bluuebunny/crossref_metadata_2025 huggingface dataset:
L51686 Effect of Defect Size and Yield to Tensile Ratio on Plastic Deformation Capacity Pipeline Steels
Authors: Rosenfeld
Published: August 2023

Micro-alloyed low-carbon linepipe steels offer an advantageous combination of high toughness and a low carbon equivalent (CE or Pcm) for good weldability. The continuing improvements in pipeline steel manufacturing practices have also led to pipeline steels with higher yield to tensile (Y/T) ratios and a corresponding reduction in strain hardening capacity. Potential users of high Y/T ratio pipeline steels are somewhat reluctant to modify their existing specifications. This is because they do not have the required information to judge the performance characteristics of such steels under a wide range of service conditions. This is not surprising knowing that yielding behaviour, and defect tolerance in particular depends not only on toughness but also on the strain hardening capacity. Therefore, the interaction between toughness and strain hardening capacity (or Y/T) for a successful application of high Y/T ratio linepipe steels must be considered. For the pipe fabricator this means that not only the yield strength of the plate, used to make the pipe, must be carefully controlled, but also that the relationship between the mechanical properties of pipe and plate must be known.

This study examined the engineering significance of the yield-to-tensile (Y/T) ratio on yielding behavior and defect tolerance of 1-inch thick X70 steels in plate form. Stress-strain characteristics were measured by tensile testing of standard round-bar, full-section square, and wide-plate specimens. The strained condition was tested to determine the effect of cold forming on the Y/T ratio and yielding behavior. Finally, defect tolerance was determined by testing 8-inch wide notched-plate specimens.
L51861 Line Rupture and the Spacing of Parallel Lines
Authors: Leis
Published: August 2023

This report addresses the need for reliable, validated models to assist gas companies in determining the minimum spacing between adjacent pipelines to help ensure safe and reliable operation in the event of a rupture. The objective is to evaluate the exposure of a pipeline due to the rupture and ignition of the escaping gas of an adjacent pipeline.
L51646 Collapse of Offshore Pipelines Seminar Proceedings
Authors: Langner
Published: August 2023

The feasibility of laying offshore pipelines in deep waters, to 3000 feet and beyond, has been established by theoretical studies by a number of different individuals and organizations over the past several years. These various theoretical studies are now being tested and refined as pipelines and production facilities are being installed in ever-deeper waters. A pipeline failure in these great depths would be intolerable, among other reasons because of the great difficulty and exorbitant expense of performing a deepwater repair. A thorough understanding of the buckling and collapse behavior of pipe is, therefore, becoming ever more critical as these oil and gas production facilities get progressively deeper.

Recognizing a need for further research into the collapse behavior of pipe, Pipeline Research Council International, Inc. undertook in 1984 a three-phase program to develop a deeper understanding of basic pipe collapse phenomena. Phase I of this program (1984-1985) focused on the effects of imperfections on pipe collapse. This work was done in the laboratory of Professor Stelios Kyriakides at The University of Texas at Austin, and involved the testing of numerous small-scale steel and aluminum tubes. The Phase II program (1986-1987), also performed at The University of Texas, considered the effects of construction loads. The final Phase III program (1988-1989) was intended as a full-scale verification of the small-scale tests conducted in the previous two phases. This program was conducted at Stress Engineering Services in Houston under the direction of Dr. Joe Fowler, and consisted of Pure Collapse Tests of 16-inch Pipe (16 samples). Pressure vs. Tension Tests of 6 5/8-inch Pipe (18 samples), and Pressure vs. Bending Tests of 6 5/8-inch Pipe (18 samples).
L51439 An Assessment of the Criteria for Cathodic Protection of Buried Pipelines
Authors: Barlo
Published: August 2023

This project was initiated as a result of the findings of earlier research on PR-3-93, "Investigation of Techniques to Determine the True Pipe-to-Soil Potential of a Buried Pipeline: Supplementary Studies". The research on project PR-3-93, conducted in 1980, showed that the present criteria for corrosion control by cathodic protection (1) evolved largely from experience, (2) can be overly conservative in some cases, (3) can be inadequate in others, and (4) are not necessarily consistent among themselves. As a result of these findings, research was undertaken on PR-3-129 to critically assess the present criteria for cathodic protection in the laboratory. The research began in September 1980, and was completed in December 1982. The overall objective of the research was to develop a method for determining the requirements to mitigate general and pitting corrosion on any individual pipeline. The method was expected to be safe, not overly conservative, and capable of being tailored to specific environmental conditions.

