Abstract: A method and a system for the transmission of information from a well (1; 20) drilled through geological formation layers (3) at least partly cased by metal tubes (4; 23; 24; 31). The method includes the placing in said well of an information transceiver (E) operating by electromagnetic waves created by the injection of an electric signal by a dipole (P1-P2) conductively connected to the metal tubes used for guiding the transmitted waves. In the method, identification takes place of the attenuation of the transmission by certain formation layers (3a, 3b; 25; 30) having a low resistivity and then there is an at least partial electrical insulation of the metal tubes located opposite the low resistivity layers.

Abstract: Seismic waves are recorded twice by a reference sensor (8) above ground and by a sensor (18) located in the drill hole (1). Measurements are synchronized by a clock system, the clock associated with sensor (18) being designed specifically for providing such synchronization in spite of operating conditions prevailing at the bottom of a drill hole (vibrations, shocks, temperature).

Abstract: This invention relates to a device for measuring the flow rate of spoil from a drilling brought to the surface by means of a drilling fluid. The device comprises means of collecting the spoil and means of continuously measuring the weight of spoil collected. The means of collecting the spoil comprise a receptacle in the shape of bucket articulated about a spindle and means of tilting the receptacle in such a way that the bucket is emptied. The measurement means comprise a measuring cell connected to the tilting means in order to measure a stress proportional to the weight of the spoil collected. The invention also relates to a method for the application of a measurement of the spoil flow rate from a drilling.

Abstract: An apparatus and process for measuring the uncoiled length or coiled length of a cable of a winding gear such as a winch marks the cable along a generatrix of winding passing from one point of one turn of a layer of turns of the cable wound on a drum or on a subsequent layer carrying the cable for each would layer and on the total length of the cable corresponding to this layer at least one pair of equi-distant bench marks. A comparison is then made between the overall length, reeled off for each layer, and corresponding to the algebraic sum of the series of equal sections between them for each layer, to that calculated for a standard layer traversed by the cable.