Adjustable shear valve mud pulser and controls therefor

A control system for generating multilevel signals in a downhole telemetry system using a pulser valve, comprising:

• a pulser valve operable in multiple positions comprising a maximum and minimum open position and at least one position in between;
• a driver connected to said pulser valve;
• and
• a controller connected to said driver so as to create pulses with said pulser valve by commanding said driver to position said pulser valve;
• a pressure sensor mounted in a position downhole to sense the amplitudes of pressure the pulses created by operation of said pulser valve and communicate said measured pressures sensed amplitudes to said controller, wherein
• said controller is capable of creating baseline amplitudes of pressure using said sensor as feedback, each baseline amplitude corresponding to a different position of said pulser valve;
• and
• said controller using said sensor determines when well conditions have changed sufficiently to that the baseline amplitudes can no longer be achieved with previously set pulser valve positions, whereupon said controller establishes new positions of said pulser valve to reobtain said previously used baseline amplitudes.

A telemetry method for sending signals from downhole to the surface, comprising:

• providing a multiposition pulser valve downhole;
• creating a plurality of pressure amplitudes pulses with said pulser valve;
• and
• providing a driver to directly position said pulser valve in predetermined increments independent of flow and pressure conditions of circulating mud so as to obtain said amplitudes pressure pulses;
• providing a sensor for measuring amplitudes of the pressure pulses created by said pulser valve;
• and
• communicating the measured amplitudes to a controller.

A telemetry method for sending signals from downhole to the surface, comprising:

• providing a multiposition pulser valve downhole;
• creating a plurality of pressure amplitudes pulses with said pulser valve;
• and
• providing a driver to directly position said pulser valve so as to obtain said amplitudes;
• providing a pressure sensor for measuring amplitude of the pressure pulses created by said pulser valve;
• communicating the measured pulses amplitudes to a controller;
• and
• regulating said driver with said controller;
• establishing a plurality of discrete baseline amplitudes as a baseline ;
• using said sensor in conjunction with said controller and said driver to obtain said baseline amplitudes;
• and
• communicating said baseline amplitudes to the surface.

A telemetry method for sending signals from downhole to the surface, comprising:

• providing a multiposition pulser valve downhole;
• creating a plurality of pressure amplitudes pulses with said pulser valve;
• and
• providing a driver to directly position said pulser valve so as to obtain said amplitudes pressure pulses;
• providing a pressure sensor for measuring amplitudes of the pressure pulses created by said pulser valve;
• communicating the measured amplitudes of the pressure pulses to a controller;
• and
• regulating said driver with said controller;
• programming said controller with a plurality of desired amplitudes;
• and
• using said pressure sensor for feedback to said controller to obtain said desired amplitudes;
• comparing the measured amplitudes to the desired amplitudes;
• and
• using said controller to actuate said driver to reposition said pulser valve to allow an approach to the desired amplitude amplitudes.

A telemetry method for sending signals from downhole to the surface, comprising:

• providing a multiposition pulser valve downhole;
• creating a plurality of pressure amplitudes pulses with said pulser valve;
• and
• providing a driver to directly position said pulser valve so as to obtain said amplitudes pressure pulses;
• providing a pressure sensor for measuring an amplitude of the pressure pulses created by said pulser valve;
• communicating the measured pulse amplitude to a controller;
• and
• regulating said driver with said controller;
• programming said controller with a plurality of desired amplitudes amplitude;
• and
• using said pressure sensor for feedback to said controller to obtain said desired amplitudes;
• processing the measured pressure amplitude and its rate of change by said controller;
• using said measured pressure amplitude and rate of change information to sending a command to said driver to alter the position of said pulser valve in a manner so as to minimize hunting or overshot of the targeted desired amplitude.

A telemetry method for sending signals from downhole to the surface, comprising:

• providing a multiposition pulser valve downhole;
• creating a plurality of pressure amplitudes pulses with said pulser valve;
• and
• providing a driver to directly position said pulser valve so as to obtain said amplitudes pressure pulse;
• providing a pressure sensor for measuring amplitude an amplitude of the pressure pulses created by said pulser valve;
• communicating the measured pulses amplitude to a controller;
• and
• regulating said driver with said controller;
• sensing when well flow conditions have changed to no longer permit the a desired amplitudes amplitude to be achieved with available positions of said pulser valve;
• creating new baseline amplitudes with said controller for the new changed well flow conditions;
• communicating to the surface a signal that new baseline amplitudes have been selected created;
• and
• using the newly created baseline amplitudes for signal transmission to the surface.

