Large Pipeline Research Articles

Key Points of Construction Management for Directional Drilling Crossing of Large Diameter and Long Distance Transmission Pipeline

Key Points of Construction Management for Directional Drilling Crossing of Large Diameter and Long Distance Transmission Pipeline

Pipeline Pressure Loss in Deep-Sea Hydraulic Systems Considering Pressure-Dependent Viscosity Change of Hydraulic Oil

The high ambient pressure in deep-sea conditions greatly increases the viscosity of hydraulic oil and then the pipeline pressure loss in deep-sea hydraulic systems. Large pipeline pressure loss can lead to a further change of viscosity on the basis of the viscosity increase caused by the ambient pressure when the hydraulic oil flows through the pipeline. Therefore, the classic Poiseuille’s law can no longer accurately calculate the pipeline pressure loss in deep-sea conditions since it treats the viscosity as a constant. In this paper, based on laminar flow theory and the viscosity-pressure characteristics of hydraulic oil, a novel equation for pipeline pressure loss is proposed, in which the viscosity change when flowing through the pipeline is taken into account. A CFD (Computational Fluid Dynamics) model of a pipeline in the deep-sea hydraulic system has been established, and CFD simulations have been conducted to verify the correctness of the proposed equation for pipeline pressure loss. Theoretical analysis shows that the proposed novel equation for pipeline pressure loss is equivalent to the classic Poiseuille’s law when the pipeline pressure loss or the viscosity change is low. The research results in this paper can provide theoretical support for work efficiency optimization, load capacity improvement, and precise control of deep-sea operation equipment or deep-sea hydraulic systems.

Study on Hydrodynamic Coefficients of a Submarine Piggyback Pipeline under the Action of Waves and Current

In this study, physical model tests are used to investigate the effects of a varying number of wave and current parameters, the gap ratios between the pipeline and seabed, the spacing ratios between the two pipelines and the diameter ratios on the hydrodynamic coefficients of the large, small pipeline and pipeline system (bundle) in a piggyback configuration under the combined action of waves and current. The results show that, compared with the pure wave field, the existence of the steady current will lead to a decrease in hydrodynamic coefficients. In addition, the results indicate clear differences between the hydrodynamic coefficients of the large pipeline, small pipeline and piggyback pipeline system. The experimental results on hydrodynamic coefficients can be used as an important basis for the safety design of a submarine piggyback pipeline.

Numerical investigation of the influence of the small pipeline on local scour morphology around the piggyback pipeline

This paper presents the results from a numerical simulation study to investigate the effect of the position angle (α) of small pipeline on the local scour and the hydrodynamic force around the piggyback pipeline in steady current conditions. Results show that the local scour depth around the piggyback pipeline increases first and then decreases with the increase of α. The scour depth and width reach the maximum values as the small pipe locates at the top of the large pipeline (i.e. α = 90°). The scour around the piggyback pipeline is accelerated when α ranges between 30° and 165°, while for α = 0°–30° and 165°–180°, the local scour around the piggyback pipeline is inhibited. Furthermore, the small pipe placed in front of the large pipe has slightly larger effect on the scour hole morphology than that when it is placed behind the large pipe. The drag force coefficient increases first and reaches the maximum value at α = 75°, and then decreases with the increase of α. Eventually the drag force coefficient approaches roughly a constant. The lift force coefficient is approximately a V-shaped with the variation of α and has the maximum value at α = 90°.

