System, method and apparatus for dowlinkable, high speed telemetry for measurement while drilling or logging while drilling
AssigneeStandard Directional Services Ltd.
InventorsDesmond Anderson, Salvador Berberov
Life of this patent
Estimating the term…
Abstract
A pulser for generating positive pressure mud pulses includes a signal shaft disposed to move between an up position and a down position within a ceramic shaft seal, the signal shaft connected at a top end to a drive shaft, the signal shaft sealing a poppet orifice when in the down position, wherein the drive shaft is connected to an actuator, the actuator connected to a hybrid bearing and a pulser coupling. The pulser is contained in a drill collar and configured to connect to a bottom end assembly. The pulser includes a pressure compensation membrane.
Claims19
A method of operating a downhole pulser coupled to a drill string, the method comprising:
- passing drilling fluid through a main orifice and into a main fluid passage of the downhole pulser, the passing with a sealing surface of a main shaft displaced away from the main orifice, and the passing with a poppet orifice of the downhole pulser closed;
- and then
- creating a positive pressure pulse in the drill string between the downhole pulser and surface equipment by:
- opening the poppet orifice and thereby equalizing pressure as between a plenum and the main fluid passage;
- forcing the main shaft to seal against the main orifice by a main spring, thereby creating the positive pressure pulse;
- ceasing the positive pressure pulse by:
- closing the poppet orifice, the poppet orifice fluidly coupled to the plenum;
- bleeding drilling fluid from the plenum through a port to the main fluid passage, the bleeding creates a differential pressure between the plenum and the main fluid passage;
- and
- compressing the main spring by the differential pressure, the compressing displaces the main shaft from the main orifice, and the displacement caused by the compressing creates fluid flow through the main fluid passage;
- repeating the creating the positive pressure pulse and ceasing the positive pressure pulse at a rate of eight pulses per second or more as predetermined by software configuration settings;
- and
- encoding data in the positive pressure pulses.
A method of operating a downhole pulser coupled to a drill string, the method comprising:
- passing drilling fluid through a main orifice and into a main fluid passage of the downhole pulser, the passing with a sealing surface of a main shaft displaced away from a main orifice, and the passing with a poppet orifice of the downhole pulser closed;
- and then equalizing pressure as between a plenum and the main fluid passage, the equalizing by opening the poppet orifice;
- closing the main shaft against the sealing surface by force of a main spring, thereby creating a positive pressure pulse;
- and then creating differential pressure as between the plenum and the main fluid passage by closing the poppet orifice, and bleeding drilling fluid from the plenum to the main fluid passage;
- opening the main orifice, the opening by compressing the main spring with force provided by the differential pressure, the opening of the main orifice ceases the positive pressure pulse;
- and
- repeating the creation of the positive pressure pulse and cessation of the positive pressure pulse at a rate of eight pulses per second or more.
Dependencies are inferred from the claim text.