Method for monitoring a point of interest in a subsoil

Method to monitor at least one area of interest of a subsurface to be observed comprising a point of interest and a neighborhood of the aforesaid point of interest, comprising:

• an extraction of the first subset (1) of raw geophysical data associated with the neighbourhood of the point of interest, among a set (0) of raw geophysical data acquired previously, and processed beforehand to generate the first previous image (Im1) of the subsurface to be monitored;
• a construction of a first projection model (MOD1) from the first subset of data (1), the first projection model (MOD1) resulting from a segregation of geophysical data, to extract useful geophysical data used while the first image (Im1) is being generated in the neighbourhood of the point of interest;
• and
• a reduction of the first subset (1) of data to the second subset (2) comprising a predetermined minimal number of raw geophysical data;
• the creation of a first reference set of useful geophysical data (B) by applying the first projection operator to the second subset (2), the first projection operator being configured so that a first correlation coefficient between the first reference set of useful geophysical data (B) obtained and the first projection model (MOD1) is greater than 0.7;
• an acquisition of raw geophysical data that forms a third subset of raw geophysical data (3) comprising the same minimal number of raw geophysical data as the second subset (2), each piece of data from the third subset (3) corresponding to a piece of data from the second subset (2);
• the creation of the first set of useful monitoring geophysical data (M), by applying the same first projection operator from the first projection model (MOD1), to the third subset (3);
• and
• a comparison of the first reference set (B) and the first monitoring set (M) to identify an evolution of the subsurface to be monitored.