Abstract: The present invention relates to a method and device for promoting oil recovery.The device according to the invention for promoting the recovery of oil contained in a reservoir formation from a well equipped with a casing, comprises an anode which is placed at the bottom of the well, below said reservoir formation, in an electro-conductive liquid, and which is connected to the positive terminal of a direct or pulsed source of unidirectional voltage. Said casing is connected to the negative terminal of said source. The method consists in applying a unidirectional voltage for periods varying between several days and several months and alternating with OFF-period (when no voltage is applied).

Abstract: The invention relates to method and apparatus for geophysical prospecting by radioactive diagraphy of a drillhole, using a probe containing a radioactive source and one or two detectors of delayed particles emitted by the terrain bombarded by the said source. The source is moved periodically, within the probe, vertically away from the detector, and the detector is moved, in synchronism with the said source, in order to locate it opposite the zone which has just been bombarded.