Class location is a risk assessment done on oil and gas lines across Canada. The main purpose is to determine the risk of a containment breach on the adjacent environment, property, and population. It is also used to determine how the environment, property, and population can cause a containment breach. Class location assessments are used to design or adjust the safe operating conditions of the pipeline such as the pipeline wall thickness, operating pressure, and depth of cover. 

When researching class location assessment, we found that the industry does not have a standard method or procedure for conducting class location. It can vary, from some firms choosing to do it by hand, to others who have automated systems built into their own pipeline risk assessment system. There is also no standard method on how to do class location; however, the most common method that can be found online is an assessment that is conducted at a static interval along the pipe, which we would call this method the static model. 

In the static model, as we can see below, we took an assessment area and shifted it by a given static interval. In this assessment area, we have done the clustering process, which is where we took the occupancy and building metadata of all the buildings that fell inside the assessment area to calculate the class location of that section of the pipe. After we were done with the first assessment area, we then shifted it by the chosen interval and then did the class location assessment in the new area. We continued this until we have reached the end of the pipe.

To ensure all of the objectives of the project were met, a concrete set of requirements was needed to be defined:

• – An automated process of conducting the class location assessment is the most important requirement of the design. A user is able to input pipeline, buildings, and structure data and output the class location assessment.
• – The design is able to work with different forms of input geospatial data such as Feature Classes and/or Shapefiles.
• – The design is being able to work with different geometries for buildings.
• – The design is able to work with geospatial datasets that are in multiple different spatial reference systems such as North American Datum 1983 (NAD83) or World Geodetic System 1984 (WGS84).
• – The design is able to take in parameters such as the spatial reference system of the output, the length and width of the assessment area, and their units such as meters or feet.
• – The design is also being able to work with large datasets.

The biggest question that engineers have to answer when doing a class location assessment using the static model is what interval to choose. When researching how the intervals are chosen, we were told that it is subjective and it is up to the discretion of the person doing the assessment. This can be seen as the inefficiency of the static model and something we can improve upon.

Therefore, we proposed to do the assessment using what we would then call a dynamic model. The dynamic model, shown below, takes the vertices of the buildings nearby a pipeline and projects them onto the pipeline. It then does the assessment at each of these points on the line. Because this model would conduct the assessment based on the buildings in the surrounding area, we would get assessment intervals that would reflect the environment.

The class location assessment for this project was conducted using ESRI tools, with added help from ArcOnline, QGIS, and FME as needed. To make this an automated assessment we decided to build it in Arc Model Builder.

The output for this project is either a Shapefile, FGDB, Geopackage, or KMZ/KML file that shows the class location assessment of the entire transmission system; as well as the model/code for the entire process.