Seismic Clock Drift Correction via Wave Symmetry Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In seismic exploration, inconsistencies in the time-bases of clocks used by surface and downhole seismic receivers can lead to inaccurate data processing, especially when there is no electrical connection between them, causing clock drift and time shifts that affect the accuracy of subsurface geophysical information.
Innovation Solution
A system and methodology that compares the symmetry of incident and reflected seismic waves to determine temporal changes in the time-base of clocks, allowing for the identification and correction of inconsistencies between clocks in seismic receivers, using a control system to process data from seismic signals and calculate mid-points or apparent slowness to determine time shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If clocks in surface and downhole seismic receivers operate independently without electrical connection, then receiver autonomy and deployment flexibility are improved, but clock drift and time-base inconsistencies occur leading to inaccurate data processing
Solution Approach 1:
The patent uses the symmetry of seismic wave propagation as a feedback mechanism to detect and correct clock drift. By comparing the travel times of incident and reflected waves, the system automatically identifies time-base inconsistencies and applies corrections, maintaining measurement precision while preserving receiver autonomy.
Solution Approach 2:
Each seismic receiver independently determines its own clock accuracy by analyzing the symmetry of seismic wave propagation. The receiver uses its recorded data to calculate mid-point times and compare apparent slowness values, enabling self-correction of time-base drift without requiring external synchronization signals or electrical connections to other receivers.
2Measurement precision
If clock synchronization is implemented through electrical connections between receivers, then time-base consistency is improved, but system complexity and installation difficulty increase
Solution Approach 1:
The patent replaces the mechanical/electrical synchronization system (wires and electrical connections between receivers) with a signal-based method. Instead of using electrical connections to synchronize clocks, the system uses seismic wave propagation characteristics and symmetry analysis to achieve time-base consistency, eliminating the need for complex electrical synchronization infrastructure.
3Productivity
If seismic data is processed without correcting for clock drift, then processing speed is improved, but accuracy of subsurface geophysical information deteriorates
Solution Approach 1:
The patent performs clock drift correction as a preliminary step during the data processing workflow. By calculating mid-point times and comparing apparent slowness values from seismic wave symmetry before final interpretation, the system corrects time-base inconsistencies early in the process, ensuring accurate geophysical information without requiring complex real-time corrections during interpretation.
Data Source
AI summary
A technique facilitates seismic exploration by identifying time differences between clocks employed during the seismic exploration. According to an embodiment, a seismic signal is output from a source and has an incident wave and a reflected wave. The seismic signal is received by at least one receiver which outputs data to a control system. The control system is employed to compare a symmetry of the propagation of the incident wave and the reflected wave. The symmetry data is then used to determine a temporal change of the time base of the at least one receiver.