Abstract: A method for controlling a pump-down operation in a wellbore includes selecting a target value for downhole tension of a support cable and a recommended job speed to convey a wireline tool string down a section of the wellbore, generating a line speed signal for controlling a line speed of the support cable and a pumprate signal to control a pumprate of a hydraulic fluid in the wellbore, determining a first error between the target value for downhole tension and a measured value of the downhole tension, determining a second error between the recommended job speed and an actual line speed, and maintaining the target value for the downhole tension by simultaneously controlling the line speed and the pumprate using a value for the line speed signal and a value for the pumprate signal generated based on the first and second errors.

Abstract: Pump-off detection, and actions to avert a pump-off event from occurring, are described that may be implemented in a wireline control system while performing a pump-down operation to position a downhole tool within a wellbore. As part of the pump-down operation, the downhole tool is attached to a wireline coupling the tool to a wireline control device located at the surface above the wellbore.

Abstract: A system for regulating a pump down operation may include a controller, a motor drive, a parameter estimation unit and a controller design unit. In examples, the controller may be configured to identify a difference between a downhole tension set-point to an actual downhole tension. The motor drive may be configured to adjust a line speed set point of the motor drive based at least in part on the difference from the controller to create an actual line speed from the motor drive to follow the downhole tension set-point. The parameter estimation unit may be configured to produce a fluid drag coefficient, a friction coefficient, and a line speed delay constant. The controller design unit may be configured to send one or more control gains to the controller based at least in part on the fluid drag coefficient, the friction coefficient, and the line speed delay constant.

Abstract: A method for controlling a pump-down operation in a wellbore includes selecting a target value for downhole tension of a support cable and a recommended job speed to convey a wireline tool string down a section of the wellbore, generating a line speed signal for controlling a line speed of the support cable and a pumprate signal to control a pumprate of a hydraulic fluid in the wellbore, determining a first error between the target value for downhole tension and a measured value of the downhole tension, determining a second error between the recommended job speed and an actual line speed, and maintaining the target value for the downhole tension by simultaneously controlling the line speed and the pumprate using a value for the line speed signal and a value for the pumprate signal generated based on the first and second errors.

Abstract: A method and system for receiving calibration information including a first power spectral density (PSD) value and a first sand concentration value at a particular frequency. Data is collected in a liquid flow at the particular frequency at a first depth in a downhole environment. A second power spectral density (PSD) value is then determined for the data in the liquid flow at the particular frequency. The second PSD value being compared with the first PSD value. Sand can also be determined to be present in the liquid flow when the second PSD value is greater than the first PSD value by a predefined threshold. A second sand concentration value of the sand present in the liquid flow being quantified based on the first sand concentration value.

Abstract: Systems, methods, and computer-readable media are provided for detecting sand in a production flow. An example method can include receiving acoustic field data generated by at least one acoustic sensor on a downhole tool lowered into a borehole of a production flow. The method can further include inputting the acoustic field data into an acoustic sand detection model and generating a sand flow signal based on output on the acoustic sand detection model.

Abstract: Disclosed are systems and methods for receiving, by at least one processor, calibration information comprising a first power spectral density (PSD) value and a first sand concentration value at a particular frequency, collecting, by at least one processor, data in a liquid flow at the particular frequency at a first depth in a downhole environment, determining, by the at least one processor, a second power spectral density (PSD) value for the data in the liquid flow at the particular frequency, comparing, by the at least one processor, the second PSD value with the first PSD value and determining that sand is present in the liquid flow when the second PSD value is greater than the first PSD value by a predefined threshold, and quantifying, by the at least one processor, a second sand concentration value of the sand present in the liquid flow based on the first sand concentration value.