To meet this objective, research was undertaken to (1) determine the specific cathodic protection requirements to prevent general and pitting corrosion from starting in various soil environments, (2) determine the effects of temperature, anaerobic bacteria, steel-surface condition, and time on the specific requirements in selected soils, (3) develop a better understanding of those factors that control the criteria for corrosion control, and (4) determine the requirements to stop active corrosion pit growth. On some pipelines, stress-corrosion cracking may occur at potentials where corrosion is prevented; therefore, the research was directed also to (1) determine the least negative potential to prevent stress-corrosion cracking, and (2) determine the most negative potential for preventing stress-corrosion cracking.
L19725 Utilizing Microseismic Techniques for the Evaluation of Underground Gas Storage Reservoir Stability
Authors: Hardy
Published: August 2023

In light of the recent energy crisis, the desirability of storing fuels close to primary distribution areas has assumed an even greater importance than in the past. The natural gas industry is faced with the problem of locating and developing sufficient underground storage reservoir capacity in high demand areas to meet peak seasonal requirements.

Since it is economically desirable to store gas at the maximum possible pressure, studies to estimate optimum operating pressures for underground gas storage reservoirs and to evaluate their stability under such operating conditions.
L41018 Back-Pressure Data On Natural-Gas Wells And Their Application To Production Practices
Authors: Rawlins E.L. , Schellhardt M.A.
Published: August 2023

The Bureau of Mines has published two reports that describe a method of determining gas-well capacities from data observed when gas deliveries are measured at high back pressures. Interpretations of the pressure data obtained when a well is allowed to flow against high back pressures reveal not only the open-flow capacity of the well but also its ability to deliver gas against different pressures.

his report presents a more extended discussion of the subject matter in earlier Bureau of Mines publications relating to the same study. It supplements the information they contain with recommended procedure for obtaining data and analyzing results that are more practical and easier to use. In addition, it includes an analysis of the application of back-pressure data to gas-production problems.
L52013 Mechanical Damage Gaps Analysis
Authors: Leis  , Hopkins
Published: August 2023

Pipelines fail due to various causes. The "outside forces" incident category includes acts of man (such as impact damage by earth moving machinery) but it also embraces acts of nature. Outside forces has been the dominant incident category in most Western World oil and gas transmission pipeline systems. Incidents due to outside forces have been the leading cause of significant failures on transmission pipelines in the USA since formal record keeping and trend analysis of incidents began in the 1970's. This trend remains currently, with these results reflecting incident experience for 2002. While this situation is not expected to change in the near term, the recent data from 2002 indicate corrosion is overtaking outside force as the main failure cause.

The objectives of this report are to evaluate current state of knowledge concerning assessment and management of mechanical damage to pipelines, and identify outstanding issues or gaps to be addressed by the industry. Motivation for such an evaluation and gaps analysis lies in several factors, including much work done has been recently done worldwide. Third-party damage is typically the largest incident category, with the largest consequences, and pending regulatory actions are consequence based, and will require a management strategy to deal with mechanical damage.
L41008 Outline of Activities During 1980 Sabbatical Leave
Authors: Hardy
Published: August 2023

During the last 15 years, the field of rock mechanics has developed at a highly accelerated rate. The purpose of the 1980 Sabbatical Leave was to provide the necessary time and environment to allow the writer to undertake a concentrated study of one area of Rock Mechanics, which was evolved in recent years and appears destined to be of increasing importance in the future. In general, the applicant concentrated his efforts on studies related to the "Design and Stability Monitoring of Underground Storage Facilities." There is little doubt that during the latter part of this century considerable use will be made of the underground for storage of solids
L51601 Review of Procedures for Welding Onto Pressurized Pipelines
Authors: Threadgill P. L. , Cola M. J.
Published: August 2023

The welding of attachments onto pressurized pipelines and storage vessels (referred to as hot tapping) is a necessary and common operation in the transmission industry. Care must be exercised to choose a welding procedure that can reduce the risk of burn through and the formation of very high hardness levels in the heat-affected zone (HAZ) that can lead to a higher than normal risk of cracking. This report summarizes a state-of-the-art review of current procedures for hot tap welding on pressurized pipelines. All open literature related to hot tap welding were examined and catalogued, and areas requiring further research were identified. Although a large volume of literature exists on this subject, the majority gives accounts of successful repair work on specific items, rather than describing generalized safe procedures. The methods and controls vary widely; no national or industry standards exist.
L51420 Elevated Temperatures and Environment on Cathodic Protection for Offshore Pipelines
Authors: Decarlo  , Walker  , Zamecnik
Published: August 2023

The corrosion rate of offshore pipelines when subjected to elevated operating temperatures and various environmental conditions on the cathodic protection requirements in seawater needed to be determined.

