Susceptibility to Erosion of Pipeline Rights-of-Way in Tropical Soils: Case of a Brazilian Pipeline

TRANSPETRO is responsible, among other activities, by operation and maintenance of pipelines throughout Brazil. Particularly in the Midwest region the company operates the OSBRA pipeline, which moves about 8.7 Mm³/years of fuel and covers approximately 1,000 km long, predominantly in tropical soils. Erosive processes are significant and constitute the main geotechnical occurrence in OSBRA pipelines rights-of-way. In order to identify the susceptibility to erosion of the area close to the pipelines were developed basic thematic maps, that overlaid will help in identifying homogeneous zones in terms of existing material susceptibility. The mapping is being accompanied by an extensive endeavor of field inspections along the pipeline rights-of-way, that comprised geotechnical investigations, verifying the conditions of use and soil management, the conservation status of existing drainage works and geotechnical characterization of soil samples of major geological formations, including erodibility tests. The methodology is being developed in ArcGIS frame, starting from the morphometric analysis and the use of Digital Elevation Models (DEM), aiming to understanding superficial flow conditions (acceleration and concentration) and consequent soil loss. The modeling results will be compared with historical occurrences erosive 15 (fifteen) years of pipeline operation, seeking for an adherence on various geological, topographical and meteorological tested. The methodology will improve further procedures for identifying potential erosions in tropical soils and will allow to anticipating preventive maintenance in the most susceptible locals the pipeline rights-of-way, suggesting mitigation measures best suited for each type of potential erosive mechanism.