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People's life and industrial activities need to be realized by energy, and the exploitation of oil and gas by human beings has gradually shifted from land to ocean. The seabed has an extremely complex environment, and the pipeline is hit and even corroded by the waves for a long time. When corrosion occurs, the pipeline will not have the initial strength, resulting in the loss of function of the pipeline and the pipeline laid on the seabed cannot assist the transportation of oil and gas. When submarine oil and gas pipelines are corroded by seawater, the strength of the pipeline will be reduced. Therefore, it is particularly meaningful to study the highest bearing strength, probability of invalidity and principles of pipelines corroded by seawater. The statistical test method is used to draw samples non-directionally, and then the probability of failure and the remaining service life of the submarine pipeline after corrosion under internal pressure are calculated. According to the data distribution of the submarine oil and gas pipeline wall thickness, corroded length and rate, and cross-sectional diameter, the influence of corrosion defect factors, operating pressure, working time and variation index on the failure probability of submarine oil and gas pipelines is analyzed. According to the calculation results, it can be known that the depth and length of corrosion defects and the increase of operating pressure will accelerate the failure of the pipeline. When the corrosion depth increases, the probability of failure gradually increases, from the lowest value of 7.0 x 10-6 to 2.2 x 10-2, and the increase rate is relatively rapid. When the length of corrosion increases, the probability of failure gradually increases from the lowest value of 4.0 x 10-6 to 2.5 x 10-3. With the increase of the variation index of corrosion defect depth and length, operating pressure, etc., the probability of failure will increase. The longer the working time of the pipeline, the smaller the impact on the probability of failure. [ABSTRACT FROM AUTHOR]

Abstract Although Oil and Gas Pipelines (OGPs) are a safe and economical mode of transportation of petroleum products around the world, they face challenges caused by risk factors. These include safety, security, design, construction and operational risks due to Third Party Disruption (TPD) and acts of terrorism, particularly in developing and unstable countries like Iraq. A lack of knowledge about managing such risks and the scarcity of past data about pipeline failures are hindering OGP risk management systems. This paper, therefore, focuses on identifying and analyzing the risks caused by TDP in order to develop a holistic Risk Management Model (RMM). A semi-structured questionnaire was designed, using 30 risk factors identified through a comprehensive literature review, distributed to OGP stakeholders in Iraq, via an online survey tool, to collect the research data. SPSS was used to analyze the data and evaluate risk factors which were ranked in order of likelihood and severity level using a risk index method. A conceptual framework for the RMM is presented, based on the literature review and survey findings. The results reveal that terrorism, sabotage, oleum product transportation, however and theft are the most critical safety risks, official corruption and lawlessness the most influential factors for regulatory risks. Pipeline location "Hot-Zones" also have a serious impact on the failure of pipelines. A computer-based risk management model will be developed at the next stage of the study using the RMM and the results of the numerical risk analysis. [ABSTRACT FROM AUTHOR]

Abstract Pipelines play a significant role in production and transportation of oil and gas. The use of film-former corrosion inhibitors is one of the most economical and reliable methods of controlling internal corrosion of oil and gas pipelines. In this paper, the general mechanisms of internal corrosion in oil and gas pipelines, formulation and chemical structure of film-forming organic corrosion inhibitors and their different types were reviewed. The mechanisms of film formation of these corrosion inhibitors are also reviewed based on electrochemical techniques. In addition, the selection process of corrosion inhibitors for pipelines is discussed. Highlights • Pipeline corrosion mechanisms and mitigation methods have been reviewed. • Film former corrosion inhibitors including molecular structure are well classified. • Various experiments case studies have been reflected. • Corrosion inhibition mechanisms by film forming are discussed. • A guide for selection of pipeline inhibitors has been provided. [ABSTRACT FROM AUTHOR]

Signals collected from the magnetic scans of metal-loss defects have distinct patterns. Experienced pipeline engineers are able to recognize those patterns in magnetic flux leakage (MFL) scans of pipelines, and use them to characterize defect types (e.g., corrosion, cracks, dents, etc.) and estimate their lengths and depths. This task, however, can be highly cumbersome to a human operator, because of the large amount of data to be analyzed. This paper proposes a solution to automate the analysis of MFL signals. The proposed solution uses pattern-adapted wavelets to detect and estimate the length of metal-loss defects. Once the parts of MFL signals corresponding to metal-loss defects are isolated, artificial neural networks are used to predict their depth. The proposed technique is computationally efficient, achieves high levels of accuracy, and works for a wide range of defect shapes. [ABSTRACT FROM AUTHOR]

