bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of Probe Blockage Effect on Compressor Test Performance
Authors: Li Bowen , Wu Hu , Hou Chunke 
Published: January 2021

Abstract
In order to study the influence of probe blockage effect on the test performance of the compressor, a full-channel steady simulation method was used to establish a regression model of the influence of the probe on the compressor performance. Taking NASA Rotor67 compressor as research objects, different sizes and quantities of probes are arranged at different axial positions of the compressor inlet and outlet respectively, the flow-efficiency and flow-pressure ratio characteristic line are obtained under different probe blockage ratios, circumferential and axial layouts at the design speed. The calculation results show that due to the blockage effect of the probe, the flow rate of the blocking point is reduced, the flow rate of the stall point is increased, the efficiency and pressure ratio of the compressor are decreased. The separation of the rotor surface layer caused by the presence of the probe and the blending loss of the probe wake and the mainstream are the main reasons for the above changes. The response surface model was used to model the regression of the data, and the regression model of the compressor characteristics in the presence/absence of the probe was obtained, and the regression model was verified. The relative error was within 3%, indicating the established regression model of probe on the influence of compressor performance has good accuracy.
H2 in an Existing Natural Gas Pipeline
Authors: Huising O. J. C. , Krom A. H. M. 
Published: January 2021

Abstract
N.V. Nederlandse Gasunie (Gasunie) has converted an existing gas transmission line from transporting natural gas to transporting a mixture of gaseous hydrogen and 30% to 0% methane. To enable this, an assessment was carried out on technical safety, process safety, work safety and external safety.
The pipeline, with two valve stations, was constructed in 1996 according to applicable Dutch regulations and actively managed in accordance with Gasunie company standards.
The pipeline was evaluated for hydrogen transportation and, based on the following measures, this was seen as being feasible:
- The water dew point of the feed must not exceed −8° C;
- The pipeline must be separated from the natural gas transport system;
- Blowdown must be performed either at the site of the supplier or the user of the hydrogen;
- Gas measurement equipment, personal safety and leak detection must be suitable for hydrogen;
- Due to the assignment of hydrogen as a chemical agent, the safety contour was reduced by performing extra measures, such as additional communication to landowners, additional requirements for the pressure-regulating system and verification of additional settlement and stresses.
The operational changes consist of a number of maintenance and management issues:
• In-service welding and hot tapping are not allowed;
• Equipment suitable for use in gas group IIC (ATEX) must be used;
• Emergency and maintenance procedures must be updated to those applicable for pipeline and valve stations containing hydrogen.
Recommended Procedures for Evaluation and Synthesis of Pipelines Subject to Multiple IMU Tool Surveys
Authors: Hart James D. , Zulfiqar Nasir , McClarty Ed 
Published: January 2021

Abstract
This paper summarizes recommended procedures for evaluation and synthesis of geometry data from pipelines subjected to repeat in-line inspections (ILI) using strapdown Inertial Measurement Unit (IMU) tools. The paper provides an overview of IMU tool instrumentation (gyroscopes, accelerometers and odometers), a brief summary of IMU tool data processing and discusses IMU tool sensitivity and accuracy specifications. The paper also provides a review of the approaches that are used to identify ground movement signatures in IMU data profiles. Based on a single IMU survey, it can be difficult to determine with certainty if a given bending strain feature was induced during construction of the pipeline (e.g., by conforming the pipeline profile to an uneven trench profile) or was the result of post-construction movement of the pipeline (e.g., due to geohazards along the alignment such as landslides, karst, etc.). Because such a large percentage of vendor identified bending strain anomalies in IMU surveys are the result of construction, comparison of pipeline geometry changes between two (or more) inertial inspections is normally a more reliable method of identifying areas of actual post-construction movement of the pipeline. This is because a high degree of repeatability is observed in overlays of the pipeline geometry data signatures obtained from different IMU surveys at construction-induced bending features whereas the geometry signals associated with real pipeline movement frequently exhibit change patterns in out-of-straightness, pitch and heading and curvature/bending strain profiles that correspond to increasing pipe curvature and deformation. The primary focus of this paper is to summarize recommended data deliverables and plots of three-dimensional pipeline geometry profile data from different IMU tool surveys at vendor-identified bending strain anomalies including multi-panel overlay plot packages as well as survey-to-survey difference or change profiles that greatly assist in distinguishing if the feature is the result of construction or due to post-construction movement and to aid in the evaluation of pipeline deformation states.
Enhancing Flooding Monitoring and Response to Improve Geohazard Management
Authors: Song Peter , Tetteh-Wayoe Debra , Pierce Kimberly , Hill Mike , Maxwell Mark 
Published: January 2021

