Assessment of internal and external corrosion control measures for crude oil transmission pipelines for asset integrity management

2014 ◽  
Author(s):  
J.I. Emmanuel
Keyword(s):  
Crude Oil ◽  
Control Measures ◽  
Corrosion Control ◽  
Integrity Management ◽  
External Corrosion ◽  
Transmission Pipelines

Improving the Value of Excavations Through Indirect Inspection and Engineering Assessments

2012 ◽  
Author(s):  
Stephen F. Biagiotti ◽  
Eric Houston ◽  
George Licina ◽  
Dilip Dedhia
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Life Cycle Management ◽  
Control Measures ◽  
Management Approach ◽  
Buried Pipe ◽  
Risk Prioritization ◽  
Integrity Management ◽  
External Corrosion ◽  
Assurance Process

U.S. nuclear power plants are implementing a life cycle management approach to underground and buried pipe integrity management. The last few years have been spent gathering information about these systems and performing relative risk ranking analyses. The next stage of this process was to further refine the risk prioritization by gathering additional indirect performance information to qualitatively characterize the effectiveness of existing corrosion control measures, thereby refining the prioritization of locations with highest potential for corrosion activity. Once these locations are better understood, strategic quantitative Direct Examination techniques (i.e., NDE) can be used to inspect and then evaluate the fitness for service and remaining life. This paper provides a brief review of the increased interest in performing excavations at nuclear sites and will present corrosion engineering techniques that uniquely evaluate both the internal and external corrosion threats using ACCORDION© and APEC©, as well as an overall strategy designed to help maximize the value of each excavation. Application of the systematic methodology presented as part of a NEI 09-14 Reasonable Assurance process [Ref 1] can increase a site’s likelihood for the proactive detection of corrosion degradation — which is a key objective for the assurance of structural and/or leakage integrity of buried piping.

Simulation of Liquid-Gas Replacement in Commissioning Process for Large-Slope Crude Oil Pipeline

2012 ◽  
Author(s):  
Yuanyuan Chen ◽  
Jing Gong ◽  
Xiaoping Li ◽  
Nan Zhang ◽  
Shaojun He ◽  
...  
Keyword(s):  
Crude Oil ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Fluid Model ◽  
Engineering Application ◽  
Computational Procedure ◽  
Control Measures ◽  
Production Operation ◽  
Oil Pipeline

Pipeline commissioning, which is a key link from engineering construction to production operation, is aim to fill an empty pipe by injecting water or oil to push air out of it. For a large-slope crude oil pipeline with great elevation differences, air is fairly easy to entrap at downward inclined parts. The entrapped air, which is also called air pocket, will cause considerable damage on pumps and pipes. The presence of it may also bring difficulties in tracking the location of the liquid head or the interface between oil and water. It is the accumulated air that needed to be exhausted in time during commissioning. This paper focuses on the simulation of liquid-gas replacement in commissioning process that only liquid flow rate exists while gas stays stagnant in the pipe and is demanded to be replaced by liquid. Few previous researches have been found yet in this area. Consequently, the flow in a V-section pipeline consisted of a downhill segment and a subsequent uphill one is used here for studying both the formation and exhaustion behaviors of the intake air. The existing two-fluid model and simplified non-pressure wave model for gas-liquid stratified flow are applied to performance the gas formation and accumulation. The exhausting process is deemed to be a period in which the elongated bubble (Taylor bubble) is fragmented into dispersed small bubbles. A mathematical model to account for gas entrainment into liquid slug is proposed, implemented and incorporated in a computational procedure. By taking into account the comprehensive effects of liquid flow rate, fluid properties, surface tension, and inclination angle, the characteristics of the air section such as the length, pressure and mass can be calculated accurately. The model was found to show satisfactory predictions when tested in a pipeline. The simulation studies can provide theoretical support and guidance for field engineering application, which are meanwhile capable of helping detect changes in parameters of gas section. Thus corresponding control measures can be adopted timely and appropriately in commissioning process.

