Simultaneous Source Separation via Seismic Apparition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current seismic data acquisition methods face challenges in separating contributions from multiple simultaneously emitting sources, particularly in marine environments where airgun sources lack the ability to design arbitrary source signatures, leading to interference and reduced separation accuracy.
Innovation Solution
The method combines seismic apparition with other simultaneous source separation techniques, such as random dithered source acquisition, to enhance separation by encoding source signatures using modulation functions and deterministic time or amplitude variations, allowing for exact separation of sources even in challenging marine environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple airgun sources are fired simultaneously to increase energy and reduce acquisition time, then productivity increases, but the ability to separate source contributions deteriorates due to interference and lack of arbitrary signature control
Solution Approach 1:
The patent applies parameter changes by modifying the temporal characteristics of source firing through deterministic time variations and random dithering. By changing the timing parameters of source activation rather than the physical source characteristics, the method enables separation of simultaneously firing airgun sources while maintaining their high energy output, thus resolving the contradiction between productivity and measurement precision
Solution Approach 2:
The patent employs periodic action through deterministic time variations where sources are fired in periodic patterns with known timing relationships. This periodic structure allows the processing system to distinguish between sources based on their temporal patterns, enabling accurate separation while maintaining simultaneous firing for productivity benefits
2Loss of time
If airgun sources are fired at the same time to reduce survey duration, then loss of time decreases, but interference between sources increases making separation difficult
Solution Approach 1:
The patent converts the harmful interference from simultaneous sources into a beneficial signal by using deterministic time variations and random dithering patterns. The interference contains encodable information about which source fired when, allowing the processing system to separate sources while maintaining the time-efficient simultaneous acquisition approach
Solution Approach 2:
The patent applies preliminary action by encoding the source identification information into the firing pattern itself before the actual seismic data collection begins. The deterministic time variations and random dithering are pre-planned and applied to each source, so that when sources fire simultaneously, their contributions are already distinguished by their temporal encoding patterns
3Ease of operation
If marine airgun sources are used without arbitrary signature control, then ease of operation is maintained, but separation accuracy deteriorates due to inability to design orthogonal source signatures
Solution Approach 1:
The patent replaces the mechanical approach of designing different physical source signatures with a signal processing approach using deterministic time variations and random dithering. Instead of modifying the airgun hardware to produce different waveforms, the method uses temporal encoding that can be applied to any airgun source, maintaining ease of operation while achieving separation accuracy
Data Source
AI summary
A method for separating the unknown contributions of two or more sources from a commonly acquired set of wavefield signals representing a wavefield where the contributions from different sources are both encoded by means of the principles of signal apparition and as well as by means of different source encoding techniques.