Abstract: A centralizer operable to connect with and centralize a downhole tool within a tubular string within a wellbore and to facilitate reception of electromagnetic signals transmitted through the Earth. The centralizer has a body, a first contacting member electrically connected to the body and extending radially away from the body such that the first contacting member contacts an inner surface of the tubular string to electrically connect the tubular string to the body, and a second contacting member electrically insulated from the body and extending radially away from the body such that the second contacting member contacts the inner surface of the tubular string to centralize at least a portion of the body within the tubular string.

Abstract: A centralizer operable to connect with and centralize a downhole tool within a tubular string within a wellbore and to facilitate reception of electromagnetic signals transmitted through the Earth. The centralizer has a body, a first contacting member electrically connected to the body and extending radially away from the body such that the first contacting member contacts an inner surface of the tubular string to electrically connect the tubular string to the body, and a second contacting member electrically insulated from the body and extending radially away from the body such that the second contacting member contacts the inner surface of the tubular string to centralize at least a portion of the body within the tubular string.

Abstract: The disclosure relates to a method for monitoring the performances of a cable for carrying a downhole assembly in a wellbore, the cable having at least a conductive core and an insulating outer layer, the method including: performing on the cable a detection operation for detecting the presence of local anomalies of the cable; generating an electrical model of a predetermined configuration of an installation including the cable and the downhole assembly disposed in the wellbore, the model being defined in function of the detected local anomalies, estimating a parameter relative to a signal transmitted by the cable between the downhole assembly and a surface equipment in the predetermined configuration on the basis of the electrical model.

Abstract: Apparatus and methods for triggering a downhole tool. The tool string may have an electrical power source and a trigger tool that may be configured for receiving electrical power from the electrical power source and outputting different forms of electrical power each being different from the form of electrical power received from the electrical power source. Each form of electrical power output by the trigger tool may initiate operation of a corresponding one of different electro-mechanical tools connectable within the downhole tool string. A trigger command is transmitted from the surface equipment to the trigger tool to cause the trigger tool to output electrical power having a form corresponding to the electro-mechanical tool connected within the tool string to thereby initiate operation of such electro-mechanical tool.

Abstract: A method for conveying an interventional tool downhole in a substantially self-piloting fashion. The method includes moving the tool in the well while using a communicative conveyance line coupled to a winch at the oilfield surface. Thus, real-time readings regarding downhole tool speed, line tension, etc. may be analyzed at surface and utilized to adjust the moving of the tool in an ongoing feedback loop. As a result, the adjustments are made based on true circumstances downhole as opposed to surface-based readings which may otherwise be less accurate. Therefore, efficiency of the operations may be maximized, operator time freed and the likelihood of catastrophic line based failures reduced.

Abstract: The disclosure relates to a method for monitoring the performances of a cable for carrying a downhole assembly in a wellbore, the cable having at least a conductive core and an insulating outer layer, the method including: performing on the cable a detection operation for detecting the presence of local anomalies of the cable; generating an electrical model of a predetermined configuration of an installation including the cable and the downhole assembly disposed in the wellbore, the model being defined in function of the detected local anomalies, estimating a parameter relative to a signal transmitted by the cable between the downhole assembly and a surface equipment in the predetermined configuration on the basis of the electrical model.

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: 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).