Wellbore Heater Thermal Insulation via Flow Restrictor

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Solution Overview

Problem

High temperatures generated by wellbore heating tools pose a challenge for deployment cables and other components, leading to heat damage and increased costs.

Innovation Solution

A method involving a flow restrictor and thermal insulator is introduced between the heater and power cable, with a bypass conduit and pressure relief valve to reduce heat transfer, using a thermally insulating medium like gas or gel to isolate the cable from the heater.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a resistance heater is activated to heat the wellbore, then the heating effectiveness is improved, but the temperature exposure to the power cable increases causing heat damage

Engineering Contradiction:

Improveheater operating temperatureVSAvoidheat damage to power cable

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

A thermal insulator is introduced as an intermediary substance between the heater and the power cable. The thermal insulator comprises a fluid-saturated porous material that blocks direct heat transfer from the heater to the cable, allowing the heater to operate at high temperatures while protecting the cable from thermal damage.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The harmful heat transfer pathway is extracted or removed from the system by placing a thermal insulator in the annular space between the heater and cable. This isolates the cable from the thermal environment, effectively taking out the heat exposure problem.

Inventive Principle:

Principle #2Taking out (Extraction)

2Productivity

If the heater operates at high temperature, then the heating efficiency is improved, but the lifespan of the power cable decreases due to thermal exposure

Engineering Contradiction:

Improveheating efficiencyVSAvoidpower cable lifespan

Core Design Contradiction:

ProductivityVSDuration of action of stationary object

Solution Approach 1:

The thermal insulator serves as a protective intermediary that enables the heater to maintain high operating temperatures for efficient heating while simultaneously protecting the power cable from thermal degradation, thereby extending the cable's operational lifespan.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If thermal insulation is provided between heater and cable, then heat transfer to cable is reduced, but device complexity increases due to additional components

Engineering Contradiction:

Improveheat transfer to cableVSAvoidnumber of components

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The thermal insulator is implemented using a fluid-saturated porous material that can be pumped into the annular space and retained by a flow restrictor. This porous material provides effective thermal insulation while allowing for a relatively simple deployment process compared to pre-installed rigid insulation systems.

Inventive Principle:

Principle #31Porous materials

4Temperature

If a flow restrictor is deployed to retain thermal insulator, then thermal insulation effectiveness is improved, but device complexity and deployment complexity increase

Engineering Contradiction:

Improvethermal insulation effectivenessVSAvoiddeployment complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The flow restrictor is deployed using pneumatic or hydraulic principles - an inflatable packer is inflated with fluid to expand and seal the annular space, or a mechanical flow restrictor is set by controlling fluid flow. This allows the flow restrictor to be deployed and positioned effectively without requiring complex mechanical assembly procedures.

Inventive Principle:

Principle #29Pneumatics and hydraulics

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 effectively reduces heat transfer to the power cable, allowing for higher temperature operation of the heater with lower temperature-rated cables and extending the lifespan of components.

Implementation Method 1

A thermal insulator is introduced into the annular space on the one side of the flow restrictor and the heater is operated

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

A flow restrictor is deployed in an annular space between the heater and a wellbore tubular

Methodology Applied

Scientific EffectFlow restriction:

Implementation Method 3

heat is generated, e.g. when a resistance heater is activated by passing electrical current along the cable

Methodology Applied

Scientific EffectResistive heating: Joule Heating

Data Source

PatentUS11466541B2Heat transfer prevention method for wellbore heating system

Publication Date: 2022.10.11 AARBAKKE INNOVATION

AI summary

A method for thermally insulating a power cable or other temperature sensitive equipment from a wellbore tool comprising a heater. The wellbore tool is deployed at an end of the power cable in a well. A flow restrictor is deployed in an annular space between the heater and a wellbore tubular. The heater is axially spaced apart from the power cable such that the heater is disposed on one side of the flow restrictor and a connection to the power cable is disposed on another side of the flow restrictor. A thermal insulator is introduced into the annular space on the one side of the flow restrictor and the heater is operated.