Sealed Electrical Connector for Downhole Power Cables

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Solution Overview

Problem

Conventional connectors for motor lead extension cables and main power cables in downhole environments fail due to harsh conditions such as high hydrogen sulfide and high temperatures, leading to unreliable electrical connections and frequent failures, which disrupt drilling operations.

Innovation Solution

A durable, sealed electrical connector assembly with a tube fitting assembly and compression nut system that forms a fluid-tight seal, using a protective rigid outer sheath and elastomeric insulating boots to ensure reliable connections between insulated conductive wires in protective tubing, capable of withstanding extreme conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional tape wrap splice connections are used to connect motor lead extension cables with main power cables, then the connection method is simple and easy to implement, but the connection lacks durability and fails under corrosive downhole conditions

Engineering Contradiction:
Improveease of connectionVSAvoidconnection reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces a sealed electrical connector as an intermediary device between the motor lead extension cable and main power cable. This connector provides a protected interface that maintains electrical connectivity while shielding the connection point from corrosive downhole environments, thereby resolving the contradiction between simple connection methods and reliable, durable connections.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The electrical connector employs composite construction combining conductive materials for electrical connection with protective sealing materials (such as elastomeric boots and sealed housings) that resist corrosion and high temperatures. This composite approach enables the connector to simultaneously provide electrical functionality and environmental protection, addressing the reliability issue while maintaining ease of installation.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If protective tubing is used to encapsulate conductive wires in harsh downhole environments, then the wires are protected from corrosive fluids, but the protective tubing breaks down under high temperatures and high hydrogen sulfide conditions

Engineering Contradiction:
Improveprotection from corrosive fluidsVSAvoiddurability of protective tubing
Core Design Contradiction:
Object-affected harmful factorsVSDuration of action of stationary object

Solution Approach 1:

The sealed electrical connector serves as an intermediary protective barrier that replaces the failing protective tubing at the critical connection point. It provides enhanced protection against corrosive fluids, high temperatures, and hydrogen sulfide exposure, preventing the breakdown that occurs with conventional protective tubing in these extreme conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The connector utilizes materials and sealing designs that maintain their protective properties across a wider range of temperature and chemical exposure parameters compared to standard protective tubing. This allows the connection to withstand the extreme downhole environment without degradation.

Inventive Principle:
Principle #35Parameter changes

3Length of moving object

If motor lead extension cables are connected to main power cables to extend power supply depth, then power can be supplied to downhole equipment at greater depths, but the connection points become vulnerable to electrical failures

Engineering Contradiction:
Improvepower supply depthVSAvoidelectrical connection stability
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The sealed electrical connector acts as a protected intermediary at each connection point along the extended power supply path. It shields the electrical connections from the harsh downhole environment, preventing the electrical failures that typically occur at splice points, thereby enabling reliable power supply to greater depths.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The connector provides pre-established protection at connection points before they are exposed to harsh conditions. The sealed design anticipates and prevents potential failure modes by creating a protective barrier against corrosion, moisture, and thermal stress that could compromise electrical connections during extended downhole operation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

The connector assembly provides a reliable, long-lasting electrical and mechanical connection resistant to corrosive and high-pressure environments, reducing the risk of failure and maintaining power supply to downhole equipment at great depths.

Implementation Method 1

a tube fitting assembly and compression nut system that forms a fluid-tight seal

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

elastomeric insulating boots to ensure reliable connections between insulated conductive wires

Methodology Applied
Scientific EffectElectrical insulation: Dielectric

Implementation Method 3

each of the three conductive wires of the motor lead extension cable are encapsulated in an individual protective tube... which protects the conductive wires and prevents them from coming in contact with well fluids

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP2054975B1Electrical connector for conductive wires encapsulated in protective tubing
Publication Date: 2016.05.11 QUICK CONNECTORS INC
  • EP2054975B1 patent drawingFigure 1
  • EP2054975B1 patent drawingFigure 2A~2B
  • EP2054975B1 patent drawingFigure 3a~3d

AI summary

A connector for electrically and mechanically connecting insulated conductor wires (170a, 170b) encapsulate in protective tubing. Embodiments of the connector provide a protective outer sheathing (450) that circumscribe the conductive and insulating structures within the connector. The connector is formed with a plurality of tubular fitting assemblies (233a, 233b, 233c) for securely attaching the connector to down hole electrical power cables (170). The connector is also formed with an internal insulating boot (470) having an internal passage adapted to surround the conductive elements of the connector to provide a reliable down hole electrical connector.