Monitoring Corrosion Defects in Oil Pipelines

Author(s):  
Hassan Sultan ◽  
Saria Ashry ◽  
Rania Mohamed
Author(s):  
Pradeep Purnana ◽  
Shiyas Ibrahim

Pipelines are one of the safest forms of transportation for oil and gas. However, Pipelines may experience defects, such as corrosion, cracks during service period. Therefore, evaluation of these defects is very important in terms of assessment and for continued safe operation. Corrosion defects at the external surface of pipelines are often the result of fabrication faults, coating or cathodic protection issues, residual stress, cyclic loading, temperature or local environment (soil chemistry). In general, corrosion may occur in most pipes due to coating failure, and a pipe without any protective coating will experience external corrosion after some years. However, corrosion can occur on the internal surface of the pipeline due to contaminants in the products such as small sand particles. At present, there are different assessment methods for different types of defects in pipelines. The most popular codes for defect assessment in oil and gas pipelines are RSTRENG, Modified B31G, BS 7910 and API 579. Besides these codes and methods, there are numerical programs, such as CorLAS, which have been used successfully for assessing crack flaws in Pipelines. RSTRENG and B 31G methods are very simple when compared with API 579. API 579 is very complex method of assessing defects but very useful for remaining life assessment of Pipelines. In this paper corrosion defects like general metal loss, localized metal loss, pitting corrosion, other defects like dents, gouges, cracks, their remediation methods assessed based on API 579 method and our experience in Oil Pipelines. Since API 579 doesn’t cover cross country pipelines explicitly, we have made a research applying API 579 to ASME B31.4. Even though, we have done research on all types of defects (Level 1 and Level 2 assessment), in this paper we have covered only General metal loss assessment.


2012 ◽  
Vol 166-169 ◽  
pp. 2124-2127
Author(s):  
Han Bing Qi ◽  
Qiu Shi Wang ◽  
Li Li Wang ◽  
Xiao Dan Wu

The finite element analysis method was used to analyze the seismic response of two oil pipelines, which have corrosion defects and no defects correspondingly. The velocity, displacement and acceleration time history of the two pipelines and the contrastive analysis of the maximum stress of two pipelines were obtained. The results show that the displacement, velocity and acceleration of the pipeline with corrosion defects are larger than those of the pipeline without corrosion defects, the corrosion has great influence on the bottom of the pipeline, and the influence also has certain wide, the farther away from the corrosion, the smaller the influence is.


2011 ◽  
Vol 46 (5) ◽  
pp. 619-627
Author(s):  
A. Žiliukas ◽  
J. Janutėnienė ◽  
H. Nykyforchyn ◽  
M. Bereisa

2020 ◽  
Vol 64 (1-4) ◽  
pp. 951-958
Author(s):  
Tianhao Liu ◽  
Yu Jin ◽  
Cuixiang Pei ◽  
Jie Han ◽  
Zhenmao Chen

Small-diameter tubes that are widely used in petroleum industries and power plants experience corrosion during long-term services. In this paper, a compact inserted guided-wave EMAT with a pulsed electromagnet is proposed for small-diameter tube inspection. The proposed transducer is noncontact, compact with high signal-to-noise ratio and unattractive to ferromagnetic tubes. The proposed EMAT is designed with coils-only configuration, which consists of a pulsed electromagnet and a meander pulser/receiver coil. Both the numerical simulation and experimental results validate its feasibility on generating and receiving L(0,2) mode guided wave. The parameters for driving the proposed EMAT are optimized by performance testing. Finally, feasibility on quantification evaluation for corrosion defects was verified by experiments.


Author(s):  
Rustam Z. Sunagatullin ◽  
◽  
Rinat M. Karimov ◽  
Radmir R. Tashbulatov ◽  
Boris N. Mastobaev ◽  
...  

