Solid-State Hydrophone Shielding for High-Pressure Sensing

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Solution Overview

Problem

Conventional hydrophones face challenges in high-pressure, high-temperature environments, requiring pressure compensation and being prone to noise interference, which complicates their design and increases costs.

Innovation Solution

A solid-state hydrophone design featuring a piezoelectric rod shielded by a metallic housing, eliminating the need for an oil cavity and allowing for compactness, while the metallic housing shields against both acoustic waves and electrical noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a piezoelectric tube with oil-filled cavity is used for high-pressure environments, then pressure compensation is achieved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvepressure compensation capabilityVSAvoidcavity and oil reservoir structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent removes the oil-filled cavity and pressure compensation reservoir from the hydrophone structure. By using a solid-state piezoelectric element without a cavity, the design eliminates the need for pressure compensation mechanisms while maintaining acoustic sensing capability in high-pressure environments.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical pressure compensation system (oil-filled cavity with capillary holes) with a solid-state piezoelectric sensing element that directly converts acoustic pressure to electrical signals without requiring fluid pressure equalization mechanisms.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Object-affected harmful factors

If a metallic housing is added for shielding, then noise interference is reduced, but device complexity increases

Engineering Contradiction:
Improveelectrical noise interferenceVSAvoidhousing structure
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent introduces a metallic housing as an intermediary shielding structure between the piezoelectric element and external electromagnetic interference. This housing acts as a Faraday cage, blocking external electrical noise from reaching the sensitive piezoelectric crystal while allowing acoustic waves to pass through to the sensing element.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 reliable acoustic signal sensing in high-pressure environments without pressure compensation, reduces manufacturing costs, and maintains sensitivity in low-noise conditions, even in high-temperature settings.

Implementation Method 1

a piezoelectric rod shielded by a metallic housing for use in high-pressure, high-temperature environments to sense acoustic signals

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

the metallic housing shields against both acoustic waves and electrical noise

Methodology Applied
Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentEP3519674B1Solid-state hydrophone with shielding
Publication Date: 2023.08.23 HALLIBURTON ENERGY SERVICES INC
  • EP3519674B1 patent drawingFigure 1
  • EP3519674B1 patent drawingFigure 2
  • EP3519674B1 patent drawingFigure 3

AI summary

A solid-state hydrophone may include a piezoelectric rod positioned between at least two electrodes. The piezoelectric rod may be disposed within a metallic housing to shield the piezoelectric rod and its connections from acoustic and electromagnetic waves. The piezoelectric rod and the electrodes may be potted in the mechanical housing using a potting material that may be positioned adjacent to the piezoelectric rod. At least a layer of the potting material may be positioned between the piezoelectric rod and the metallic housing to physically separate the piezoelectric rod from the metallic housing.