Abstract: A tool and a method for determining material quality of a hydrocarbon wellbore cross section, having one or more tubular elements having filling materials in between, is described. A tool includes a body and moveable assemblies, having multiple arms configured to be in contact with an inner wall of a downhole tubular element, that that are configured to move between a retracted position where the multiple arms of the moveable assemblies are within a housing located in the body of the tool and an extended position where the multiple arms of the moveable assemblies are protruding from the housing and are in contact with the inner wall of the downhole tubular element. The moveable assemblies comprise both an acoustic broad band source array that operates in the frequency range of 0-100 kHz and an acoustic broad band receiver array having a radially spaced acoustic broad band receiver.

Abstract: Methods are disclosed for evaluating a material on a remote side of a partition separating first and second domains wherein flexural waves within the partition are received by spaced-apart ultrasonic receivers and processed to determine the velocity of the waves propagating into the second domain from a first receiver to a second receiver located more remote from the transmitter than the first receiver and whose separation from the first receiver is known. Comparison of a theoretical phase velocity with the measured phase velocity of the recorded waves allows determination as to whether the flexural wave is propagating through solid. This may be based on a measurable deviation between the two curves occurring at a critical frequency, which may be identified by a perturbation in a group velocity plot. Discrimination may also be based on the gradient of a straight line that best-fits the attention dispersion of the frequency spectrum.

Abstract: Methods are disclosed for evaluating a material on a remote side of a partition separating first and second domains wherein flexural waves within the partition are received by spaced-apart ultrasonic receivers and processed to determine the velocity of the waves propagating into the second domain from a first receiver to a second receiver located more remote from the transmitter than the first receiver and whose separation from the first receiver is known. Comparison of a theoretical phase velocity with the measured phase velocity of the recorded waves allows determination as to whether the flexural wave is propagating through solid. This may be based on a measurable deviation between the two curves occurring at a critical frequency, which may be identified by a perturbation in a group velocity plot. Discrimination may also be based on the gradient of a straight line that best-fits the attention dispersion of the frequency spectrum.

Abstract: A tool and method for determining material quality of hydrocarbon wellbore cross sections comprising tubular elements and filling materials, the tool comprising: a body; moveable assemblies having arms configured to be in contact with an inner wall of a downhole tubular element, wherein the plurality of the moveable assemblies are configured to move between a retracted position where the arms are within a housing located in the body of the tool and an extended position where the arms protrude from the housing and are in contact with the inner wall of the downhole tubular element, wherein at least one of the plurality of moveable assemblies comprises an acoustic broad band source array operating in the frequency range of 0-100 kHz and at least one of the plurality of moveable assemblies comprises an acoustic broad band receiver array comprising one or more radially spaced acoustic broad band receivers.

Abstract: A semi-passive acoustic transponder providing identity information related to the transponder when it is reflecting a received pulsed acoustic signal underwater. The transponder includes a memory unit holding ID-sequence data controlling operation of the switching device, and an electronic circuit includes frequency adjusting means for adjusting the frequency and duration of the switch such that the duration of the ID-sequence data is shorter than the duration of pulses of the received acoustic signal. Additionally, a method and system may provide position and identity information related to one or more of said semi-passive acoustic transponders.

Abstract: A tool and a method for determining material quality of a hydrocarbon wellbore cross section, having one or more tubular elements having filling materials in between, is described. A tool includes a body and moveable assemblies, having multiple arms configured to be in contact with an inner wall of a downhole tubular element, that that are configured to move between a retracted position where the multiple arms of the moveable assemblies are within a housing located in the body of the tool and an extended position where the multiple arms of the moveable assemblies are protruding from the housing and are in contact with the inner wall of the downhole tubular element. The moveable assemblies comprise both an acoustic broad band source array that operates in the frequency range of 0-100 kHz and an acoustic broad band receiver array having a radially spaced acoustic broad band receiver.

Abstract: A semi-passive acoustic transponder providing identity information related to the transponder when it is reflecting a received pulsed acoustic signal underwater. The transponder includes a memory unit holding ID-sequence data controlling operation of the switching device, and an electronic circuit includes frequency adjusting means for adjusting the frequency and duration of the switch such that the duration of the ID-sequence data is shorter than the duration of pulses of the received acoustic signal. Additionally, a method and system may provide position and identity information related to one or more of said semi-passive acoustic transponders.