Abstract: An acoustic telemetry unit comprising an acoustic receiver for receiving acoustic telemetry signals is disclosed. The acoustic telemetry unit comprises a filter for filtering signals received by the acoustic receiver, a processor for processing signals passed by the filter to recover a data signal, the processor being operable in a sleep mode, and means for waking the processor from the sleep mode in dependence on an output of the filter. An energy storage module may be charged using signals received by the acoustic receiver which are not passed by the filter. The disclosed techniques may help to conserve battery power.

Abstract: An acoustic telemetry unit comprising an acoustic receiver for receiving acoustic telemetry signals is disclosed. The acoustic telemetry unit comprises a filter for filtering signals received by the acoustic receiver, a processor for processing signals passed by the filter to recover a data signal, the processor being operable in a sleep mode, and means for waking the processor from the sleep mode in dependence on an output of the filter. An energy storage module may be charged using signals received by the acoustic receiver which are not passed by the filter. The disclosed techniques may help to conserve battery power.

Abstract: A setting tool is disclosed for setting an acoustic telemetry unit in tubing, such as wellbore tubing. The setting tool comprises an anchor motor for driving an expandable anchor, a control unit for controlling the anchor motor, and an acoustic receiver. The control unit is arranged to determine whether an acoustic signal is successfully received by the acoustic receiver and to control the anchor motor in dependence thereon. By providing the setting tool with the acoustic receiver and determining whether an acoustic signal is successfully received by the acoustic receiver, it can be judged whether an acoustic signal from another acoustic telemetry unit in the tubing can be successfully received by the acoustic telemetry unit which is being set. This may facilitate deployment of a repeater unit at an optimum distance from another acoustic telemeter unit which is already in the tubing.

Abstract: An acoustic telemetry unit comprising an acoustic receiver for receiving acoustic telemetry signals is disclosed. The acoustic telemetry unit comprises a filter for filtering signals received by the acoustic receiver, a processor for processing signals passed by the filter to recover a data signal, the processor being operable in a sleep mode, and means for waking the processor from the sleep mode in dependence on an output of the filter. An energy storage module may be charged using signals received by the acoustic receiver which are not passed by the filter. The disclosed techniques may help to conserve battery power.

Abstract: A gauge hanger for deployment in a wellbore using a setting tool is disclosed. The gauge hanger comprises a switchable magnet for attaching the gauge hanger to a wellbore wall, and a coupling assembly for coupling the gauge hanger to the setting tool. The switchable magnet and the coupling assembly are arranged to be actuated by a common actuator such as a motor in the setting tool.

Abstract: A setting tool is disclosed for setting an acoustic telemetry unit in tubing such as wellbore tubing. The setting tool comprises an anchor motor for driving an expandable anchor, a control unit for controlling the anchor motor, and an acoustic receiver. The control unit is arranged to determine whether an acoustic signal is successfully received by the acoustic receiver and to control the anchor motor in dependence thereon. By providing the setting tool with the acoustic receiver and determining whether an acoustic signal is successfully received by the acoustic receiver, it can be judged whether an acoustic signal from another acoustic telemetry unit in the tubing can be successfully received by the acoustic telemetry unit which is being set. This may facilitate deployment of a repeater unit at an optimum distance from another acoustic telemeter unit which is already in the tubing.

Abstract: An energy storage system is disclosed. The energy storage system comprises an energy storage device configured to operate above ambient temperature, and a thermal insulator at least partially surrounding the energy storage device, wherein heat losses from one or more other devices are received within the thermal insulator to provide heat energy to the energy storage device. Utilizing heat losses from one or more other devices, such as associated electronic components, enables the energy storage device to be maintained at its elevated operational temperature for longer providing extended battery life. In the application of wireline logging, this results in more data log available per trip in a well.

Abstract: A method for identifying the location of a binding zone between a stuck tubular and a borehole includes the steps of passing a demagnetizing stress sensor through the tubular on a baseline magnetization pass to magnetize the tubular. Next, the demagnetizing stress sensor measures a baseline magnetization of the tubular. Once the baseline magnetization has been established, the method continues by applying a stress to the tubular and passing the demagnetizing stress sensor through the tubular on a scanning pass while the tubular is stressed. The demagnetizing stress sensor then measures a stress-induced magnetization of the tubular. The method concludes by comparing the baseline magnetization of the tubular against the stress-induced magnetization of the tubular. Notably, in preferred embodiments, the method includes the magnetization of the tubular in a substantially radial direction and the stresses are applied in vectors perpendicular to the radial magnetization of the tubular.

