Abstract: Methods and devices for determining the quality of an oil well reserve or the like delivering a given fluid derived from a productive layer, by measuring the response R of the well. The method implemented by the device comprises modulating the fluid flow rate (4) in the well (1) by a sinusoidal function with a controllable preventer (5), and measuring the variations in flow rate and pressure of the fluid respectively with a flow meter (7) and a pressure sensor (9), the response Rc of the well (1); if the productive layer comprises a damaged zone having a positive formation damage of non-null thickness, is obtained by the equation (I), and the response Rf of the well; if the productive layer comprises a fracture having a negative formation damage, is obtained by the equation (II). The invention is applicable to oil prospecting.

Abstract: The invention concerns methods and devices for determining the quality of an oil well reserve or the like delivering a given fluid derived from a productive layer, by measuring the response R of the well. The inventive method implemented by the device is characetrised in that it consists in modulating the fluid flow rate (4) in the well (1) by a sinusoidal function by means of a controllable preventer (5), and in measuring the variations in flow rate and pressure of the fluid respectively with a flow meter (7) and a pressure sensor (9), the response Rc of the well (1); if the productive layer comprises a damaged zone having a positive formation damage of non-null thickness, is obtained by the equation (1), and the response Rf the well; if the productive layer comprises a fracture having a negative formation damage, is obtained by the equation (11). The invention is applicable to oil prospecting.

Abstract: The present invention relates to analysis tools for analyzing the ground 1, from a surface 2 thereof, by means of a sonde 3 having a given analysis lobe 4 and a resolution time T. The tool of the invention is essentially characterized by the fact that it comprises a drive head 10 driven to move in continuous translation at a speed V relative to the surface 2 and along a direction 11 parallel to the surface 2, a skid 12, means 13 for associating the sonde 3 and the skid 12 so that the sonde can analyze the rocks contained in its lobe 4, and means 14 for coupling together the drive head 10 and the skid 12 so that the two elements can be displaced relative to each other along the direction 11 over a distance D. The tool of the invention finds a particularly advantageous application in analyzing oil-bearing rocks surrounding the wall 30 of an oil well 31, in order to determine both the distribution of the porosity of the rocks, and their associated permeability.