Blockage Detection and Characterization in Natural Gas Pipelines by Transient Pressure-Wave Reflection Analysis

SPE Journal ◽  
2012 ◽  
Vol 18 (02) ◽  
pp. 355-365 ◽  
Author(s):  
Najeem Adeleke ◽  
Mku T. Ityokumbul ◽  
Michael Adewumi
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Preventive Measure ◽  
Gas Production ◽  
Gas Pipelines ◽  
Transient Pressure ◽  
Viscous Effects ◽  
Natural Gas Pipelines ◽  
Compositional Model ◽  
Cubic Equation

Summary Pipeline blockage is a major problem in gas production and transportation processes. Safety and economic costs of pipeline blockages are compelling the industry to design innovative means for early detection of partial blockages along pipe systems as a preventive measure. This paper presents a simple numerical model to be used for accurate blockage characterization in natural gas pipelines. The transport phenomenon is modeled with a quasi-1D set of partial differential equations for isothermal natural gas flow in pipes. The variable area formulation maintains the simplicity of a 1D formulation and yet allows for the complex geometries associated with natural gas pipeline blockages. Viscous effects are also included in the formulation of the governing equations, and a cubic equation of state is incorporated into the model to provide the quasi-compositional effect of real gases without the complexities of a fully compositional model. The generalized Newton-Raphson technique is used to solve the piece-wise finite-volume formulation iteratively as an optimization problem with pressure and velocity as perturbed variables. Reflected pressure waves observed at the pipe inlet node were analyzed for blockage characterization. It was observed that viscous losses have no effect on blockage length and location prediction accuracy, but has significant impact on the accuracy of blockage severity predictions.

Assessing Hydrate Formation in Natural Gas Pipelines Under Transient Operation / Ocena zjawiska tworzenia się hydratów w warunkach nieustalonego przepływu gazu w gazociągach

2013 ◽  
Vol 58 (1) ◽  
pp. 131-144
Author(s):  
Andrzej Osiadacz
Keyword(s):  
Natural Gas ◽  
Gas Flow ◽  
Hydrate Formation ◽  
Operating Conditions ◽  
Gas Pipelines ◽  
Natural Gas Pipelines ◽  
Hydrate Phase ◽  
Real Gas Effects ◽  
Classical Thermodynamics

This work presents a transient, non-isothermal compressible gas flow model that is combined with a hydrate phase equilibrium model. It enables, to determine whether hydrates could form under existing operating conditions in natural gas pipelines. In particular, to determine the time and location at which the natural gas enters the hydrate formation region. The gas flow is described by a set of partial differential equations resulting from the conservation of mass, momentum, and energy. Real gas effects are determined by the predictive Soave-Redlich-Kwong group contribution method. By means of statistical mechanics, the hydrate model is formulated combined with classical thermodynamics of phase equilibria for systems that contain water and both hydrate forming and non-hydrate forming gases as function of pressure, temperature, and gas composition. To demonstrate the applicability a case study is conducted.

Applications of alternative energy for electrochemical corrosion protection devices on natural gas pipelines

2021 ◽  
Vol 4 ◽  
pp. 12-17
Author(s):  
Sergey Astashev ◽  
Oxana Medvedeva
Keyword(s):  
Natural Gas ◽  
Corrosion Protection ◽  
Alternative Energy ◽  
Gas Flow ◽  
Oil And Gas ◽  
Electrochemical Corrosion ◽  
Oil And Gas Industry ◽  
Gas Pipelines ◽  
Natural Gas Pipelines ◽  
Protection Devices

Natural gas pipeline corrosion has a high impact on economics. That is why efficiency of corrosion prevention and protection is one of crucial factors contributing to reliability and endurance of natural gas distribution pipelines. In this paper, the authors discuss a novel renewable energy-based installation which is intended for power supply of electrochemical corrosion protection devices on natural gas pipelines. The mentioned installation is driven by a natural gas flow transforming its energy into electric power to be supplied to electrochemical corrosion protection devices protecting underground steel pipelines in the oil and gas industry

scholarly journals The Conceptual Principles of Improving the Management of the Gas Production Complex of Ukraine on the Bases of the Experience of Leading Oil and Gas Companies

2020 ◽  
Vol 12 (515) ◽  
pp. 165-172
Author(s):  
N. M. Andriishyn ◽  
Keyword(s):  
Natural Gas ◽  
Crude Oil ◽  
Management System ◽  
Oil And Gas ◽  
Gas Production ◽  
Gas Pipelines ◽  
Geophysical Research ◽  
Oil Refineries ◽  
Natural Gas Pipelines ◽  
Production Complex