Abstract
In March 2019, snow melt and heavy rainfall resulted in major flooding at one of Enbridge’s (Company) pipeline river crossings. Based on an earlier hydrotechnical assessment, it was identified that the estimated scour in the river channel during a flood event of this magnitude could have the potential to create a pipe span of length where vortex induced vibration (VIV) may be initiated, potentially causing pipe failure and product release. As a precautionary measure, the Company shut down and isolated the pipeline; the two mainline block valves on either side of the river were closed for several days. This un-planned pipeline shut down impacted customers and resulted in revenue loss. An extended shutdown period would have also impacted downstream refineries. In order to promptly restart of the pipeline, bathymetric surveys (measuring the depth of a water body as well as mapping the river bottom profile and the underwater features of a water body) were performed in high flow conditions to verify the pipeline burial condition.
This crossing had been identified in the Company’s long range forecast with a planned remediation completion in 2020. However, the potential residual threat to the integrity of the pipeline due to high flow events existed until the remediation could be completed. Consequently, Company Pipeline Integrity group had been closely monitoring this crossing.
The Company’s Pipeline Integrity (PI) Department is on the journey to become a High Reliability Organization (HRO) where there is a strong preoccupation with failure and emphasis on determining the root cause of an incident, with the goal of striving for error free performance. As such, this incident was treated with as much emphasis as a pipeline failure, and several lessons learned from this incident were identified.
This paper will discuss the enhancements made to the Company’s flood monitoring program, including the incorporation of the flood forecast monitoring into the flood monitoring program, identification of high priority crossings, development of purge plan, utilization of new technology for surveying during flooding and the development of a flood response guideline.
Analysis of Hazardous Liquid Pipeline Spill Volumes
Authors: Paxman Tyler , Stephens Mark 
Published: January 2021

Abstract
For onshore pipelines transporting hydrocarbon products that remain in a liquid state after release, environmental damage and socioeconomic impact are the dominant concerns. It is reasonable to assume that the magnitude of impact from such a release event is, at least in part, a function of the volume of product released. Analytical models exist for estimating the release volume from pipelines as a function of the physical and operational parameters of the line, and the effective size of the opening at the point of line break. While the estimates of release volumes obtained from such models are an important component of risk assessments and serve to inform emergency response planning activities, it is also important to understand what historical data indicates in terms of actual release volumes and how they are affected by key pipeline attributes. This paper summarizes the findings of an analysis of product release events associated with the onshore United States (US) hazardous liquid pipeline network, as obtained from reportable incident data publicly available from the Pipeline and Hazardous Materials Safety Administration (PHMSA). The findings of the study suggest that, for major releases resulting from large pipeline openings, release volumes are correlated with line diameter; whereas, releases as the result of a leak are largely independent of line diameter. Based on this, simple models have been developed from which both the average release volume and the range of likely release volumes can be estimated as a function of the pipeline diameter and mode of failure. These simple release volume estimation models are useful for benchmarking exercises where the goal is to estimate expected or most likely release volumes for calibrating and/or validating more complex release volume estimation models, and for estimating worst-case release volumes for emergency response planning purposes.
Experimental Investigation of the Difference in Wax Deposition Aging Rate Between Polyethylene and Steel Pipes
Authors: Li Rongbin , Li Yaping , Cao Danfu , Wang Junfang , Liu Xin 
Published: January 2021

Abstract
Wax deposition is an intrinsic problem existing in the production and transportation of waxy crude oil. In the oilfield, non-metallic pipe especially high-density polyethylene pipe (HDPE) has been widely used to solve corrosion problems due to its excellent performance in intensity and corrosion. However, the wax deposition problem in polyethylene (PE) pipe has never been evaluated using dynamic and systemic apparatus. Only a few studies focus on the wax deposition on the coated polyethylene surface by using the cold finger apparatus in recent decades. In this study, the wax deposition experiments were performed using an in-door flow-loop with detachable PE and stainless steel (SS) test sections under the laminar flow regime at the same time to investigate the difference in wax deposition aging rate between the PE and SS pipes. The wax deposits under different operating conditions in both PE and SS pipes were sampled by three layers to study the aging rate at different radial locations during the wax deposition. The wax precipitation characteristics of the wax deposits were determined by using the differential scanning calorimetry (DSC) method. It was found that the wax contents of the wax deposits in PE pipe were lower than that in the SS pipe. And the difference of the wax content between PE pipe and SS pipe decreases with the depositing duration. Eventually, the wax contents of the wax deposits in PE pipe were almost the same as that in the SS pipe. The heat conduction and heat transfer processes in PE pipe and SS pipe were analyzed. The thermal gradient and the concentration gradient at wall were calculated and combined with the heat and mass transfer of wax during the wax deposition to illustrate the difference in wax content. It was found that the variations of the thermal and concentration gradients have significant effects on the diffusion process of wax molecules within the wax deposit layer and thus changing the aging rate. The comparisons and findings of wax deposition between the two kinds of pipes have provided a significant reference for the application of non-metallic pipe in the oilfield.
Advanced Eddy Current Array Tools for Stress Corrosion Cracking Direct Assessment on Pipelines
Authors: Sirois Michael , Bouchard Mathieu , Sweedy Ahmed 
Published: January 2021

