Abstract: A mud pulser for generating pulses in a fluid flow in a wellbore. The mud pulser has a valve housing having an uphole opening for receiving fluid flow, and a piston valve situated in a piston chamber is longitudinally moveable between an open and closed position by closing and opening a pilot port downhole of the uphole opening and in fluid communication with the piston chamber. A first channel extends in the sidewall of the valve housing and fluidly connects the uphole opening and the pilot port. One or more fluid egress ports are in communication with the piston chamber. A metering orifice may be inserted in said one or more fluid egress ports for first channel. Opening and closing the downhole pilot port moves the piston valve and thus opens and closes the uphole opening thereby generating pressure pulses in the fluid flow. A downhole valve is further disclosed.

Abstract: A mud pulser for generating pulses in a fluid flow in a wellbore. The mud pulser has a valve housing having an uphole opening for receiving fluid flow, and a piston valve situated in a piston chamber is longitudinally moveable between an open and closed position by closing and opening a pilot port downhole of the uphole opening and in fluid communication with the piston chamber. A first channel extends in the sidewall of the valve housing and fluidly connects the uphole opening and the pilot port. One or more fluid egress ports are in communication with the piston chamber. A metering orifice may be inserted in said one or more fluid egress ports for first channel. Opening and closing the downhole pilot port moves the piston valve and thus opens and closes the uphole opening thereby generating pressure pulses in the fluid flow. A downhole valve is further disclosed.

Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: A method for conducting survey measurements in a ranging operation between a first well and a second well include generating an electromagnetic field in a downhole location in the first well and scanning for the electromagnetic field in a downhole location in the second well. When at least one characteristic of the electromagnetic field is detected, the method includes automatically initiating survey measurements for a ranging operation without receiving a downlink command from surface.

Abstract: An electromagnetic (EM) telemetry system includes an EM transmitter configured to transmit EM signals downhole and multiple sensors each configured to communicate with the EM transmitter and with another of the multiple sensors. Each sensor is placed a distance from another sensor along a length of a wellbore in the EM telemetry system. The EM telemetry system also includes a processor configured to select two or more sensors of the multiple sensors based on a signal to noise ratio (SNR) of an EM signal received from the two or more selected sensors, a depth of the EM transmitter, or both.

Abstract: A method for conducting survey measurements in a ranging operation between a first well and a second well include generating an electromagnetic field in a downhole location in the first well and scanning for the electromagnetic field in a downhole location in the second well. When at least one characteristic of the electromagnetic field is detected, the method includes automatically initiating survey measurements for a ranging operation without receiving a downlink command from surface.

Abstract: A rotational speed measurement system may include a rotational speed measuring device for measuring a rotational speed of a motor or component thereof. The downhole rotational speed measuring device may include a magnet and a magnetic sensor. A telescoping unit may position the magnetic sensor into sensing proximity of the magnet. A method for measuring downhole rotational speed may include coupling a rotational speed measuring device to a measurement assembly and a motor. The rotational speed measuring device may include a magnet and a magnetic sensor. The position of the magnetic sensor, the magnet, or both, may be adjusted with a telescoping unit to place the magnetic sensor into sensing proximity of the magnet.