Integrating Coral Restoration Data With a Novel Coral Sample Registry

In the past decade, the field of coral reef restoration has experienced a proliferation of data detailing the source, genetics, and performance of coral strains used in research and restoration. Resource managers track the multitude of permits, species, restoration locations, and performance across multiple stakeholders while researchers generate large data sets and data pipelines detailing the genetic, genomic, and phenotypic variants of corals. Restoration practitioners, in turn, maintain records on fragment collection, genet performance, outplanting location and survivorship. While each data set is important in its own right, collectively they can provide deeper insights into coral biology and better guide coral restoration endeavors – unfortunately, current data sets are siloed with limited ability to cross-mine information for deeper insights and hypothesis testing. Herein we present the Coral Sample Registry (CSR), an online resource that establishes the first step in integrating diverse coral restoration data sets. Developed in collaboration with academia, management agencies, and restoration practitioners in the South Florida area, the CSR centralizes information on sample collection events by issuing a unique accession number to each entry. Accession numbers can then be incorporated into existing and future data structures. Each accession number is unique and corresponds to a specific collection event of coral tissue, whether for research, archiving, or restoration purposes. As such the accession number can serve as the key to unlock the diversity of information related to that sample’s provenance and characteristics across any and all data structures that include the accession number field. The CSR is open-source and freely available to users, designed to be suitable for all coral species in all geographic regions. Our goal is that this resource will be adopted by researchers, restoration practitioners, and managers to efficiently track coral samples through all data structures and thus enable the unlocking of a broader array of insights.

Feasibility of hydropower generation on existing Legedadi water supply scheme, Addis Ababa-Ethiopia

Hydropower can be harnessed by installing in-pipe turbines with the reduced cost compared with hydropower dam construction. Legedadi Water Supply Scheme is found in Addis Ababa and is fed by gravity. This research assesses the hydropower potential of the existing large water transmission pipelines in line with their financial viability. The research required the collection of data from pipe flow (for 29 years from the system record) and pipe layout drawings believed to be useful for estimating the power. The available pipe layout drawing was processed to prepare a profile view with the help of AutoCAD CIVIL 3D. From the profile view, the gross heads and length of the pipelines were obtained. The exploitable power and financial viability of the projects were estimated by RET Screen software. The raw water main (DN1200) was discovered to have a head of 12.46 m and to convey up to 1.47 m3/s at 90% exceedance over a length of 550 m. The two treated water mains have a head of 19.15 m with a flow of 1.14 m3/s at 90 % exceedance via DN1200 and 0.29 m3/s at 90% exceedance via DN900 over a length of 18.4 km. The most suitable sites for the installation of turbines were at the inlet of the treatment plant and the Kotebe Terminal Reservoir. The Toshiba Hydro-eKIDS turbine was selected since it might work efficiently with large flow variation.The annual energy output from the raw water main to be obtained was 1,208 Mwh,with an estimated cost of $461,000 and an annual savings or revenue of $75,946. For the treated water mains, 1,193 Mwh (DN1200) and 344 Mwh (DN900) could be extracted with an estimated cost of 414,500$ (DN1200) and 135,900$ (DN900). The annual revenue for treated water mains is 75,068$ (DN1200) and that for DN900 is 18,842$.

Strain capacity analysis of the mismatched welding joint with misalignments of D 1,422 mm X80 steel pipelines: An experimental and numerical investigation

Anomalies as misalignment, microcrack are inevitable for large diameter high strength steel pipelines. To ensure the strain capacity of mismatched welding joint with misalignments of D 1,422 mm X80 steel pipeline, a comprehensive study via wide plate experiments and finite element model simulations was conducted. The full-scale tensile experiment of a X80 pipe wide plate with weld joint was conducted. Strain distributions on the plate was derived by DIC technic. Trends of CMOD at the precrack in the weld joint with tensile strains monitored. A FE model was established to inverse the wide plate experiment and prove the accuracy of numerical model’s prediction results for crack driving forces. Using the same modeling method, a parametrical 3D numerical simulation model for X80 line pipe with cracks in automatic welding joints was established. The double V-shaped groove type welding joint was precisely considered in the geometric model. Difference of the stress-strain relationships of yielding-to-tensile ratio of the BM, softening rate of the HAZ and strength matching coefficient of WM were considered in the material model. A CTOD extracting program coded was employed. Parametric analysis was performed to investigate the effects of load conditions, strength matching coefficient of WM, yielding-to-tensile ratio of BM and softening rate of HAZ on the strain capacity with a critical fracture toughness adopted in pipeline industry. Based on the derived results, mismatched ratio requirements of D 1,422 mm X80 pipes were listed, which provides guidance for the welding parameter design and safety evaluation of automatic welding joints.