An External Corrosion Direct Assessment Module for a Pipeline Integrity Management System

2006 ◽  
Author(s):  
Menno T. van Os ◽  
Piet van Mastrigt ◽  
Andrew Francis
Keyword(s):  
Management System ◽  
Structural Reliability ◽  
Individual Performance ◽  
Corrosion Activity ◽  
Time Saving ◽  
Survey Techniques ◽  
Direct Assessment ◽  
Integrity Management ◽  
External Corrosion ◽  
The Individual

A significant part of the high pressure gas transport system of Gasunie cannot be examined by in-line inspection techniques. To ensure safe operation of these pipelines, an External Corrosion Direct Assessment (ECDA) module for PIMSLIDER (a pipeline integrity management system) is currently under development. The functional specifications of this module are based on NACE RP0502-2002, a recommended practice for ECDA. In addition to this, a new probabilistic methodology has been adopted, to take account for uncertainties associated with ECDA and to quantify the contributions from aboveground surveys and excavations to the integrity of a pipeline. This methodology, which is based on Structural Reliability Analysis (SRA) and Bayesian updating techniques, is presented in more detail in paper IPC2006-10092 of this conference. The DA module of PIMSLIDER enables computerized storage, retrieval and processing of all appropriate pipeline data and therefore guarantees highly accurate, reproducible and time saving integrity analyses of the Gasunie grid. Another important function of this system is the ability to use the complete database of all pipelines to pre-assess the integrity of a particular pipeline. This automated retrieval of data from pipelines with similar characteristics and/or environmental conditions results in a substantial increase of accessible data and enables Gasunie to improve the reliability of applied statistics throughout the process. As a consequence, the overall cost of inspections and excavations can be greatly reduced. In the Pre-Assessment phase, the DA module assists the integrity manager in gathering and analyzing data necessary to determine the current condition of a pipeline. After collection and visualization of the available data, the user can identify suitable ECDA regions. Furthermore, the gathered data are used to construct prior distributions of parameters relevant to the SRA model, such as the number and size of corrosion defects and pipeline-related parameters. In the Indirect Inspections step, the DA module allows the user to store and analyze the data from aboveground surveys, in order to identify and define the severity of coating faults and areas at which corrosion activity may occur. The probabilistic methodology accounts for the individual performance of each applied survey technique in terms of missed defects and false indications, in general a major source of uncertainty in ECDA. In the Direct Examinations phase, excavations are carried out to collect data to assess possible corrosion activity. Subsequently, the ECDA module uses this information to update, among other things, the parameters concerning the performance of survey techniques, the number of defects and the corrosion rate. As a result, updated failure frequencies are calculated for each ECDA-region (after each excavation if required), which are then used by the DA module to advise the integrity manager if additional mitigating activities are necessary, or by defining a reassessment interval.

When Metals and Microbes Meet: Preventing Microbial Corrosion in Crude Oil Transmission Pipelines

2020 ◽  
Author(s):  
Lisa M. Gieg ◽  
Mohita Sharma ◽  
Trevor Place ◽  
Jennifer Sargent ◽  
Yin Shen
Keyword(s):  
Crude Oil ◽  
Oil And Gas ◽  
Combined Treatment ◽  
Oil And Gas Industry ◽  
Test Methods ◽  
Microbial Corrosion ◽  
Gas Industry ◽  
Chemical Treatments ◽  
Transmission Pipeline ◽  
Transmission Pipelines

Abstract Corrosion of carbon steel infrastructure in the oil and gas industry can occur via a variety of chemical, physical, and/or microbiological mechanisms. Although microbial corrosion is known to lead to infrastructure failure in many upstream and downstream operations, predicting when and how microorganisms attack metal surfaces remains a challenge. In crude oil transmission pipelines, a kind of aggressive corrosion known as under deposit corrosion (UDC) can occur, wherein mixtures of solids (sands, clays, inorganic minerals), water, oily hydrocarbons, and microorganisms form discreet, (bio)corrosive sludges on the metal surface. To prevent UDC, operators will use physical cleaning methods (e.g., pigging) combined with chemical treatments such as biocides, corrosion inhibitors, and/or biodispersants. As such, it necessary to evaluate the efficacy of these treatments in preventing UDC by monitoring the sludge characteristics and the microorganisms that are potentially involved in the corrosion process. The efficacies of a biocide, corrosion inhibitor, and biodispersant being used to prevent microbial corrosion in a crude oil transmission pipeline were evaluated. A combination of various microbiological analyses and corrosivity tests were performed using sludge samples collected during pigging operations. The results indicated that the combined treatment using inhibitor, biocide 1 and biodispersant was the most effective in preventing metal damage, and both growth-based and Next-Generation Sequencing approaches provided value towards understanding the effects of the chemical treatments. The efficacy of a different biocide (#2) could be discriminated using these test methods. The results of this study demonstrate the importance of considering and monitoring for microbial corrosion of crucial metal infrastructure in the oil and gas industry, and the value of combining multiple lines of evidence to evaluate the performance of different chemical treatment scenarios.

