BEM™ DATA ANALYSIS

Post Survey processing and analysis of data by RSG will provide apparent wall thickness along with other details.

Preliminary Results

Each individual BEM™ data set processed to Preliminary Stage consists of a Preliminary Data Summary and Two Preliminary Plots. The Preliminary Data Summary file is a regular Excel file with the file name following format provided by the MetCon© software assigned by the operator on site.

This map shows the Discrete & Localized Anomaly (D&LA) of BEM™ signal defined by values of BEM™ Signal Shift. An anomaly in the BEM™ signal can be caused by material flaws in the scanned wall (a pit, a crack), structural change of the wall material (a weld) and by an antenna lift off (coating, lining) from the metal pipe wall. The more negative the processed response the more significant the impact of anomaly on the BEM™ signal. Any removed reading or not scanned areas are replaced by solid color.

The General Wall Condition (GWC) map shows the variation in BEM™ Signal recorded. The data is plotted from minimum to maximum of the BEM™ Signal Variation data set for each individual site. Any removed reading or not scanned areas are replaced by color.

Final Results

Final Plots graphically display the wall condition at each site and are a combination of the General Wall Condition and Discrete & Localized Anomaly Preliminary maps (the large main map of right hand side). Final plotting provides comprehensive BEM™ information of scanned locations as described by BEM™ Signal Intensity (%), where 100% represents the expected signal intensity based on the information supplied by the client or as obtained from RSG data analysis. The BEM™ Signal Shift ranges from black (high probability of locating an isolated flaw) to white where the probability of locating an isolated flaw is low.  Any removed reading or not scanned areas are replaced by solid color on D&LA plot.

Final Plots are plotted from 0% to 120% of BEM Signal Intensity.

One of the most commonly requested modelling processes of the BEM™ data is that of converting BSI values to Apparent Wall Thickness (AWT). This is done with the aid of proprietary software and calibration databases. It is important to understand what the modelling process does and how the results need to be interpreted and the pit-falls in modelling BSI values.

AWT Plots are plotted in millimeter / inch values.

Preliminary Plot - Discrete & Localized Anomaly

Preliminary Plot - General Wall Condition

Final Plot - BEM™ Combined Plot

Final Plot - Apparent Wall Thickness Model