US 2007/0182583 A1 · METHOD AND APPARATUS FOR MUD PULSE TELEMETRY

Abstract

An apparatus for mud pulse telemetry for transmitting information from a drill string positioned at a down hole location in a bore hole to a surface location, the drill string having a flow passage through which a drilling fluid flows is provided. In one aspect, the apparatus includes a rotor pulser having an uncompensated drive train comprising a unique uncompensated seal comprising a stacked array of seal elements. The uncompensated drive train provides for the direct coupling of a rotor to a drive motor. The drive motor is located within an internal housing that is filled with gas at atmospheric pressure. Additionally, a method of operating the apparatus is provided. The method includes measuring drilling fluid pressure within the flow passage to determine when a pipe connection is being made to the drill string to initiate the measurement of a down hole parameter. The down hole parameter information is transmitted to the surface through a series of encode pressure pulse generated in the drilling fluid.

Claims31

Dependent claims

A telemetry apparatus for transmitting information from a drill string positioned at a down hole location in a bore hole to a surface location, the drill string having a flow passage through which a drilling fluid flows, the telemetry apparatus comprising:

a pulser positioned within the flow passage approximate the down hole location for generating a series of positive pressure pulses in the drilling fluid which are encoded to contain the information to be transmitted, said pulser comprising:
a rotor capable of at least partially blocking the flow passage;
a motor positioned within an internal housing defined by said pulser, said housing being filled by a gas at atmospheric pressure;
a drive shaft extending from said drive motor to a position external of said internal housing, said drive shaft connected to said rotor;
and
a seal positioned about said drive shaft such that said seal seals said internal housing.

3 more elements

A method for transmitting information from a drill string positioned at a down hole location in a bore hole to a surface location, the drill string having a flow passage through which a drilling fluid flows, the method comprising the steps of:

measuring drilling fluid pressure to detect a predetermined drop of drilling fluid pressure and then a subsequent predetermined rise of drilling fluid pressure;
and
generating a sequence of positive pressure pulses in the drilling fluid at a position approximate the down hole location that propagates in a direction towards the surface location, the sequence of positive pressure pulses being generated at a time after the predetermined rise of drilling fluid pressure is detected, the sequence of positive pressure pulses are encode with the information to be transmitted to the surface location.

Dependencies are inferred from the claim text.

Method and apparatus for mud pulse telemetry

Life of this patent

Method and apparatus for mud pulse telemetry

Life of this patent

Abstract

Claims31