The objective of this research project was to determine the effect of elevated operating temperatures up to 250F (121C) and various environmental conditions on the cathodic protection (CP) requirements of offshore pipelines in 35 (1.7C) and 60F (16C) seawater. Offshore environments were simulated in laboratory and field tests conducted in order to observe the effect of increasing surface temperature on the -850 mV potential criterion (versus a copper/copper sulfate reference cell) and the current density required to achieve cathodic protection. This study was funded in two programs. The laboratory work in the initial program was done at Lockheed"s Carlsbad, California, facility. The laboratory work in the subsequent project was done in Santa Clara, California. All the field work was done in a seawater lagoon in Carlsbad.
L51693 Most Accurate Method for Measuring an Off-Potential
Authors: Thompson  , Lawson
Published: August 2023

�During a prior Gas Research Institute (GRI) research program, a spiking phenomenon was identified that prevented the measurement of the off potential directly from the pipe-to-soil potential waveform. Furthermore, the spike made it impossible to measure an off potential during current interruption for some period of time following interruption. In recent years, there has been discussion that the spike in the pipe-to-soil potential waveform affects the ability of the CP system to mitigate corrosion. In addition, the increased significance that has been placed on off-potential measurements within the industry has made it important to understand any phenomenon that may affect the ability to measure the off potential.

Because of the above concerns, the Corrosion Supervisory Committee of the Pipeline Research Committee authorized this two-year program to establish the cause and effects of the spiking phenomenon. To accomplish this program, a Work Plan was established that provided for the following four tasks: Task 1 - Field Measurements, Task 2 - Circuit Analog Model, Task 3 - Effect of the Spike on Off- Potential Measurements, and Task 4 - Laboratory Experiments. Through this combined effort of field evaluations, modeling, and laboratory experiments, the root cause of the spike was established along with guidelines for making the off-potential measurement. The results of this project provides the CP engineer with a standard practice for measuring off-potentials in the presence of the spiking phenomenon.
L52016 Active Flux GTAW Welding Process for Carbon Steel Line Pipe Applications - Phase 1
Authors: Melton  , Bertaso
Published: August 2023

The Gas Tungsten Arc Welding (GTAW) process has been used for many years in the joining of carbon steel, alloy steel and non-ferrous alloys. Its capacity to deposit an external root, the ability to choose filler metals for a wide variety of base metals, and its favorable deposition characteristics make this a versatile process which is associated with low defect susceptibility, and excellent weld metal properties. Unfortunately, the GTAW process has not historically been associated with high productivity rates. Past efforts to enhance productivity through "hot wire" technology have improved the GTAW process markedly. Nevertheless, even with "hot wire"technology, the establishment of a GTAW root pass has not been considered competitive with existing GMAW mechanized processes.

The objective of this project is to optimize the productivity of the GTAW process for girth welding of pipelines using activating fluxes.
L51939 Weldability of High-Strength Enhanced Hardenability Steels
Authors: Wang Yong-Yi , Feng Zhili , Cheng Wentao , Babu Sudarsanam Suresh
Published: August 2023

Since the 1970s, the development of high-strength pipeline steels has followed the route of progressively reduced harden ability through lower carbon and alloying element contents. Micro-alloying, controlled rolling (CR), and thermo-mechanical controlled processing (TMCP) have been used extensively to achieve the high-strength and other material property requirements despite the trend towards lower carbon content. The primary driving force behind the evolution of these alloying and processing strategies stems from the concerns over the weld ability, particularly the hydrogen induced cracking (HIC), at ever-increasing strength levels. Accompanying the extensive reliance on micro-alloying, CR, and TMCP, there has been a movement to tighter restrictions on micro-alloy variability, the increased use of heavy reduction at low inter-critical temperatures and, in some instances, the reliance on cold expansion.

The objective of this project was to evaluate alternate steels with enhanced harden ability and identify those that would have a potential to (1) meet the high strength/high toughness requirement but without the adverse effects of the early trial heats of micro-alloyed TMCP X80 and X100 line pipe steels, and (2) exhibit sufficient resistance to hydrogen induced cracking (HIC) when welded with processes and consumables representative of state-of-the-art, low-hydrogen field girth welding practices. The focus of the project was on the weld ability and properties of the base metal and the heat-affected zone (HAZ). The selection and development of suitable weld consumables were not part of this project.
PR-186-104504-R01 Guidelines to Address Pipeline Construction Quality Issues
Authors: Bruce
Published: August 2023

The objective of this project was to develop guidelines pertaining to these issues and how they should be addressed in the field. A review of recent incidents involving girth weld failures in newly-constructed pipelines indicate that all incidents involved production welds in pipelines constructed using conventional techniques (i.e., using cellulosic-coated electrodes) � particularly welds at wall thickness transitions � and repair and tie-in welds made using cellulosic-coated electrodes in pipelines otherwise constructed using mechanized gas-metal arc welding. None of the recent failures involved mechanized gas-metal arc welds. Many of these failures were attributed, at least in part, to hydrogen-assisted cracking and high stresses. A review of the factors related to hydrogen cracking in modern pipeline girth welds indicates that managing weld hydrogen levels and the stresses acting on these welds is the most appropriate strategy for controlling the risk of hydrogen-assisted cracking, which became the primary focus of this project.
L00330 Noise Abatement Volume IV - Noise Measurement and Suppression at Gas Compressor Stations
Authors: Kiefner  , Vieth
Published: August 2023

