Study on the Technology of Supplying Water Safely by Long-Distance Pipeline

The extensively built long-distance water transmission pipelines have become the main water sources for urban areas. To ensure the reliability and safety of the water supply, from the viewpoint of overall management, it would be necessary to establish a system of information management for the pipeline. The monitoring, calculating and analyzing functions of the system serve to give controlling instructions and safe operating rules to the automatic equipment and technician, making sure the resistance coefficient distribution along the pipeline is reasonable; the hydraulic state transition is smooth when operating conditions change or water supply accidents occur, avoiding the damage of water hammer. This paper covered the composition structures of the information management system of long-distance water transmission pipelines and the functions of the subsystems, and finally elaborated on the approaches and steps of building a mathematics model for the analysis of dynamic hydraulic status.

Research on laser-arc hybrid welding technology for long-distance pipeline construction

In recent years, the research on pipeline laser-arc hybrid welding technology has been the important and difficult in the field of welding all over the world. China Petroleum Pipeline Research Institute Co. Ltd. has firstly developed pipeline laser-arc hybrid welding system in China, and executed the welding tests based on X70/X80 steel. Preliminary experiment results showed that hybrid welding could meet the requirements of related standards such as API1104,ASME,etc., the mechanical properties of girth seam are qualified in the case that there were no internal defects. With the development of high-power fiber laser and the continuous improvement of welding equipment, laser-arc hybrid welding technology for pipeline field welding will be available soon.

Simulation of long-distance pipeline transportation properties of whole-tailings paste with high sliming

Based on Bingham rheological model,a three-dimensional numerical simulation model for long-distance pipeline transportation is established by computational fluid dynamics(CFD)to study the pipeline transportationproperties of high sliming paste from a copper mine in China.Based on the rheological properties test,the pressure and velocity of pipeline and elbow are simulated by CFD under different mass concentrations and different stowing capacities.The results show that the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with high sliming and pumping agent at the same mass concentration,and the pipeline resistance of whole-tailings paste with high sliming while without pumping agent is much higher than that with low sliming while without pumping agent.It is very important to add pumping agent to whole-tailings paste with high sliming,and the resistance changes with mass concentration and stowing capacity at the same cement-to-sand ratio of1:5and tailings-to-waste ratio of6:1.However,the change is just limited,that is to say,the paste transportation system is of good stability.Furthermore,at the elbow,the maximum pressure and velocity transfer to the outside of the pipe from the inside.However,lubricating layer is formed at the pipe wall because of high content of fine particles in whole-tailings paste,which will protect the elbow from abrasion.CFD provides an intuitive and accurate basis for pipeline transportation study,and would have a wider application space in the study of paste rheological properties and resistance reduction methods.

Development of Automatic Phased Array Inspection System for Long-distance Pipeline

In the paper the development of phased array technique home and abroad is summarized, the overall structure and main research on phased array inspection system are introduced,and meanwhile the future field of study and development of phased array ultrasonic inspection technique is pointed out.

Novel Methodologies for Preventing Crack Propagation in Steel Gas Pipelines Considering the Temperature Effect

Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃ to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃ and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines.

Criterions and Measures of Route Selection of Shallowly Embedded Long-Distance Oil and Gas Pipeline in Mountain Areas

According to the engineering investigation of long-distance oil and gas pipelines, the criterions and measures of route selection are drawn as follows： the flat landform is the first choice in route alignment. The foot of mountain is the first choice when the route passes by the valley. The route should pass by but the shady and deposited slope and not in sunny and erosive slope as possible as it can. The pipeline should be vertical to contour climbing and descending the mountain except steep slope. Tunnel can be used in crossing foothill. Perpendicularly traversing the river is better than beveling; the worst choice is to put the pipeline along the river. Bypass is the best choice in karsts area. The order of route selection should be pre-choosing, investigation, optimization and adjustment.

