An Approach to Corrosion Mitigation for Wet Gas Pipelines

2002 ◽  
Author(s):  
Nguyen N. Bich
Keyword(s):  
Internal Surface ◽  
Flow Regimes ◽  
Liquid Hydrocarbon ◽  
Management Program ◽  
Mitigation Measures ◽  
Corrosion Monitoring ◽  
Monitoring Methods ◽  
Wet Gas ◽  
Start Up ◽  
Corrosion Mechanisms

Relationship between flow regimes and corrosion mechanisms in pipelines is discussed. Flow regime affects how the water is delivered to the internal surface of the pipeline and the protective nature of the corrosion products / liquid hydrocarbon barrier film. Differences in corrosion mechanisms between CO2, CO2 + low H2S, and CO2 and high H2S are also presented. Mitigation measures should be designed to match expected flow regimes and corrosion mechanisms during all phases of production including start up, steady state, shut-in, acid stimulation, etc. Different corrosion monitoring methods are compared. Verification of pressure containing capability by inspection is also key to a pipeline corrosion management program.

Corrosion Monitoring as an Integral Component of an Effective Corrosion Management Program

2004 ◽  
Author(s):  
Nguyen N. Bich ◽  
Eric Kubian
Keyword(s):  
Case Studies ◽  
Early Warning ◽  
Management Program ◽  
Mitigation Measures ◽  
Corrosion Monitoring ◽  
Monitoring Device ◽  
Comprehensive Understanding ◽  
Monitoring Plan ◽  
Integrity Management ◽  
Corrosion Mechanisms

An effective pipeline integrity management program requires four components: a comprehensive understanding of corrosion mechanisms taking place in the pipeline, an effective corrosion mitigation plan responsive to the expected mechanisms, a monitoring plan to provide feedback to the corrosion mitigation plan and a selective inspection plan to validate the corrosion mechanisms and mitigation effectiveness and to confirm the pressure-containment capability of the pipeline. This paper describes several case studies where the use of a suitable corrosion monitoring device has led to an early warning of the lack of performance of the mitigation measures which, if left unchecked, could result in more severe corrosion and eventually, failure.

Internal Corrosion Direct Assessment for Pipelines Carrying Wet Gas - Methodology

2004 ◽  
Author(s):  
Oliver Moghissi ◽  
Deanna Burwell ◽  
Rick Eckert ◽  
Jose Vera ◽  
Narasi Sridhar ◽  
...  
Keyword(s):  
Corrosion Rate ◽  
Flow Regimes ◽  
Distribution Model ◽  
Liquid Volume ◽  
Internal Corrosion ◽  
Integrity Verification ◽  
Direct Assessment ◽  
Wet Gas ◽  
Pipeline Segment ◽  
Flow Effects

An Internal Corrosion Direct Assessment methodology is proposed for wet gas pipelines (WG-ICDA). Wet gas systems (i.e., those normally containing liquids) include storage and gathering systems with large gas-to-liquid volume ratios. Wet gas systems are not well represented by ICDA for normally dry gas, and existing corrosion models applied to wet gas systems are not sufficiently targeted at integrity verification. The essential focus of WG-ICDA compared to other internal corrosion models is the discrimination of conditions along the length of a pipeline so that possible local integrity threats with respect to internal corrosion are identified and mitigated. The basis of WG-ICDA is to prioritize locations along a pipeline segment by factors of traditional corrosion rate, flow effects, and other influencing factors. Corrosion rate depends on gas quality, liquid chemistry, pressure, and temperature. The corrosion rate can be normalized because WG-ICDA as integrity verification only concerns itself with corrosion distribution (i.e., the location along a pipeline segment where corrosion is more severe than other locations). Flow effects include possible flow regimes and the presence of water from condensation (at locations of heat loss). Expected possible flow regimes are stratified, slugging, and annular. The final term captures other factors influencing corrosion rate distribution. These factors include corrosion inhibition (batch and continuous, solubility and dispersibility in hydrocarbon and aqueous phases), biocide treatments, hydrocarbon condensates (including emulsion characteristics), maintenance pigging, bacteria, solids/scale, and other products. WG-ICDA follows the same four-step process as all other Direct Assessment (DA) methods: 1) Pre-Assessment: Data is collected, a feasibility analysis is performed, and the pipeline segment is divided into regions. 2) Indirect Inspections: Measurements are taken or calculations are performed to prioritize locations along a particular pipeline segment for susceptibility to corrosion. For WG-ICDA, the factors contributing to the distribution of corrosion will be included and an initial assumption about corrosion distribution will be made. WG-ICDA is sufficiently flexible to allow the use of existing wet gas models within the framework of the overall process. 3) Direct (or Detailed) Examinations: The pipe is excavated and examined at locations prioritized to have the highest likelihood of corrosion. The examination must have sufficient detail to determine the existence, extent, and severity of corrosion. Examination of the internal surface of a pipe can involve non-destructive examination methods sufficient to identify and characterize internal defects. 4) Post-Assessment: Analysis of the indirect and direct examination data is performed to determine overall pipeline integrity, prioritize repairs, and set the interval for the next assessment. If the results of excavations do not match the original assumption, the corrosion distribution model will be updated to guide the next excavations (i.e., the operator returns to step 2).

