Marine Seismic Noise Attenuation via Wavefield Equalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Marine seismic survey data is contaminated with noise, particularly in low-frequency particle motion measurements, which hinders the separation of up-going and down-going wavefields and affects the accuracy of reservoir monitoring and hydrocarbon extraction.
Innovation Solution
The method involves equalizing near-continuous measurements from pressure and particle motion sensors, collapsing the coherent portion of the particle motion measurement to isolate noise, deriving a noise model, and subtracting it from the data to attenuate noise, allowing for more effective use of particle motion sensor data even when it is noisier than pressure sensor data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If particle motion sensor data is used for marine seismic survey, then measurement precision may improve, but noise contamination increases
Solution Approach 1:
The patent segments the particle motion measurement into coherent portions and incoherent noise portions. By separating these components, the method can selectively process the coherent signal while removing the noise contamination, thereby maintaining measurement precision while reducing harmful noise effects.
Solution Approach 2:
The patent extracts the coherent portion from the particle motion measurement data and removes it for separate processing. This extraction allows the noise to be isolated and eliminated, while the coherent signal is preserved and enhanced, resolving the contradiction between using particle motion data and its noise contamination.
2Measurement precision
If noise model subtraction is applied to particle motion data, then signal-to-noise ratio improves, but data processing complexity increases
Solution Approach 1:
The patent performs preliminary actions by equalizing the particle motion measurement with pressure sensor data before deriving the noise model. This pre-processing step simplifies subsequent noise subtraction by ensuring both datasets are on comparable scales, reducing the overall processing complexity while improving the signal-to-noise ratio.
Solution Approach 2:
The patent uses pressure sensor data as an intermediary to help characterize and remove noise from particle motion data. By using the cleaner pressure data as a reference, the method can more easily identify and subtract noise components from the particle motion measurement, improving signal quality without requiring overly complex processing of the particle motion data itself.
Data Source
AI summary
Noise can be attenuated in marine seismic data from a marine seismic survey. A first near-continuous measurement of a wavefield and a second near-continuous measurement of the wavefield recorded from a marine seismic survey can be equalized, a coherent portion of the equalized second near-continuous measurement can be collapsed, and a noise model can be derived. The noise model can be subtracted from the second near-continuous measurement.