AutoDidge Digitizing scanned well log images

Autodidge AUTODIDGE is a program that allows you to digitize scanned well log images to capture curve data in digital format.

AUTODIDGE may be started by selecting the program from the Windows Program menu, or from a Desktop Shortcut icon.

The main AUTODIDGE screen.

The first step in the digitizing process is to create the well file. Click on File, then New Well. The “New Well” dialog box will appear. Fill in the appropriate information about the well. Click OK.

Next, we must open the scanned image file. This file must be in the form of a BMP or TIFF file. Click File on the main menu bar, then “Open Scanned Image File” The “Open” dialog box will appear. Select the appropriate bitmap file that contains the scanned log image. Click on Open once the file is selected. Images should be scanned at 200 dpi and TIFF images must be monochrome (black and white - not color or gray scale)

At this point, your scanned image should appear in the Image Window. For scanning purposes, your image MUST be oriented with the curves going horizontally across the screen. To rotate the image, select “Image” from the main menu, and choose “Rotate Right” or “Rotate Left” as necessary.

Once oriented properly, you may zoom in or out on the image to adjust the display. To do so, click on the icon. Place your mouse on the scanned image and left-click to zoom in, right-click to zoom out. Zoom until you have selected the portion that you wish to digitize.

Once we have zoomed in on our digitizing interval, we must tell AUTODIDGE what curve we will be digitizing. Go to Curve on the main menu, and select “Add a Curve”.

The curve information dialog box will appear once you have elected to add a curve. Specify here the curve name, axis type, left and right ranges for the curve, and the curve color.

Before we begin to digitize our Gamma Ray curve, we must eliminate the grid lines from our scanned image file.

We will first remove all the horizontal gridlines. Click the tool bar button circled above. AUTODIDGE will prompt you through the process to delete the horizontal lines: Click on the first horizontal grid line to remove. Click on the second horizontal grid line to remove. Click on the last horizontal grid line to remove. Your final image should appear as follows:

Similarly, the vertical gridlines may be removed from the scanned image by using the “Remove All Vertical Grid Lines” button. AUTODIDGE will again prompt you through the line-removal process, whereby you will: * Click on the top point of the first vertical grid line * Click on the bottom point of the first vertical grid line * Click on the top point of the second vertical grid line * Click on the top point of the last vertical grid line.

Once the gridlines are removed, you must define the area to digitize. Specifically, you must define the initial depth interval by clicking on the “Set Digitizing Area” icon on the toolbar: Set the depth interval for the area to be digitized by entering the minimum and maximum depths in the boxes shown on the bottom left of the AUTODIDGE window.

AUTODIDGE will now walk you through setting up the first digitizing interval. Follow the screen prompts to place a box around the digitizing area. Once complete, your screen should appear as follows: *Notice the red box around the first digitizing interval.

You are now ready to Auto-Digitize the Gamma Ray curve. Press the “Automatically Digitize Lines” icon on the toolbar: Click the left-most point of the Gamma Ray curve. As soon as you do this, the software will begin to track the log curve:

The resulting digitized curve is displayed in red, and is also reflected in the area below the image.

You may notice that portions of the curve may have been missed by the digitization process. To adjust those portions of the curve, simply click on the area where you think the tracking was off. Portion of the log missed by initial digitizing operation.

The software will correct the curve, and the completed interval will be shown. You may now proceed to digitize the next section.

To move to the next digitizing interval, simply press the right-arrow key on the toolbar: You will be moved to the next digitizing interval.

You may have to delete any vertical lines that still appear. Simply follow the procedure outlined earlier. Once the grid lines are removed, proceed to digitize the log curve in the same fashion as before. Once you have finished digitizing the curves of your scanned log image, you may output your data to an *.LAS file. On the File menu, select “Export File”. Save the well to a location of your choice. The well along with all digitized curve data will be exported to an LAS file (but only if you have bought a copy!).