Standard friction prediction model of long-distance hot oil pipelines

We developed a predictive model for the pipeline friction in the 520-730 m^3/h transmission range using the multi-layerperceptron-back-propagation(MLP-BP)method and analyzing the unit friction data after the pigging of a hot oil pipeline.In view of the shortcomings of the MLP-BP model,two optimization methods,the genetic algorithm(GA)and mind evolutionary algorithm(MEA),were used to optimize the MLP-BP model.The research results were applied to the standard friction prediction of three sections of a hot oil pipeline.After the GA and MEA optimizations,the average errors of the three sections were 0.0041 MPa for the GA and 0.0012 MPa for the MEA,and the mean-square errors were 0.083 and 0.067,respectively.The MEA-BP model prediction results were characterized by high precision and small dispersion.The MEABP prediction model was applied to the analysis of the wax formation 60 and 90 days after pigging.The analysis results showed that the model can effectively guide pipe pigging and optimization.There was little sample data for the individual transmission and oil temperature steps because the model was based on actual production data modeling and analysis,which may have affected the accuracy and adaptability of the model.

DISTRIBUTED OPTICAL FIBER SENSOR FOR LONG-DISTANCE OIL PIPELINE HEALTH

A fully distributed optical fiber sensor （DOFS） for monitoring long-distance oil pipeline health is proposed based on optical time domain reflectometry （OTDR）. A smart and sensitive optical fiber cable is installed along the pipeline acting as a sensor, The experiments show that the cable swells when exposed to oil and induced additional bending losses inside the fiber, and the optical attenuation of the fiber coated by a thin skin with periodical hardness is sensitive to deformation and vibration caused by oil leakage, tampering, or mechanical impact. The region where the additional attenuation occurred is detected and located by DOFS based on OTDR, the types of pipeline accidents are identified according to the characteristics of transmitted optical power received by an optical power meter, Another prototype of DOFS based on a forward traveling frequency-modulated continuous-wave （FMCW） is also proposed to monitor pipeline. The advantages and disadvantages of DOFSs based on OTDR and FMCW are discussed. The experiments show that DOFSs are capable of detecting and locating distant oil pipeline leakages and damages in real time with an estimated precision of ten meters over tens of kilometers.

THE RISK ASSESSMENT OF THE LONG-DISTANCE OILPIPELINE ENGINEERING

The oilfield construction and long-distance oil pipeline engineering has been developed extensively in China. The risk assessment of oil industry will, however, be an important objective to cope with the development of oil industry , The risk assessment of oil industry has many subjects worthy to be studied.The major purpose of the paper is to research the risk cases of long-distance oil pipeline engineering in Ganshu and Shaanxi provinces.

Pipeline Flex血流导向装置治疗颅内动脉瘤疗效观察

目的观察使用Pipeline Flex血流导向装置(PED)治疗颅内动脉瘤的疗效及安全性。方法回顾性分析2020年6月至2022年6月中山市人民医院使用PED治疗的25例颅内动脉瘤(共29个动脉瘤)患者的临床资料,25例患者中2例存在2个串联动脉瘤,1例有3个串联动脉瘤。29个动脉瘤分布在颈内动脉26个,大脑中动脉1个,椎基底动脉2个。术后进行临床及影像学随访,评估术后即刻动脉瘤栓塞情况和出院时患者改良Rankin评分量表(mRS),并在术后6个月及12个月时随访进行影像学检查以明确动脉瘤闭塞情况。结果25例患者均成功置入PED,其中15个动脉瘤联合弹簧圈栓塞,14个动脉瘤单独置入PED支架。术中有1例使用球囊扩张,24例经导丝微导管按摩均贴壁良好,术后临床随访中1例(4%)患者有缺血症状。术后6个月随访22个(75.9%)动脉瘤完全闭合,术后12个月随访2个(6.9%)动脉瘤影像学随访中未见闭合,27个(93.1%)动脉瘤完全闭合。结论PED治疗颅内动脉瘤短期随访安全有效,并发症较少,动脉瘤闭塞率较高。

