Phase-Controlled Multi-Source Seismic Survey System

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Solution Overview

Problem

S-waves do not propagate in sea areas, making it difficult to generate effective shear waves for seismic surveys, and the use of P-S converted waves requires high sound pressure, affecting marine organisms and survey stability.

Innovation Solution

A subaqueous underground survey system that applies a phase difference to sound waves generated from multiple sound sources to control the generation of shear waves at the water bottom surface, allowing them to propagate into the ground, using a controller to manage the phases of low-frequency generators and geophones for stable surveying.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If P-S converted waves are used to generate shear waves in sea areas, then shear wave propagation is achieved, but high sound pressure is required which affects marine organisms and survey stability

Engineering Contradiction:
Improvesurvey stabilityVSAvoidimpact on marine organisms
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical parameters of wave generation by using multiple sound sources with controlled phase differences instead of single high-power sources. This transforms the approach from high sound pressure to coordinated multi-source interference patterns that generate shear waves through constructive interference at the seabed interface.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent divides a single high-power sound source into multiple lower-power sound sources distributed in the water column. Each source operates at reduced power levels that are safe for marine organisms, while their combined effect through phase-controlled interference produces the necessary shear wave generation at the seabed.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If single air gun is used as seismic source, then equipment simplicity is maintained, but sufficient P-S converted waves cannot be obtained without tremendously great sound pressure

Engineering Contradiction:
Improveshear wave amplitudeVSAvoidnumber of sound sources
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent combines multiple sound sources in a coordinated manner, merging their individual wave fields through phase control to create a unified shear wave generation system. The combined effect of multiple sources produces sufficient shear wave amplitude that would be impossible with a single source at safe sound pressure levels.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent uses phase difference control as an intermediary mechanism to transform the collective output of multiple sound sources into coherent shear waves. By controlling the phase relationships between sources, the system mediates between the individual P-wave outputs and the desired S-wave generation at the seabed.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If high sound pressure is applied to generate sufficient P-S converted waves, then shear wave generation is achieved, but control of S-wave generation becomes difficult and survey stability is hindered

Engineering Contradiction:
Improvecontrol of S-wave generationVSAvoidsurvey stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent implements phase difference control as a feedback mechanism where the relative phases of multiple sound sources are adjusted to optimize shear wave generation. This controlled phase relationship provides a stable and repeatable method for generating S-waves, making the process easier to control and more reliable than high sound pressure approaches.

Inventive Principle:
Principle #23Feedback

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 method enables the controlled generation of shear waves, facilitating a stable and accurate subaqueous underground survey by converting compressional waves into shear waves at the water bottom surface, reducing the impact of seabed properties and enhancing survey stability and accuracy.

Implementation Method 1

applies a phase difference to sound waves generated from multiple sound sources to control the generation of shear waves

Methodology Applied
Scientific EffectPhase difference interference: Interference

Implementation Method 2

converting compressional waves into shear waves at the water bottom surface

Methodology Applied
Scientific EffectP-S wave conversion:

Data Source

PatentEP2947481B1Underwater/underground survey system and underwater/underground survey method
Publication Date: 2020.07.01 IHI CORP
  • EP2947481B1 patent drawingFigure 1
  • EP2947481B1 patent drawingFigure 2
  • EP2947481B1 patent drawingFigure 3

AI summary

A subaqueous underground survey system using a reflection seismic survey method includes: multiple sound sources 1 for generating sound waves in the water; a controller 2 for controlling phases of the sound waves; a geophone 3 for receiving reflected waves of the sound waves; and an observation ship 4 equipped with the sound sources 1, wherein the controller 2 controls phases of the sound sources 1 so that the sound waves generated from the respective sound sources 1 have a phase difference at a water bottom surface B, thereby controlling generation of shear waves to propagate into the ground.