Abstract: A downhole tool orientation determination system to determine a radial orientation of a tool conveyed downhole into a pipe via a carrier and a method of determining a radial orientation of a tool conveyed downhole into a pipe via a carrier are described. The system includes an orientation tool conveyed downhole by the carrier that conveys the tool, and a distributed acoustic sensor (DAS). The DAS includes an optical fiber disposed axially along an outer surface of the pipe; and a processor to determine an orientation of the orientation tool with respect to the optical fiber based on a measurement by the optical fiber at different rotational positions of the orientation tool. The processor determines the radial orientation of the tool with respect to the optical fiber based on the orientation of the orientation tool with respect to the optical fiber.

Abstract: A method of monitoring acoustic energy using distributed acoustic sensing. The method involves supplying a fluid flow at different pressures and sensing fluid flow characteristics in at least one location at each pressure. The data may be processed to provide a fluid resistance value related to a particular fluid flow at each location, collectively forming a fluid resistance index (FRI). The method may include following the initial fluid flow with a process flow, which may then be followed by another fluid flow. The flow characteristics of the latter fluid flow may be measured and compared with the initial fluid flow, providing a measure of the success of the process flow. In application, this method may be used to enhance downhole operations, including acid stimulation treatments.

Abstract: A system includes a distributed acoustic sensing (DAS) optical fiber configured to be disposed with a downhole component, an interrogation device including an optical signal source configured to inject an optical signal into the DAS optical fiber and a receiver configured to detect return signals reflected from sensing locations in the fiber, and an acoustic telemetry unit configured to receive a communication from the downhole component and generate an acoustic signal having a frequency within a selected frequency range and encoded to carry the communication, the acoustic signal applied to a first section of the DAS optical fiber. The system also includes a processor configured to associate a first portion of the return signals with the first section and reproduce the communication based on the first portion, and associate a second portion of the return signals with a second section of the fiber and detect one or more acoustic events.

Abstract: An apparatus for monitoring vibration of a downhole component includes an optical fiber sensor including at least one optical fiber operably connected to an interrogation unit. The at least one optical fiber has a resonant segment that is fixedly attached to the component via attachment points on the component, the resonant segment between the attachment points being separate from the component and having a resonant frequency based at least on the length of the resonant segment.

Abstract: A system includes a distributed acoustic sensing (DAS) optical fiber configured to be disposed with a downhole component, an interrogation device including an optical signal source configured to inject an optical signal into the DAS optical fiber and a receiver configured to detect return signals reflected from sensing locations in the fiber, and an acoustic telemetry unit configured to receive a communication from the downhole component and generate an acoustic signal having a frequency within a selected frequency range and encoded to carry the communication, the acoustic signal applied to a first section of the DAS optical fiber. The system also includes a processor configured to associate a first portion of the return signals with the first section and reproduce the communication based on the first portion, and associate a second portion of the return signals with a second section of the fiber and detect one or more acoustic events.

Abstract: A method of monitoring fluid flow in a borehole includes measuring acoustics at a plurality of locations along a downhole assembly in a borehole and calculating a fluid flow rate at the plurality of locations along the downhole assembly based on measuring the acoustics at the plurality of locations.

Abstract: A method of monitoring and assessing valve conditions in a pump includes collecting data regarding timing of a pump piston and vibration of a pump fluid end, processing the data to form a filtered and transformed vibration signal, banding the vibration signal into high energy bands and low energy bands, and comparing a ratio of at least one high energy band to at least one low energy band of the vibration signal with at least one constant to determine valve condition.

Abstract: A downhole tool orientation determination system to determine a radial orientation of a tool conveyed downhole into a pipe via a carrier and a method of determining a radial orientation of a tool conveyed downhole into a pipe via a carrier are described. The system includes an orientation tool conveyed downhole by the carrier that conveys the tool, and a distributed acoustic sensor (DAS). The DAS includes an optical fiber disposed axially along an outer surface of the pipe; and a processor to determine an orientation of the orientation tool with respect to the optical fiber based on a measurement by the optical fiber at different rotational positions of the orientation tool. The processor determines the radial orientation of the tool with respect to the optical fiber based on the orientation of the orientation tool with respect to the optical fiber.

Abstract: A passive acoustic system and a method of utilizing the passive acoustic system in a subsurface borehole are discussed. The method includes disposing the passive acoustic system in the borehole, the passive acoustic system including at least one passive acoustic resonator, and monitoring a frequency of an acoustic signal at the at least one passive acoustic resonator. The passive acoustic system includes a protective tubing, a fiber optic cable disposed within the protective tubing, a fluid layer between the fiber optic cable and the protective tubing, and at least one passive acoustic resonator, the at least one passive acoustic resonator representing an area within the protective tubing having a known geometry, wherein the fluid layer affects a frequency of an acoustic signal obtained from the at least one passive acoustic resonator.

Abstract: A downhole acoustic sensing system includes a pulsator device configured and disposed to be arranged in a downhole environment, and a control system operatively connected to the pulsator device. The control system delivers at least one control input to the pulsator device to generate a sinusoidal acoustic signal.

Abstract: A method of monitoring fluid flow in a borehole includes measuring acoustics at a plurality of locations along a downhole assembly in a borehole and calculating a fluid flow rate at the plurality of locations along the downhole assembly based on measuring the acoustics at the plurality of locations.

Abstract: A system and method for measuring the vibration of a structure of interest are disclosed. The disclosure provides an acoustic isolation structure to substantially reduce response to acoustic energy generated by external physical stimuli. The acoustic isolation structure is formed by placing a housing, such as an outer conduit, around an inner conduit, forming a gap between the housing and the inner conduit. The gap is then configured to serve as an acoustic isolation layer by either filling the gap with an acoustic isolation material or by substantially evacuating the gap and sealing the ends thereof.

Abstract: An apparatus for monitoring vibration of a downhole component includes an optical fiber sensor including at least one optical fiber operably connected to an interrogation unit. The at least one optical fiber has a resonant segment that is fixedly attached to the component via attachment points on the component, the resonant segment between the attachment points being separate from the component and having a resonant frequency based at least on the length of the resonant segment.

Abstract: A method of monitoring acoustic energy using distributed acoustic sensing. The method involves supplying a fluid flow at different pressures and sensing fluid flow characteristics in at least one location at each pressure. The data may be processed to provide a fluid resistance value related to a particular fluid flow at each location, collectively forming a fluid resistance index (FRI). The method may include following the initial fluid flow with a process flow, which may then be followed by another fluid flow. The flow characteristics of the latter fluid flow may be measured and compared with the initial fluid flow, providing a measure of the success of the process flow. In application, this method may be used to enhance downhole operations, including acid stimulation treatments.

Abstract: A passive acoustic system and a method of utilizing the passive acoustic system in a subsurface borehole are discussed. The method includes disposing the passive acoustic system in the borehole, the passive acoustic system including at least one passive acoustic resonator, and monitoring a frequency of an acoustic signal at the at least one passive acoustic resonator. The passive acoustic system includes a protective tubing, a fiber optic cable disposed within the protective tubing, a fluid layer between the fiber optic cable and the protective tubing, and at least one passive acoustic resonator, the at least one passive acoustic resonator representing an area within the protective tubing having a known geometry, wherein the fluid layer affects a frequency of an acoustic signal obtained from the at least one passive acoustic resonator.