Gas Pipe Research Articles

Hidden hydrosphere under the Caspian Sea: Geophysical evidence and sea-level influence

We analyzed geologic-geophysical data, both from archives and collections in recent expeditions by the Shirshov Institute of Oceanology of Russian Academy of Sciences, and revealed many anomalies in the seismoacoustic wavefield. Anomalies are of two types: horizontal disturbed layers and vertical pipes. Anomalies form associations — pipes (chimneys) are rooted in disturbed layers and go through sediments up to the seafloor and form pockmarks. We consider all specified seismic anomalies and bottom microrelief as a possibility of vertical migration of gas and water via sediments (fluid from sediments to water and from seawater to sediments). It is expected that the fluids form a huge underground hydrosphere below the Caspian Sea. To test the fluid flow, we made a mathematical model of fluid discharge and absorption in bottom sediments. We hypothesize that the Caspian Sea level fluctuates, at least partially, due to cycles of the submarine ground water discharge and sea water absorption back into the sediments. This cyclicity of fluid discharge and absorption correlates with regional seismic events. The earthquakes cause tectonic relaxation, triggering the absorption process, and sea-level drop due to reverse flow into sediments. In other periods, the tectonic tension causes sediment compression and fluid discharge to sea water, which causes sea-level rise. The model was tested on the recent (past 100 years) sea-level change curve. As a result, we got a distribution of the general volume of fluid flows depending on the infiltration coefficient. The real change in the Caspian Sea volume is at the lower range of the calculated values, so we cannot neglect the effect of “gas pipes” (“chimneys”) on the Caspian Sea-level change.

Consequence Assessment of Hazardous Liquid Pipelines Using Gray Relational Analysis

Pipelines are the most common and economical way of transporting hazardous liquid hydrocarbons. Steel pipelines suffer different degradation mechanisms due, in part, to corrosion reactions. Failure in a hazardous liquid pipeline can result in catastrophic environmental damage as well as societal health and safety threats. There are many standard methods for performing consequence analysis of oil, gas, and petrochemical piping systems, but there is no standard procedure for calculating the consequence of a failure of a transmission pipeline. Lacking accurate formulations, the majority of pipeline consequence analysis is performed employing qualitative assessment techniques. The qualitative methods are highly dependent on the proficiency and experience of the assessment team, and suffer a lack of repeatability and reliability of the results. This study improved the efficiency of the consequence analysis during qualitative risk-based inspection analysis of liquid pipelines by utilizing gray theory. The input parameters for a practical analysis include the most essential design, operation, and commissioning parameters, which can be captured easily from project documents. The suggested gray method for consequence analysis of the pipeline minimizes the participation of the appraiser in the decision-making process, reduces variability of the analysis by reducing human error, and thus increases the reproducibility and accuracy of the results.

Challenges in delivering effective noise management at gas compressor stations

The basic principles applied in gas compressor stations to manage noise and demonstrate compliance with statutory acoustic requirements are not different from those used with most other industrial activities. Well-known and proven standard procedures involve sound emission assessment, acoustic modeling, model verification, development of a noise control concept and its optimisation until compliance can be demonstrated. However, noise control for some of the typical equipment in gas compression is extremely demanding in terms of both acoustic and operational/safety aspects so that it requires special attention. Examples are the exhausts of the gas turbines driving the compressors and the extensive network of gas piping. Because of their high and strongly varying sound emissions the exhausts pose a significant challenge in designing effective silencers. In addition, flow-generated self-noise in the silencers is a risk that needs to be avoided. For the piping sound attenuation by acoustic lagging is in conflict with corrosion and maintenance/accessibility problems and makes an optimised lagging concept an ambitious task. The present contribution illustrates typical problems encountered and possibilities to deal with them. It is based on data and experiences with gas compressor stations with very stringent acoustic requirements.

Experiment and numerical simulation of distribution law of water-based corrosion inhibitor in natural gas gathering and transportation pipeline

The transmission medium of natural gas gathering and transportation pipelines usually contains corrosive gases, which will cause serious corrosion on the inner wall of the pipelines when they coexist with water. Therefore, it is necessary to add corrosion inhibitor to form a protective film to protect the pipeline. The distribution of corrosion inhibitors in a gathering and transportation pipeline in Moxi gas field was studied by combining experiment and simulation. The Pearson function was used to calculate the experimental and simulation results, and the correlation was more than 80%, indicating a high degree of agreement. The simulation results show that: ① The larger the pipe angle, filling speed and gas flow rate, the smaller the particle size, the better the distribution of corrosion inhibitor particles in the pipe. The filling amount will affect the concentration, but the distribution trend is unchanged; ② A method to determine the filling mode based on the loss was proposed, and for this pipeline, the loss of corrosion inhibitor was determined to be 5.31 × 10−3 kg/s, and the filling amount was recommended to be adjusted to 20 L/h, which has certain guiding significance for the actual filling strategy of pipeline corrosion inhibitor.

