Marine Seismic Source Separation via Dynamic Position Tracking

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Solution Overview

Problem

Marine seismic surveys face challenges in obtaining high-fidelity seismic data due to the inability to implement multiple source vibrator techniques, which require fixed source positions, unique encoding, and are hindered by ocean currents and unique reflectance properties.

Innovation Solution

The method involves performing periodic seismic sweeps at different locations with simultaneously excited seismic sources, reorganizing data based on common source-receiver centerpoints, and applying conventional source separation techniques to achieve accurate source separation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple source vibrator techniques are used in marine environments, then data quality and productivity are improved, but the requirement for fixed source positions and unique encoding cannot be met due to ocean currents and marine conditions

Engineering Contradiction:
Improveseismic data qualityVSAvoidadaptability to marine environment
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by transitioning from static fixed-source positions to dynamic moving-source positions. Multiple seismic sources are deployed on moving vessels that continuously change positions during data acquisition. The system dynamically tracks and records the actual positions of sources and receivers, enabling source separation techniques to be applied even as sources move through the marine environment, thus resolving the contradiction between maintaining measurement precision and adapting to marine conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of source position from fixed to variable/moving. By continuously updating the position coordinates of seismic sources and receivers during acquisition, the system allows sources to move while maintaining the ability to perform source separation through computational methods that account for the changing position parameters. This parameter change enables adaptation to marine environments without sacrificing data quality.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If multiple sweeps are performed with fixed source locations for source separation, then source separation accuracy is improved, but acquisition time and productivity are reduced

Engineering Contradiction:
Improvesource separation accuracyVSAvoidacquisition speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent implements continuity of useful action by performing seismic data acquisition without requiring sources to return to fixed positions between sweeps. Sources continue moving and acquiring data continuously, eliminating the time loss associated with repositioning sources to predetermined fixed locations. The source separation process works with the continuous stream of data and position information, maintaining separation accuracy while significantly improving acquisition productivity.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent applies preliminary action by pre-planning and pre-positioning multiple sources in the marine environment before acquisition begins. The system establishes the initial configuration of sources and receivers, and their movement trajectories, in advance. This preliminary setup allows the acquisition to proceed efficiently without needing to repeatedly return to fixed positions, as the sources are already positioned to cover the survey area systematically.

Inventive Principle:
Principle #10Preliminary action

3Productivity

If conventional marine seismic acquisition with multiple air-gun sources is used, then productivity is improved, but data quality deteriorates due to flip-flop shooting and increased noise

Engineering Contradiction:
Improveacquisition efficiencyVSAvoidseismic data quality
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent applies segmentation by dividing the composite seismic signal from multiple sources into separate source-specific signals through computational source separation. Instead of treating multiple air-gun sources as a single combined source, the system segments the recorded data according to the individual contribution of each source, using their unique position and encoding characteristics. This segmentation eliminates the harmful effects of flip-flop shooting and allows high-productivity multi-source acquisition to produce high-quality data.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces computational source separation as an intermediary process between data acquisition and final imaging. This intermediary step processes the composite signals recorded by receivers, separating them into individual source contributions before further processing. The intermediary computation removes the harmful artifacts introduced by multiple simultaneous sources while preserving the beneficial high-productivity acquisition pattern, thus resolving the contradiction between productivity and data quality.

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

This approach allows for high-fidelity seismic data acquisition and processing in marine environments, overcoming the limitations of fixed source positions and encoding requirements, resulting in improved data quality and productivity.

Implementation Method 1

Conventional land-based seismic assays employ multiple, simultaneously energized seismic sources (e.g., trucks with vibrating baseplates) to impart vibratory energy into the ground. The imparted vibratory energy travels through the ground, is reflected and/or refracted by various discontinuities in the ground, and the reflected vibratory energy is detected by multiple seismic receivers

Methodology Applied
Scientific EffectVibratory energy propagation: Vibration

Implementation Method 2

The imparted vibratory energy travels through the ground, is reflected and/or refracted by various discontinuities in the ground

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 3

The imparted vibratory energy travels through the ground, is reflected and/or refracted by various discontinuities in the ground

Methodology Applied
Scientific EffectRefraction: Refraction

Implementation Method 4

conventional multiple source vibrator technology requires uniquely encoded (e.g., phase, frequency, and/or amplitude encoded) vibratory energy for each sweep, so that source separation of the resulting composite data can be performed

Methodology Applied
Scientific EffectPhase encoding: Phase Modulation

Implementation Method 5

conventional multiple source vibrator technology requires uniquely encoded (e.g., phase, frequency, and/or amplitude encoded) vibratory energy for each sweep

Methodology Applied
Scientific EffectFrequency encoding: Phase Modulation

Implementation Method 6

conventional multiple source vibrator technology requires uniquely encoded (e.g., phase, frequency, and/or amplitude encoded) vibratory energy for each sweep

Methodology Applied
Scientific EffectAmplitude encoding:

Implementation Method 7

Multiple sources mean flip-flop shooting, decreased fold, aliased multiples and other undesirable acquisition patterns. Multiple streamers mean increased minimum-offset for some bins and increased noise from the diverging side wings for other bins

Methodology Applied
Scientific EffectAcoustic wave generation: Sound

Data Source

PatentEP2350690B1Marine seismic acquisition
Publication Date: 2018.05.30 CONOCOPHILLIPS CO
  • EP2350690B1 patent drawingFigure 1
  • EP2350690B1 patent drawingFigure 2
  • EP2350690B1 patent drawingFigure 3

AI summary

A method of conducting multiple source, multiple signal seismic surveys in a marine environment are provided.