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: The disclosure provides a formation fluid pumping method and pump, and a wellbore system that in one example includes wellbore surface equipment connected to a downhole tool including a formation fluid container having a fluid input port and a fluid output port, and a moveable piston inside the formation fluid container having two fluid chambers positioned to alternately pump a quantity of formation fluid in the formation fluid container from the fluid input port to the fluid output port. The wellbore system further includes a mechanical piston actuator having a rotary portion attached to the formation fluid container and a linear portion attached to the moveable piston, and a brushless direct current motor coupled to the rotary portion of the mechanical piston actuator and controlled to alternately rotate the rotary portion of the mechanical piston actuator in opposite directions to pump the quantity of formation fluid.

Abstract: Downhole tractor control systems and methods to adjust a load of a downhole motor to drive one or more wheels of the downhole tractor are disclosed. A method to adjust a load of a downhole motor includes receiving a user input of a desired speed and torque for a plurality of motors, where the plurality of motors powering rotation of wheels of a downhole tractor. The method also includes determining a minimum actual motor speed of the plurality of motors. For at least one motor of the plurality of motors, the method includes determining a power controller output and determining a torque controller output. The method further includes adjusting a voltage source invertor based on a lesser of the power controller output and the torque controller output to modulate voltage provided to the at least one motor.

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: Downhole tractor control systems and methods to maintain a load among multiple tractors are disclosed. A method to adjust a load among multiple tractors includes receiving first power feedback of a first downhole tractor, receiving second power feedback of a second downhole tractor, identifying an unbalance load condition when a difference between the first power feedback and the second power feedback exceeds a predetermined threshold, and adjusting, in response to identifying the unbalance load condition and based on the difference, power reference of the first downhole tractor and the second downhole tractor.

Abstract: A cable comprises a protective jacket and a plurality of conductor bundles symmetrically arranged within the protective jacket. The cable comprises optical fibers arranged within the protective jacket relative to the plurality of conductor bundles such that an orthogonal mode electrical field symmetry for the plurality of conductor bundles is retained.

Abstract: Downhole tractor control systems and methods to maintain a load of a downhole tractor are disclosed. A method to maintain a load of a downhole tractor includes identifying a reduction of power of a first set of motors of a plurality of motors of the downhole tractor, determining whether the reduction of power of the first set of motors is below a first threshold, and increasing, in response to the determination, a first power limit of a second set of motors of the plurality of motors to a maximum acceptable power limit of the second set of motors while maintaining the load of the downhole tractor.

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: Downhole tractor control systems and methods to adjust a load of a downhole motor to drive one or more wheels of the downhole tractor are disclosed. A method to adjust a load of a downhole motor includes receiving a user input of a desired speed and torque for a plurality of motors, where the plurality of motors powering rotation of wheels of a downhole tractor. The method also includes determining a minimum actual motor speed of the plurality of motors. For at least one motor of the plurality of motors, the method includes determining a power controller output and determining a torque controller output. The method further includes adjusting a voltage source invertor based on a lesser of the power controller output and the torque controller output to modulate voltage provided to the at least one motor.

Abstract: Downhole tractor control systems and methods to maintain a load among multiple tractors are disclosed. A method to adjust a load among multiple tractors includes receiving first power feedback of a first downhole tractor, receiving second power feedback of a second downhole tractor, identifying an unbalance load condition when a difference between the first power feedback and the second power feedback exceeds a predetermined threshold, and adjusting, in response to identifying the unbalance load condition and based on the difference, power reference of the first downhole tractor and the second downhole tractor.

Abstract: Downhole tractor control systems and methods to maintain a load of a downhole tractor are disclosed. A method to maintain a load of a downhole tractor includes identifying a reduction of power of a first set of motors of a plurality of motors of the downhole tractor, determining whether the reduction of power of the first set of motors is below a first threshold, and increasing, in response to the determination, a first power limit of a second set of motors of the plurality of motors to a maximum acceptable power limit of the second set of motors while maintaining the load of the downhole tractor.

