Downhole Imaging Distortion Correction via Temperature Lookup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing downhole imaging tools face challenges in capturing undistorted 360° views of pipe or conduit interiors due to optical system distortions, which are exacerbated by varying temperatures in downhole environments.
Innovation Solution
A method that involves contemporaneously capturing images and recording temperatures, selecting pre-defined distortion data sets based on the temperature, and applying these data sets to the images to correct for distortion, thereby creating undistorted images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a wide angle lens is used to capture 360° view, then the field of view is improved, but image distortion increases especially at the periphery
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing distortion correction data for multiple temperature conditions before actual imaging. The system selects and applies the appropriate correction data based on the current temperature, thereby pre-resolving the distortion issue before it affects the final image quality.
Solution Approach 2:
The patent employs parameter changes by using temperature as a key parameter to select appropriate distortion correction data. Since optical distortion varies with temperature, the system changes the correction parameters based on the measured temperature, thereby adapting to the varying optical conditions and maintaining image accuracy across different thermal environments.
2Area of stationary object
If multiple cameras are used to achieve 360° coverage, then the field of view is improved, but image stitching complexity increases due to distortion
Solution Approach 1:
The patent reduces stitching complexity by performing preliminary distortion correction on each individual camera image before the stitching process. By correcting distortion early in the pipeline using temperature-based lookup tables, the subsequent stitching operation becomes simpler and more accurate, as it deals with already-corrected images rather than highly distorted ones.
Solution Approach 2:
The patent applies segmentation by dividing the 360° imaging task into multiple camera views, each corrected independently using temperature-based distortion data. This segmentation allows each camera's image to be processed separately with appropriate correction, making the overall stitching process more manageable and accurate compared to trying to correct the entire 360° view as a single distorted image.
3Loss of time
If distortion correction is applied without temperature consideration, then processing time is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent resolves this contradiction by performing preliminary action in the form of pre-calculating distortion correction data for various temperature conditions and storing it in lookup tables. During actual operation, the system simply retrieves the appropriate correction data based on measured temperature and applies it, which is much faster than performing complex iterative distortion correction calculations in real-time, thereby maintaining both speed and precision.
Solution Approach 2:
The patent uses parameter changes by incorporating temperature as a selecting parameter for the appropriate distortion correction data. This allows the system to quickly switch between pre-computed correction sets based on temperature, maintaining measurement precision across different thermal conditions without incurring the high computational cost of calculating corrections from scratch each time.
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 method effectively reduces distortion in downhole images, allowing for more accurate stitching of images to form complete 360° views and enabling precise measurement of objects within the images.
Implementation Method 1
an optical system including a lens and an image sensor
Implementation Method 2
an optical system including a lens and an image sensor
Data Source
AI summary
This invention relates to a method of imaging a downhole region of interest. In particular this invention relates to a method of processing images captured downhole to remove or reduce distortions due to the optical system as a function of the temperature experienced by the optical system in the downhole environment. A method of imaging a downhole region of interest comprises contemporaneously capturing an image of a region of interest and recording a temperature associated with the region of interest; selecting a pre-defined set of distortion data from a plurality of pre-defined sets of distortion data based on the recorded temperature; and applying the selected set of distortion data to the captured image to create an un-distorted image, wherein the pre-defined set of distortion data comprises distortion values associated with a range of field angles at a specified temperature.