the axis of a drillstring connected to a conventional drillbit and wherein the drillstring has an arrangement of strain gages and accelerometers mounted thereon in such a way as to measure axial and torsional vibrations of the drillstring. Signals indicating vibrations induced by the drillbit or another source and transmitted through the drillstring are compared with signals received by the seismometer array to determine the characteristics of the formation based on measurement of acoustic velocity from direct and reflected transmission of acoustic vibrations through the formation.