Abstract: A power system a method for enhanced voltage protection. The system may comprise a surface high voltage power supply, a voltage controller connected to the surface high voltage power supply that sends commands to the surface high voltage power supply to control an output voltage of the surface high voltage power supply, one or more power cables attached to the surface high voltage power supply, a downhole tool connected to the one or more power cables at an end opposite of the surface high voltage power supply, and a dynamic clamp circuit connected to the surface high voltage power supply. A method may comprise creating a setpoint with a dynamic clamp circuit based at least in part on the command, activating the dynamic clamp circuit when the output voltage is higher than the setpoint, and absorbing excess energy from the high voltage power supply with the dynamic clamp circuit.

Abstract: Downhole tractor control systems and methods to adjust a load of a downhole motor to drive one or more wheels of the downhole tractor are disclosed. A method to adjust a load of a downhole motor includes receiving a user input of a desired speed and torque for a plurality of motors, where the plurality of motors powering rotation of wheels of a downhole tractor. The method also includes determining a minimum actual motor speed of the plurality of motors. For at least one motor of the plurality of motors, the method includes determining a power controller output and determining a torque controller output. The method further includes adjusting a voltage source invertor based on a lesser of the power controller output and the torque controller output to modulate voltage provided to the at least one motor.

Abstract: A cable comprises a protective jacket and a plurality of conductor bundles symmetrically arranged within the protective jacket. The cable comprises optical fibers arranged within the protective jacket relative to the plurality of conductor bundles such that an orthogonal mode electrical field symmetry for the plurality of conductor bundles is retained.

Abstract: The disclosure provides a formation fluid pumping method and pump, and a wellbore system that in one example includes wellbore surface equipment connected to a downhole tool including a formation fluid container having a fluid input port and a fluid output port, and a moveable piston inside the formation fluid container having two fluid chambers positioned to alternately pump a quantity of formation fluid in the formation fluid container from the fluid input port to the fluid output port. The wellbore system further includes a mechanical piston actuator having a rotary portion attached to the formation fluid container and a linear portion attached to the moveable piston, and a brushless direct current motor coupled to the rotary portion of the mechanical piston actuator and controlled to alternately rotate the rotary portion of the mechanical piston actuator in opposite directions to pump the quantity of formation fluid.

Abstract: A hybrid electro-optic (EO) wireline cable includes optical fibers strategically placed within to allow acoustic sensing methods as well as provide power and electrical telemetry. The hybrid EO wireline cable contains optical fibers in the interstices among symmetrically arranged electrical wire bundles to allow a hybrid EO cable to be concurrently used for electrical telemetry and optical fiber sensing without interference in a wellbore environment. This hybrid EO cable maintains electric and magnetic field symmetry which allows an optimal electrical signaling rate through orthogonal propagation modes. By placing optical fibers symmetrically inside the interstitial spaces between electrical wire bundles, the cable maintains its optimal signaling rate and avoids the mechanical and electrical limitations that would be introduced when combining electrical wires and optical fibers in a wireline cable.

Abstract: Systems, apparatus, and methods are described for formatting and for performing data communications between a surface modem and one or more modems located in a logging tool of a bottom hole assembly for use in a wellbore environment.

Abstract: One or more adjustment to a set of telemetry communication parameters utilized for providing communications between a surface modem and at least one downhole modem of a borehole logging system are described. The one or more adjustments to the telemetry communication parameters may be made following completion of an initial training of the modems and without the need to power down the surface modem or any of the downhole modem(s) included in the at least one downhole modem.

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: One or more adjustment to a set of telemetry communication parameters utilized for providing communications between a surface modem and at least one downhole modem of a borehole logging system are described. The one or more adjustments to the telemetry communication parameters may be made following completion of an initial training of the modems and without the need to power down the surface modem or any of the downhole modem(s) included in the at least one downhole modem.