Preventive Structural Risk Assessment of Buried Gas Pipelines in Liquefaction of Ground

Recently, a number of earthquakes have been detected in Korea and damage has been reported. Actually, ground liquefaction was reported due to the earthquake that occurred in the Pohang. In Korea, the risk of liquefaction in the event of an earthquake is relatively higher as there are many landfill areas such as Busan's coastline, Incheon, and Cheongna International City. In this study, the effect of underground structures when liquefaction occurs is evaluated by dividing it into stages of liquefaction. Moreover, detailed evaluation methods for buried gas pipelines are presented in case of regional liquefaction that can be used in all regions. For the risk assessment of liquefaction, the Standard Penetration Test (SPT) result or Cone Penetration Test (CPT) result of the borehole is used. To evaluate buried gas pipelines, Finite Element (FE) analysis is performed using the subsidence calculation method linked with the borehole data. By defining ground and gas pipe variables, structural analysis is conducted in several cases, and the desired area is evaluated based on this. A Winkler foundation spring-based optimal finite element analysis model is developed to evaluate the structural seismic performance of gas pipelines across areas where liquefaction is expected.

AN APPROACH TO TRANSMISSION AND DISTRIBUTION NETWORK CONNECTION CHARGES

The article sets out the results of elaboration and analysis of the basic features and premises for an approach to charges for connecting consumer and generator of electricity to the transmission and distribution network. The scope and significances of basic and modified versions of approaches to connection charge in the general context of electrical energy system and the electrical energy market are shown. All the aspects are illustrated from available world experience and practice as well as according to results of analogous methodological treatment applied to networked thermal energy and gas piping systems. It is the intention of the authors to draw attention to the essential features and assumptions of the different approaches to connection charges, the importance of transparency in the relations between connection charges and network use charges, and the consequences of different approaches to network users, particularly of renewable energy source generating plants.

Computational Fluid Dynamic Analysis on Carbon Fibre Reinforced Polymer Wrapped on Defected Oil and Gas Piping System Using Solidwork Flow Simulation

Utilising Carbon Fibre Reinforced Polymer (CFRP) as a wrapping structure on defected piping system is not a very new approach in maintaining the defected pipe structure. But simulating the entire approach using computational simulation technique makes this research to be unique. This composite material was regarded as a one-of-a-kind wrapping material since it might have the combined properties of the element or significantly different properties than the constituents individually. Computational Fluid Dynamic (CFD) analysis is needed to make sure that the proposed wrapping structure doesn’t disrupt the fluid flow after the repair is done. The research is keen to fully utilise Solidwork flow simulation in evaluating the capability of proposed CFRP wrapping structure without any leaks or opening. Based on simulated data, this technique provides a preliminary analysis and visual deformations in selecting the suitable optimised lamination orientation of CFRP in real-world applications. Furthermore, the flow simulation study in SolidWorks has identified areas where possible fluid accumulation could occur after the repair has been done. This approach may prevent two primary failure modes by achieving the right lamination orientation and thickness which is CFRP overloading due to excessive thickness and CFRP delamination of the composite laminate from the substrate.

Design and performance study of a proportional counter for low-energy X-rays

A cylindrical proportional counter based on a noble gas was designed to accurately measure low-energy X-ray radiation. The detection capability of the proportional counter with different gases and geometries was calculated through the Monte Carlo method. The optimal filling gas and applicable pipe diameter were determined according to the results of the Monte Carlo simulation. Then, energy calibration was performed at the monoenergetic X-ray radiation facility (MXRF) based on Bragg diffraction, and the energy calibration results were verified using the radionuclides 241Am and 129I. The relative deviation of the theoretical and measured values of the energy does not exceed 1.4%, and the energy resolution of the designed proportional counter is approximately 10%. It was proved that the linearity of the channel and energy of the proportional counter can be used for energy spectrum analysis, and the proportional counter has a good radionuclide recognition capability. Finally, the detection efficiency of the designed proportional counter was simulated and verified at multiple energy points. A detection efficiency calculation model was established through MCNP5, and the detection efficiency of the proportional counter was measured at the MXRF. The results of the experiment and simulation showed that the proportional counter could reach a highest detection efficiency of 92% in the low-energy region. The average deviation between the experiment and simulation was 1.63% at 10–34 keV and 3.90% at 34–75 keV. The proportional counter can be used for measurement and application of X-rays in the low-energy region.

