Electric Seismic Source Signal Differentiation
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Solution Overview
Problem
Traditional seismic surveys using vibroseis methods are limited by the need for long signal sweeps, which are time-consuming and restricted by hydraulic vibrators' ability to generate only simple frequency sweeps, leading to challenges in differentiating unique vibratory source signals and reducing interference from harmonics and coherent noise.
Innovation Solution
The introduction of an electric seismic source that can modulate phase, rhythm, frequency, amplitude, and tonality, allowing the generation of complex 'songs' instead of traditional sweeps, enabling unique and distinguishable seismic source signals that can be separated using advanced inversion techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional vibroseis methods use long signal sweeps, then the seismic signal can be generated, but the survey time becomes excessive and the signals from multiple sources cannot be easily differentiated
Solution Approach 1:
The patent applies periodic action by using coded sweep signals with distinct temporal patterns and phase encoding. Multiple vibrators transmit sweeps with different coding sequences (e.g., different phase shifts, modulation patterns) that allow receivers to differentiate between sources through correlation processing, eliminating the need for sequential operation and reducing survey time while maintaining signal distinguishability
Solution Approach 2:
The patent changes signal parameters by modulating frequency, phase, and amplitude according to specific coding sequences. Each vibrator is assigned unique parameter variations (e.g., different sweep rates, phase shifts, frequency modulations) that enable mathematical separation of simultaneous signals through inverse filtering and correlation techniques, solving both the differentiation and time consumption problems
2Adaptability or versatility
If hydraulic vibrators are used to generate seismic signals, then the equipment is proven reliable, but the ability to generate complex distinguishable signals is limited
Solution Approach 1:
The patent applies dynamics by implementing real-time controllable vibrators that can dynamically adjust signal parameters (frequency, phase, amplitude, sweep rate) during operation. This dynamic control enables generation of complex coded sweeps with unique temporal patterns for each vibrator, providing both high adaptability for signal differentiation and maintained reliability through electronic control systems that replace or supplement hydraulic mechanisms
3Productivity
If multiple vibrators are activated simultaneously, then survey efficiency improves, but interference from harmonics and coherent noise increases
Solution Approach 1:
The patent applies segmentation by dividing the composite seismic signal into separable components through coding. Each vibrator's signal is segmented in the frequency-time domain using unique phase encoding and modulation patterns, allowing correlation processing to extract individual source records from the mixed signal while suppressing interference from harmonics and coherent noise through mathematical separation techniques
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 allows for more efficient seismic surveys by reducing survey time, improving signal-to-noise ratios, and enabling the use of complex signals that can be easily differentiated, even when multiple sources are activated simultaneously, thereby enhancing the accuracy and efficiency of seismic data acquisition.
Implementation Method 1
an electric vibrator 200 that generates a vibratory signal in the form of an electrical signal
Implementation Method 2
A reaction mass in association with a baseplate is driven by a hydraulic system to produce vibratory motion that travels downward into the earth via the base plate
Implementation Method 3
seismic surveys image or map the subsurface of the earth by imparting acoustic energy into the ground and recording the reflected energy or 'echoes' that return from the rock layers below
Data Source
AI summary
Improved methods of providing acoustic source signals for seismic surveying, wherein a plurality of signals can be easily separated from one another after data acquisition, wherein the source signals are not sweep based.