Abstract
Magnetic Particle Inspection (MPI) has been the main reference for Stress Corrosion Cracking (SCC) detection in pipeline integrity for years. Although this technique is relatively economical and easy to deploy — thanks to a large pool of certified technicians — it remains time consuming and highly user dependent. Some of the factors impacting results during SCC Direct Assessment (SCCDA) include the total surface area requiring examination, hard-to-reach positions underneath pipes during inspection, improper surface preparation due to poor sandblast or contrast, condensation on pipes, and operator fatigue.
Recent trials have proved that Eddy Current Array (ECA) technology compares favorably against MPI on many aspects in the field, and that ECA has the potential to become the new standard for SCCDA on pipelines. Offering an impressive speed, combined with a particularly high Probability of Detection (PoD), ECA could transform the work of technicians in ditches and above all, offer greater control over the human factor.
Besides detection, ECA has also proven its reliability for SCC characterization on real SCC colonies in both lab and field environments. Comparisons to metallography sections, grinding measurements and X-Ray Computed Tomography (XCT) data have greatly contributed to optimized depth sizing algorithms for this new solution, providing accurate SCC depth readings. Although ECA and Phased Array Ultrasonic Testing (PAUT) are often complementary techniques in the field, the main advantage of ECA over PAUT resides in the short amount of time required to locate and size the deepest cracks among colonies containing sometimes thousands of cracks. Within a few minutes, technicians and engineers know where to concentrate and how critical SCC really is so that decisions can be made instantly. Combining ease of use and repeatability (ways to control the human factor) is another key benefit of ECA technology.
This paper provides information about a complete ECA solution for SCC detection and depth sizing on pipelines. It reveals results from the field, comparing ECA with MPI, covering several key points and demonstrating how ECA stands out as improving the overall screening process efficiency during examinations in digs. Furthermore, it also exposes and compares ECA data with both destructive and non-destructive testing performed on test pieces containing real SCC.
Hydrate Formation in Water-in-Oil Emulsions in the Presence of Resins
Authors: Zhang Dongxu , Huang Qiyu , Li Rongbin , Cao Danfu , Li Huiyuan 
Published: January 2021

Abstract
Gas hydrate is one of the main concerns in the flow assurance issues for under water multiphase pipelines. Hydrate nucleation and growth in the water-in-oil emulsions have not been completely understood due to the complex factors, such as the composition of crude oils. Resins, as a common component in crude oil, can pose great effects on hydrate formation, which is still lack of investigation. This paper aims to bridge this gap with a custom-designed high pressure autoclave. Different with other hydrate investigation apparatus, an online viscometer was equipped for the real time viscosity measurement. Resins were separated from the Venezuelan residue for the purpose, following the saturates, aromatics, resins, and asphaltenes fractionation method. A series of experiments of hydrate formation were carried out in the emulsions with the presence of different resin contents, under the condition of 2.7 °C, 2.6 MPa, and 40 vol. % water cut.
It was observed that resins hindered hydrate formation in water-in-oil emulsions. The induction time increased with the increasing of resin content. The induction time in the emulsion with the presence of 1.0 wt. % resin content was almost 200 min longer than that in the emulsion without resins. It was found that an increase in resin concentration led to the significant reduction in temperature peak. In addition, a time delay phenomenon of temperature and pressure in the growth onset was found in the system with 0.5 or 1.0 wt. % resin content, by virtue of the online viscometer. It demonstrated the impeding effect of resins on hydrate growth. Moreover, the microphotographs of water-in-oil emulsions were obtained. It was observed that the resins can be adsorbed on the water droplet surface, and hence occupied the hydrate nucleation sites and formed a barrier for the further penetration of gas molecules. The adsorption phenomenon can preliminarily account for the inhibiting effect of resins on hydrate formation. It provides a scientific understanding for the effect of resins on hydrate formation in water-in-oil emulsions, excluding the interference of wax and other components. It would be useful to an appropriate flow assurance strategy designing for the under-water multiphase pipelines.
Crack Driving Force Calculation in Arbitrarily Shaped Defects Based on 3D Non-Destructive Evaluation and Finite Element Analysis
Authors: Hertelé Stijn , Adriano Vitor , Chaudhuri Somsubhro , De Wilde Laurens , Huising Otto Jan 
Published: January 2021

