The new integrity management standard will be operating for main pipelines in Mexico. In order to
achieve that standard, a new methodology was developed where different variables and models of
Geographic Information Systems (GIS) were combined in a geodatabase capable of identifying hot
spots for corrosion on pipelines. Such geodatabase, integrated into GIS with a graphical user interface,
facilitates data review when performing preassessments on an External Corrosion Direct Assessment
campaign.
Using multilayer systems from the Mexican Institute of Geography, factors influencing the corrosion rate
of buried hydrocarbon pipelines can be visualized. Variables like soil pH, porosity, salinity, temperature,
humidity, resistivity, redox potentials, and bacteria concentration can be categorized in order to
estimate the likelihood of pipeline corrosion or soil corrosivity at a given area. In order to represent the
physical-chemical properties of the soil, these are converted to a raster data format (data model in
which geographic entities are represented by pixels arranged forming a grid, with many bands of data).
This conversion discretizes continuous variables in order to render them easier to manage visually and
mathematically. Data obtained from Close Inspection Survey (CIS), Direct Current Voltage Gradient
(DCVG), Alternate Current Voltage Gradient (ACVG), and In-Line Inspection (ILI) studies can also be
integrated to the database allowing more complete corrosion likelihood, and risk assessments.
Key words: Corrosiveness, raster image, soil properties, environmental factor, corrosion map, multi-layer, pipeline integrity, Close Inspection Survey, Direct Current Voltage Gradient, Alternate Current Voltage Gradient, In-Line Inspection