An apparatus for generating pressure pulses in a fluid flowing in a wellbore, comprising:

• a stator in a path of the fluid;
• a rotor proximate the stator, said rotor generating pressure pulses in the fluid when oriented at a plurality of positions proximate the stator;
• and
• a driver controllably orienting the rotor in an open direction and a closed direction at the plurality of positions to obstruct flow of the fluid to generate pressure pulses in the fluid at more than one amplitude;
• and
• a sensor for taking measurements downhole relating to the pressure pulses.

An apparatus for generating pressure pulses in a fluid flowing in a wellbore, comprising:

• a stator in a path of the fluid;
• a rotor proximate the stator, said rotor generating pressure pulses in the fluid when oriented at a plurality of positions proximate the stator;
• a driver controllably orienting the rotor in an open direction and a closed direction at the plurality of positions to obstruct flow of the fluid to generate pressure pulses in the fluid at more than one amplitude;
• and
• a controller that controls the driver to change amplitude of the pressure pulses in response to a pressure measurement made by a sensor downhole.

An apparatus for generating pressure pulses in a fluid flowing in a wellbore, comprising:

• a first member having an opening that allows the fluid to pass therethrough;
• a second member that is adapted to be oriented at multiple positions to obstruct the fluid flow through the first member to generate pressure pulses having different amplitudes;
• and
• a driver that positions the second member at the multiple positions to generate the pressure pulses having different amplitudes;
• and
• a controller that controls the driver in response to a measurement made by a sensor downhole.

An apparatus for generating signals in a downhole fluid flow path, comprising:

• a stationary member having an opening that allows the fluid to pass therethrough;
• a rotatable member having an opening and adapted to be rotated relative to the stationary member to create openings of different sizes for the fluid flow path through the stationary member to generate signals in the downhole fluid;
• and
• a controller that controls the rotatable member in response to a measurement made by a sensor downhole.

A telemetry system, comprising:

• a drill string having a fluid flowing therethrough;
• a pulser in a path of the fluid in the drill string, the pulser including a rotor proximate a stator, each of the rotor and stator having an opening to allow fluid flow therethrough;
• and
• a driver controllably rotating the rotor in an open direction and a closed direction to obstruct flow of the fluid to generate pressure pulses in the fluid at more than one amplitude;
• and
• a controller that controls the driver in response to a measurement made relating to the generated pulses.

A pulser system for generating pressure pulses in a downhole flowing fluid, comprising:

• a tubular string having a first member disposed therein, the first member having a first opening for flowing fluid therethrough;
• a second member substantially coaxial with and rotatable relative to the first member proximate the first member, the second member having a second opening for flowing fluid therethrough;
• and
• a motor coupled to the second member, the motor rotating the second member in a first direction and a second opposite direction to locate the second member at a predetermined position such that the second member at least partially obstructs the fluid flowing through the first opening thereby generating a pressure pulse, the predetermined position comprising (i) a maximum open position, (ii) a minimum open position, and (iii) at least one intermediate position;
• and a controller that is configured to re-position the second member in fixed positions independent of flow and pressure conditions of the fluid flow.

A telemetry method, comprising:

• providing a pulser in a fluid flow path downhole, the pulser having a rotor proximate a stator, each said stator and rotor having an opening to allow the fluid to flow therethrough;
• and
• generating pressure pulses in the downhole fluid by controllably rotating the rotor to obstruct the flow of the fluid through the stator;
• and
• taking a measurement of a characteristic of the pressure pulses downhole and controlling the rotor in response to the measurement.

A shear valve pulser for transmitting information in the form of pressure pulses in a fluid stream downhole in a wellbore, comprising:

• a stationary plate having an opening that allows flow of the fluid therethrough;
• a rotatable plate proximate the stationary plate adapted to rotate relative to the stationary plate to close and open the opening in the stationary plate to generate the pressure pulses in the fluid stream;
• a motor coupled to the rotatable plate for controllably rotating the rotatable plate;
• and
• a controller controlling the rotatable plate in response to a pressure measurement made downhole to position the rotating plate in different positions relative to the fixed plate to control the generated pressure pulses.