Abstract: When manufacturing a pipeline that carries an array of electrical cables, insulation resistance monitoring is performed by a monitoring unit that is connected to the cables of the array and is mounted to a leading end of the pipeline. The monitoring unit tests the cables cyclically in succession. Monitoring is performed on the cables after their application to the pipeline and while the pipeline and the cables advance together through further manufacturing processes, such as insertion of the pipeline into the outer pipe of a pipe-in-pipe structure. If a fault is detected in any of the cables, an alert can be raised quickly enough to stop the process and to rectify the fault before the fault is covered and rendered inaccessible. The pipeline and the cables can advance continuously unless a fault is detected.

Abstract: The present invention relates to a drill string fitted with information transmission means. The hollow rods of conductive material have their inside faces covered in an insulating material. The transmission means comprise a first electrical unit having at least a first annular electrode secured to the insulating inside face of the drill string, said electrode being in electrical contact with the mud contained inside the drill string so as to establish a flow of current in the conductive mud; and a second electrical unit disposed in said borehole, close to the top end of the drill string in order at least to receive the information contained in said electrical current.

Abstract: The invention relates to a hollow drilling rod for transmitting information, said rod being for placing in a borehole filled with drilling mud. The rod comprises an electrically conductive cylindrical wall (521, 522) having an inside face, an outside face, a first end provided with a male coupling sleeve (62), and a second end provided with a female coupling sleeve (60), and being characterized in that it further comprises: a layer of electrically insulating material (70) covering the inside face over its entire length; and a conductive layer (80) covering said insulating layer and electrically connected at its ends to two electrically conductive rings, said conductive layer itself being covered by a second insulating layer (86) leaving said conductive rings in contact with the drilling mud.

Abstract: The invention relates to a hollow drilling rod for transmitting information, said rod being for placing in a borehole filled with drilling mud.

Abstract: The present invention relates to a drill string fitted with information transmission means. The hollow rods of conductive material have their inside faces covered in an insulating material. The transmission means comprise a first electrical unit having at least a first annular electrode secured to the insulating inside face of the drill string, said electrode being in electrical contact with the mud contained inside the drill string so as to establish a flow of current in the conductive mud; and a second electrical unit disposed in said borehole, close to the top end of the drill string in order at least to receive the information contained in said electrical current.

Abstract: A device for determining the position of a moving part, particularly to a device containing a sensor carried by the moving part and designed to supply two out-of-phase signals, each assuming alternately the value 0 or 1 as the sensor is carried in one or the other direction.

Abstract: A method of obtaining the peak value of a signal. The signal is sampled at certain intervals of time. The value of the sampled signal is compared subsequent to sampling with a value previously stored in a memory. The higher of the two compared values is stored in the memory for later comparison with a value obtained during a subsequent sampling. The higher of the values stored in the memory is stored in another memory after a maximum signal has been obtained.