Effect of suction pipeline resistance on cavitation surge in a turbopump with inducer

Cavitation surge is one of the vital flow instabilities in turbopumps, which should be avoided in actual operation. According to the past stability analyses, it is shown that the suction pipeline resistance has a suppression effect of cavitation surge. In the present study, we experimentally examined this effect by changing the suction pipeline resistance through the opening of butterfly valve installed upstream of inlet pipe. As a result, it was found that the onset range of cavitation surge could be significantly narrowed by the large suction pipeline resistance, which agreed with the above finding by the theoretical analyses.

NOAA Scientific Support for a Natural Gas Pipeline Release During Hurricane Harvey Flooding in the Neches River Beaumont, Texas

ABSTRACT During the height of historic flooding from Hurricane Harvey's rainfall, a rupture occurred in a 16-inch, 80 psia (65 psig) natural gas pipeline crossing the Neches River east of Beaumont, Texas. Over the preceding five days, Hurricane Harvey stalled over the area, generating rainfall totals between 35 and 60 inches. The storm broke the record for rainfall totals in the U.S., with 60.58 inches reported in Nederland, Texas and 60.54 inches near Groves, Texas. The Neches River was in extreme flood conditions, cresting the day after the pipeline rupture at a historic high of 19.59 feet (nearly 10 feet above major flood stage and nearly 7 feet above the former historic record from 1994). At the request of the U.S. Coast Guard Marine Safety Unit (MSU) Port Arthur, NOAA's Emergency Response Division provided scientific support for the incident including on-scene support from the NOAA Scientific Support Coordinator (pre-deployed in Port Arthur, Texas for disaster response) as well as technical assistance from the NOAA Scientific Support Team in Seattle and Baton Rouge. Products and support provided by NOAA included air hazard modeling using ALOHA (Areal Locations of Hazardous Atmospheres) as well as the overall hazards assessment. ALOHA modeling indicated that several significant ignition sources were located within the specific threat zone identified. However, no ignition occurred and no injury or further damage resulted from the release. This incident highlights the advantages and limitations of using ALOHA to model a subsurface natural gas release from a large underwater pipeline provided in the context of an ongoing response to historic flooding and high intensity search and rescue and emergency port operations resulting from a natural disaster.

Cleanup and Restoration of 1000-ha of Oiled Mangroves, Bodo, Eastern Niger Delta, Nigeria

ABSTRACT A 1000 ha (2471 ac) area around the community of Bodo in Rivers State, Nigeria, was affected by two large pipeline spills in 2008 and numerous smaller discharges between 2009 and present, primarily related to oil theft, transport and indigenous refining. This paper describes the remediation of affected environments which represents the largest cleanup and restoration of a mangrove ecosystem due to oil-related damage ever undertaken and serves as a potential model for other areas of the Niger Delta similarly affected. Cleanup activities include: (1) raking / mixing of surface sediments to break up a thick algal mat and removal of heavily polluted dead mangrove debris while lesser-oiled (most common) debris is broken up and left in place to aid re-establishment of mangrove plants and animal life used as a food source by the Bodo Community; (2) pressure flushing using ambient water from adjacent channels; (3) compressed air with water from a barge-mounted system, (4) use of hard boom and sorbents around the work area to capture off-floating oil, and (5) manual collection of floating oil using sorbents and hand bailers, followed by transfer to a central collection point and disposal at a government approved facility. High-volume low-pressure flushing system proved effective in releasing much of the deeply penetrated oil without damaging the sedimentary structure of the mangrove platform. Innovative methods are continually being sought. After confirmation of cleanup requirements, former mangrove areas (~860 ha, 2125 ac) will be planted with mangrove seedlings to phytoremediate remaining oil. Close-out criteria are based upon visual assessment followed by chemical sampling to meet government approved risk-based site-specific target levels. Potential major impediments to the successful completion of this Project are community unrest, security issues and reoiling from illegal activities and pipeline operations.

