Automated Class Location Analysis, Identifying High Consequence Areas.

This is an aspect of your integrity management planning where we can streamline your analysis and save you time and money. Our solutions help to enhance safety and environmental protection.

Our in-house software classifies the pipeline automatically using the rules laid out in either 854.1(c) in ASME B31.8 or the UK equivalent, IDE/TD/1. The software solution aids in determining class locations by analysing the number and type of buildings and population density within a certain proximity to the pipeline.

Our class location program segments the pipeline according to the density of inhabited or publicly used structures nearby.

A high number of residences or high-occupancy buildings (such as schools, restaurants, or multi-story buildings) near the pipeline will result in the pipeline segment being given a higher numbered class.

The acceptable limits for numbers of houses and other infrastructure in the vicinity of a pipeline subsequent to initial construction are given in Table 854.1(c) in ASME B31.8 (UK equialent is IDE/TD/1).

The wall thickness and other operating parameters (such as MAOP) will also determine the class assigned to a pipeline segment. A pipeline segment with a high class location is probably passing through a highly urbanized area, and thus it should have a higher wall thickness for example.

Our classification program utilises disparate data sources including:

• PIG data
• Surveyed data
• Paper maps from planning office
• DXF files from planning office
• Satellite / Aerial Photography
  
  By using GIS we can help identify parts of your pipeline which are subject to more rigorous regulation – helping to keep operating costs low while ensuring that the pipelines are operating as safely as they should.

By classifying the pipeline we can identify areas where pipeline needs to be thickened or diverted. Updating assets and features near to the pipeline provides information to asses the need in some cases to re-route to avoid areas of dense population.

In calculating the design pressure of a pipeline which is being considered for uprating, it is necessary to assess the current Location Class of every point on the line, and to use this Location Class in the calculation of the design pressure, rather than the Location Class at the time of construction. Where the Location Class has altered over time, due to the construction of additional housing or other infrastructure, this may be an impediment to uprating.

Class Location Surveys

We provide pipeline asset surveys and can incorporate this data into a GIS for a variety of uses such as class location risk analysis.

Our surveyors walk the pipeline route mapping features for integration into GIS. Data collected includes:

• Buildings- use, construction materials, occupancy
  Transport features (bridges, roads etc…)
• Drainage features, erosion features…that pose a risk/threat to the line.
• Information on planned/future developments is obtained through interviews and visits to local planning office.
• Vegetation and other miscellaneous features.

Each surveyed point has an associated photograph and attributes associated with the point can be assigned. The attributes recorded have an influence on determining the classification of the pipeline.

Thorough data collection includes combining surveyed asset information with other data sources such as aerial mapping and three dimensional Digital Terrain Models (DTM).

A three dimensional Digital Terrain Model (DTM) is useful for modelling overland flow in the event of a failure in an oil pipeline. High quality DTM's can be created from an airborne LiDAR survey

A LiDAR survey will provide a DTM with a grid spacing of 0.5-1m allowing for the identification of micro terrain features that may channel the oil flow into a narrow width even on a steep slope. This channeling and modelling thereof is especially useful in determining whether oil flow would infringe upon a High Consequence Area (HCA).

Aerial photography combined with a 3D DTM will provide up to date land classifications, show areas of dense foliage which will reduce oil mass, illustrate areas where oil will pool and even indicate soil type.