Comportamiento del agua de formación del petróleo y de las aguas residuales en instalaciones petroleras desde el punto de vista de la corrosión

Abstract

The internal corrosion in pipelines used for petroleum transportation, occurs by the action of the formation water that is deposited in the low areas of the profile of the ducts. This water presents different pollutants that increase its aggressiveness on the steels usually used in the construction of these structures. The hydrogen sulphide, carbon dioxide, and chlorides have a bigger interest from the corrosion points of view. The objective of the present work consisted in analyzing the influence physical-chemical and microbiological parameters and to determine the presence of bacteria in the aggressiveness in a formation water that it accompanying the petroleum, gathered during the cleaning of a pipeline, as well as to determine the corrosion rate in the steel in a line of handling wastewaters treatment tank by lineal polarization resistance tests. The BOD (Biochemistry of Oxygen Demands) and COD (Chemistry of Oxygen Demands) indicators in the first type of water, the presence of bacteria, mushrooms, yeasts and total microorganisms demonstrate their high contamination with organic matter, as a product of the bacterial activity, it facilitates the depositions formation and so the localized corrosion. This water presented a low resistivity and high concentration of chlorides ions that classifies it as salted and highly corrosive. The second type of water, because of its high chlorides and sulphide ions, and salts concentration, as well as their high electric conductivity favors the transport of charges to the corrosion processes. The lineal polarization resistance tests in a line of handling of wastewaters, belonging to