High Frequency Acoustic Signal Analysis for Internal Surface Pipe Roughness Classification

2011 ◽  
Vol 83 ◽  
pp. 249-254
Author(s):  
Z. M. Hafizi ◽  
Che Ku Eddy Nizwan ◽  
M.F.A. Reza ◽  
M.A.A. Johari
Keyword(s):  
Surface Roughness ◽  
Acoustic Emission ◽  
Control Valve ◽  
Internal Surface ◽  
Corrosion Monitoring ◽  
Emission Analysis ◽  
Pressure Water ◽  
Pipe Roughness ◽  
The Time Domain ◽  
Roughness Classification

This research highlights a method of acoustic emission analysis to distinguish the internal surface roughness of pipe. Internal roughness of pipe indicates the level of corrosion occurring, where normally it is difficult to be monitored online. Acoustic Emission (AE) technique can be used as an alternative solution for corrosion monitoring in pipes, especially for complex pipelines that are difficult to achieve by other monitoring devices. This study used a hydraulic bench to provide fluid flow at two different pressures in pipes with different internal surface roughness (rough and smooth). The main source of acoustic emission was from activity in the control valve, coupled with high pressure water flow friction on the surface of the pipe. The signal from these sources was detected by using the AED-2000V instrument and assisted by the Acoustic Emission Detector (AED) software. The time domain parameter; root mean square, RMS amplitude were processed and compared at different pressures for each type of internal pipe roughness at ten different locations. It was observed that a unitless Bangi number, AB, derived from RMS values, can be used for discriminating different level of internal surface roughness. Internal surface pipe can still be considered as smooth if AB value is above 1.0.

HYDROCARBON GASES IN SEAFLOOR SEDIMENTS, OTWAY AND GIPPSLAND BASINS: IMPLICATIONS FOR PETROLEUM EXPLORATION

1989 ◽  
Vol 29 (1) ◽  
pp. 96 ◽  
Author(s):  
G.W. O'Brien ◽  
D.T. Heggie
Keyword(s):  
Liquid Hydrocarbon ◽  
Source Rocks ◽  
Petroleum Exploration ◽  
Gas Content ◽  
Hydrocarbon Gases ◽  
Near Surface ◽  
Wet Gas ◽  
Well Data ◽  
Seafloor Sediments ◽  
Gippsland Basin

During April- May 1988, the BMR research vessel Rig Seismic carried out a 21- day geochemical and sedimento- logical research program in the Otway (17 days) and Gippsland (4 days) Basins. The concentrations and molecular compositions of light hydrocarbon gases (C1- C4) were measured in sediments at 203 locations on the continental shelf and upper continental slope: the presence of thermogenic hydrocarbons was inferred from the molecular compositions of the gas mixtures. Thermogenic hydrocarbons were identified in near- surface sediments at 32 locations in the Otway Basin; 6 of these locations were on the Crayfish Platform, 7 were on the Mussel Platform and 17 were in the Voluta Trough. Thermogenic hydrocarbons were identified at 10 locations in the Gippsland Basin. Data from the Otway Basin indicated that total C1- C4 gas concentrations were higher in the Voluta Trough than on the basin margins, probably because intense faulting in the trough facilitates gas migration from deeply buried source rocks and/or reservoirs to the seafloor. However, anomalies were detected where the Tertiary sequence was thick and relatively unfaulted. The wet gas contents of the anomalies were highest on the basin margins, lower in the Voluta Trough and co- varied with the depth of burial of the basal Early Cretaceous sedimentary sequence. These data, when integrated with geohistory, thermal maturation modelling and well data, suggest that the areas with the best potential for liquid hydrocarbon entrapment and preservation are the Crayfish Platform and the inshore part of the Mussel Platform. In contrast, the Late Cretaceous Sherbrook Group and much of the Voluta Trough appear to be gas prone.Thermogenic anomalies in the Gippsland Basin were concentrated within and along the margins of the Central Deep where mature Latrobe Group source rocks are present. The wet gas content of these anomalies was variable, which is consistent with the spatial heterogeneity of hydrocarbon accumulations in the Gippsland Basin.