This report is divided into two parts. Part A contains field test procedures and measurement and analysis techniques for compressor station noise. The results of a field test program conducted at nine mainline compressor stations are also included. Part B discusses various techniques for suppressing compressor station noise, including an evaluation of a noise treatment method applied at a typical mainline compressor station.
L51550 Current Requirement for Cathodic Protection
Authors: Thompson
Published: August 2023

Examines current requirement method to establish whether sufficient cathodic protection has been achieved. The basic concept was validated although current field measurement equipment must be improved to be usable.
L51632 Evaluation of the Time Delay for Cold Cracking
Authors: Pargeter
Published: August 2023

Program to determine the potential delay times required to cause cold cracking (hydrogen cracking). Cracking induced in welds deposited into circumferential grooves has been monitored by ultrasonic techniques. Initial use of an array of fixed transducers which were switched electronically was found to be inadequate for the determination of delay times under near threshold cracking conditions. Since delay times are expected to be greatest for such conditions, a change was made to intermit tent monitoring using P-scan equipment. By plotting percentage projected area free from reflections of less than -28dB against time from completion of welding, it was found possible to monitor the progress of cracking for near threshold conditions. Single pass welds in 0 .12" (3 mm) grooves and multipass welds 0.24" (6 mm) grooves in 22" (559 mm) diameter, 0.43711 (11 mm) wall thickness, grade X48 pipe, welded with AWS E7010G and E8010G consumables have been used.
PR-312-12208-R02 Limitations and Costs Associated with Raising Existing RICE Stack Heights
Authors: Panek  , Young
Published: August 2023

Modeling of actual and hypothetical compressor station facilities concluded increasing reciprocating engine stack height as one potential mitigation measure to reduce modeled impacts below the primary 1-hour NO2 National Ambient Air Quality Standards (NAAQS). Increasing stack heights to between 50-75 feet appears to offer considerable relief based on typical facility configurations (e.g., compressor house height, stack parameters). This white paper discusses potential stack design criteria to be considered when increasing existing exhaust stack heights or planning considerations for new units. To assist in gathering information on practical concerns and issues associated with raising existing compressor driver stacks, a questionnaire was developed and provided to operations and engineering staff, OEMs, and members to provide insight into physical constraints, engineering considerations, and costs to be considered and evaluated in developing this report. This white paper summarizes stack height limitations for reciprocating engines based on operating (e.g., back pressure, effective stack heights) and physical (e.g., guy-wire and structural requirements) constraints. Where available, cost implications are also provided. Criteria addressed include: Good Engineering Practice (GEP) for stack heights, engine back pressure limitations, structural integrity of the exhaust system, wind and seismic loads on the exhaust stack, and other specifications for structural designs. Proper stack design should address local environmental regulations, local building codes (e.g., height requirements, wind and seismic loads), structural integrity, base configuration, and lateral support.
PR-186-074504-R02 Development of Guidelines for an Alternative to the Pre-Service Hydrotest
Authors: Bruce Bill
Published: August 2023

It has been shown that measures, other than the hydrotest, are available for detecting or preventing defects that may be introduced during pipe manufacture or pipeline construction. Most measures require enhanced quality management practices, which offer the added benefit of providing more information on the condition of the pipeline after construction. A combination of those measures, in conjunction with a robust quality management system, could be considered as a viable alternative to the pre-service hydrotest.
L51810 Guidelines for the Assessment of Dents on Welds
Authors: Rosenfeld
Published: August 2023

The Guidelines for the Assessment of Dents on Welds describes a method for evaluating the serviceability of pipeline girth welds affected by otherwise plain, shallow indentations that are free to reround under pressure. The user makes a cumulative fatigue damage assessment, considering the effects of dent size, weld quality, and the severity of the pipeline operating pressure spectrum. An accompanying diskette provides a rainflow cycle-counting algorithm for use in evaluating the operating pressure spectrum, along with other spreadsheet tools to facilitate the analysis. The serviceability is established by an estimate of the pressure-fatigue life of the weld-dent combination. Examples are presented. Field inspection and repair issues are also discussed.
L51620 Pipeline Monitoring--Limit State Criteria
Authors: Stephens  , Olson  , Rosenfeld
Published: August 2023

With the growing emphasis on extending the useful operation of existing pipelines and reducing the operating costs, the pipeline industry is sensitive to keeping pipelines in service and having a rational basis for doing so. When pipelines undergo fault displacement, mining subsidence, thaw settlement, or landslide induced soil loading, monitoring of pipeline strains and/or displacements must protect their integrity. Currently, there is little information available to indicate when remedial action is necessary for such a pipeline.

