METHOD FOR INTERPRETING REPETITIVE SEISMIC RECORDINGS UTILIZING THE SEISMIC FREQUENCY BAND IN THE EVALUATION OF PORE PRESSURE

摘要

Method for exploiting an underground porous medium by injection or production of a fluid, in which repetitive seismics are interpreted taking into account the seismic frequency band in the evaluation of pore pressures. After inverting 4D seismic data, there are at least two sets of seismic velocities corresponding to different times. A Hertz-type power law is then used to evaluate the pore pressures, in which the Hertz coefficient is determined from ultrasonic or sonic measurements in laboratories, then by correcting these coefficients from measurement of the attenuation of the waves. ultrasonic or sonic. We then follow the evolution of the fluid within the porous medium by determining whether a variation in seismic velocities is due to a variation in pore pressure or a substitution of fluid, by means of the corrected Hertz law.