Pipeline transportation is a safe and reliable way for transporting dangerous and flammable substances, such as oil and gas. In the process of transportation, third-party damage, corrosion destruction, design flaws, misuse of factors and other risk factors can also cause leakage or rupture of pipelines, which has a serious influence on social security and environment. In this paper, a comprehensive risk evaluation method based on a fuzzy Petri net (FPN) model for long-distance oil and gas transportation pipelines is proposed. In the process of the fuzzy reasoning, to tackle the impact of subjective factors and objective factors, the related parameters are optimized. In terms of risk factors weights, the combination weighting method is proposed, which combines AHP model and EM model. To reflect the fuzziness and randomness of risk factors, apply the cloud model to calculate the initial degrees of membership of the risk factors under the different risk grades. Furthermore, the risk evaluation values can be modified via the credibility. It is verified that the risk evaluation method based on the FPN model applies for the long-distance oil and gas transportation pipelines and provides some decision support for the risk management of the oil and gas pipelines. [ABSTRACT FROM AUTHOR]

This paper presents the concept o f introducing a third line of defense in the form of a metallic underlayer coating--in addition to the traditional polymeric coating and applied cathodic protection (CP)--to protect the external surface of oil and gas pipelines. The three levels of protection would he the metallic under-layer coating, the polymeric top-layer coating, and the applied CP. This three-level system would be beneficial when the applied CP current is shielded from the pipeline by a disbonded polymeric coating, thermal insulator, or highly resistive soil. Two different combinations of metallic under-layer and polymeric top-layer coatings are presented to demonstrate this concept: 48%Zn and 52%Al under-layer with four different top-layer coatings: fusion-bonded epoxy (FBE), composite. urethane, and coal tar epoxy. Urethane top-layer coating with four different metallic underlayers: 48%Zn-52%Al, 85%Zn-15%Al, Al, and Zn. The criteria for the successful application of this concept also have been described. [ABSTRACT FROM AUTHOR]

Abstract: Based on research interviews and field research, this article explores the “interpretive flexibility” of two large pipelines: the $4.6billion Baku-Tbilisi-Ceyhan (BTC) oil pipeline exporting petroleum from the Caspian Sea near Azerbaijan and then traversing parts of Georgia and Turkey; and parts of the $14.2billion Trans-ASEAN Gas Pipeline (TAGP) Network connecting the gas reserves of Indonesia, Myanmar, and Thailand with each other and Singapore. Each pipeline is the product of differing interpretations and ideologies, meaning they have “interpretive flexibility” because their meaning is under constant interpretation. The article depicts four differing interpretive frames for each pipeline, revealing the views of the Association of Southeast Asian Nations, government of Thailand, government of Myanmar, and state-owned energy Malaysian energy company Petronas for the TAGP, and the World Bank Group, British Petroleum, European Union, and the government of Azerbaijan for the BTC. The article finds that pipelines not only mark the physical landscape and distribute energy fuels, they also transfer what were once customary public resources into private hands, concentrate political power, facilitate human rights abuses and possible acts of genocide, become intertwined in national discourses of revitalization and strength, and validate distinct approaches to economic and social development. [Copyright &y& Elsevier]

Following the breakup of the Soviet Union in 1991, many commentators started talking about the "New Great Game". This article seeks to understand one small portion of this game, the part that relates to Eurasia, including Central Asia and the Caspian Sea Basin, and within the context of energy security. The focus of this piece is on events that have occurred in the past 18 or so months. During this period, there have been significant changes in world energy markets, brought about by the global economic downturn, the opening of new reserves of natural gas through the process of fracturing or "frackting", and growing concern over the effects of climate change. These and other considerations may be changing the nature of the "game" being played in global energy markets, with significant consequences for all of the players, especially those in Eurasia. This article is an attempt to identify what those changes may be, and the impacts they may have. [ABSTRACT FROM AUTHOR]

A model has been developed to predict internal pitting corrosion of oil and gas pipelines. This model is based on experiments carried out in the laboratory at high pressure and high temperature under the operating conditions of the oil and gas pipelines. There are two kinds of inputs: construction (pipe diameter, pipe wall thickness, and pipe inclination) and operational (production rates of oil, water, gas, solid, temperature, total pressure, partial pressures of hydrogen sulfide [H2S] and carbon dioxide [CO2], concentrations of sulfate, bicarbonate, and chloride). The model accounts for the statistical nature of the pitting corrosion, predicts the growth of internal pits based on the readily available operational parameters from the field, includes the pit growth rate driven by variables not included in the model, considers the variation of the pitting corrosion rate as a function of time, and determines the error in the prediction. The validity of this model was checked using data obtained from seven operating pipelines. [ABSTRACT FROM AUTHOR]

Experiments were conducted in six operating oil and gas production pipelines over four years to determine internal pitting corrosion rates under realistic operating conditions. -Pitting corrosion rates were similar when the compositions of surface layers were similar. -When a compact layer of single species formed, the surface was protected from pitting corrosion; the iron sulfide (FeS) layer was more protective than the siderite (FeCO3) layer. -When multiple layers of several species formed, the susceptibility of the surface to pitting corrosion increased. Frequent changes in the pipeline operating conditions facilitated the formation of multiple layers. -When no surface layer formed, the susceptibility of the surface to pitting corrosion decreased but was not eliminated. Extraneous materials (e.g., sand) on the surface facilitated pitting corrosion. -In the absence of surface layer and extraneous materials, no pitting corrosion was observed. [ABSTRACT FROM AUTHOR]

