Multi-Component Seismic Datum Layer Ghost Removal
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Solution Overview
Problem
Current geophysical exploration methods face challenges in accurately sampling and processing seismic data due to ghost reflections and limitations in spatial sampling, leading to distortion and noise, especially in marine-based surveys where shallow streamer depths increase noise susceptibility and limit bandwidth.
Innovation Solution
The use of multi-component seismic receivers that include pressure sensors and particle motion sensors to detect seismic wavefields, allowing for the separation and propagation of upgoing and downgoing waves, and the definition of a datum layer for virtual receiver locations to accurately propagate seismic data and reduce ghost effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If shallow streamer depth is used, then higher frequencies are captured effectively, but low frequency distortion increases due to noise susceptibility
Solution Approach 1:
The patent transitions from single-component pressure sensors to multi-component sensors that measure both pressure and particle motion (velocity gradient). This additional measurement dimension enables separation of upgoing and downgoing waves through wavefield decomposition, allowing ghost removal while maintaining both high and low frequency content.
Solution Approach 2:
The patent introduces a datum layer as an intermediate reference plane for virtual receiver locations. By propagating seismic energy to this intermediate datum layer and then to virtual receivers, the system can effectively remove ghost effects while preserving the full frequency spectrum, resolving the contradiction between shallow and deep streamer limitations.
2Object-affected harmful factors
If deep streamer depth is used, then low frequency noise is reduced, but high frequency capture effectiveness decreases
Solution Approach 1:
By adding particle motion sensor measurements to the traditional pressure sensor data, the system gains an additional measurement dimension. This enables mathematical separation of upgoing and downgoing wavefields, allowing effective ghost removal that preserves both low and high frequency content regardless of streamer depth.
Solution Approach 2:
The patent changes the measurement parameters from single-component pressure to multi-component (pressure and particle motion). This parameter change enables the system to operate effectively at various streamer depths by removing ghost effects through wavefield decomposition, thus resolving the depth-dependent frequency trade-off.
3Measurement precision
If interpolation is used to predict measurements between streamers, then spatial sampling is improved, but data inaccuracies are introduced and amplified
Solution Approach 1:
The patent introduces a datum layer as an intermediary computational plane where seismic energy is propagated to virtual receiver locations. This intermediary approach allows accurate prediction of measurements between physical streamers by using wavefield propagation physics rather than statistical interpolation, maintaining data accuracy while improving spatial sampling.
Solution Approach 2:
The patent replaces statistical interpolation methods with physics-based wavefield propagation. By using the acoustic wave equation to propagate energy from physical receivers to virtual receivers on the datum layer, the system achieves accurate spatial sampling without introducing the errors and amplification problems associated with model-fitting interpolation.
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 enables more accurate and efficient seismic data processing by reducing ghost reflections and improving spatial sampling, allowing for better resolution of seismic images without introducing data errors typically associated with interpolation methods.
Implementation Method 1
multi-component seismic receivers that include pressure sensors and particle motion sensors to detect seismic wavefields
Implementation Method 2
multi-component seismic receivers that include pressure sensors and particle motion sensors to detect seismic wavefields
Implementation Method 3
The reflection from the sub-surface may, however continue upwards to the surface of the water, where it may again be reflected by the boundary between the water and the air above the water
Implementation Method 4
separate propagation of the upgoing and downgoing waves to a defined datum layer
Data Source
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AI summary
Methods, apparatuses, and systems are disclosed for datuming multi-component seismic data. In one example of such a method, a plurality of seismic traces are accessed, the plurality of seismic traces including data representative of amplitude and spatial gradient samples of a seismic wavefield at a plurality of recording locations in a medium. Using a computer-based processing unit, a wavefield propagation from the plurality of recording locations through a medium is initialized, using the amplitude and spatial gradient samples of the seismic wavefield. Seismic traces are generated that correspond to the propagated wavefield at defined locations within the medium.