Abstract: Tools, systems, and methods may be configured for or include detecting one or more underground acoustic sources and localizing them in depth and radial distance from a wellbore using an array of at least three acoustic sensors disposed in the wellbore in conjunction with array-signal-processing that accounts for movement of the acoustic sensors and spatial aliasing by using adaptive time dependent modelled steering vector weights.

Abstract: The disclosed embodiments include leak detection systems and methods of downhole leak detection. In one embodiment, the method includes obtaining physical signals measured by at least one physical sensor traveling along a wellbore. The method also includes performing a frame decomposition operation on the physical signals of a first of the at least one the physical sensor to obtain a plurality of virtual signals associated with an array of virtual sensors, each virtual sensor of the array of virtual sensors being located at a virtual distance relative to the first physical sensor, the virtual distance corresponding to a physical distance. The method further includes synchronizing the virtual signals of the array of virtual sensors. The method further includes computing a spatial spectrum indicative of a location of a leak based on the synchronized virtual signals.

Abstract: The disclosed embodiments include leak detection systems and methods of downhole leak detection. In one embodiment, the method includes obtaining physical signals measured by at least one physical sensor traveling along a wellbore. The method also includes performing a frame decomposition operation on the physical signals of a first of the at least one the physical sensor to obtain a plurality of virtual signals associated with an array of virtual sensors, each virtual sensor of the array of virtual sensors being located at a virtual distance relative to the first physical sensor, the virtual distance corresponding to a physical distance. The method further includes synchronizing the virtual signals of the array of virtual sensors. The method further includes computing a spatial spectrum indicative of a location of a leak based on the synchronized virtual signals.

Abstract: A digital excitation signal generator can be used to modulate excitation current or voltage to be injected into a subterranean formation by a downhole logging tool. The digital excitation signal generator can include a processor and a pulse-width modulator (“PWM”) device. The processor can generate a digital waveform and provide the digital waveform to the PWM device. The PWM device can convert the digital waveform into PWM pulses. The PWM device can be coupled to an interface. The interface can use the PWM pulses to modulate a voltage or current to be provided to an excitation electrode in the downhole logging tool. The digital excitation signal generator can also include a feedback module for maintaining a constant current output or constant voltage output to the excitation electrode.

Abstract: Tools, systems, and methods may be configured for or include detecting one or more underground acoustic sources and localizing them in depth and radial distance from a wellbore using an array of at least three acoustic sensors disposed in the wellbore in conjunction with array-signal-processing that accounts for movement of the acoustic sensors and spatial aliasing by using adaptive time dependent modelled steering vector weights.