Frequency Converter for Induction Heating Oil in Oil Pipelines

Heating oil in oil pipelines to the required temperature, with the most efficient use of electrical energy,is possible with using of the induction heating method. The most important parameter of induction heating settings is frequency. For each process, there is an optimal frequency range that provides the best technological and economic results. Induction heating of the oil pipeline occurs as follows, if alternating high-frequency current is passed through the windings of the oil pipeline inductor (Fig. 1), an alternating magnetic field is formed, which intersects the metal walls of the oil pipeline and induces eddy currents in them. These currents heat the metal walls of the pipeline to the desired temperature and, accordingly, the oil. MITSUBISHI's VIPM Series Intelligent Power Transistor Modules (IPM), which is a functionally complete product, are currently developed and marketed. These transistor modules are designed for high voltages, currents and power. A frequency converter made on these transistor modules allows to heat large diameter oil pipelines. A prototype IGBT transformer was designed and manufactured. Figure 2 shows a prototype of a frequency converter with a power of 6 kW at frequencies from 2 to 20 kHz. Induction heating of metal was used as a load for the frequency converter

Experimental and Numerical Investigations of Multi-leaks Detection in a Nonhomogenous Pipeline System

This paper focuses on an experimental procedure to localize multiple leaks in a nonhomogenous hydraulic pipeline system made up of three portions of two different materials. Then, an experimental setup originally designed for water hammer study was modified and adapted for leak detection using transients. Two leaks were made in some particular locations in the main pipe and a transient event through a rapid closure of a downstream valve was created. To mimic common practical issues that may be encountered, three main leakage cases were considered; a single leak, two simultaneous leaks and two successive leaks (i.e., one leak that appears followed by an abrupt appearance of a second leak after a period of time). Leaks were experimentally localized by analyzing obtained pressure signals in the excitation point. Results were validated through comparison with numerical ones obtained using the method of characteristics. Additionally, a novel formula to localize the second leak in a successive leaks scenario was presented and its accuracy was confirmed for our test case. Experimental techniques presented in this paper and performed on a test bench at lab scale can be extended and tested on large scale hydraulic pipeline systems.

Pitometry as a validation tool for water flow measurement in large diameter pipelines

Accurate measurement of water flow rates in large diameter pipelines is a challenge for water companies that need to produce, transport and distribute increasing quantities of water. To a large extent, this challenge results from the impossibility of recalibration of the flow meters within the periodicity established in the metrological regulations since the removal of a large size flow meter from its site of operation in the field and its transport to a calibration laboratory is in most cases technically and economically impracticable. Because of this scenario, this paper presents the pitometry technique as an interesting alternative to solve problems related to the validation of water flow measurements performed by flow measurement systems installed in large diameter conduits. The technique is based on the determination of the water flow rate by mapping the velocity profile of the water flow inside the pipe by means of Cole type Pitot tubes. The water flow rate is determined in a cross section of the pipe located near and in series to the flowmeter to be evaluated. Based on the results obtained in a great number of water flow measurements already performed by applying the pitometry technique in large diameter pipelines in the field, it is possible to conclude that this methodology is perfectly applicable in the validation of the performance of flow meters installed in these conduits solving satisfactorily the issues related to its operation.

