Wellbore Telemetry Signal Compensation via Impulse Response Estimation

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Solution Overview

Problem

Mud pulse telemetry systems face signal degradation due to attenuation, reflections, and noise while transmitting information from a wellbore to the surface, making it difficult to accurately interpret the data received.

Innovation Solution

A method and module for interpreting signals by estimating the channel impulse response and applying it to predict the original message signals from distorted signals received through the wellbore telemetry channel, using a processor and decoder to identify the specific message signals within the distorted signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If pressure waves are transmitted through the mud stream for telemetry, then information can be conveyed from the wellbore to the surface, but the signal quality degrades due to attenuation, reflections, and noise

Engineering Contradiction:
Improvesignal qualityVSAvoiddata interpretation accuracy
Core Design Contradiction:
Loss of informationVSReliability

Solution Approach 1:

The system performs preliminary characterization of the telemetry channel by transmitting known test signals and measuring the actual received signals to estimate the channel impulse response before normal data transmission. This advance preparation allows the system to understand and compensate for channel effects such as attenuation, reflections, and noise characteristics specific to each wellbore environment.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback by comparing the known transmitted test signals with the actually received signals to estimate the channel impulse response. This feedback mechanism allows the system to continuously monitor and adapt to changing channel conditions, improving signal interpretation accuracy by compensating for observed distortions in real-time.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If channel effects are compensated using estimated impulse response, then signal interpretation accuracy improves, but computational complexity increases

Engineering Contradiction:
Improvesignal interpretation accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system changes parameters by estimating the channel impulse response characterizes the telemetry channel's frequency response, attenuation characteristics, and reflection patterns. By transforming the problem into the frequency domain and using spectral analysis, the system efficiently captures channel effects with a limited set of parameters that can be applied to compensate multiple signals.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system creates a mathematical model (copy) of the channel's behavior through the estimated impulse response. This model can then be applied to predict and correct distortions in received signals without requiring complex real-time processing of each individual signal, as the channel characteristics are captured once and reused for multiple interpretations.

Inventive Principle:
Principle #26Copying

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach improves the accuracy of signal interpretation by compensating for channel effects, reducing noise interference, and enhancing the reliability of data transmission in wellbore communication systems.

Implementation Method 1

estimating a channel impulse response describing the effects of transmission of the selected one of the finite number of message signals through the telemetry channel

Methodology Applied
Scientific EffectImpulse response:

Implementation Method 2

applying the estimated channel impulse response to at least one of the finite number of distinct message signals to generate at least one predicted signal

Methodology Applied
Scientific EffectSignal convolution:

Data Source

PatentUS10066480B2Channel impulse response identification and compensation
Publication Date: 2018.09.04 SCIENTIFIC DRILLING INTERNATIONAL INC
  • US10066480B2 patent drawing
  • US10066480B2 patent drawing
  • US10066480B2 patent drawing

AI summary

A method of interpreting a signal transmitted through a drilling fluid disposed within a telemetry channel of a wellbore that includes defining a finite number of distinct message signals for representing conditions within the wellbore. The method also includes transmitting one of the message signals through the telemetry channel, and receiving a distorted signal that includes the message signal as distorted by transmission through the telemetry channel. A channel impulse response is estimated and applied to at least one of the message signals to generate at least one predicted signal. A comparison is made between the predicted signal and the distorted signal, and an estimation is made as to which of the finite number of message signals is included in the distorted signal based on the comparison.