Seismic Frequency Sweep Enhancement via Composite Force Profile
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current seismic prospecting methods using vibratory seismic sources face limitations in generating optimal seismic frequency sweeps, which affect the quality and efficiency of subsurface data acquisition, as existing techniques do not adequately control the force profile of seismic vibrators to achieve desired sweep characteristics.
Innovation Solution
The method involves constructing a composite force profile using experimental data from steady state, transient force, and transient frequency sweeps to determine an optimal force profile for seismic vibrators, allowing for the generation of enhanced seismic sweeps that include single frequency, upsweep, downsweep, or combinations thereof, by regulating the hydraulic fluid flow to control the reaction mass's movement and frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional seismic vibrator methods are used to generate sweep signals, then seismic data can be acquired over relatively long periods, but the frequency sweep characteristics are not optimal and data quality is limited
Solution Approach 1:
The patent applies preliminary action by pre-determining the optimal force profile through experimental measurements and mathematical modeling before actual seismic data acquisition. The system characterizes the vibrator's mechanical properties in advance and uses this information to generate optimized sweep signals, eliminating the need for complex real-time control during field operations.
Solution Approach 2:
The patent implements parameter changes by systematically varying the force profile parameters (amplitude, frequency, phase) based on experimental data. The system measures the vibrator's response to different input parameters and adjusts the force profile to achieve optimal sweep characteristics, transforming the approach from fixed-frequency sweeps to dynamically optimized frequency modulation.
2Measurement precision
If the vibrator operates at predetermined frequencies for extended periods, then energy levels remain manageable, but the frequency sweep range and resolution are insufficient for high-quality subsurface imaging
Solution Approach 1:
The patent applies dynamics by transitioning from static, predetermined frequency operation to dynamic frequency modulation. The system continuously adjusts the vibrator's operating frequency according to a pre-calculated optimal force profile, enabling the frequency to vary smoothly over time while maintaining optimal energy transfer and sweep characteristics throughout the extended signal duration.
3Power
If impulse generators like dynamite are used, then high energy levels are achieved quickly, but the energy level is too high and the duration is too short for optimal sweep signal generation
Solution Approach 1:
The patent implements periodic action by generating seismic signals through repeated, controlled vibratory cycles rather than a single impulse. The optimized force profile dictates periodic modulation of the vibrator's output, creating a sequence of frequency-modulated sweeps that maintain high energy levels throughout the extended duration, unlike the brief, high-intensity impulse from conventional generators.
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 creation of targeted seismic frequency sweeps that improve the quality and efficiency of seismic data acquisition by optimizing the force profile, leading to better subsurface data resolution and reduced noise, enhancing the ability to identify subsurface structures and properties.
Implementation Method 1
moving the reaction mass by moving hydraulic fluid in a hydraulic system
Implementation Method 2
A seismic vibrator in its simplest form is merely a heavy vehicle that has the ability to shake the ground at a predetermined range of frequencies
Implementation Method 3
The imparted energy, known as the seismic source signal or 'pilot' signal, travels through the subsurface and reflects some of the energy from certain subsurface geological boundaries or layers
Data Source
Figure 1
Figure 2
Figure 3~3A
AI summary
A method of performing a seismic sweep includes forming a composite force profile; constructing a target seismic frequency sweep using the composite force profile; and operating a seismic source using the constructed target frequency seismic sweep.