Method for absolute preserved amplitude processing of seismic well data

Method intended for absolute preserved amplitude processing of data obtained by seismic prospecting known as VSP. It comprises reception, by seismic receivers (R) arranged in a well and coupled with the surrounding formations, of seismic waves generated by a source (S) and reaching directly the receivers (direct or downgoing waves DW) or after reflections on discontinuities (D) (upgoing waves UW). In order to recover the absolute amplitude ratios between the upgoing waves and the downgoing waves, the direct arrivals are normalized in form of a zero-phase unit amplitude pulse obtained after signature deconvolution of the total field of the downgoing and upgoing waves by the downgoing waves, followed by separation of the upgoing and downgoing waves, and the differences between the amplitudes received by each seismic receiver, due to the spherical divergence between the paths of the upgoing waves and the paths of the downgoing waves coming directly from the seismic source, are compensated. A compensation of the plane wave attenuation between the direct arrivals and the reflected arrivals is preferably applied to the signals received at each receiver. Application: precise measurement of the amplitudes of reflected and diffracted seismic events on monocomponent or tricomponent VSP data, in addition to conventional seismic wave propagation time and velocity measurements for example.