Useful Trends for Predicting Corrosion Growth

2012 ◽  
Author(s):  
Shahani Kariyawasam ◽  
Hong Wang
Keyword(s):  
Growth Rates ◽  
Critical Size ◽  
Rate Variation ◽  
Growth Data ◽  
Limit States ◽  
Critical Limit ◽  
Inspection Interval ◽  
Integrity Management ◽  
External Corrosion ◽  
Insight Into

The objective of an effective corrosion management program is to identify and mitigate corrosion anomalies before they reach critical limit states. Often as there are many anomalies on pipelines an optimized program will mitigate the few corrosion anomalies that may grow to a critical size within the next inspection interval, without excavating many of the anomalies that will not grow to a critical size. This optimization of the inspection interval and the selection of anomalies to mitigate depend on understanding of corrosion growth. Prediction of corrosion growth is challenging because growth with time is non linear and highly location specific. These characteristics make simplistic approaches such as using maximum growth rates for all defects impractical. Therefore it is important to understand the salient aspects of corrosion growth so that appropriate decisions on excavation and re-inspection can be made without compromising safety or undertaking undue amounts of mitigative activities. In the pipeline industry corrosion growth between two in line inspections (ILIs) has been measured by comparing one ILI run to the next. However many types of ILI comparison methodologies have been used in the past. Within the last decade or two comparison techniques have evolved from box matching of defect samples to signal matching of the total defect populations. Multiple comparison analyses have been performed on the TransCanada system to establish corrosion growth rates. Comparison of the results from these various analyses gives insight into the accuracy and uncertainty of each type of estimate. In an effective integrity management process the best available corrosion growth data should be used. To do so it is important to understand the conservatism and the uncertainty involved in each type of estimate. When using a run-comparison to predict future growth it is assumed that the growth within the last ILI interval will continue (with associated uncertainty) during the next inspection interval. The validity of these assumptions is examined in this study. In the context of this paper these assumptions are validated for external corrosion on onshore pipelines. Characteristics of internal and offshore corrosion are very different in space and time variation. Correlations of external corrosion growth in onshore pipelines with defect size and location are also examined. Learning from multiple corrosion growth studies gives insight into the actual corrosion rate variation along a pipeline as well as general growth characteristics. Different types of corrosion growth modeling for use in probabilistic or deterministic integrity management programs are also discussed.

Using Ultrasound to Gauge Pipeline Internal Corrosion With Coating for ICDA

2006 ◽  
Author(s):  
Qingshan Feng ◽  
Zupei Yang
Keyword(s):  
Test Time ◽  
Thickness Gauge ◽  
Internal Corrosion ◽  
Direct Assessment ◽  
Metal Thickness ◽  
Integrity Management ◽  
External Corrosion ◽  
Key Steps ◽  
Thickness Measurements ◽  
Non Destructive

Internal corrosion direct assessment (ICDA) for pipeline enhances the abilities to assess internal corrosion in pipeline and is based on the principle that corrosion is most likely where water first accumulates. ICDA employs the same four-step process as all other direct assessment methods. The important step is direct examinations: the pipeline is excavated and examined at locations prioritized to have the highest likelihood of corrosion. A variety of inservice non-destructive examination processes are available to pipeline operators to inspect for internal corrosion. Manual assessment of internal corrosion is considered more challenging than normal external corrosion assessments since the corrosion feature is not visible and must be interpreted by the ultrasonic response, but in the past ultrasonic test need always remove the coating and then measure on the surface of bare pipe, which brings the measurement point of the pipe body more risk because of weaker quality of patch coating. Recently, advances in the design of ultrasonic corrosion thickness gauges utilizing dual element transducers have made it possible to take accurate metal thickness measurements while coatings need not to be removed. This feature is often referred to as echo-to-echo thickness measurements. Using the ultrasound thickness gauge to measure pipeline internal corrosion while external coatings need not to be removed can keep the integrity of coating, make pipeline operating and monitoring more economical and improve inspection activities to estimate corrosion in pipelines for ICDA. Gauge equipment requirement, Measurement procedures and Accuracy were validated in laboratory. How to arrange the gauge locations, interval test time and data treatment and analysis also are the key steps of ICDA for integrity management.