The results of investigations of the main causes and the most significant factors of intensification of paraffin deposition in main oil pipelines are presented. A comprehensive analysis of the composition and properties of commercial oils and their sediments was carried out, according to which phase diagrams of equilibrium of oil dispersed systems were obtained using the example of commercial oils from Bashkir fields. Based on the phase diagrams, a curve of wax oil saturation was constructed, the analysis of which confirms that the existing thermobaric conditions during the operation of main oil pipelines do not allow transporting oil without the risk of waxing. It was noted a special influence of the value of the temperature gradient in the near-wall zone and the imbalance of the ratio of high-molecular oil components in commercial batches formed in the process of joint pumping on the intensity of waxing of sections of oil pipelines complicated by deposits, which was confirmed by statistical data on the frequency of pigging. The regularities obtained in this way are proposed to be used as an express method for predicting complications associated with intensive waxing of main oil pipelines. In order to quickly assess the risks of waxing of sections of main oil pipelines, an indicator is introduced that characterizes the ratio of the content of solid paraffins to the total content of resins and asphaltenes of oil, called the criterion of instability of a commercial oil batch.


Author(s):  
Wojciech Paweł SZYDŁO

Aim: The paper discusses cases in which a refusal by an energy enterprise to connect other enterprises to the network is treated as a prohibited abuse of the enterprise's dominant position and, equally, will represent behavior prohibited by art. 12 of the Treaty on the Functioning of the European Union and by art. 9 par. 2 item 2 of the Competition and Consumer Protection Law as well as legal consequences of such refusal. It is important to pinpoint such cases since the EU sectoral regulation does not provide for obligating any undertakings which manage and operate oil pipelines to enter into contracts with other undertakings such as contracts on connecting into their network or contracts on providing crude oil transfer services. Conditions for accessing oil pipelines and selling their transfer capacities are determined by the owners of the networks: private oil companies in the countries across which the pipelines are routed. These conditions are not governed by the EU law.  Furthermore, the very obligation of connecting other entities to own network by energy undertakings operating in the oil transfer sector in Poland will only arise from generally applicable provisions of the Polish competition law.  Design / Research methods: The purpose of the paper has been reached by conducting a doctrinal analysis of relevant provisions of Polish and EU law and an analysis of guidelines issued by the EU governing bodies. Furthermore, the research included the functional analysis method which analyses how law works in practice. Conclusions / findings: The deliberations show that a refusal to access the network will be a manifestation of a prohibited abuse of a dominant position and will be a prohibited action always when the dominant's action is harmful in terms of the allocation effectiveness. It will be particularly harmful when delivery of goods or services objectively required for effective competition on a lower level market, a discriminatory refusal which leads to elimination of an effective competition on the consequent market, a refusal leading to unfair treatment of consumers and an unjustified refusal. Originality / value of the article: The paper discusses the prerequisites which trigger the obligation to connect entities to own network by energy undertakings operating in the oil transfer sector. The obligation has a material impact on the operations of the oil transmitting undertakings, in particular on those who dominate the market. The regulatory bodies in the competition sector may classify a refusal of access to own network by other enterprises as a prohibited abuse of the dominant position, exposing such undertakings to financial consequences.Implications of the research: The research results presented in the paper may be used in decisions issued by the President of the OCCP and in judgement of Polish civil courts and EU courts. This may cause a significant change in the approach to classifying prohibited practices to prohibited behavior which represent abuse of the dominant position. The deliberations may also prompt the Polish and EU legislator to continue works on the legislation.


2011 ◽  
Vol 8 (1) ◽  
pp. 201-210
Author(s):  
R.M. Bogdanov

The problem of determining the repair sections of the main oil pipeline is solved, basing on the classification of images using distance functions and the clustering principle, The criteria characterizing the cluster are determined by certain given values, based on a comparison with which the defect is assigned to a given cluster, procedures for the redistribution of defects in cluster zones are provided, and the cluster zones parameters are being changed. Calculations are demonstrating the range of defect density variation depending on pipeline sections and the universal capabilities of linear objects configuration with arbitrary density, provided by cluster analysis.


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