A downhole telemetry method and system are disclosed. In some embodiment, a method includes driving a pulser device based on an input data stream, wherein driving the pulser device includes generating modulated pressure pulses including modulated pulse shapes within a fluid telemetry medium. In some embodiments in which bi-modulation is utilized, the method further includes driving the pulser device including modulating pressure pulses including pulse position modulating pressure pulses.

A downhole telemetry method and system are disclosed. In some embodiment, a method includes driving a pulser device based on an input data stream, wherein driving the pulser device includes generating modulated pressure pulses including modulated pulse shapes within a fluid telemetry medium. In some embodiments in which bi-modulation is utilized, the method further includes driving the pulser device including modulating pressure pulses including pulse position modulating pressure pulses.

A method including receiving a waveform, identifying the presence of a pulse in the waveform, and subtracting a reflection template from the received waveform when a pulse is present in the waveform to obtain a corrected waveform, is presented. The method may further include reading the corrected waveform using a digital processing protocol and adjusting a drilling parameter according to the reading. A device configured to perform a method as above is also provided. A method as above, further including modifying a drilling parameter in a wellbore based on the reading of a pulse sequence including the waveform is also provided.

An intelligent drilling riser telemetry system includes a mud pulse telemetry transmitter deployed in a drill string. At least one annular pressure sensor is deployed on a drilling riser and is configured to sense mud pulse telemetry signals in an annular region thereof. A surface processor is in electronic communication with the annular pressure sensor via an electrical transmission line that extends along a length of the drilling riser from the annular pressure sensor to the drilling rig. The processor is configured to decode a transmitted mud pulse telemetry signal.

An example mud pulse telemetry method includes positioning an external acoustic or vibration sensor on or near a pump to collect acoustic or vibration data during operation of the pump. The method also includes monitoring a pressure of fluid in a tubular, the fluid conveying a data stream as a series of pressure variations. The method also comprises processing the monitored pressure to demodulate the data stream. The processing uses a pump noise estimate obtained at least in part from analysis of the acoustic or vibration data.

A system is disclosed for optimizing mud-pulse communications in a wellbore. The system may include a mud pulser positionable in the wellbore and a surface detection system. The mud pulser can transmit a sequence of waveforms having various data rates to the surface detection system for synchronizing the mud pulser with the surface detection system. The surface detection system may receive the sequence of waveforms from the mud pulser and may determine one or more waveforms of the sequence of waveforms having amplitudes exceeding a predefined threshold. The surface detection system may then determine which of the one or more waveforms has a fastest data rate, and select the fastest data rate for use in subsequent communications with the mud pulser.

Methods and apparatus are disclosed for generating fluid pulses in a fluid column, such as within a well. Various described example fluid pulse generators each have a valve structure including a plurality of rollers rotatable around axes that are oriented perpendicular or otherwise angled with respect to the flow direction, the rollers being arranged to collectively at least partially obstruct the cross-sectional area of the fluid conduit. The rotational positions of the rollers may be varied to change the degree of obstruction in the conduit, thereby to generate pressure pulses in the fluid column detectable at a location remote from the fluid pulse generator; these pressure pulses can be used to encode a signal received at the fluid pulse generator.

A message to be sent from a downhole tool in a wellbore is modulated into a data uplink signal of pressure variations in the drill string. The pressure variations are generated by varying the torque on the rotor of the generator by varying the electric load on the generator. The pressure variation sequence of the data uplink signal may be selected from a look up table of known sequences. The message may be received by a surface receiver using one or more pressure sensors. The message may be demodulated from the detected pressure data using digital and analog signal processing. The frequency of the data uplink signal may be selected based in part on detected noise in the wellbore. The data uplink signal may be modulated using a spread spectrum protocol.

A method for transmitting data from a downhole location to a location at the surface of the earth includes determining a minimum value and a maximum value of M-samples of data values, determining a keycode for the M-samples of data values that provides an indication of the maximum and minimum values of the M-samples, and encoding the keycode and the data values into one or more encoded words. The one or more encoded words are then transmitted as an acoustic signal in drilling fluid by modulating a mud-pulser. The acoustic signal is received by a transducer uphole from the mud-pulser and converted into an electrical signal. The electrical signal is demodulated into a received encoded word, which is decompressed into the M-samples in accordance with the keycode. The M-samples are then received by a computer processing system disposed as the surface of the earth.

A pressure measurement apparatus for a downhole measurement-while-drilling tool comprises a feed through connector and a pressure transducer. The feed through connector comprises a body with a first end and an opposite second end, at least one electrical interconnection extending axially through the body and out of the first and second ends, and a pressure transducer receptacle in the first end and a communications bore extending from the receptacle to the second end. The pressure transducer is seated in the receptacle such that a pressure at the first end can be measured, and comprises at least one electrical contact that extends from the pressure transducer through the communication bore and out of the second end. The pressure transducer can take pressure measurements used to predict wear of a primary seal in a motor subassembly of the tool, detect a pressure-related battery failure event, and control operation of a dual pulse height fluid pressure pulse generator.