Pipeline Coating Failures and Preventions

2019 ◽  
Author(s):  
Manish Jain ◽  
Piyush Thakor
Keyword(s):  
Oil And Gas ◽  
Gap Analysis ◽  
Internal Flow ◽  
Gas Pipelines ◽  
Corrosion Failure ◽  
Internal Surfaces ◽  
Depth Analysis ◽  
Electro Osmosis ◽  
Flow Improvement ◽  
External Coating

The coating and cathodic protection protect pipeline against the corrosion. The failure of these two defense systems leads to corrosion failure of pipelines. Any changes in chemical, physical or electrochemical properties of coating which affect their properties to isolate tFhe pipes from the corrosive atmosphere is considered as failure of coating. The failure mechanism and the gap analysis need to be continuously done for improvements in specifications and its executions. Majority of the global oil and gas pipelines are being protected externally with either 3-Layer Polyolefin coating system or fusion bonded coatings. Some of the gas pipelines are provided with a flow improvement internal coatings considering nil corrosive challenges on internal surfaces. The failures in the external coating appear in the form of edge disbondment from cutbacks and near holidays, complete loss of adhesion of coating, loss of cohesion within coating, cracking in the coating, swelling & blistering around holidays, distortions in the coating, electro osmosis, electrophoresis and highly alkaline atmosphere near holidays, continual increase in CP currents and corrosion of the substrate. The internal surfaces of pipes are suffering corrosion mainly due to presence of corrosive gases viz. carbon dioxide, oxygen, condensates and other corrosive substances even in traces. The common methods like Dehydration, Inhibitors, Buffering, Biocide and Cleaning pigs are not adequate to protect the pipelines to from the corrosion. A very thin internal flow coat can hardly resist any corrosion and gets failed. This paper presents the in-depth analysis of the major causes of coating failures and the improvements required in the external and internal coating selections, specifications, coating applications, testing and its maintenance.

scholarly journals Creation of start-of-the-art steels and technology of large diameter pipes production for oil and gas pipelines

2019 ◽  
Vol 75 (4) ◽  
pp. 497-506
Author(s):  
Yu. D. Morozov ◽  
M. Yu. Matrosov ◽  
B. F. Zin’ko
Keyword(s):  
Oil And Gas ◽  
Large Diameter ◽  
Operating Pressure ◽  
Gas Pipelines ◽  
Oil Pipelines ◽  
Large Diameter Pipes ◽  
High Level ◽  
Pipe Manufacturing ◽  
External Coating ◽  
Steel Works

The pipelines are one of most important section of the fuel and energy complex of Russia. About 75% of them are presented by gas pipelines of large diameter (1020–1420 mm) for the operating pressure up to 7.4 MPa. CNIIchermet after I.P. Bardin put a big contribution into creation of pipe steels and mastering of technologies for their production at steel-works of Russia. The Institute in cooperation with leading steels-works developed an array of pipe steel, which are successfully used at construction of modern gas and oil pipelines. Tendencies of requirements increasing to characteristics of steels for large diameter pipes for pipelines considered, creation stages of grade range of steels and technology of rolled products production analyzed. Main technological requirements for achieving mechanical properties high level determined. It was shown, that K60–K65 strength class steels meet requirements to northern pipelines for a pressure up to 11.8 MPa, to thick walled underwater pipelines for a pressure of 25.0 MPa and to pipes for seismic arears. Steel-works and pipe-manufacturing plant of Russia provide the production of longitudinal-welded pipes with wall thickness up to 40–60 mm with anticorrosion external coating and smooth internal coating.

scholarly journals DEFECTIVENESS OF EXTERNAL AND INTERNAL SURFACES OF THE MAIN OIL AND GAS PIPELINES AFTER LONG-TERM OPERATION

2016 ◽  
Vol 22 (2) ◽  
pp. 279-286 ◽  
Author(s):  
Pavlo MARUSCHAK ◽  
Olegas PRENTKOVSKIS ◽  
Roman BISHCHAK
Keyword(s):  
Oil And Gas ◽  
Morphological Characteristics ◽  
Mechanical Degradation ◽  
Gas Pipelines ◽  
Term Operation ◽  
Surface Areas ◽  
Internal Surfaces ◽  
Oil And Gas Pipelines ◽  
Pipeline Networks ◽  
Technological Defects

Damage by pitting corrosion of the surface areas of the local oil and gas pipelines was identified and numeri-cally analysed in this paper. Having used the methods of optical and scanning electron microscopy, the basic laws of structural and mechanical degradation were established. Based on the data of fractographic control, the shape of defects and substantiated morphological characteristics were examined. It was established that certain informative signs of the defects correspond to certain stages of operation. Having used methods of fractodiagnostics, the main reasons for the performance defects of main oil and gas pipelines were established, and the mechanisms of degradation as well as frac-ture of the materials they are made from were described. According to the findings, the cause of the decrease in the reli-ability of the main oil and gas pipeline networks is general and localised corrosion as well as technological defects in the pipeline metal. These studies are essential for the establishment of the complex of mechanical and corrosion-mechanical properties, particularly sensitive to degradation in the steel used for the pipe wall after a lengthy use of a pipe.

Sign in / Sign up

Export Citation Format

Share Document