This report focuses on assisting pipe-monitoring programs by providing data and criteria for monitoring intervention. The objective of the work reported herein was to compile data and define criteria for monitoring intervention for local buckling, denting, and tensile failure, based upon data and experience from the pipeline industry. It was established that three separate quantities might be defined for each loading condition; a limit state criterion, a damage state criterion, and an intervention criterion.
L51582 Scaling of Multiphase Pipe Flow Behavior at High Gas Density
Authors: Johnson
Published: August 2023

This report contains data that demonstrates the scaling of flow regime, pressure drop, and holdup multiphase flow with pipe diameter. In addition, entrance length effects, the onset of liquid entrainment, and interfacial shear modeling at high gas density were studied for purposes of validating multiphase flow design methods. Stratified, slug and annual flow regimes were observed in a 112-foot long 3.5-inch diameter test section. Air, freon, and water were used to represent pipeline fluids.
PR-015-07603-R01 Effect of Orifice Plate Manufacturing Variations on Orifice Meter Performance - Blinded
Authors: Nored  , James
Published: August 2023

An investigation to flow test and measure a large set of orifice plates to determine the proportion of existing orifice plates have measured discharge coefficients outside of the Reader-Harris/Gallagher equation 95% confidence limits. The research determined if the existing tolerance specifications adequately describe the dimensions of an orifice plate required to conform to the Reader-Harris/Gallagher equation calculated discharge coefficient. The testing also underscored the influence of manufacturing variations on orifice plate performance.
L51586 A Review of Gas Industry Pipeline Coating Practices
Authors: Nunez
Published: August 2023

Reports the results of a survey of 27 pipeline transmission companies concerning their coating practices. The survey focused on coating problems and coating preferences. Prepared by the Corrosion Supervisory Committee of the Pipeline Research Committee.
PR-186-123715-R01 State of the Art for Subsea Pipeline and Equipment Life Extension
Authors: Bubenik
Published: August 2023

The objective of this study was to document the status of regulations, industry standards, best practices, and experiences relevant for life extension of subsea pipeline systems. The report covers a literature review, industry survey, analysis and critical review, and recommendations to further work.
L51573c Pipe Connection Methods and Effects on Deepwater Construction C
Authors: Litzelfelner
Published: August 2023

A study to review and evaluate the various mechanical pipeline connectors currently available for J-curve pipelay methods offshore. The connectors were compared by listing the advantages and disadvantages of each. A test program to evaluate connectors was developed.
PR-179-10203-R01 Characterization of Oxidation Catalyst Performance - VOCs and Temperature Variation
Authors: Olsen
Published: August 2023

Oxidation catalysts are typically specified to reduce carbon monoxide (CO), Hazardous Air Pollutants (HAPs) and/or Volatile Organic Compounds (VOCs) from lean-burn engines. The application of catalysts to HAPs and VOC destruction is more recent, so greater effort has been placed on optimizing for CO oxidation than HAPs or VOC oxidation. In general, the catalysts consist of a porous, high surface area -alumina carrier material on a ceramic (typically cordierite) or stainless steel substrate. Although the alumina has some effectiveness in oxidation at high temperature, its primary role here is to provide a high surface area support for a well dispersed layer of platinum (Pt) and/or palladium (Pd) which provides numerous catalytic sites for oxidation activity. This work extends the current knowledge-base for application of oxidation catalysts in three areas: (1) species specific removal efficiencies, (2) temperature dependence, and (3) space velocity.
PR-015-05217-R01 High BTU Gas Effects on Performance and Emissions in a Two-Stroke Integral Engine
Authors: Bourn
Published: August 2023

This report documents an investigation into the effects of high BTU (by volume) fuel gas on performance and emissions from a GMVH-6 two-stroke integral engine compressor operating with the OEM fuel-air curve control strategy. The high BTU fuel gas was blended to simulate imported LNG compositions with high ethane content. The testing was performed by blending pure ethane into typical pipeline natural gas to achieve ethane contents ranging from two to seventeen percent by mole. A laboratory GMVH-6 engine was tested with these various fuel blends in both pre-combustion chamber and open-chamber configurations. Three speed-load conditions were tested with the pre-combustion configuration and one additional speed-load condition was tested with the open-chamber configuration. For each configuration and operating condition, a constant NOX fuel-air curve was mapped and programmed into the engine controller. Ignition timing was set slightly retarded from optimal for each operating speed to provide margin against detonation with the high ethane content blends.
PR-179-11201-R01 Performance Evaluation of Multiple Oxidation Catalysts on a Lean Burn Natural Gas Engine
Authors: Badrinarayanan  , Olsen
Published: August 2023

