Composite Far Offset Impulsive Source Activations for Marine Seismic Surveying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional marine seismic survey methods face challenges in minimizing environmental impact, achieving accurate data imaging, and efficiently processing signals, particularly due to interference between near and far offset source energies and the need to balance signal energy requirements with environmental energy limits.
Innovation Solution
The implementation of composite far offset impulsive source activations, where multiple component source activations are used to create a composite source activation pattern that reduces interference and meets signal energy requirements while staying within environmental limits, allowing for efficient data processing and imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional single far offset source activations are used, then signal energy requirement is met, but interference with near offset source energy increases
Solution Approach 1:
The patent divides a single far offset source activation into multiple component source activations (e.g., multiple air gun groups) that are activated at different times. This segmentation allows the total signal energy to be distributed across multiple lower-energy impulses, reducing the peak interference with near offset sources while maintaining the cumulative signal energy required for deep subsurface imaging.
2Object-affected harmful factors
If multiple component source activations are used to reduce interference, then environmental impact is minimized, but device complexity increases
Solution Approach 1:
The patent employs periodic activation of multiple air gun groups in a predetermined sequence, where each group is activated at specific time intervals. This periodic action pattern allows for controlled distribution of acoustic energy over time, minimizing environmental impact by keeping individual impulse energies below thresholds while maintaining systematic control over the overall activation process.
3Measurement precision
If far offset source activations are performed, then imaging accuracy of subsurface features is improved, but interference with near offset data increases
Solution Approach 1:
The patent activates near offset air gun groups first, then subsequently activates far offset air gun groups after the near offset sources have ceased operation. This preliminary action sequencing ensures that near offset data is recorded during a period free from far offset interference, while far offset activations still occur to provide the necessary signal energy for deep subsurface imaging accuracy.
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 interference with near offset source energy, enables cost-effective and accurate seismic data processing, and allows for the generation of high-quality images of subsurface geological features while minimizing environmental impact.
Implementation Method 1
Each of the plural number of air gun groups may be activated individually or in combination to emit an acoustic energy impulse into the body of water
Implementation Method 2
Acoustic energy generated by the source activations penetrates into underlying earth layers and ultimately is reflected back upward to the sensors
Implementation Method 3
Acoustic energy generated by the source activations penetrates into underlying earth layers and ultimately is reflected back upward to the sensors
Implementation Method 4
techniques to be described below in relation to the following drawings... reduces interference with near offset source energy
Data Source
AI summary
Techniques are described for utilizing far offset impulsive source activations in various contexts, including when performing marine seismic surveys, when manufacturing a geophysical data product in conjunction with such surveys, or when generating an image of geological features of a subsurface. According to some embodiments, near offset impulsive source activations are caused in a body of water at each of a plurality of near offset shot points, and composite far offset impulsive source activations are caused in the body of water at each of a plurality of far offset shot points. Each of the composite far offset impulsive source activations comprises a succession of component impulsive source activations occurring over a far offset shot length. The far offset shot length is short enough to satisfy a stationary source assumption for frequencies at or below a maximum frequency of interest for the far offset shot points.