Study on corrosion behaviour of buried pipeline in saline soil is presented, the protected by coating and impressed current cathodic protection system. In this work, spectrometric spectroscopic techniques were used to characterise pipe/coating/soil interfaces. The results show coating/pipe interface forms products including following phases: magnetite, goethite, akaganeite hematite. However, main phases found at coating/soil are magnetite ferric ion. behavior consistent with carbon steel...

The aim of this study is to evaluate the internal corrosion process on X52 and X80 steels/real petroleum interfaces containing condensed hydrocarbon plus oilfield-produced water, which were subjected stimulated emulsions using 50/50 vol ratio mixtures at 45 °C, different hydrodynamic conditions, 1 h, 24 h. A washing by deionized water was proposed simulate identify corrosiveness phase after h exposure time. characterization electrochemical impedance spectroscopy monitoring polarization...

Simple and accurate approaches to predict failure pressures in corroded pipelines are outlined this work. It is shown that for can be predicted from the solution undamaged using an equivalent wall thickness. Three different yield criteria (Tresca, ASSY (average shear stress yield), von Mises) reviewed light of reported experimental burst pressures. At first, cylindrical vessels with infinitely long groove studied by means numerical simulations. The effect size (depth width) over pipeline...

A probabilistic formulation to determine the level of pipeline system safety after obtaining information on corrosion damage by non-destructive inspection is developed in this paper. The useful estimate reliability each region containing detected defects, and failure probability a or given segment. To probability, contribution defects that are undetectable an tool taken into account. Then, density functions maximum depths rate undetected determined. mean estimated means Bayesian analysis....

ABSTRACT Cornell’s, Esteva’s, and classical formulations for seismic hazard analysis are theoretically described mathematically unified by a suitable treatment of the random ground-motion variable. Differences connections among schemes discussed, allowing better understanding underpinning principles probabilistic analysis. The formulation is equivalent to that Esteva, they correspond general scheme. Although equivalent, two each has its own particular approach express rate, so results may...

Purpose The purpose of this paper is to study the susceptibility corrosion processes X60, X65 and X70 steels immersed in sand-clay soil with pH 3.0, using electrochemical techniques, scanning electron microscopy (SEM), energy dispersive spectroscopy X-ray diffraction (XRD). Design/methodology/approach Natural acidic sample was collected as close possible buried pipes (1.2 m depth) a Right Way from south Mexico. Both were characterized through SEM XRD. Then, open circuit potential recorded...

In the present work, life prediction of a buried pipeline was estimated based on corrosion rates. From alternating current (AC) impedance measurements and by using transmission line model, polarization resistance values structure were calculated with different coating defects exposed in electrolyte conditions. A modification to classic Stern-Geary equation basis estimate rates that used calculate reliability functions for this metallic structure. By means functions, expected an underground...

Abstract Seismic reliability functions of multistorey frame systems are expressed as values Cornell's βindex in terms two alternative measures the earthquake intensity, normalized with respect to yield displacement or deformation capacity a simplified model global behaviour system obtained by pushover analysis. The safety margin is defined difference natural logarithms intensity that leads collapse and assumed act on system. problem defining for circumvented this manner. method proposed...

The mathematical model to predict failure pressures in corroded pipelines proposed this work is based on the analysis of original by Cronin and Pick. New definitions interpretations order obtain new are given. As a consequence this, can be more adequately interpreted easier apply under practical conditions. finite element method applied for with corrosion defects elliptic irregular geometries, predictions similar. used pressure actual compared results experimental tests model. This study...

This work outlines a probabilistic model for predicting temporal evolution of the internal corrosion damage depth in active sites pipelines. The is specified by stochastic process with stationary independent increments and characterised state at given time instant from propagation function that describes velocity. related Bayesian can incorporate all available information such as inspections velocities obtained coupons or laboratory measurements. quality inspection expressed terms detection...

This work analyzed the physicochemical effect of different types Mexican clay soils on corrosion and stress cracking (SCC) behavior in contact with X60 X65 steels. Four were obtained from right way land southern Mexico at 1.5 m depth close to pipelines. Two state Oaxaca (SO1 SO2), two others Veracruz (SV1 SV2). Physicochemical textural analysis was performed correlated SCC susceptibility mechanism. It observed that soil texture might be related corrosivity. A index (ratio between sand silt +...

Abstract The work introduces a numerical external damage prediction method for buried pipelines. pitting initiation and corrosion rate of oil or gas pipelines are affected by pipeline age, physicochemical properties soils cathodic protection performance as well coating conditions. Before developing the model, influencing factors were weighed grey relational analysis, then relationship among depth was established through artificial neural network (ANN). Subsequently, ANN applied to predict...