Downhole data communication
AssigneeExpro North Sea Limited
InventorSteven Martin Hudson
Life of this patent
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Abstract
A data communication technique for use in producing wells. Signals are transmitted through the product (p) by varying and monitoring flow rate at respective ends of the communication channel. At low data rates robust communication can be provided.
Claims25
A method of downhole data communication in a producing well in which there is a flow path for a flow of produced product from the formation towards the surface, the data communication taking place between two locations in the flow path, at least one of which is downhole in the well, and the method comprising the steps of:
- collecting the produced product from the formation and causing or allowing the produced product to flow toward the surface;
- controlling a flow rate of the produced product at a first of the two locations in dependence on data to be transmitted;
- detecting, at the second of the two locations, the effect of said controlling of the flow rate of the produced product at the first location;
- and
- using the results of the detecting step to extract the data transmitted, wherein the step of controlling the flow rate of the produced product at the first of the two locations comprises modulating the flow rate so as to encode said data onto a carrier frequency that is below 0.1 Hz.
Downhole data communication apparatus for use in a producing well in which there is a flow path for a flow of produced product from the formation towards the surface and where the data communication takes place between two locations in the flow path, at least one of which is downhole in the well, the apparatus comprising:
- means for collecting the produced product from the formation and causing or allowing the produced product to flow toward the surface;
- a flow rate controller for controlling a flow rate of the produced product at a first of the two locations in dependence on data to be transmitted;
- a detector disposed at the second of the two locations, for detecting the effect of controlling of the flow rate of the produced product at the first location;
- and
- an analyzer to extract transmitted data using the output of the detector, wherein the flow rate controller is arranged to modulate the flow rate so as to encode said data onto a carrier frequency that is below 0.1 Hz.
A method of downhole data communication in a producing well in which there is a flow path for a flow of product from the formation towards the surface, the data communication taking place between two locations in the flow path, at least one of which is downhole in the well, and the method comprising the steps of:
- collecting the produced product from the formation and causing or allowing the produced product to flow toward the surface;
- controlling a flow rate of the produced product at a first of the two locations in dependence on data to be transmitted;
- measuring, at the second of the two locations, the flow rate of the produced product to detect variations in flow rate of the produced product at the second location caused by said controlling of the flow rate of the produced product at the first location;
- and
- using the results of the measuring step to extract the data transmitted, the method comprising the further steps of altering the flow rate of the produced product at the first location by at least +/−20% about an average flow rate to encode data to be transmitted and controlling the flow rate of the produced product at the first location to apply tones to the flow having a frequency in the order of 0.1 Hz or below.
Downhole data communication apparatus for use in a producing well in which there is a flow path for a flow of produced product from the formation towards the surface and where the data communication takes place between two locations in the flow path, at least one of which is downhole in the well, the apparatus comprising:
- means for collecting the produced product from the formation and causing or allowing the produced product toward the surface;
- a flow rate controller for controlling a flow rate of the produced product at a first of the two locations in dependence on data to be transmitted;
- a flow rate detector disposed at the second of the two locations, for detecting the effect of controlling of the flow rate of the produced product at the first location;
- and
- an analyzer to extract transmitted data using the output of the detector, wherein the flow rate controller is arranged for altering the flow rate of the produced product at the first location by at least +/−20% about an average flow rate to encode data to be transmitted and moreover is arranged for controlling the flow rate of the produced product at the first location to apply tones to the flow having a frequency in the order of 0.1 Hz or below.
Dependencies are inferred from the claim text.