Software-defined data protection

Most modern data processing pipelines run on top of a distributed storage layer, and securing the whole system, and the storage layer in particular, against accidental or malicious misuse is crucial to ensuring compliance to rules and regulations. Enforcing data protection and privacy rules, however, stands at odds with the requirement to achieve higher and higher access bandwidths and processing rates in large data processing pipelines. In this work we describe our proposal for the path forward that reconciles the two goals. We call our approach "Software-Defined Data Protection" (SDP). Its premise is simple, yet powerful: decoupling often changing policies from request-level enforcement allows distributed smart storage nodes to implement the latter at line-rate. Existing and future data protection frameworks can be translated to the same hardware interface which allows storage nodes to offload enforcement efficiently both for company-specific rules and regulations, such as GDPR or CCPA. While SDP is a promising approach, there are several remaining challenges to making this vision reality. As we explain in the paper, overcoming these will require collaboration across several domains, including security, databases and specialized hardware design.

Population Genomic Analysis of Listeria monocytogenes From Food Reveals Substrate-Specific Genome Variation.

Listeria monocytogenes is the major causative agent of the foodborne illness listeriosis. Listeriosis presents as flu-like symptoms in healthy individuals, and can be fatal for children, elderly, pregnant women, and immunocompromised individuals. Estimates suggest that L. monocytogenes results in ∼1,600 illnesses and ∼260 deaths annually in the United States. L. monocytogenes can survive and persist in a variety of harsh environments, including conditions encountered in production of fermented dairy products such as cheese. For instance, microbial growth is often limited in soft cheese fermentation because of harsh pH, water content, and salt concentrations. However, L. monocytogenes has caused a number of deadly listeriosis outbreaks through the contamination of cheese. The purpose of this study was to understand if genetically distinct populations of L. monocytogenes are associated with particular foods, including cheese and dairy. To address this goal, we analyzed the population genetic structure of 504 L. monocytogenes strains isolated from food with publicly available genome assemblies. We identified 10 genetically distinct populations spanning L. monocytogenes lineages 1, II, and III and serotypes 1/2a, 1/2b, 1/2c, 4b, and 4c. We observed an overrepresentation of isolates from specific populations with cheese (population 2), fruit/vegetable (population 2), seafood (populations 5, 8 and 9) and meat (population 10). We used the Large Scale Blast Score Ratio pipeline and Roary to identify genes unique to population 1 and population 2 in comparison with all other populations, and screened for the presence of antimicrobial resistance genes and virulence genes across all isolates. We identified > 40 genes that were present at high frequency in population 1 and population 2 and absent in most other isolates. Many of these genes encoded for transcription factors, and cell surface anchored proteins. Additionally, we found that the virulence genes aut and ami were entirely or partially deleted in population 2. These results indicate that some L. monocytogenes populations may exhibit associations with particular foods, including cheese, and that gene content may contribute to this pattern.

The Effect of Backfilling Stiffness on the Lateral Response of Deeply Buried Pipelines: an Experimental Study

Subsea pipelines passing through the shallow area are physically protected against the environmental, accidental, and operational loads by trenching and backfilling. Depending on construction methodology, environmental loads, and seabed soil properties, the stiffness of backfilling material may become largely different from the native ground (softer than native ground in most of the cases). The different stiffness between the backfill and native ground affects the soil failure mechanisms and lateral soil resistance against large pipeline displacements that may happen due to ground movement, landslides, ice gouging, and drag embedment anchors. This important aspect is not considered by current design codes. In this paper, the effect of trench-backfill stiffness difference on lateral pipeline-backfill-trench interaction was investigated by performing centrifuge tests. The soil deformations and failure mechanisms were obtained by particle image velocimetry (PIV) analysis. Three experiments were conducted by using three different backfills including loose sand, slurry, and chunky clay that represent the purchased, natural in-fill, and pre-excavated materials, respectively. The study shows that the current design codes underestimate the lateral soil resistance for small to moderate pipe displacements inside the trench and overestimate it for large lateral displacement, where the pipeline is penetrating into the trench wall.

