A system is provided including at least one pump for pumping a fluid into a wellbore, a pressure sensor provided at a wellhead of the wellbore for measuring a backpressure of the fluid being pumped into the wellbore, and a diagnostic manager. The diagnostic manager obtains pressure data associated with a pressure signal from the pressure sensor, wherein the pressure data includes pressure measurements of the fluid over a selected time period. The diagnostic manager converts, based on the pressure data, at least a portion of the pressure signal into frequency domain. The diagnostic manager detects a change in frequency of the pressure signal in the Fourier spectrum and determines that a fault associated with the wellbore has occurred based on the changed frequency of the pressure signal.

A downhole tool includes a y-tubular section sized to run into a wellbore and configured to couple to a production tubing. The y-tubular section includes a main tubular section, a primary tubular leg coupled to the main tubular section, and a secondary tubular leg coupled to the main tubular section and offset from the primary tubular leg. The secondary tubular leg is sized to receive an electrical submersible pump (ESP). A hydraulic flow control device is positioned in the primary tubular leg and configured to selectively modulate toward an open position to fluidly couple the main tubular section to a portion of the primary tubular leg and selectively modulate toward a closed position to fluidly decouple the secondary tubular leg from a portion of the primary tubular leg based on a hydraulic signal from a hydraulic fluid system positioned at or near a terranean surface.

A downhole valve is described. The downhole valve has a pilot valve section and a tool section. The pilot valve section has a first tube. The tool section has a second tube slidably coupled to the first tube of the pilot valve section so as to provide fluid communication between the pilot valve section and the tool section. The tool section can be in the form of a signal valve section of a mud pulse telemetry valve, a reamer, a vertical steerable tool, a rotary steerable tool, a by-pass valve, a packer, a whipstock, or stabilizer.

A downhole valve is described. The downhole valve has a pilot valve section and a tool section. The pilot valve section has a first tube. The tool section has a second tube slidably coupled to the first tube of the pilot valve section so as to provide fluid communication between the pilot valve section and the tool section. The tool section can be in the form of a signal valve section of a mud pulse telemetry valve, a reamer, a vertical steerable tool, a rotary steerable tool, a by-pass valve, a packer, a whipstock, or stabilizer.

A unified mud-pulse (MP)-electromagnetic (EM) telemetry assembly and a downhole telemetry tool are provided including a downhole EM telemetry transmitter apparatus. The EM telemetry transmitter apparatus comprises a modulator configured to transmit at least one EM signal through transmission medium. The modulator comprises a first reactive circuit and a second reactive circuit, and a plurality of switches controlled by a controller to alternatingly switch the modulator between a first configuration and a second configuration. The EM signals are transmitted by passing one of the reactive circuits and bypassing the other reactive circuit.

A unified mud-pulse (MP)-electromagnetic (EM) telemetry assembly and a downhole telemetry tool are provided including a downhole EM telemetry transmitter apparatus. The EM telemetry transmitter apparatus comprises a modulator configured to transmit at least one EM signal through transmission medium. The modulator comprises a first reactive circuit and a second reactive circuit, and a plurality of switches controlled by a controller to alternatingly switch the modulator between a first configuration and a second configuration. The EM signals are transmitted by passing one of the reactive circuits and bypassing the other reactive circuit.

An apparatus and method of use for dampening shock and vibration imparted on a unified (e.g., single) and/or dual telemetry measurement-while-drilling (MWD) assembly by a drilling system during the drilling of a wellbore in a subterranean formation is provided. The apparatus may be configured to be threadably engaged and housed within the drilling system, wherein the apparatus reciprocates axially with the MWD assembly, dampening axial and torsional shock and vibration imparted on the assembly, while maintain mud-pulse and electromagnetic signals transmitted by the assembly.

An apparatus and method of use for dampening shock and vibration imparted on a unified (e.g., single) and/or dual telemetry measurement-while-drilling (MWD) assembly by a drilling system during the drilling of a wellbore in a subterranean formation is provided. The apparatus may be configured to be threadably engaged and housed within the drilling system, wherein the apparatus reciprocates axially with the MWD assembly, dampening axial and torsional shock and vibration imparted on the assembly, while maintain mud-pulse and electromagnetic signals transmitted by the assembly.

A servo valve in a servo pulser used to restrict flow to a larger main valve includes external stops on a housing to define rotational starting/stopping points and sweep zones for a servo rotor having digits for contacting the stops. The digits extend longitudinally away from the servo valve seat and extend into the sweep zones. Interaction between the stops and the digits in the sweep zones limit rotation of the rotor to a swept arc between the stops. The servo pulser rotor oscillates between stopping points in alternating clockwise/counterclockwise sweeps. Each sweep in a given direction creates one full pulse: closed, open, and closed. The servo pulser carries out a feedback/decision loop between hydraulic pulses (and sweeps) that receives information on one or more previous pulses and calculates how fast or slow it should drive the servo rotor for the current pulse.

A servo valve in a servo pulser used to restrict flow to a larger main valve includes external stops on a housing to define rotational starting/stopping points and sweep zones for a servo rotor having digits for contacting the stops. The digits extend longitudinally away from the servo valve seat and extend into the sweep zones. Interaction between the stops and the digits in the sweep zones limit rotation of the rotor to a swept arc between the stops. The servo pulser rotor oscillates between stopping points in alternating clockwise/counterclockwise sweeps. Each sweep in a given direction creates one full pulse: closed, open, and closed. The servo pulser carries out a feedback/decision loop between hydraulic pulses (and sweeps) that receives information on one or more previous pulses and calculates how fast or slow it should drive the servo rotor for the current pulse.