Abstract: A positional feedback system includes a seal assembly coupled to a running tool, the seal assembly having a seal ring and an energizing ring positioned between a hanger and a subsea wellhead. The energizing ring moves relative to the seal ring from an unset position to a set position to seal to the wellhead and the hanger. The system includes a magnet disposed on the energizing ring and having a magnetic field. One or more sensing devices are disposed on running tool and positioned in the magnetic field of the magnet in the set position and the unset position. The sensing devices are configured to communicate with a surface platform when the rare earth magnet passes a magnetic field through the sensing devices.

Abstract: An apparatus for determining the concentration of a conductive fluid present in a fluid filled bore hole is described. Such apparatus are known as water hold-up meters and are frequently used in oil, gas and water filled bore holes. In bore hole applications, data bandwidth between a down hole device and the surface can be limited, while determining water hold-up based on down hole measurements can be data intensive. A technique is proposed for calculating the water hold up that requires less data to be transmitted between the down hole device and the surface.

Abstract: A method for identifying the location of a binding zone between a stuck tubular and a borehole includes the steps of passing a demagnetizing stress sensor through the tubular on a baseline magnetization pass to magnetize the tubular. Next, the demagnetizing stress sensor measures a baseline magnetization of the tubular. Once the baseline magnetization has been established, the method continues by applying a stress to the tubular and passing the demagnetizing stress sensor through the tubular on a scanning pass while the tubular is stressed. The demagnetizing stress sensor then measures a stress-induced magnetization of the tubular. The method concludes by comparing the baseline magnetization of the tubular against the stress-induced magnetization of the tubular. Notably, in preferred embodiments, the method includes the magnetization of the tubular in a substantially radial direction and the stresses are applied in vectors perpendicular to the radial magnetization of the tubular.

Abstract: A positional feedback system includes a seal assembly coupled to a running tool, the seal assembly having a seal ring and an energizing ring positioned between a hanger and a subsea wellhead. The energizing ring moves relative to the seal ring from an unset position to a set position to seal to the wellhead and the hanger. The system includes a magnet disposed on the energizing ring and having a magnetic field. One or more sensing devices are disposed on running tool and positioned in the magnetic field of the magnet in the set position and the unset position. The sensing devices are configured to communicate with a surface platform when the rare earth magnet passes a magnetic field through the sensing devices.

Abstract: An energy storage system is disclosed. The energy storage system comprises an energy storage device configured to operate above ambient temperature, and a thermal insulator at least partially surrounding the energy storage device, wherein heat losses from one or more other devices are received within the thermal insulator to provide heat energy to the energy storage device. Utilising heat losses from one or more other devices, such as associated electronic components, enables the energy storage device to be maintained at its elevated operational temperature for longer providing extended battery life. In the application of wireline logging, this results in more data log available per trip in a well.

Abstract: An apparatus for determining the concentration of a conductive fluid present in a fluid filled bore hole is described. Such apparatus are known as water hold-up meters and are frequently used in oil, gas and water filled bore holes. In bore hole applications, data bandwidth between a down hole device and the surface can be limited, while determining water hold-up based on down hole measurements can be data intensive. A technique is proposed for calculating the water hold up that requires less data to be transmitted between the down hole device and the surface.

Abstract: A shock absorbing tool for use in pipelines and oil wells, particularly in combination with perforation guns comprises a central mass supported on two springs between the end terminal members. The shock wave is absorbed in the free oscillation of the mass. The mass is constituted by a piston assembly. A steel rope permits the shock absorbing tool to be maneuvered within the bore hole without damage to the springs.

Abstract: A tubular cutting tool includes two or more sets of electrically actuated retractable anchoring legs mounted at longitudinally spaced apart locations and an electrically driven rotary cutting head with a retractable cutting blade. The anchoring legs can be arranged such that they are capable of compensating for variations in the internal radii of the tubular to be cut, thereby ensuring that the cutting tool is clamped rigidly in position.

Abstract: A shock absorbing tool for use in pipelines and oil wells, particularly in combination with perforation guns comprises a central mass supported on two springs between the end terminal members. The shock wave is absorbed in the free oscillation of the mass. The mass is constituted by a piston assembly. A steel rope permits the shock absorbing tool to be maneuvered within the bore hole without damage to the springs.

Abstract: A tubular cutting tool includes two or more sets of electrically actuated retractable anchoring legs (52,54) mounted at longitudinally spaced apart locations and an electrically driven rotary cutting head (14) with a retractable cutting blade (14). The anchoring legs can be arranged such that they are capable of compensating for variations in the internal radii of the tubular to be cut, thereby ensuring that the cutting tool is clamped rigidly in position.