Two-way catalysts or oxidation catalysts are the common after-treatment systems used on lean burn natural gas engines to reduce CO, VOCs and formaldehyde emissions. The study evaluates the performance of oxidation catalysts from commercial vendors for varying catalyst temperature and space velocity. For this study, a part of the exhaust from a Waukesha VGF-18 GL lean burn natural gas engine was flowed through a catalyst slipstream system to assess the performance of the oxidation catalysts. The slipstream is used to reduce the size of the catalysts and to allow precise control of temperature and space velocity. Analyzers used include Rosemount 5-gas emissions bench, Nicolet Fourier Transform Infra-Red spectrometer and HP 5890 Series II Gas Chromatograph. The oxidation catalysts were degreened at 1200oF (650oC) for 24 hours prior to performance testing. The reduction efficencies for the emission species varied among the oxidation catalysts tested from different vendors. Most oxidation catalysts showed over 90% maximum reduction efficiencies on CO, VOCs and formaldehyde. VOC reduction efficiency was limited by poor propane emission reduction efficiency at the catalyst temperatures tested. Saturated hydrocarbons such as propane showed low reduction efficiencies on all oxidation catalysts due to high activation energy. Variation in space velocity showed very little effect on the conversion efficiencies. Most species showed over 90% conversion efficiency during the space velocity sweep. Adding more catalyst volume may not increase the reduction efficiency of emission species. Varying cell density showed very little effect on performance of the oxidation catalysts. The friction factor correlation showed the friction factor for flow through a single channel is inversely proportional to cell density.
PR-003-063526-R01 Leak vs Rupture Boundary for Pipes with a Focus on Low Toughness and-or Ductility
Authors: Leis  , Zhu
Published: August 2023

While the technology to manage corrosion is largely mature, just one high-profile corrosion incident, like that at Carlsbad, NM, rekindles the public�s concern for safety, with far reaching effects possibly into Congress and the regulatory management. Such incidents also bring into question the viability of related integrity management tools and practices � particularly those used to assess incident consequences and prioritize related maintenance. Reliably discriminating between leaks and ruptures thus is important � but remains elusive for many applications.

This project sought new understanding and a methodology to determine the leak versus rupture (L vs R) boundary for pipe-body corrosion. The first phase of this project formulated this new methodology and evaluated it in regards to factors such as defect acuity, constraint, loading mode (hydrostatic versus pneumatic), and material toughness and ductility. Because of concern in regard to its use for higher-strength grades, possible limitations due to grade were evaluated relative to the literature and full-scale data in the second phase of the project.
PR-420-133721-R01 Comparison of Radar Satellite Methods for Observation of Stability
Authors: Deschamps  , Robert  , Henschel
Published: August 2023

This report discusses the use of Synthetic Aperture Radar (SAR) satellites for monitoring above ground pipelines and buried pipeline Rights-Of-Way (ROWs) using Interferometric Synthetic Aperture Radar (InSAR) techniques. The main thrust of the research was to evaluate the suitability of above-ground pipeline support members as InSAR measurement points, and to adapt existing techniques to allow for precise monitoring of jacking and subsidence caused by permafrost degradation and dynamics. The study site at Prudhoe Bay, Alaska includes more than 60,000 horizontal pipeline supports. The known locations of supports were used to identify and isolate supports in the radar imagery, and the phase and intensity of supports were analyzed to determine their ability to provide reliable estimates of deformation. An additional component of this research was the comparison of two satellites operating at different frequencies, RADARSAT-2 operating at C-band and TerraSAR-X operating at X-band. One year of data was acquired with both sensors in similar acquisition geometries and resolutions, at 24-day intervals for RADARSAT-2 and 11-day intervals for TerraSAR-X. Recommendations are made on the choice of wavelength and concerning future work in this area. A list of technical requirements is also provided. The technologies for obtaining ground deformation estimates from natural targets, coherent targets and homogeneous and distributed targets are explained and supported by three operational case-studies in different environments. The work should provide above-ground pipeline operators working in permafrost areas with a clear view of the current state of research towards the operationalization of InSAR monitoring, but also of current operational capabilities in other pipeline applications, including ROW geohazard monitoring and monitoring of buried pipelines crossing Enhanced Oil Recovery (EOR) fields.
PR-186-133738-R01 Procedure for Determining Lower Bound Yield Strength of Pipe from Hardness Data
Authors: Amend
Published: August 2023

This project is a JIP project with the overall objective of demonstrating that hardness data from randomly selected pipe samples could be used to determine the lower bound YS of an entire pipeline segment at a quantified confidence level, and that results would be conservative in comparison to results determined using the methods currently described in 49 CFR Part 192 and 195. Three different types of field portable hardness testers and a laboratory Rockwell B tester were used on 50 pipe sample. The hardness testing using field portable testers was performed in accordance with ASME CRTD-Vol. 91. The hardness test results were converted to a calculated lower bound YS values using the correlations described in ASME CRTD-Vol. 57. The calculated lower bound YS was compared to the results of standard API 5L tensile tests. In addition, the metallurgical attributes of each pipe were characterized to determine if certain subsets of pipes produced better (or worse) correlations of lower bound YS calculated from hardness data to YS determined from tensile tests. The results showed that hardness data can be used to determine conservative values of lower bound YS using a range of different confidence levels.
GRl-00-0056 Diagnosis Treatment and Monitoring of MIP in Natural Gas Storage Facilities
Authors: Pope Daniel , Pope Rebecca
Published: August 2023

This project works to identify state-of-the-art methods for diagnosis, treatment, and monitoring of microbiologically influenced productivity (MIP) in natural gas storage facilities. It is meant to provide theoretical and practical information about MIP, how it works, how to diagnose it, and how to treat it.
L52230 SCC In Areas of Local Deformation
Authors: Denys
Published: August 2023

In Task 1, a questionnaire was sent to the PRCI member companies to query them on their experience with SCC at areas of local deformation. Follow-up telephone contacts were made with those companies that have had significant experience with this problem or did not respond to the survey. In addition, CC Technologies has performed a number of failure investigations over the past several years in which local deformation played a role in SCC. Some of these failures have been with non-PRCI member companies. CC Technologies contacted these companies to obtain permission to release the information for use in the survey. Relevant data was included in this report on a confidential basis.

