Mud Pulse Telemetry via Flow Rate Crossings

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Solution Overview

Problem

Current mud pulse telemetry methods for communicating signals between the surface and downhole tools in wellbores are complex, time-consuming, and require precise fluid flow control, limiting the efficiency of signal transmission and operation of downhole tools during drilling.

Innovation Solution

A method and system that utilize changes in fluid flow rate to transmit signals from the surface to downhole tools, detected by flow meters or pressure sensors, where the number and timing of flow rate crossings define the signals, allowing for simplified command-based operation of downhole tools, including steering and sensor control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If complex mud pulse telemetry methods are used to transmit signals from surface to downhole tools, then signal transmission capability is improved, but device complexity and time consumption increase

Engineering Contradiction:

Improvesignal transmission capabilityVSAvoidtelemetry system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and utilizes only the essential characteristic of mud flow (flow rate variations) for signal transmission, eliminating the need for complex encoding schemes and precise flow control systems. By taking out only the necessary element (flow rate change detection) from the complex mud pulse telemetry system, the invention achieves reliable signal transmission with simplified surface apparatus and downhole detectors.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of using complex encoded signals that require precise control and decoding, the invention inverts the approach by using simple flow rate variations where the presence or absence of flow changes directly represents commands. This inversion simplifies both the transmission mechanism at the surface and the detection/decoding process downhole, reducing overall system complexity while maintaining transmission capability.

Inventive Principle:

Principle #13The other way round (Inversion)

2Measurement precision

If precise fluid flow control is implemented for signal transmission, then signal accuracy is improved, but operational time and complexity increase

Engineering Contradiction:

Improvesignal detection accuracyVSAvoidsignal transmission time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by using only sufficient flow rate variations to detectable levels without requiring precise control. Instead of implementing full precision flow control, the system uses adequate flow changes that are easily detectable by downhole sensors, thereby reducing the time and complexity associated with precise fluid management while maintaining sufficient detection accuracy for reliable command transmission.

Inventive Principle:

Principle #16Partial or excessive action

3Productivity

If automated drilling with limited commands is implemented, then drilling efficiency is improved, but control flexibility may be reduced

Engineering Contradiction:

Improvedrilling efficiencyVSAvoidcommand flexibility

Core Design Contradiction:

ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent implements periodic action through a standardized sequence of flow rate changes that represent different commands in an automated drilling system. By establishing regular patterns of flow variations (periodic signals), the system enables efficient automated control with limited command types while maintaining adaptability through the structured versatility of the periodic signal sequences, which can represent various drilling operations in a systematic manner.

Inventive Principle:

Principle #19Periodic action

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

Enables efficient and automated control of downhole tools with a reduced number of commands, facilitating complex well path drilling by correlating detected flow rate changes with pre-defined commands, thereby improving drilling efficiency and reducing operational complexity.

Implementation Method 1

Flow rate changes are detected downhole to determine the surface sent signals

Methodology Applied

Scientific EffectFlow rate detection:

Implementation Method 2

detected by flow meters or pressure sensors

Methodology Applied

Scientific EffectPressure sensing:

Data Source

PatentUS7518950B2Method and apparatus for downlink communication

Publication Date: 2009.04.14 BAKER HUGHES CO

AI summary

The present invention provides a method and system in which signals from the surface are sent by changing flow rate of the drilling fluid supplied to the drill string during drilling of a wellbore. The signals are sent based on a fixed or dynamic time period schemes so that the sent signals cross a threshold value in a known manner. A detector measures the changes in the flow rate. A controller downhole determines the number of times a downhole parameter, such as voltage, relating to the changes in the flow rate crosses a predefined threshold value. Based on the number of the crossings and the timing of such crossings, signals are assigned to commands. The controller controls or operates a steering device based on the commands.