Raster log digitization system and method
A system and method for well log vectorization are described that assist geologists or other technicians to rapidly and accurately vectorize well log curves that are visually evident in a raster well log image. The resulting digital well log curves are instrumental for qualitative interpretation and quantitative analysis of geologic information measured along well bores. The system and method simplifies and makes more efficient and accurate the process of vectorizing well log curves that are displayed in a digital raster log image.
1. A system for digital well vectorization, comprising:
a processor, a memory, and a display;
a digital well vectorizer being executed by the processor, the digital well vectorizer that receives a digital well log from a storage device, the digital well log having one or more points on a curve that is part of the digital well log, wherein the one or more points on the curve represent measured physical values as functions of measured depth;
the digital well vectorizer having an image pre-processor that removes noise from the digital well log and separates at least one of one or more horizontal grid lines or one or more vertical grid lines from the digital well log to separate the curve from a background of the digital well log to generate a pre-processed digital well log;
the digital well vectorizer having an interpolater that interpolates the one or more points on the curve to generate a vectorized well log from the pre-processed digital well log, the vectorized well log having one or more curve sections, wherein the interpolator applies a cost function to the one or more points on the curve to generate the one or more curve sections; and
the display displaying the vectorized well log having one or more curve sections to a user.
2. The system of claim 1 , wherein the digital well vectorizer combines the one or more curve sections and one or more automatically digitized curve sections.
3. The system of claim 1 , wherein the interpolater uses an image guided shortest path process.
4. The system of claim 3 , wherein the interpolater vectorizes a grid and guides image rectification using the vectorized grid.
5. The system of claim 3 , wherein the shortest path process connects the one or more points on the curve.
6. The system of claim 4 , wherein the interpolater vectorizing a grid further comprises the interpolater making the grid lines vertical and horizontal.
7. The system of claim 1 , wherein the image pre-processor removes noise from the digital well log by detecting and removing connected components below a particular number of connected pixels of the digital well log.
8. The system of claim 1 , wherein the image pre-processor smoothes the digital well log using an exponential or Gaussian smoothing function.
9. The system of claim 1 , wherein the image pre-processor enhances the curve of the digital well log through a color separation process or a local Hough transform or anisotropic diffusion.
10. The system of claim 6 , wherein the interpolater making the grid lines vertical and horizontal comprises the interpolater warping the grid lines into strictly vertical and horizontal lines.
11. A method for digital well vectorization, comprising:
processing a digital well log that comprises a digital well log curve, the processing comprising removing noise from the digital well log and separating at least one of one or more horizontal grid lines or one or more vertical grid lines from the digital well log to separate the digital well log curve from a background of the digital well log to generate a processed digital well log curve;
identifying two or more control points on the processed digital well log curve, the processed digital well log curve having one or more points that represent measured physical values as functions of measured depth;
selecting a neighboring pair of control points;
interpolating using the selected neighboring pair of control points to connect the selected neighboring pair of control points to find a least-cost path between two points within an image;
applying a cost function to the selected neighboring pair of control points;
generating a vectorized curve from the two or more control points; and
displaying the vectorized curve to a user.
12. The method of claim 11 further comprising extending the generated vectorized curve by adding one or more additional control points, the two or more control points having a starting location and an ending location wherein the one or more additional control points are between the starting location and the ending location.
13. The method of claim 11 further comprising extending the generated vectorized curve by adding one or more additional control points, the two or more control points having a starting location and an ending location wherein the one or more additional control points are one of before the starting location and after the ending location.
14. The method of claim 11 , wherein applying the cost function comprises determining that two horizontally aligned samples is less than a connection cost between two vertically aligned samples.
15. The method of claim 11 , wherein interpolating the selected neighboring pair of control points further comprises generating a vectorized well log curve segment connecting the selected neighboring pair of control points.
16. The method of claim 11 , wherein interpolating the selected neighboring pair of control points further comprises using linear interpolation of the selected neighboring pair of control points.
17. The method of claim 11 , wherein interpolating the selected neighboring pair of control points further comprises using logwire interpolation of the selected neighboring pair of control points.
18. The method of claim 11 further comprising displaying the selected control points.
19. The method of claim 11 further comprising unwrapping the vectorized curve to make the curve a continuous function of vertical position.
20. The method of claim 11 further comprising smoothing the generated curve.