Abstract: The process consists in generating a primary tube wave, in using a reflecting element for the tube wave and in recording the times of emission of the induced waves radiated by the reflecting element, in receiving and recording at least part of the induced waves, then in processing the recorded signals so as to determine the characteristics of the medium to be explored. Application in particular to exploration between boreholes.

Abstract: A method for measuring vibrational stresses and velocities of waves propagated within formations surrounding a wellbore essentially consists in simultaneously measuring the vibrational stress and vibrational velocity produced by propagation of the vibration within the medium, then in establishing a ratio of magnitudes relating to the vibrational stress and velocity in respect of one and the same measuring point. The method and device provided by the invention also find applications in the separation of different types of secondary waves generated during propagation of a primary wave in a medium.

Abstract: Method of instantaneous acoustic logging within a wellbore.The method is characterized in that it consists of locating on drill-pipe and ground recordings elementary recordings corresponding to one and the same depth level of the drilling tool, in grouping these elementary recordings in pairs, then in intercorrelating said recordings of the pairs so as to produce in respect of each pair a correlated signal which is representative of the acoustic energy produced and of the difference in travel times of the waves received on sensors from which the pair of recordings has been obtained.A particular application is for the determination of a seismic wellbore profile.

Abstract: Method for the processing of recordings of signals resulting from a seismic exploration of a medium.It consists, after grouping recordings in pairs and crosscorrelation of the recordings of each pair, in grouping the elementary crosscorrelation functions thus obtained in at least one family in which the measuring spaces are included in a same predetermined reference space, in transforming the time variables of the said functions in order to bring the measuring space dimension to that of the reference, then in adding the transformed functions.Application in particular to acoustic logging seismic reflection or refraction.

Abstract: The invention relates to a method of seismic exploration by acoustic well logging.It is characterized in that in the traces recorded corresponding to each transmitter-receiver pair, each type of wave of interest is identified using the results of a velocity analysis, then the time of appearance in the trace of a characteristic event of the phase of the wave of interest is determined and the velocity of the wave is deduced from this time and from the thickness of the layer of formation studied.