In Task 2, the open literature was surveyed for information for different SCC types, characteristics of stresses at pipeline dents, and modeling of SCC and mechanical damage. The literature search included on-line computer databases, symposium and conference proceedings and CC Technologies' in-house library. Relevant papers were reviewed to assess the extent of and identify the probable contributing factors to the problem of SCC at local areas of deformation.

In Task 3, some limited FEA modeling was performed to evaluate the stress fields associated with the typical instances of areas of local deformation on pipelines. This approach was used to evaluate the primary and secondary stresses associated with typical dent geometries.
PO-316-10208-R01 Guideline for Assembly and Maintenance of Bolted Joints in High Vibration Environments
Authors: Rimpel
Published: August 2023

This guideline is intended to provide a practical review of installation and maintenance practices for bolted joints that will minimize the likelihood of leakage or joint failure. The guideline addresses topics such as preload selection, installation tools, lubrication, gaskets, assembly procedures, preload verification tools, maintenance procedures, and vibration loosening. The guideline is designed to provide engineers and technicians with the knowledge necessary for successful assembly and maintenance of bolted joints.

Use with caution. GMRC decided to pull this document from circulation due to unresolved issues with certain sections of the guideline. (6/6/2011)
PR-186-104502-R01 Improved Methods for Estimating Remaining Life of ERW Pipelines
Authors: Polacik
Published: August 2023

The objectives of this project SIA-1-1 are to: (1) improve the understanding of the most commonly used crack growth models (for pipelines); (2) determine the fundamental differences between those models; and (3) evaluate the need for, and benefits of, various refinements to the analysis process. This report for Task 1 "Description of Methodology" provides a detailed description of the crack growth calculation methodology utilized by DNV.
L52037 Ductile Fracture Propagation Resistance for Advanced Pipeline Designs
Authors: Biagio Di
Published: August 2023

The development of a method able to evaluate the ductile fracture behavior on pipelines has been documented. Therefore, methods for the determination of material fracture resistance and crack driving force have been accurately investigated. In particular, the techniques to determine the critical fracture characterizing parameter CTOA (crack tip opening angle) have been reviewed in-depth (back-slotted drop weight tear tests [DWTT], two specimen CTOA tests, etc.), and in view of a future pipe-mill application. For a more reliable CTOA estimate the needed following parameters have been investigated: 1) rotation factor in a DWTT and 2) the material flow stress to be used in dynamic tests. On the other hand, as far as the crack driving force is concerned, a finite element code developed by CSM (PICPRO) has been successfully used to evaluate the correlation between the CTOA inferred by DWT tests and that measured on pipe. In addition PICPRO has been used to determine the driving force acting on pipe in a wide range of operating conditions, finally supplying an appropriate formula for its calculation. Once the driving force and the fracture resistance have been determined their comparison allows crack arrest assessment.
PR-244-9827-R01 Local Buckling and Collapse of Corroded Pipes
Authors: Chen
Published: August 2023

This project address local buckling (or wrinkling) associated with pipe wall instability in the axial direction when subjected to bending or axial compression. It considered the collapse of the cross-section under circumferential compression due to external pressure.
L52023 Inspection of Welds in Thin-Wall Pipe Using Mechanized Ultrasonic Inspection
Authors: Lozev  , Spencer
Published: August 2023

Generally, the inspection of welds in pipes with a wall thickness less than 6 mm is performed using radiography.� Because radiography is very sensitive to the orientation of planar weld defects, these types of defects often go undetected.� In contrast, ultrasonic testing (UT) offers a better solution for detecting and sizing of these defects. In this project a method to inspect welds in thin-walled pipe less than 6-mm thick using mechanized ultrasonic weld inspection was developed.�The project investigated the application of time-based high-frequency (up to 15 MHz) single/multi-probe techniques and phased-array (PA) technology, multiple-skip time-of-flight diffraction (TOFD), and shear horizontal (SH) waves inspection as possible solutions.
NR199307 Pipe Database and Pipe Sample Storage Program
Authors: Thompson  , Lawson
Published: August 2023

�The report provides a compilation of data generated on Project NG-18 that has been developed over a number of years. This report consists of two topics: one is a summary of the pipe properties developed for pipe materials used in Project NG-18; a pipe sample storage program that has been initiated to set aside samples of virgin pipe material so that when future problems develop on pipelines, original pipe materials will be available for the conduct of research.

