Insulating Sleeve Isolates Electrodes on Downhole Mandrel

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing ranging tools in well drilling operations face challenges in maintaining structural integrity and reliability due to direct electrode placement on downhole tools, which can lead to shorting issues and reduced performance.

Innovation Solution

The use of an insulating sleeve wrapped around the downhole tool to isolate electrodes, preventing direct coupling and enhancing structural strength and reliability by reducing current flow through the tool while increasing current delivery to the formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional electrode sources are placed directly on the mandrel, then the ranging tool can perform measurements, but the structural integrity and reliability are compromised due to shorting issues

Engineering Contradiction:

Improvereliability of ranging toolVSAvoidcomplexity of insulating gap subs

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the insulating function from complex gap sub assemblies and consolidates it into a single continuous insulating sleeve that surrounds the mandrel. This sleeve is positioned between the electrodes and the mandrel, eliminating the need for multiple discrete insulating components and their associated gap subs, thereby simplifying the overall device structure while maintaining reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The insulating sleeve acts as an intermediary element between the electrodes and the mandrel. It provides the necessary electrical isolation without requiring complex gap sub assemblies, serving as a simple yet effective mediator that prevents shorting while allowing the ranging tool to function properly.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If insulating gap subs are used to prevent shorting, then electrode isolation is achieved, but structural integrity and reliability are difficult to maintain

Engineering Contradiction:

Improvestructural integrity of ranging toolVSAvoidshorting between electrodes and mandrel

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs a continuous insulating sleeve that functions as a flexible shell surrounding the mandrel. This sleeve provides comprehensive electrical isolation between the electrodes and the mandrel without creating structural weak points, thereby preventing shorting while maintaining the structural integrity of the ranging tool assembly.

Inventive Principle:

Principle #30Flexible shells and thin films

3Use of energy by moving object

If electrodes are directly coupled to the downhole tool, then the design is simpler, but current flows through the tool instead of being delivered to the formation

Engineering Contradiction:

Improvecurrent delivery to formationVSAvoidcomplexity of electrode isolation structure

Core Design Contradiction:

Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent extracts the current path from the mandrel by introducing an insulating barrier. The insulating sleeve removes the electrical connection between electrodes and mandrel, forcing current to flow through the formation instead, thereby improving energy utilization for ranging measurements while keeping the isolation structure simple.

Inventive Principle:

Principle #2Taking out (Extraction)

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 improves the structural integrity and reliability of downhole tools by eliminating the need for insulating gap subs, maintaining effective isolation and increasing current delivery to the formation, thus enhancing ranging measurement accuracy and tool stability.

Implementation Method 1

an insulating sleeve wrapped around the downhole tool to isolate electrodes, preventing direct coupling

Methodology Applied

Scientific EffectElectrical insulation: Electrical Resistance

Implementation Method 2

ranging tools are used to determine the position, direction and orientation of a conductive pipe... using electrode sources

Methodology Applied

Scientific EffectElectromagnetic field generation: Electromagnetic Induction

Data Source

PatentUS10465496B2Sleeve excitation for ranging measurements using electrode sources

Publication Date: 2019.11.05 HALLIBURTON ENERGY SERVICES INC

AI summary

The structural integrity and reliability of a downhole tool or mandrel may be improved by implementation of a design and configuration that does not require several separate components to be coupled together. An insulating sleeve is wrapped around the outside of a mandrel. Electrodes, both transmit and return, are wrapped around the insulating sleeve. The outside diameter of the mandrel is increased but the structural integrity and reliability of the mandrel is maintained as no gap sub is used to electrically isolate the electrodes from the mandrel. The insulating sleeve may be tapered at the edges to prevent excessive wear on the sleeve. The insulating sleeve may also extend the full distance between the electrodes to provide even more insulation.