Inductive Rotary Coupler for Drilling Data Transmission

Solution Overview

Problem

In directional drilling operations, positioning sensors near the drill bit is hindered by the rotational operation of the mud motor, which obstructs the provision of electrical wiring and data transmission to electronics below the motor.

Innovation Solution

A rotary coupler system is employed, featuring a first and second inductor positioned on a rotating and stationary member respectively, to transfer electrical signals and power across the rotating gap, enabling operational connection between electronic devices on either side of the mud motor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are positioned near the drill bit to obtain real-time positional data, then measurement precision and control are improved, but the rotational operation of the mud motor obstructs electrical wiring and data transmission

Engineering Contradiction:

Improvepositional data accuracyVSAvoidelectrical wiring installation

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The patent replaces mechanical electrical wiring with an inductive coupling system that uses electromagnetic fields to transmit power and data signals across the rotating gap between the mud motor stator and rotor, eliminating the need for physical electrical connections in the rotating assembly

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces inductive coupling elements (stationary inductor in stator, rotating inductor in rotor) as intermediary components that enable wireless transmission of electrical energy and data signals across the rotating gap, allowing sensors to be positioned near the drill bit without direct electrical wiring

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of information

If electrical wiring is provided to sensors below the mud motor, then data transmission capability is improved, but the rotational operation prevents reliable electrical connection

Engineering Contradiction:

Improvedata transmissionVSAvoidelectrical connection reliability

Core Design Contradiction:

Loss of informationVSReliability

Solution Approach 1:

The patent replaces mechanical electrical wiring with an inductive coupling system that uses electromagnetic fields to transmit power and data signals across the rotating gap between the mud motor stator and rotor, eliminating the need for physical electrical connections in the rotating assembly

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The inductive coupling system operates continuously through the rotational cycle, maintaining constant electromagnetic coupling between stationary and rotating inductors throughout the rotation, ensuring uninterrupted data transmission without the reliability issues of mechanical sliding contacts

Inventive Principle:

Principle #19Periodic action

3Ease of operation

If a rotary coupler with inductive coupling is used to transmit power and data across the rotating gap, then ease of operation and data transmission are improved, but device complexity increases

Engineering Contradiction:

Improvedata transmission across rotating gapVSAvoidrotary coupler structure

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The inductive coupling system serves multiple functions simultaneously: it transmits electrical power to the rotating rotor assembly, transmits data signals bidirectionally, and provides a sealed interface that prevents drilling fluid contamination, reducing the need for separate systems for each function

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The rotating inductor is positioned within the magnetic field of the stationary inductor, with the rotor assembly nested within the stator assembly, creating a compact structure where the inductive coupling elements are integrated into the existing mud motor geometry rather than adding external components

Inventive Principle:

Principle #7Nested doll (Nesting)

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 solution allows for efficient transmission of data and power across the rotating gap, facilitating real-time positional data collection and control during drilling operations, even in challenging directional drilling scenarios.

Implementation Method 1

A rotary coupler system is employed, featuring a first and second inductor positioned on a rotating and stationary member respectively, to transfer electrical signals and power across the rotating gap

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS8810428B2Electrical transmission between rotating and non-rotating members

Publication Date: 2014.08.19 SCHLUMBERGER TECH CORP

AI summary

A rotary coupler for transferring electrical power and data between members is presented wherein the coupler has a first member having an internal surface, a first inductor positioned on the internal surface, a second member and a second inductor carried on a portion of the second member and positioned internal of the first inductor, wherein one of the inductors rotates relative to the other inductor.