Permanent Digital Record
Another advantage is that with the ability to capture all as found data and review it at any time, correlations no longer need to be done in the ditch. This not only saves time and money during excavations but allows the correlations to be done carefully, by engineers with the benefit of high powered analysis tools. These scans can also be compared with future ILI runs and provide an invaluable tool for measuring growth without the need for additional costly excavations.
Visual Correlati on
The red boxes represent the data from the ILI log. The green and yellow areas represent features captured with the laser scanner. The challenge here is that the laser tends to capture every detail of a feature while the ILI tool tends to capture only features of a certain depth and size. Looking at the data in this format it is very difficult to determine which as found features correlate with the Log data.
In this image the scanned data has been manipulated to match that of the ILI Tool. By doing this we can reduce the amount of shallow features that are visible in the scanned data but are not detected by the ILI tool. Now scanned features appear to be the same size and shape as those seen by the ILI tool making it much easier to compare with the ILI Log.
An additional benefit is that all of the features can be compared as a group. This way you can use the most obvious features as a reference giving you much greater certainty that you are correlating to the same feature as described in the ILI log .
The result is a very accurate correlation that greatly reduces the uncertainty of the human element.