This paper proposes a practical implementation of robust ensemble learning models for accurate prediction of the internal corrosion rate in oil and gas pipelines. A correct assessment of the corrosion rate in fluid flowed oil and gas pipelines has a significant influence on the system's safety and the ability to control operation. The developed predictive data driven models include four ensemble learning approaches, namely random forest, adoptive boosting, gradient boosting regression tree, and extreme gradient boosting. The implementation procedure of these predictive models integrates a comprehensive database of eight system descriptors, extracted from the literature, while k -fold cross validation is employed to guarantee high performance and generalization. In addition, the obtained results of the internal corrosion rate are subjected to rigorous statistical and graphical analysis to evaluate the models performance and compare their abilities. The extreme gradient boosting model indicate the highest performance in the prediction of the internal corrosion rate in oil and gas pipelines based on the calculated single and global metrics, with a mathematical RMSE value of internal corrosion rate 0.031 mm/y and performance index, PI = 0.61. Besides, the significance of the input variables is determined through a sensitivity analyses by using feature importance criteria, whereas for the applied dataset strongest corrosion rate dependency to temperature and the pressure was shown beside the CO 2 contribution. In overall, the ensemble learning models show a significant performance in the internal corrosion rate predictions, while the extreme gradient boosting model is beneficial to model the internal corrosion rate in oil and gas pipelines due to its high performance. • A novel framework for the internal corrosion rate prediction in oil and gas pipelines is proposed using Ensemble Learning techniques. • Single and global criteria are used to evaluate and compare the performance of the proposed EL-models. • The proposed EL-models show superior accuracy compared to the single ML-models and empirical correlation. • The extreme gradient boosting model provide the highest performance with RMSE = 0.031 mm/y and R2 = 0.99. [ABSTRACT FROM AUTHOR]

With the Soviet Union's collapse in 1991, Russia gradually lost its position as the dominant foreign power in Central Asia. The United States, Europe, and the Muslim World, among others, started to assert their influence over the post-Soviet states in this region. Since the late 1990s, China has been increasingly active there as well, mainly in search for energy resources to sustain its rapid economic growth. This article provides an overview of the Sino-Turkmen relations after 1991. In particular, the latest developments concerning the Turkmenistan-China gas pipeline project are discussed, which in the summer of 2007 entered the final stage of implementation. The authors conclude by arguing that it is the quest for Turkmenistan's natural gas that is becoming the focal point of the newly emerging geopolitics of Central Asia. [ABSTRACT FROM AUTHOR]

This article presents an account and analysis of contemporary Kazakh-Chinese relations in the energy sector as well as the geopolitical and legal dimensions of such cooperation. The current trends and challenges in the energy industry is also analyzed. In order to understand the specific problems facing the two countries on the issue of energy cooperation, this author examines the major legal instruments between the two and describes the peculiarities of Chinese energy policy towards the Central Asian region. The article also tries to define the dynamics of Kazakh-Chinese energy relations and look at the possible implications and involvement of the Shanghai Cooperation Organization and other regulative principles and institutions. [ABSTRACT FROM AUTHOR]

Oil and gas pipelines are safe and economic to petroleum products transportation. Nevertheless, enormous risk influencing factors are threatening the safety of these pipelines during the planning, construction and operations stages of these projects. Risk analysis in these projects is hindered by the inaccurate data about the probability and severity levels of the risk influencing factors. This problem is exacerbated further in troubled and developing countries, where the documentations and records are not at the best conditions. This study aims to identify and analyze potential risk influencing factors using a more integrated risk analysis framework. In this a such framework, the critical risk influencing factors and some of applied risk mitigation methods were identified based on a comprehensive review of pipelines projects worldwide. The impact of the identified factors and the effectiveness of mitigation methods were evaluated based on an industry-wide questionnaire survey, which was conducted in Iraq. A Computer-Based Risk Analysis Model (CBRAM) was designed to analyze the risk influencing factors using a fuzzy logic theory to consider any uncertainty that is associated with stakeholders' judgments and data scarcity. The CBRAM has confirmed the most critical risk influencing factors, which this study has explained the effective methods to manage them. [ABSTRACT FROM AUTHOR]

Integrity management of pipeline is vital for sustainable production. Among all of pipeline failure threats, contribution of corrosion is significant and has been reported up to 50%. This paper focuses on the corrosion risks risen from internal media in contact with pipe wall either sweet or sour service. Internal corrosion concerns have been divided into two categories including general/localized metal loss and environmentally assisted cracking. Modes and mechanisms for both aspects have been comprehensively reviewed and discussed. Each type of defined corrosion mechanism has been actualized by some failure case studies and filed histories. Image 1 • Internal corrosion as the biggest threat of pipeline integrity has been discussed. • Failure modes have been included to metal loss and environmentally assisted cracking. • Useful base is provided for integrity assessment and risk analysis studies. • Failures from actual case studies have been addressed. • Experimental studies and practices of various researchers have been incorporated in this study. [ABSTRACT FROM AUTHOR]