Pipeline血流导向装置治疗复杂性颅内动脉瘤预后的影响因素及列线图预测模型构建

目的 探讨Pipeline血流导向装置(PED)治疗复杂性颅内动脉瘤预后的影响因素。方法选择2021年1月至2023年4月安岳县人民医院和桂林医学院第二附属医院接诊的复杂性颅内动脉瘤患者98例。患者入组后均行PED治疗,收集可能影响复杂性颅内动脉瘤预后的影响因素。据改良Rankin量表得分将患者分为2组,≤2分为预后良好组,>2分为预后不良组,比较2组的临床资料。建立Nomograms模型并对模型进行验证。结果 98例患者中,10例(10.20%)出现预后不良。预后不良组与预后良好组患者年龄、高血压病史、糖尿病史、氯吡格雷抵抗、Fisher分级、动脉瘤多次破裂、动脉瘤位置、瘤体大小、瘤颈、多发及入院时Hunt-Hess分级差异均有统计学意义(P<0.05)。多因素分析结果显示,高血压病史、氯吡格雷抵抗、动脉瘤多次破裂、动脉瘤位置、多发及入院时Hunt-Hess分级为PED治疗复杂性颅内动脉瘤预后的独立性影响因素。Nomograms模型预测PED治疗复杂性颅内动脉瘤预后的AUC为0.849(95%CI:0.758~0.939)。模型组与验证组预测曲线与标准曲线基本拟合。决策曲线分析结果显示,当Nomograms模型预测PED治疗复杂性颅内动脉瘤预后不良的概率阈值为0.10~0.90时,患者的净受益率大于0。结论 PED治疗复杂性颅内动脉瘤预后不良的影响因素主要有高血压病史、氯吡格雷抵抗、动脉瘤多次破裂等,Nomograms模型可预测PED治疗复杂性颅内动脉瘤预后不良风险。

Pipeline thickness estimation using the dispersion of higher-order SH guided waves

Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures.

Numerical study on local scour characteristics around submarine pipelines in the Yellow River Delta silty sandy soil under waves and currents

Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil around submarine pipelines is prone to local scour,severely affecting their operational safety.With the Yellow River Delta as the research area and based on the renormalized group(RNG)k-εturbulence model and Stokes fifth-order wave theory,this study solves the Navier-Stokes(N-S)equation using the finite difference method.The volume of fluid(VOF)method is used to describe the fluid-free surface,and a threedimensional numerical model of currents and waves-submarine pipeline-silty sandy seabed is established.The rationality of the numerical model is verified using a self-built waveflow flume.On this basis,in this study,the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed in the prototype environment are explored and the influence of the presence of pipelines on hydrodynamic features such as surrounding flow field,shear stress,and turbulence intensity is analyzed.The results indicate that(1)local scour around submarine pipelines can be divided into three stages:rapid scour,slow scour,and stable scour.The maximum scour depth occurs directly below the pipeline,and the shape of the scour pits is asymmetric.(2)As the water depth decreases and the pipeline suspension height increases,the scour becomes more intense.(3)When currents go through a pipeline,a clear stagnation point is formed in front of the pipeline,and the flow velocity is positively correlated with the depth of scour.This study can provide a valuable reference for the protection of submarine pipelines in this area.

Analysis of faulting destruction and water supply pipeline damage from the first mainshock of the February 6,2023 Türkiye earthquake doublet

In 2023,two consecutive earthquakes exceeding a magnitude of 7 occurred in Türkiye,causing severe casualties and economic losses.The damage to critical urban infrastructure and building structures,including highways,railroads,and water supply pipelines,was particularly severe in areas where these structures intersected the seismogenic fault.Critical infrastructure projects that traverse active faults are susceptible to the influence of fault movement,pulse velocity,and ground motions.In this study,we used a unique approach to analyze the acceleration records obtained from the seismic station array(9 strong ground motion stations)located along the East Anatolian Fault(the seismogenic fault of the MW7.8 mainshock of the 2023 Türkiye earthquake doublet).The acceleration records were filtered and integrated to obtain the velocity and displacement time histories.We used the results of an on-site investigation,jointly conducted by China Earthquake Administration and Türkiye’s AFAD,to analyze the distribution of PGA,PGV,and PGD recorded by the strong motion array of the East Anatolian Fault.We found that the maximum horizontal PGA in this earthquake was 3.0 g,and the maximum co-seismic surface displacement caused by the East Anatolian Fault rupture was 6.50 m.As the fault rupture propagated southwest,the velocity pulse caused by the directional effect of the rupture increased gradually,with the maximum PGA reaching 162.3 cm/s.We also discussed the seismic safety of critical infrastructure projects traversing active faults,using two case studies of water supply pipelines in Türkiye that were damaged by earthquakes.We used a three-dimensional finite element model of the PE(polyethylene)water pipeline at the Islahiye State Hospital and fault displacement observations obtained through on-site investigation to analyze pipeline failure mechanisms.We further investigated the effect of the fault-crossing angle on seismic safety of a pipeline,based on our analysis and the failure performance of the large-diameter Thames Water pipeline during the 1999 Kocaeli earthquake.The seismic method of buried pipelines crossing the fault was summarized.

