Composite Wireline Cable With Conductive Outer Tube for Deep Wellbore Use

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional downhole wireline cables are prone to breaking due to excessive frictional force, limiting their ability to be lowered further into the wellbore, and often require separate return conductors which increase complexity and cost.

Innovation Solution

A cable system with an inner tube for electrical conductors and an outer tube made of composite material, such as carbon fiber in a polymer matrix, which acts as a conductive return path, eliminating the need for a separate return conductor and enhancing the cable's ability to withstand stresses.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional wireline cable is lowered into a wellbore, then the cable can transmit data and power, but the cable breaks due to excessive frictional force between the cable and wellbore

Engineering Contradiction:

Improvecable integrityVSAvoidfrictional force

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The outer tube is made of a composite material comprising carbon fibers arranged in a polymer matrix, providing electrical conductivity and mechanical strength to withstand frictional forces during cable deployment into the wellbore

Inventive Principle:

Principle #40Composite materials

2Reliability

If a separate return conductor is included in the cable, then current return path is provided, but the cable complexity and cost increase

Engineering Contradiction:

Improvecurrent return pathVSAvoidcable structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The outer tube serves dual functions: it provides mechanical protection for the inner tube and electrical conductors, and simultaneously acts as the current return path through its electrically conducting composite material, eliminating the need for a separate return conductor

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The protective outer tube and the electrical return path are merged into a single component by making the outer tube electrically conducting through the use of carbon fiber composite material

Inventive Principle:

Principle #5Merging (Combining)

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 the cable to be lowered deeper into the wellbore without breaking and allows for reliable data and power transmission, even when the traditional return path is compromised, reducing the number of cables needed and improving operational efficiency.

Implementation Method 1

the outer tube is made of a composite material being electrically conducting

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

the outer tube is made of a composite material comprising carbon fibers arranged in a polymer matrix

Methodology Applied

Scientific EffectComposite materials: Composite Materials

Data Source

PatentEP3864251B1Intervention system and method for operating an intervention system

Publication Date: 2024.02.21 WELLTEC AS

Figure 1
Figure 2
Figure 3a~3b

AI summary

An intervention system (100) is provided. The intervention system (100) comprises a cable (10) being configured to be lowered into a wellbore (1), said cable (10) having an inner tube (11) enclosing one or more electrical conductors (12), and an outer tube (13) surrounding the inner tube (11). The intervention system (100) further comprises a downhole tool (50) being connected to a distal end (15) of the cable (10) and being configured to pull the cable (10) into the wellbore (1).