Abstract: A method for distributed acoustic sensing includes sending a first optical pulse down an optical fiber, wherein light from the first optical pulse is backscattered from positions along a length of the optical fiber according to coherent Rayleigh scattering; splitting backscattered light from the first optical pulse into a first portion for a first interferometer and a second portion for a second interferometer, the first interferometer having a first gauge length and the second interferometer having a second gauge length, wherein the first gauge length is different from the second gauge length; detecting a first interferometric signal from the first interferometer responsive to the first portion of backscattered light; detecting a second interferometric signal from the first interferometer responsive to the second portion of backscattered light; and processing the first and second interferometric signals for two different sensing applications adapted for the first and second gauge lengths, respectively.

Abstract: A method for distributed acoustic sensing includes sending a first optical pulse down an optical fiber, wherein light from the first optical pulse is backscattered from positions along a length of the optical fiber according to coherent Rayleigh scattering; splitting backscattered light from the first optical pulse into a first portion for a first interferometer and a second portion for a second interferometer, the first interferometer having a first gauge length and the second interferometer having a second gauge length, wherein the first gauge length is different from the second gauge length; detecting a first interferometric signal from the first interferometer responsive to the first portion of backscattered light; detecting a second interferometric signal from the first interferometer responsive to the second portion of backscattered light; and processing the first and second interferometric signals for two different sensing applications adapted for the first and second gauge lengths, respectively.

Abstract: In the general context of oilfield equipment and, in particular, in the context of downhole tools, the systems and methods relate to characterizing flow in a wellbore using data collection devices, which may be temporarily attached on the outside of a work string to be run into the wellbore. More particularly, the systems and methods may be used for obtaining flow data at a plurality of different locations and correlated with wellbore depth for evaluation of production profiles of wellbores. A system may be provided that comprises a work string, multiple external support devices temporarily secured to an exterior of the work string at a plurality of different locations, and at least one data collection device such as a resistivity gauge, flow meter, and/or Doppler sensor, coupled to the external support devices. This data, once recovered on surface, could be incorporated into an overall production profile model of the well.

Abstract: Screen-outs can be detected from acoustical signals in a wellbore. Data based on an acoustic signal generated during a hydraulic fracturing operation in a wellbore formed through a subterranean formation can be received. An expected total flow rate of fluid being injected into the wellbore can be determined based on the data. An actual total flow rate of the fluid being injected into the wellbore can be determined. A screen-out that occurred can be identified by comparing the expected total flow rate and the actual total flow rate.

Abstract: Disclosed are systems and methods for receiving surface data and downhole sensor data associated with at least one first hydraulic fracturing well, generating a prediction model for the at least one first hydraulic fracturing well that determines a prediction for a subsurface value for the at least one first hydraulic fracturing well, generating an error model for the at least one first hydraulic fracturing well that determines an estimated prediction error between the prediction for the subsurface value for the at least one first hydraulic fracturing well and an actual subsurface value for the at least one first hydraulic fracturing well, determining a status of at least one feature associated with the estimated prediction error between a prediction for a subsurface value for at least one second hydraulic fracturing well and an actual subsurface value for the at least one second hydraulic fracturing well, and collecting additional downhole sensor data.

Abstract: The present disclosure generally relates to oilfield equipment and, in particular, to downhole tools, and related systems and methods for characterizing flow in a wellbore. More particularly, the present disclosure relates to methods and systems for obtaining flow data for evaluation of production profiles of wellbores. A system may be provided that comprises a work string, an external support device secured to an exterior of the work string, and at least one data collection device coupled to the external support device.

Abstract: In accordance with presently disclosed embodiments, a method and system for performing real-time evaluation of a restimulation operation using coiled tubing with fiber optics is provided. The method involves performing a restimulation treatment by pumping a slurry with diverter materials through an annulus in the wellbore surrounding the coiled tubing, and using fiber optics in the coiled tubing to identify the order and magnitude of fractures being created during the restimulation treatment. The fiber optics in the coiled tubing may include one or more fiber optic cables designed to collect distributed acoustic sensing (DAS) or distributed temperature sensing (DTS) data. The evaluation of the restimulation operation may be used to validate and/or adjust the restimulation treatment as needed to improve the lateral distribution of transverse fractures through a subterranean formation. The coiled tubing may also be used to remove sand bridges from the wellbore throughout the restimulation treatment.

Abstract: Screen-outs can be detected from acoustical signals in a wellbore. Data based on an acoustic signal generated during a hydraulic fracturing operation in a wellbore formed through a subterranean formation can be received. An expected total flow rate of fluid being injected into the wellbore can be determined based on the data. An actual total flow rate of the fluid being injected into the wellbore can be determined. A screen-out that occurred can be identified by comparing the expected total flow rate and the actual total flow rate.

Abstract: In accordance with presently disclosed embodiments, a method and system for performing real-time evaluation of a restimulation operation using coiled tubing with fiber optics is provided. The method involves performing a restimulation treatment by pumping a slurry with diverter materials through an annulus in the wellbore surrounding the coiled tubing, and using fiber optics in the coiled tubing to identify the order and magnitude of fractures being created during the restimulation treatment. The fiber optics in the coiled tubing may include one or more fiber optic cables designed to collect distributed acoustic sensing (DAS) or distributed temperature sensing (DTS) data. The evaluation of the restimulation operation may be used to validate and/or adjust the restimulation treatment as needed to improve the lateral distribution of transverse fractures through a subterranean formation. The coiled tubing may also be used to remove sand bridges from the wellbore throughout the restimulation treatment.