The main directions of improvement of the gas production complex management and the role of individual factors affecting the efficiency of its activities are determined. Taking into account that the oil and gas complex is a system of enterprises and organizations for various functional purposes, united to meet the needs of consumers in provision of natural gas, on the example of improving the organizational structure and management system of NK «YUKOS», all stages of its transformation into a world–class oil company are considered. Recommendations on the use of positive experience in Ukraine are provided. It is shown what achievements of NK «YUKOS» have already been taken into account in the reform of the management system of JSC «Ukrgasvydobuvannya», – in particular, today it is conditionally represented by three large sectors: upstream, midstream and downstream. The upstream sector includes the search for potential underground or underwater natural gas fields, drilling of exploration wells, drilling and operation of the wells extracting unprocessed natural «wet» gas; the midstream sector provides transportation (pipelines, railways, barges, oil trucks or regular trucks), storage and wholesale of gas, while networks of natural gas pipelines aggregate gas from natural gas purification stations and deliver it to consumers – local utilities; the downstream sector usually refers to the processing and purification of natural gas, crude oil, as well as the sale and distribution of products derived from natural gas and crude oil. Distribution by sector in gas production allows to classify fixed assets in accordance with the above–mentioned sectors: drilling rigs, offshore drilling platforms, well repair machines, software for geological exploration and geophysical research – upstream; well plumes, inter–industrial gas pipelines, condensate pipelines, oil pipelines, booster compressor stations, equipment for the complex gas preparation – midstream; gas processing and oil refineries, petrol stations – downstream. Much attention is paid to the development of the intellectual potential of the gas production complex, as it ensures both the successful development of production and the formation of effective management of the company.

Validation of EMAT ILI for Management of Stress Corrosion Cracking in Natural Gas Pipelines

2014 ◽  
Author(s):  
Toby Fore ◽  
Stefan Klein ◽  
Chris Yoxall ◽  
Stan Cone
Keyword(s):  
High Resolution ◽  
Natural Gas ◽  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Corrosion Cracking ◽  
Probability Of Detection ◽  
Gas Pipelines ◽  
Line Pipe ◽  
Natural Gas Pipelines ◽  
Electro Magnetic

Managing the threat of Stress Corrosion Cracking (SCC) in natural gas pipelines continues to be an area of focus for many operating companies with potentially susceptible pipelines. This paper describes the validation process of the high-resolution Electro-Magnetic Acoustical Transducer (EMAT) In-Line Inspection (ILI) technology for detection of SCC prior to scheduled pressure tests of inspected line pipe valve sections. The validation of the EMAT technology covered the application of high-resolution EMAT ILI and determining the Probability Of Detection (POD) and Identification (POI). The ILI verification process is in accordance to a API 1163 Level 3 validation. It is described in detail for 30″ and 36″ pipeline segments. Both segments are known to have an SCC history. Correlation of EMAT ILI calls to manual non-destructive measurements and destructively tested SCC samples lead to a comprehensive understanding of the capabilities of the EMAT technology and the associated process for managing the SCC threat. Based on the data gathered, the dimensional tool tolerances in terms of length and depth are derived.

Comparison of PIR to PIPESAFE-Based 1% Lethality Zones for Natural Gas Pipelines

2014 ◽  
Author(s):  
Aleksandar Tomic ◽  
Shahani Kariyawasam
Keyword(s):  
Natural Gas ◽  
Small Diameter ◽  
Gas Pipeline ◽  
Accurate Estimation ◽  
Simple Relationship ◽  
Gas Pipelines ◽  
Friction Forces ◽  
Natural Gas Pipelines ◽  
Decay Factor ◽  
Outflow Rate

A lethality zone due to an ignited natural gas release is often used to characterize the consequences of a pipeline rupture. A 1% lethality zone defines a zone where the lethality to a human is greater than or equal to 1%. The boundary of the zone is defined by the distance (from the point of rupture) at which the probability of lethality is 1%. Currently in the gas pipeline industry, the most detailed and validated method for calculating this zone is embodied in the PIPESAFE software. PIPESAFE is a software tool developed by a joint industry group for undertaking quantitative risk assessments of natural gas pipelines. PIPESAFE consequence models have been verified in laboratory experiments, full scale tests, and actual failures, and have been extensively used over the past 10–15 years for quantitative risk calculations. The primary advantage of using PIPESAFE is it allows for accurate estimation of the likelihood of lethality inside the impacted zone (i.e. receptors such as structures closer to the failure are subject to appropriately higher lethality percentages). Potential Impact Radius (PIR) is defined as the zone in which the extent of property damage and serious or fatal injury would be expected to be significant. It corresponds to the 1% lethality zone for a natural gas pipeline of a certain diameter and pressure when thermal radiation and exposure are taken into account. PIR is one of the two methods used to identify HCAs in US (49 CFR 192.903). Since PIR is a widely used parameter and given that it can be interpreted to delineate a 1% lethality zone, it is important to understand how PIR compares to the more accurate estimation of the lethality zones for different diameters and operating pressures. In previous internal studies, it was found that PIR, when compared to the more detailed measures of the 1% lethality zone, could be highly conservative. This conservatism could be beneficial from a safety perspective, however it is adding additional costs and reducing the efficiency of the integrity management process. Therefore, the goal of this study is to determine when PIR is overly conservative and to determine a way to address this conservatism. In order to assess its accuracy, PIR was compared to a more accurate measure of the 1% lethality zone, calculated by PIPESAFE, for a range of different operating pressures and line diameters. Upon comparison of the distances calculated through the application of PIR and PIPESAFE, it was observed that for large diameters pipelines the distances calculated by PIR are slightly conservative, and that this conservativeness increases exponentially for smaller diameter lines. The explanation for the conservatism of the PIR for small diameter pipelines is the higher wall friction forces per volume transported in smaller diameter lines. When these higher friction forces are not accounted for it leads to overestimation of the effective outflow rate (a product of the initial flow rate and the decay factor) which subsequently leads to the overestimation of the impact radius. Since the effective outflow rate is a function of both line pressure and diameter, a simple relationship is proposed to make the decay factor a function of these two variables to correct the excess conservatism for small diameter pipelines.

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