The transportation system for hydrocarbons consists of an important and complex network of pipelines used by oil and gas logistics companies, designed to quickly and efficiently transport oil and gas from its origin, to areas of some demand along territory where operates. Currently Brazil has 15,000 km of transportation pipelines within about 7,500 km of right-of-way pipelines. Along its territorial extension it faces several influences along its route, being the main ones influenced by the external hazards from nature and by third party actions. TRANSPETRO has about 450 water crossings in cataloged water bodies currently. These crossings are currently characterized only according to their geometric characteristics, not considering several aspects inherent to them. The inspections at these crossings are laborious and have a high cost due to necessity of divers and bathymetry in some cases.
To monitor the condition of all pipeline water crossings it is important to ensure the pipeline integrity. Depending on hydraulic phenomena, it is possible result in an exposure of the pipelines, free spans, changes in the original pipeline or excessive vibration. These changes can generate high mechanical stresses with both static and dynamic loads. The present study was characterized by the development of a methodology for assessing the susceptibility to the exposure of pipelines as a result of the hydrological hazards present at the crossings in which they are found. Moreover, this evaluation methodology offers a tool to define inspection extent and frequency, as well as the corresponding risk control actions. For this purpose, a pipeline management program has been set up, which consists in the definition of water crossings that constitute a potential hydrological hazard and where they can interact with the pipeline considering the probability of a specific hydrotechnical hazard leading the pipeline the exposure.
As a result of this research it was defined a methodology to characterize pipeline crossing areas as well as field survey, evaluation of the susceptibility of pipeline exposure at crossings and the programming of control actions were defined according to the susceptibility found. Finally, the study has also presented a cost analysis of crossings inspections comparing the traditional method to the new premises adopted in this project.