scholarly journals Determination of Transient Fluid Temperature and Thermal Stresses in Pressure Thick-Walled Elements Using a New Design Thermometer

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 222 ◽  
Author(s):  
Magdalena Jaremkiewicz ◽  
Dawid Taler ◽  
Piotr Dzierwa ◽  
Jan Taler
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Critical Pressure ◽  
Thermal Stresses ◽  
Thermal Inertia ◽  
Internal Surface ◽  
Transient Temperature ◽  
Fluid Temperature ◽  
Start Up

In both conventional and nuclear power plants, the high thermal load of thick-walled elements occurs during start-up and shutdown. Therefore, thermal stresses should be determined on-line during plant start-up to avoid shortening the lifetime of critical pressure elements. It is necessary to know the fluid temperature and heat transfer coefficient on the internal surface of the elements, which vary over time to determine transient temperature distribution and thermal stresses in boilers critical pressure elements. For this reason, accurate measurement of transient fluid temperature is very significant, and the correct determination of transient thermal stresses depends to a large extent on it. However, thermometers used in power plants are not able to measure the transient fluid temperature with adequate accuracy due to their massive housing and high thermal inertia. The article aims to present a new technique of measuring transient superheated steam temperature and the results of its application on a real object.

An electromechanical impedance-instrumented corrosion-measuring probe

2019 ◽  
Vol 30 (14) ◽  
pp. 2135-2146 ◽  
Author(s):  
Weijie Li ◽  
Tiejun Liu ◽  
Shasha Gao ◽  
Mingzhang Luo ◽  
Jianjun Wang ◽  
...  
Keyword(s):  
Mass Loss ◽  
Lead Zirconate Titanate ◽  
Oil And Gas ◽  
Structural Complexity ◽  
Lead Zirconate ◽  
Corrosion Monitoring ◽  
Monitoring Methods ◽  
Accelerated Corrosion ◽  
Electromechanical Impedance ◽  
Measuring Probe

Corrosion of metallic structures widely existed in multiple industries, such as oil and gas, civil infrastructure, aerospace, mechanical, mining, and processing. Current available corrosion-monitoring methods are based on different sensing principles, which have their own advantages, and some drawbacks that may limit their application on some aspects. This article presents an electromechanical impedance-instrumented corrosion-measuring probe for corrosion monitoring. The proposed probe is fabricated by attaching a circular lead zirconate titanate patch onto a metal rod. Compared to other electromechanical impedance-based corrosion-monitoring methods, the probe is capable of isolating the influence of structural complexity, variations in loading and boundary conditions. Five probes were fabricated in the experimental study and three of them were subjected to accelerated corrosion tests to mimic the corrosion-induced mass loss damage. Results showed that the peak magnitude of the conductance signatures was reduced with the increase in corrosion amount. The variations in the conductance signatures were quantified by three statistical quantifying metrics, that is, root-mean-square deviation, mean absolute percentage deviation, and correlation coefficient deviation. All these metrics increase with the increase in corrosion amount, which can be used as an indicator of the corrosion process. This study proves that the proposed corrosion-measuring probe is effective in monitoring corrosion and shows promising application potential. This research also serves as a proof-of-concept study to demonstrate the capability of the electromechanical impedance technique in monitoring mass loss due to corrosion.

Research on Corrosion and Monitoring Methods of Pressure Vessels in Sulfur-Containing Natural Gas Purification Plants

2012 ◽  
Vol 549 ◽  
pp. 655-659
Author(s):  
Jian Feng Shang ◽  
Gang Tian ◽  
Yuan Zhi Liu ◽  
Guo Qing Xiao ◽  
De Cai Long ◽  
...  
Keyword(s):  
Weight Loss ◽  
Natural Gas ◽  
Pressure Vessels ◽  
Corrosion Monitoring ◽  
Gas Purification ◽  
Monitoring Methods ◽  
Advantages And Disadvantages ◽  
Natural Gas Purification ◽  
Slice Method ◽  
Sulfur Containing

