METHOD FOR INTERPRETING REPEATING SEISMIC RECORDINGS IN ACCORDANCE WITH THE SEISMIC FREQUENCY BAND IN EVALUATING PORE PRESSURES

摘要

A method of operating a subterranean porous medium by injection or fluid production, wherein repetitive seismic is interpreted taking into account the seismic frequency band in the evaluation of pore pressures. After inversion of 4D seismic data, at least two sets of corresponding seismic velocities are available at different times. A Hertz power law is then used to evaluate the pore pressures, in which the Hertz coefficient is determined from ultrasonic or sonic measurements in laboratories, and then by correcting these coefficients from the measurement of the attenuation of the waves. ultrasound or sonic. The evolution of the fluid in the porous medium is then monitored by determining whether a change in seismic velocities is due to a variation in pore pressure or fluid substitution, by means of the corrected Hertz law.