Characteristics of long-distance mobile mRNAs from shoot to root in grafted plant species

Thousands of long-distance mobile mRNAs were identified from different grafting systems,based on high-throughput sequencing technology.Moreover,the long-distance delivery of RNAs was proved to involve multiple mechanisms.Here,we analyzed the homology,motif,and tRNA-like structure(TLS)of long-distance mobile mRNAs identified by RNA-seq as well as the RNA-binding protein(RBP)in nine grafting combinations including Arabidopsis thaliana,Vitis vinifera,Cucumis sativus,Citrullus lanatus,Nicotiana benthamiana,Malus domestica,Pyrus spp.,Glycine max and Phaseolus vulgaris.Although several mRNAs were found to be shared in herbaceous,woody,and related species,the vast majority of long-distance mobile mRNAs were species-specific.Four non-specific movement-related motifs were identified,while the TLS was not necessary for mRNA long distance mobility.In addition,we found that RBPs were conserved among herbaceous and woody plants as well as related species.This paper reports a further in-depth analysis of the endogenous mechanisms by which the species-specific transportable m RNAs were selected by bioinformatics,in order to provide insights for future research on long-distance mobile mRNAs.

Experimental and numerical simulation study on the erosion behavior of the elbow of gathering pipeline in shale gas field

During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUENT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%.

New insights into the deposition of natural gas hydrate on pipeline surfaces:A molecular dynamics simulation study

Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent NGH blockages.Previous studies suggested the water film can greatly increase hydrate adhesion in gas-dominant system.Herein,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion surfaces.Specifically,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film exists.As water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate deposition.While absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fe<Fe_(2)O_(3)<FeO<Fe_(3)O_(4)).This is because the detachment of deposited hydrate prefers to occur at soft region of liquid layer,the process of which becomes harder as liquid layer vanishes.As a result,contrary to gas-dominant system,the water film plays the weakening roles on hydrate adhesion in water-dominant system.Overall,our results can help to better understand the hydrate deposition mechanisms on Fe and its corrosion surfaces and suggest hydrate deposition can be adjusted by changing water affinities on pipeline surfaces.

Behavior of transporting pipeline sections without and with hydrogen exposure based on full-scale tests

Pipeline transport of hydrogen is one of today’s economic and environmental challenges.In order to find safe and reliable application of both existing gas and build new pipelines,it is essential to carry out tests on full-scale pipeline section,including the potentially more dangerous places than the main pipe,the girth welds.For the investigations,pipeline sections of P355NH steel with girth welds were prepared and exposed to pure hydrogen at twice the maximum allowable operating pressure for 41 days.Subsequently,full-scale burst tests were carried out and specimens were cut and prepared from the typical locations of the failed pipeline sections for mechanical,and macro-and microstructural investigations.The results obtained were evaluated and compared with data from previous full-scale tests on pipeline sections without hydrogen exposure.The results showed differences in the behavior of pipeline sections loaded in different ways,with different characteristics of the materials and the welded joints,both in the cases without hydrogen exposure and in the cases exposed to hydrogen.

Experimental and Finite Element Analysis of Corroded High-Pressure Pipeline Repaired by Laminated Composite

Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.