Up-Down Deconvolution for 4-D Ocean Bottom Seismic Repeatability
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Solution Overview
Problem
Current seismic data processing methods fail to adequately address water column variations and source-side differences in 4-D ocean bottom seismic data, leading to inconsistencies in seismic traces and reduced repeatability, especially due to uncontrollable factors like tidal effects and sea surface variability.
Innovation Solution
The method employs up-down deconvolution to separate and redatum seismic wavefields, allowing for the attenuation of water column effects without requiring knowledge of water velocity or depth changes, and compensates for source-side variations by applying shot signature and source directivity deconvolution, ensuring consistent subsurface illumination across surveys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional seismic data processing methods are used, then basic seismic imaging is achieved, but water column variations and source-side differences cause inconsistencies in seismic traces and reduced repeatability
Solution Approach 1:
The patent extracts and removes water column variation effects from the seismic data by separating the water column response from the subsurface signal. Through deconvolution processes, the harmful water column variations are isolated and eliminated, leaving only the subsurface reflectivity information, thereby improving repeatability between surveys.
Solution Approach 2:
The patent introduces an intermediary deconvolution process that acts as a mediator between the raw seismic data and the final processed data. This intermediary step specifically targets and removes water column effects and source-side variations, serving as a bridge that transforms inconsistent data into repeatable results.
2Measurement precision
If conventional processing methods are used, then seismic traces are processed, but uncontrollable factors like tidal effects and sea surface variability cause inconsistencies
Solution Approach 1:
The patent extracts and removes tidal effects and sea surface variability from the seismic data through deconvolution. By separating these harmful factors from the subsurface signal, the method achieves precise and consistent seismic trace measurement, eliminating the influence of uncontrollable environmental factors.
3Reliability
If up-down deconvolution is applied to remove water column effects, then seismic data repeatability is improved, but processing complexity increases
Solution Approach 1:
The patent extracts water column effects through deconvolution, separating them from the subsurface signal. This extraction process, while adding processing steps, systematically removes the source of inconsistency, achieving reliable repeatable data through a structured approach to data cleaning.
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 the generation of high-fidelity, repeatable 4-D seismic data by minimizing water column effects and residual source-side multiples, improving the repeatability and accuracy of seismic imaging, even under varying sea surface conditions.
Implementation Method 1
Most hydrophones are based on a piezoelectric transducer that generates electricity when subjected to a pressure change. Such piezoelectric materials, or transducers, can convert a sound signal into an electrical signal.
Implementation Method 2
A geophone is a velocity-sensitive seismic detector that is typically used for receivers in land seismic data acquisition because it converts ground movement, e.g., particle velocity, into electrical energy—voltage, which may be recorded.
Data Source
AI summary
Device and method for processing 4-dimensional (4-D) seismic traces. The method includes receiving at least two vintages of seismic traces recorded by seismic receivers for a same subsurface area, wherein said seismic receivers are located at the ocean floor; applying up-down deconvolution to each of said vintages of seismic traces to obtain a representation of a reflectivity of said subsurface area from each vintage of seismic traces; and redatuming the up-down deconvolution result of each vintage from the ocean floor to a desired water depth of the ocean to reduce one or more changes in said seismic traces associated with water layer variations between recordings of said series of seismic traces. The redatumed seismic data is used to generate one or more images representing characteristics of said subsurface area.