Abstract
The actual shape of a real defect differs from the simplified shapes that are assumed within an engineering critical assessment. Additionally, the re-characterization of interacting defects into one simplified defect is known to introduce conservatism, which may be undesirably large. Ongoing and expected technological advances of 3D NDE techniques (such as full-matrix capture ultrasonics and X-ray CT) allow to assume that defect simplification will no longer be required in the future, thus bypassing the uncontrolled conservatism resulting from defect simplification. A recently finished EPRG project has shown the feasibility of integrating the information provided by 3D NDE systems into finite element models. Promising results are obtained which, with additional effort, will provide a solid basis for in-the-field application.
This paper first reports on the overall procedure of defect assessment by the adopted finite element analysis (both linearelastic and elastic-plastic). Next, the ability to couple FE model construction with non-destructive evaluation results is demonstrated for three scans obtained from different sources (one X-ray CT and two ultrasonic full matrix capture scans). Finally, concrete opportunities to improve the robustness, speed and accuracy of the methodology are addressed, which will be tackled in a follow-up project funded within PRCI.
Papua New Guinea Earthquake Proves the Value of Robust Pipeline Materials Selection and Construction
Authors: Macia Mario L. , Crapps Justin , Noecker Fredrick F. , Nissley Nathan E. , Cook Michael F. 
Published: January 2021

Abstract
In 2018, the PNG LNG project sustained a Mw7.5 earthquake, and ca. 300 aftershocks, epicentered directly under key facilities. Around 150 km of high-pressure gas and condensate pipelines were affected. In anticipation of such an earthquake event and due to the challenging terrain that the pipeline traverses, two design methodologies were used in specifying the pipe and welds for the onshore pipelines: strain-based design and allowable stress design with robust materials selection. The strain-based design approach was used for segments crossing faults and was the subject of IPC2014-33550 [1]. In this paper, the robust allowable stress design that was used for the remainder of the onshore pipeline route will be discussed along with the performance of the pipeline designed with this methodology when it was subjected to the earthquake. Robust allowable stress design involved the selection of line pipe and welding procedures that would reduce the risk of failure during unanticipated ground movements. Lower grade, thicker wall pipe was selected, and enhanced weld properties were specified to increase weld strength overmatch and toughness. Additionally, enhanced testing of pipe and weld properties was performed in order to enable prediction of pipeline strain capacity and assessment of fitness for service of any portion of the pipeline that experienced longitudinal plastic strains due to ground movement. These efforts enabled the pipeline to safely sustain the ground movement experienced during the earthquake and allowed safe project operations to be rapidly restored.
This paper provides details of the selection of pipe grade and wall thickness and the specification of material properties for pipe and girth welds. The property distributions achieved and the impact on strain capacity are presented along with estimates of the strain experienced by the pipeline due to the earthquake. The performance of the pipeline during the earthquake illustrate the benefits of the robust allowable stress design approach for pipelines in challenging environments.
Development of Soil Restraints for Buried Pipelines in Muskeg Soils Subjected to Lateral Ground Displacements
Authors: Wijewickreme Dharma , Jayasinghe Thushara 
Published: January 2021

Abstract
A systematic research program was undertaken with the objective of developing quantitative geotechnical parameters to support soil-pipe interaction assessment for buried pipelines in muskeg. For this purpose, a field geotechnical investigation program comprising cone penetration testing (SCPT) with shear wave velocity (Vs) measurements, electronic field vane shear testing (eVST), full-flow ball penetration testing (BPT), and pressuremeter testing (PMT), along with fixed-piston tube soil sampling was undertaken in a muskeg soil terrain. The data from field testing were initially interpreted to obtain typical stiffness and strength parameters for the subject soils. These parameters were then used to numerically simulate pressuremeter tests and the results were compared with those obtained from field pressuremeter testing; the intent was to calibrate a suitable constitutive model to represent the muskeg soil mass. These ascalibrated constitutive model was then applied on numerical models developed to simulate buried pipelines in muskeg soil subject to relative lateral ground movements. The work is aimed at developing a framework to generate soil restraint versus relative ground displacement relations (“soil springs”) to assess soil-pipe interaction of pipelines buried in muskeg soils. Initial results from the research are presented herein, with a comparison made between soil springs developed from numerical analyses and those generated from current practice guidelines.