The influence of the drilling rate of the raise boring machine on the stability of the surrounding rock of a inclined shaft with large dip angle

The drilling method of counter-well drilling rig has become an important construction method for the construction of large inclination Angle pressure pipeline in pumped storage power station. In order to study the effect of the drilling rate on the stability of the surrounding rock of the inclined well. The method of numerical analysis is used to simulate the drilling rate of backwell drilling machine by changing the drilling depth of certain calculation step, and the drilling depth is along the inclined shaft line. The selection of drilling parameters is optimized and the drilling rate of the reverse well rig is determined. The results show that the tunneling rate has a significant influence on the deformation rate of surrounding rock and the change rate of stress gradient in the process of drilling with reverse-well drill. With the increase of drilling rate, the deformation rate and the change rate of stress gradient increase. The variation amplitude of the surrounding rock deformation and stress value at the monitoring point increases first and then decreases, and finally tends to be stable. Under this formation condition and drilling scheme, the deformation of surrounding rocks in wellbore after drilling at the same depth is small, and the effect of stress disturbance is not significant. The maximum deformation of surrounding rocks in inclined Wells is only 0.27mm, and the strong disturbance zone is about 2.0m. Combined with field drilling test results, the optimal drilling rate of reverse well reaming is determined to be 1.2m/h.

SSWT and VMD Linked Mode Identification and Time-of-Flight Extraction of Denoised SH Guided Waves

Ultrasonic guided wave testing technology is currently widely used in industrial nondestructive testing (NDT), including defect detection in the floors of large tanks and oil pipelines. However, in addition to noise, practical scenarios of signal detection also present mode aliasing problems, which make it difficult to accurately identify and locate defects. In this paper, we propose an improved shear horizontal guided wave mode identification method using a variational mode decomposition (VMD) algorithm and a time-of-flight (TOF) extraction method using the synchrosqueezed wavelet transform (SSWT) algorithm. Moreover, we use the wavelet denoising method to denoise the original signal before applying VMD. The results show that the TOF errors obtained by the VMD method are all less than 5% and that the wavelet denoising of the original guided wave data can further reduce the errors (to less than 2%). In addition, the SSWT can modify the time-frequency analysis results of intrinsic mode functions obtained by the VMD method and provides accurate TOF data for different modes. Therefore, the proposed ultrasonic guided wave signal method is helpful for improving the defect detection sensitivity and accuracy of SH waves.

Detection of torsional guided wave generation using macro-fiber composite transducers and basis pursuit denoising

In engineering structures, such as large fluid-filled pipelines, continuous monitoring for damage detection is needed. To address this issue, we study the generation of guided waves in pipes by using a circumferential strip of macro fiber composite transducer to generate and detect torsional and flexural lower modes. The propagated elastic waves and their resulting reflected and mode-converted signals at the interaction wave discontinuity are post-processed with basis pursuit denoising using a Gabor dictionary to improve signal identification. Numerical results are obtained and experimentally tested on a stainless-steel pipe A-36 (43.6 and 48.2 mm in inner and outer diameter). It was found that the proposed method makes it possible to identify an artificial discontinuity by detecting the scattered wave and converted modes of a propagated torsional wave.

Quantitative risk analysis of a hazardous jet fire event for hydrogen transport in natural gas transmission pipelines

With the advent of large-scale application of hydrogen, transportation becomes crucial. Reusing the existing natural gas transmission system could serve as catalyst for the future hydrogen economy. However, a risk analysis of hydrogen transmission in existing pipelines is essential for the deployment of the new energy carrier. This paper focuses on the individual risk (IR) associated with a hazardous hydrogen jet fire and compares it with the natural gas case. The risk analysis adopts a detailed flame model and state of the art computational software, to provide an enhanced physical description of flame characteristics.This analysis concludes that hydrogen jet fires yield lower lethality levels, that decrease faster with distance than natural gas jet fires. Consequently, for large pipelines, hydrogen transmission is accompanied by significant lower IR. Howbeit, ignition effects increasingly dominate the IR for decreasing pipeline diameters and cause hydrogen transmission to yield increased IR in the vicinity of the pipeline when compared to natural gas.