Electroactive Polymer Downhole Actuator

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Solution Overview

Problem

Existing downhole actuation devices require large weight and volume due to their hardware, including motors, which also demand significant power, making them inefficient for use in wellbores.

Innovation Solution

The use of electroactive polymers (EAPs) in downhole actuators, which respond to electrical stimulation to provide a significant change in shape or size, allowing for lighter, more compact actuation mechanisms such as ratcheting devices and linkage systems, enabling efficient actuation of components like clamping arms, valves, and pumps without the need for heavy motors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If traditional motors and mechanical actuation systems are used in downhole tools, then reliable actuation force can be achieved, but the device weight and volume increase significantly

Engineering Contradiction:

Improveactuation forceVSAvoidactuator weight

Core Design Contradiction:

ForceVSWeight of moving object

Solution Approach 1:

The patent replaces traditional motor-based mechanical actuation systems with electroactive polymer-based actuators. The EAPs convert electrical energy directly to mechanical motion through electrochemical mechanisms, eliminating the need for motors, gears, and other heavy mechanical components. This substitution maintains actuation force capability while dramatically reducing the weight and volume of the actuation system.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes the unique properties of electroactive polymers that change their physical parameters (shape, size, stiffness) in response to electrical stimulation. The EAPs exhibit large strains and force generation capabilities through electrochemical reactions, allowing them to replace traditional mechanical systems with a material-based actuation approach that is inherently lighter and more compact.

Inventive Principle:

Principle #35Parameter changes

2Power

If traditional motors are used for downhole actuation, then sufficient power can be delivered, but the power consumption increases significantly

Engineering Contradiction:

Improveactuation powerVSAvoidpower consumption

Core Design Contradiction:

PowerVSUse of energy by moving object

Solution Approach 1:

By replacing motor-based actuation with electroactive polymer actuators, the system eliminates the need for high-power electrical motors and associated power electronics. The EAPs generate mechanical work through electrochemical energy conversion, which is inherently more energy-efficient and requires lower power input compared to traditional motor systems, especially for intermittent actuation tasks.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If traditional motor-based actuation systems are used, then reliable actuation can be achieved, but the device volume increases

Engineering Contradiction:

Improveactuation reliabilityVSAvoidactuator volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent replaces bulky motor assemblies, gearboxes, and mechanical linkages with compact electroactive polymer actuators. The EAPs generate motion directly through material deformation, eliminating the need for complex mechanical transmission systems. This results in a dramatically reduced actuator volume while maintaining actuation reliability through the inherent robustness of the electrochemical actuation mechanism.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Weight of moving object

If electroactive polymers are used for actuation, then weight and volume are reduced, but the actuation mechanism complexity increases

Engineering Contradiction:

Improveactuator weightVSAvoidactuation mechanism complexity

Core Design Contradiction:

Weight of moving objectVSDevice complexity

Solution Approach 1:

While the electroactive polymer material itself introduces new operational considerations, the overall system complexity is reduced by eliminating motors, power electronics, mechanical transmissions, and associated control systems. The EAP actuators provide direct coupling between electrical stimulation and mechanical output, simplifying the actuation mechanism architecture despite the electrochemical nature of the material.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

EAPs enable efficient and compact actuation in downhole tools, reducing weight and volume requirements while providing the necessary motivating force for various downhole operations, including acoustic signal generation and vibration compensation, with improved resilience and response speed compared to traditional materials.

Implementation Method 1

electroactive polymers (EAPs) in downhole actuators, which respond to electrical stimulation to provide a significant change in shape or size

Methodology Applied

Scientific EffectElectroactive polymer response: Electroactive Polymer

Data Source

PatentUS7559358B2Downhole uses of electroactive polymers

Publication Date: 2009.07.14 BAKER HUGHES CO

AI summary

A downhole actuator comprising a electroactive polymer, an advancement device, and an electrical source for stimulating the electroactive polymer. The advancement device is motivated by stimulation of the electroactive polymer. The electroactive polymer can be stimulated by the electrical source. The embodiments of the actuator can be utilized in subterranean downhole environments. Alternatively, the device can comprise a downhole acoustic source comprising an electroactive polymer.