A New Probabilistic Methodology for Undertaking External Corrosion Direct Assessment

2006 ◽  
Author(s):  
Andrew Francis ◽  
Marcus McCallum ◽  
Menno T. Van Os ◽  
Piet van Mastrigt
Keyword(s):  
Surface Characteristics ◽  
Survey Techniques ◽  
Direct Assessment ◽  
Ground Survey ◽  
Pressure Test ◽  
Integrity Management ◽  
Corrosion Defects ◽  
Low Probability ◽  
External Corrosion ◽  
Pipeline Safety

External Corrosion Direct Assessment (ECDA) has now become acknowledged, by the Office of Pipeline Safety (OPS) in North America, as a viable alternative to both in-line inspection (ILI) and the hydrostatic pressure test for the purpose of managing the integrity of high pressure pipelines. Accordingly an ECDA standard is now in existence. The essence of ECDA is to use indirect above ground survey techniques to locate the presence of coating and corrosion defects and then to investigate some of the indications directly by making excavations. However, one of the problems of above ground survey techniques is that they do not locate all defects and are susceptible to false indication. This means that the defects will not be present at all indications and that some defects will be missed. In view of the limitations of above ground survey techniques the ECDA standard requires that at least two complimentary survey techniques should be used. The selected survey techniques will depend on the nature of a particular ‘ECDA segment’, taking account of the surface characteristics. However, in many situations the surveys will include a coating survey and a corrosion survey. In general the outcome from these two surveys will be NH locations at which just the coating survey gives an indication, NC locations at which just the corrosion survey gives an indication and NHC locations at which both surveys give an indication. This paper presents a new probabilistic methodology for estimating the distributions of the actual numbers of coating and corrosion defects, taking account of the outcomes of the surveys and the probabilities of detection and false indication of both techniques. The method also shows how the probabilities of detection and false indication are updated depending on what is found during the excavations and the distributions of the numbers of remaining corrosion and coating defects are subsequently modified. Based on a prescribed repair criterion the analysis is used to determine the probability that at least one remaining corrosion defect will exceed the repair criteria. As excavations are sequentially performed the probability naturally reduces. The attainment of an acceptably low probability is used as a trigger to terminate the excavation programme. A detailed description of the development of the method is given in this paper and the application is illustrated through a simple numerical example. A description of how the method is used to build a Direct Assessment module for a pipeline integrity management system is described in an accompanying paper.

Improving and Expanding Guided Wave Ultrasonics as an Assessment Option

2008 ◽  
Author(s):  
Robert W. Smith ◽  
Zach Barrett
Keyword(s):  
Subject Matter ◽  
Collaborative Research ◽  
Hazardous Materials ◽  
Guided Wave ◽  
Subject Matter Experts ◽  
Direct Assessment ◽  
Development Technology ◽  
Integrity Management ◽  
External Corrosion ◽  
Pipeline Safety

The Pipeline and Hazardous Materials Safety Administration (PHMSA), the pipeline industry and standards developing organizations (SDOs) are collaborating to improve the effectiveness and expand the application of Guided Wave Ultrasonics (GWUT). This paper will illustrate how these initiatives through integrity management (IM) regulation, collaborative research and development, technology demonstrations and consultation with subject matter experts (SME) are driving these improvements. These efforts are integrating GWUT technology with External Corrosion Direct Assessment (ECDA) and Pipeline Safety IM protocols and supporting higher confidence inspection of cased crossings. Previous to these initiatives only In-Line Inspection, Pressure Testing and Direct Assessment provided assessment options for the pipeline industry.

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