Pipe properties from over 400 pipe lengths is contained in the pipe database. This database focuses on pipe diameters from 8 inches to 42 inches and from Grade A through Grade X100. The properties that are included are the mechanical, chemical, fracture, grain size, pipe fracture data, metallurgical data, and environmental effects data. These data were collected on pipe lengths donated to the program from 1959 to present by PRCI-member companies and pipe mills. A second part of this program was to develop a procedure for the collection and storage of short pipe lengths from new construction. The goal was to have individual PRCI companies store the pipe but records of the stored pipe properties and location. The goal is to develop a supply of pipe to so that if problems occur in future years with pipe of a similar nature original pipe will be available for study of the changes in properties during the service years.
L51457 Effects of Real Defects on Girth Weld Fracture Behaviour
Authors: Glover
Published: August 2023

Presents the full-scale fracture behavior of pipeline girth welds. Eleven full-scale tests were conducted. The use of BSI standard PD 6493:1980 for defining tolerable defects was evaluated against the full-scale results.
L51469 Post-Weld Stress Relief of High-Strength Line Pipe Steels
Authors: Lazor  , Glover
Published: August 2023

Presents the results of an analytical study on the necessity for post-weld heat treatment on thick-walled fittings and pipeline girth welds.
L51391 Measuring the Resistance of Pipe Steels to Blistering and Internal Cracking to Sour Gas
Authors: Williams
Published: August 2023

The increasing demand for pipelines capable of transporting sour gas has led to interest in test procedures for measuring the resistance of pipe steels to hydrogen blistering and hydrogen-induced stepwise cracking when exposed to a sour-gas environment. one such procedure that has arroused considerable interest in recent years is that developed by H. C. Cottom of the British Petroleum Co. The present study was undertaken to provide a better understanding of the procedures used to perform the test and the usefulness of the results that are obtained from the test.
L51403 The Effects of Dents on the Failure Characteristics of Line Pipe
Authors: Eiber
Published: August 2023

This report presents detailed results of research done on the potential of plain dents to produce failures in line pipe. This research formed the basis for a change in the American National Standard Code for Pressure Piping, Gas Transmission, and Distribution Piping Systems, permitting the depth of a dent to be 2% of the pipe diameter rather than 0.25 inch. Plain dents were not found to produce failures unless they are on or near the longitudinal weld where cracks can develop in or adjacent to the welds.
L41014 Report on European Trip Undertaken in Fall 1979 Relative to Underground Storage Research
Authors: Hardy
Published: August 2023

The 4th Congress of the International Society for Rock Mechanics was attended by some 1,000 persons representing most of the Worlds technologically developed countries. The program included some 30 papers of direct interest to our current PRCI studies [namely: microseismic - 5, cavern storage - 10, mechanical behavior of salt (field and laboratory) - 15]. In particular there were a number of important papers dealing with the development of mechanical models for salt behavior (creep and plasticity) and finite element techniques for cavity design. Many of the most interesting of these papers were in either French or German and therefore actual attendance at the meeting was extremely important, since simultaneous translation of the papers and the associated questions were available. Furthermore the ability to actually discuss the research in detail with the authors following their presentations was very advantageous.
L52205 Mechanical Damage Inspection Using MFL Technology
Authors: Nestleroth  , Davis  , Flamberg
Published: August 2023

This report describes a design of a magnetic flux leakage tool designed to detect both metal loss and mechanical damage defects.
L51964 Corrosion Rates on Aging Pipelines
Authors: Payer  , Wei  , Kempe
Published: August 2023

The objective of this project was to determine the pipeline steel corrosion rate beneath a sand layer and polymer coating. An analysis was performed to correlate the corrosion rate of steel with the permeability of oxygen through the coating. The effectiveness of cathodic protection was evaluated for various sand or coating conditions. The findings are based upon the results of experiments to measure (a) the corrosion rate and electrochemical behavior of steel, (b) the oxygen permeability in soils and through coatings, (c) the electrical properties of coatings and (d) the effects of carbon dioxide on corrosion. The results are interpreted based on models of steel corrosion under concentration polarization control, models of transport through solutions and soil, and models of transport through coatings.
L22284 Study on the Dimension of Arc Burns in Pipe Steels
Authors: Lazor R. B.
Published: August 2023

This study attempts to establish correlations between the internal dimensions of an arc burn, such as depth, and surface dimensions, such as length and width. The results show that only 10% of all possible arc strikes would be deeper than predicted using a 2.3:1.0 ratio of weld metal width to total burn depth. If the center of the arc burn has a hollowed-out region, then the estimate should be increased by a factor of 2. The hardness of the weld metal was found to be independent of the composition of the base material. However, the maximum heat-affected zone hardness could be estimated from the carbon content and degree of alloying of the base materials.