Pressure vessels in high sulfur-containing natural gas purification plants are likely corroded in acid media. Corrosion monitoring and control must be carried out to ensure safety and efficiency of purification system. So corrosion cause and service characters of pressure vessels in the purification plants were analyzed in this paper. The factors which influence pressure vessels corrosion include acid gas load, flow rate, phase state, temperature, heat-stable salts and degradation products. Then adaptability, advantages and disadvantages of the methods such as weight loss hanging slice method, electrochemical monitoring, ultrasonic thickness measurement, etc. were also analyzed in the paper. The results show that current on - line corrosion monitoring methods are hard to be applied in high sulfur-containing natural gas purification plants. Weight loss hanging slice method is an effective approach for pressure vessels corrosion monitoring. The data obtained are reliable and the investment is relatively lower. Based on characteristics of different technology units, corrosion coupon monitoring scheme is established. The research result provides a solid base for ensuring safe operation of high sulfur-containing natural gas purification plants.

Proactive Approaches to Geohazard Management

2017 ◽  
Author(s):  
S. Ruik Beyhaut
Keyword(s):  
Technological Development ◽  
Seismic Intensity ◽  
Management Program ◽  
Slope Instability ◽  
Mitigation Measures ◽  
Critical Element ◽  
Bending Strain ◽  
Actual Movement ◽  
Integrity Management ◽  
External Forces

To control the threats from external forces, pipeline owners and operators require detailed information about their pipeline infrastructure and the environment surrounding that infrastructure. The contribution from geographic data is recognized as an increasingly important part of a complete integrity management program, particularly for the identification of geohazards. This is because geohazards are generally characterized by high spatial variability, are complex and difficult to quantify but may result in catastrophic failure of pipelines. In recent years we have seen widespread technological development surrounding the processes to capture information in order to deliver quantitative inputs for pipeline engineers, risk & geotechnical experts. International codes & best practices (e.g. AS 2885.1-2012) state that “Environmental impact assessment is not simply a vehicle to obtain regulatory approval, it is a critical element of the planning for design, construction and operation of the pipeline.” Furthermore, geohazards frequently develop during the service life of pipelines. Consequently, regulators recommend that assessments are conducted on an ongoing basis to identify all potential threats and implement mitigation measures. A process has been developed to create efficient and economical solutions for monitoring and assessing the significance of pipeline bending strain and whether actual movement has taken place. This process can make use of a variety of inputs including slope gradient, climate, groundwater conditions, slope instability, seismic intensity, and environmental impacts, and can provide important information in the determination of potential mitigations. This paper will review the benefits which can be gained from the implementation of integrated approaches to inform geohazard management.

Comparison of Non-Destructive Examination Techniques for Crack Inspection

2020 ◽  
Author(s):  
Axel Aulin ◽  
Khurram Shahzad ◽  
Robert MacKenzie ◽  
Steven Bott
Keyword(s):  
Internal Surface ◽  
Large Data ◽  
Field Measurements ◽  
Management Program ◽  
Destructive Testing ◽  
Data Set ◽  
Examination Techniques ◽  
Welded Pipe ◽  
Non Destructive

Abstract Effective and efficient crack management programs for liquids pipelines require consistent, high quality non-destructive examination (NDE) to allow validation of crack in-line inspection (ILI) results. Enbridge leveraged multiple NDE techniques on a 26-inch flash-welded pipe as part of a crack management program. This line is challenging to inspect given the presence of irregular geometry of the weld. In addition, the majority of the flaws are located on the internal surface, so buffing to obtain accurate measurements in the ditch is not possible. As such, to ensure a robust validation of crack ILI performance on the line, phased array ultrasonic testing (PAUT), time-of-flight diffraction (TOFD), and a full matrix capture (FMC) technology were all used as part of the validation dig program. PAUT and FMC were used on most of the flaws characterized as part of the dig program providing a relatively large data set for further analysis. Encoded scans on the flash welded long seam weld were collected in the ditch and additional analyses were performed off-site to characterize and size the flaws. Buff-sizing where possible and coupon cutouts were selected and completed to assist with providing an additional source of truth. Secondary review of results by an NDE specialist improved the quality of the results and identified locations for rescanning due to data quality concerns. Physical defect examinations completed after destructive testing of sample coupon cutouts were utilized to generate a correlation between the actual defect size from fracture surface observation and the field measurements using various NDE methods. This paper will review the findings from the program, including quality-related learnings implemented into standard NDE procedures as well as comparisons of detection and sizing from each methodology. Finally, a summary of the benefits and limitations of each technique based on the experience from a challenging inspection program will be summarized.

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