Communication with a downhole tool
AssigneeSchlumberger Technology Corporation
InventorsWolfgang E. J. Herrmann, Kenneth R. Goodman, Vladimir Vaynshteyn, Merlin D. Hansen
Life of this patent
Estimating the term…
Abstract
A system that is usable with a subterranean well includes a downhole assembly and an apparatus. The downhole assembly is adapted to respond to a command that is encoded in a stimulus that is communicated downhole. The apparatus is adapted to change a pressure of a gas in communication with the well to generate the stimulus.
Claims69
A system usable with a subterranean well, comprising:
- a downhole assembly adapted to respond to a command encoded in a stimulus communicated downhole, wherein the stimulus has a first pressure signature and the downhole assembly is adapted to compare the first pressure signature to a second pressure signature to determine an error between the first and second pressure signatures and determine whether the first signature indicates the command based on the error;
- and
- an apparatus to change a pressure of a gas in communication with the well to generate at least part of the stimulus.
A method usable with a subterranean well, comprising:
- establishing a gas layer above a downhole assembly located in the well;
- selectively changing a pressure of the gas layer to generate a stimulus to propagate through the gas layer to the downhole assembly, the stimulus having a first pressure signature;
- controlling the pressurizing of the gas layer to encode a command for the downhole assembly in the stimulus;
- comparing the first pressure signature to a second pressure signature to determine an error between the first pressure signature and the second pressure signature;
- and
- determining whether the first pressure signature indicates the command based on the error.
A method usable with a subterranean well, comprising:
- receiving a stimulus downhole, the stimulus having a first pressure signature;
- comparing the first pressure signature to a second pressure signature to determine an error between the first and second pressure signatures;
- and
- determining whether the first signature indicates a command based on the error.
A downhole assembly usable with a subterranean well, comprising:
- a sensor to receive a stimulus communicated downhole, the stimulus having a first pressure signature;
- and
- a controller coupled to the sensor and adapted to:
- compare the first pressure signature to a second pressure signature to determine an error between the first pressure signature and the second pressure signature, and
- determine whether the first pressure signature indicates a command based on the error.
The downhole assembly of 55, wherein the controller is further adapted to:
- determine a mathematical function to approximate at least a portion of the first pressure signature;
- and
- use the mathematical function to form at least part of the second pressure signature.
Dependencies are inferred from the claim text.