Seismic Source Separation via Low-Cross-Correlation Sweep Sequences
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional seismic data acquisition methods require complex firing schedules and layouts to separate overlapped source firings, leading to increased time and cost, as well as environmental and safety concerns, due to prolonged survey times.
Innovation Solution
Implementing low-cross-correlation sweep sequences for seismic energy generation and recording source signature information, followed by data processing techniques to separate wave fields from time-overlapping shots, allowing for simultaneous source firings without complex schedules and layouts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple seismic sources are fired simultaneously or in time overlapping manner to reduce survey time, then productivity is improved, but source separation becomes complex requiring different frequency characteristics or predefined spatial/temporal separation
Solution Approach 1:
The patent applies preliminary action by pre-planning and coordinating the firing schedules of multiple vibratory sources before data acquisition. The system predeterminedly assigns specific time windows and frequency ranges to each source, and records metadata about each source's firing time and characteristics. This preliminary organization enables automatic source separation during processing without requiring complex real-time separation algorithms, thus maintaining high productivity while reducing processing complexity.
2Measurement precision
If conventional source separation methods are used to separate overlapped source firings, then source separation is achieved, but complex firing schedules and layouts are required increasing time and cost
Solution Approach 1:
The patent introduces an intermediary approach by using recorded source signature information and metadata as a bridge between simultaneous source firing and accurate source separation. Instead of directly separating mixed signals in the field (which would require complex schedules), the system records auxiliary information about each source's characteristics and firing times, then uses this intermediary data during processing to automatically attribute seismic energy to its originating source. This eliminates the need for complex firing schedules while maintaining separation accuracy.
3Device complexity
If sources are fired with predefined spatial and temporal separation to facilitate separation, then source separation is simplified, but productivity decreases due to longer survey times
Solution Approach 1:
The patent replaces the mechanical approach of physically separating sources in space and time (which reduces productivity) with a computational approach. Instead of using predefined spatial/temporal separation during data acquisition, the system records metadata about each source's characteristics and uses computer-based processing to separate sources after data collection. This substitution of mechanical separation with computational separation maintains survey efficiency while simplifying the separation process through automated algorithms.
4Measurement precision
If factors associated with local sample area are considered to improve separation, then separation accuracy is improved, but source separation strategies become sensitive to signal distortion
Solution Approach 1:
The patent applies parameter changes by transforming the separation problem from one sensitive to local signal characteristics into one based on stable, recorded source parameters. Instead of relying on signal distortion patterns that vary with local geology, the system uses predetermined source signature information and firing metadata as separation parameters. These parameters are invariant to local geological conditions, making the separation strategy robust against signal distortion while maintaining accuracy through precise parameter matching during processing.
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 reduces the time required for seismic surveys, decreases environmental impact, and minimizes hazardous exposure by effectively separating seismic data from multiple sources fired simultaneously, thereby enhancing survey efficiency and reducing costs.
Implementation Method 1
seismic data acquisition involves the generation of elastic waves
Implementation Method 2
the generation of elastic waves, the collection of reflected/refracted versions of those elastic waves
Implementation Method 3
separating sources in seismic data
Data Source
Figure 1
Figure 2
Figure 3(a)~3(b)
AI summary
Methods and systems for separating seismic data acquired using a plurality of substantially simultaneously fired sources are described. The sources use sweep sequences having low cross correlation levels to generate seismic waves, and their source signatures are determined. Using the source signatures, the wave fields associated with each of the sources are extracted from the seismic data by, for example, performing a time domain deconvolution.