Abstract: The present invention relates to a method for monitoring an area of interest in a subsoil comprising a point of interest, the method comprising:•extracting a first subset (I) of raw geophysical data that are associated with the point of interest from among a set (0) of previously acquired raw geophysical data to generate a first image (hnl) of the subsoil;•constructing a projection model (MODI) on the basis of the first subset of data (I);•reducing the first subset (I) of data to a second subset (2);•creating a reference set (B) by applying the projection model (MODI);•carrying out an acquisition forming a third subset (3);•creating a monitoring set (M) by applying the projection model (MODI);•comparing the first reference set (B) and the first monitoring set (M) to identify a change in the subsoil to be monitored.

Abstract: The present invention concerns a method for determining the optimum positioning of source-receiver pairs capable of acquiring seismic data, comprising: a first step of identifying a zone of interest having been the subject of an earlier seismic acquisition, in order to obtain an image of the subsoil of same; a second step of obtaining seismic data acquired during the earlier seismic acquisition of said zone of interest during a time of interest; a third step of applying a partial or total demigration of seismic data, in order to determine the positions of each source-receiver pair having contributed to the image of said subsoil of said zone of interest during said time of interest; a fourth step of obtaining unprocessed traces for said source-receiver pair positions; a fifth step of selecting at least one optimum unprocessed trace from among said unprocessed traces; and a sixth step of determining the source-receiver pair positions corresponding to said at least one optimum unprocessed trace.

Abstract: A method for monitoring a subsurface during a 4-dimensional (4D) survey. The method includes obtaining an area of the subsurface that needs to be monitored; identifying receiver and source locations for the area and source frequencies to be emitted into the area based on demigration or inverse ray tracing; performing a light base survey for the area; performing a light monitor survey for the area; and generating an image of the area based on a comparison of (i) the light base survey, and (ii) the light monitor survey for the area.