Simplified Model for Concentration Analysis of Catalytic Conversion of Carbon Gas into Hydrogen

The annual energy matrix has been changing in the last years because of the necessity of less dependence on fossil fuels, which are running out on the planet. Therefore, a study was begun to simulate the most efficient production of H2 through COMSOL Multiphysics®, as it is a gas that in the future will be essential to supply the world’s energy necessities, due to it being easy to access and insert in gas pipes. From this study, we were able to present an optimization of parameters that presents good indications of how to obtain efficient hydrogen production in an idealized reactor.

Field Survey of Trunk Line Heating Gas Leaks in Commercial Broiler Houses

Highlights Producers can spend less than 30-min per house to check for trunkline leaks and should check annually or when a drastic increase in fuel usage occurs. Leaking fittings on 101 houses surveyed were not correlated with either house age or floor area and averaged 6.9% ± 0.6% per house. Leaks seemed to be more about regulator quality and installation craftsmanship with variation across farms and houses within farms. Producers should get written verification from contractors/installers that newly constructed houses are free of leaks. Rigid gas piping systems should include periodic union fittings to allow for easy repair of leaks. Abstract. A field survey was conducted on 23 farms (101 broiler houses ranging in age from new to 33 years old) in central and south Alabama to evaluate the presence of gas leaks on the high-pressure trunk line. Gas trunk lines usually run on the outside of poultry houses exposing them to temperature fluctuations that cause expansion and contraction of the rigid steel piping. Each threaded connection has the potential to leak. A soap solution in a hand sprayer was used to spray each connection and evaluate the presence of a leak through bubble formation. Leaking fittings were evaluated as percentage of total fittings to account for variation across houses. Pearson correlation matrices were used to determine correlations of house age and floor area on total number of fittings and percentage of leaking fittings. Total number of fittings ranged from 36 to 170 per house and was strongly correlated to floor area [r(99) = 0.70, p < 0.0001]. Larger floor areas require more heaters and longer piping systems. Percentage leaking fittings ranged from minimum of 0% to maximum of 32% per house and was not correlated with either house age [r(99) = 0.03, p = 0.74] or floor area [r(99) = 0.05, p = 0.65] for the houses surveyed. Leaks seemed to be more about regulator quality and installation craftsmanship with variation across farms and houses within farms. Of houses surveyed, the overall mean leaking fittings was 6.9% ± 0.6%. Poultry producers should get written verification from the gas line contractor/installer that newly constructed houses are free of leaks before operating the farm. It would be useful for poultry producers to check for leaks annually to verify system integrity and to monitor any developing leaks. Keywords: Broiler house, Gas leaks, Heating fuel, Natural gas, Propane.

Implementation of Lean Manufacturing for Improvement of Gas Pipe Product Quality with Six Sigma Approach andValue Stream Mapping in Oil and Gas

A company in the oil and gas manufacturing industry produces gas pipe products using the Polyethylene model. During the period of January to June 2020, the company experienced a defect rate of 2% in the total production. This research utilized a descriptive method to analyze the production process in order to identify and eliminate the rejected products. The objective of this study was to achieve a decrease in defects below 2%. By applying the Six Sigma (DMAIC) method and conducting calculations and analysis, an improvement proposal was developed to address the defects found during the Radiography Test. The proposed solution involves providing specialized training for workers, implementing clear procedures and methods for work, and conducting training sessions to enhance operator skills and understanding of Standard Operating Procedures (SOPs). As a result of the proposed improvements, a comparison of cycle times was conducted. Prior to the implementation of the improvements, the cycle time was 390 minutes. However, after the implementation, the cycle time reduced significantly to approximately 245 minutes. Overall, the proposed improvements aim to reduce the defect rate below 2% and optimize the production process for gas pipe products with the Polyethylene model in the oil and gas manufacturing company.

メーターガス栓および灯外内管・供給管への挿通・撤収が可能な空気圧駆動型ガス管内移動ロボットの開発

To observe the inside of gas pipes, we have been developing a pneumatically driven inspection robot that can locomote in service line including bended areas. In this paper, the robot accomplished insertion from a meter gas cock and shortage of the transmit time. To enable it to insert from a meter gas cock, the diameter of the robot is decreased to 12 [mm]. Furthermore, to shorten the transit time, we developed a way to increase the airflow rate of the robot by applying a wider tube stored in a helical shape inside the body. Finally, the robot could insert from the meter gas cock throughout a 7[m] service line within 81[min].

Environmental stress cracking of chemically aged HDPE-100 gas pipe under impact fracture mode

Environmental stress cracking of chemically aged HDPE-100 gas pipe under impact fracture mode

Degradation and characterization methods for polyethylene gas pipes after natural and accelerated aging

How to solve the divergence between natural and accelerated aging behavior is the core for the lifetime prediction of polymeric materials, so special attention should be paid to the degradation mechanism and fitness of engineering-based characterization methods of materials in various conditions. In this paper, the degradation of polyethylene (PE) pipes was evaluated by accelerated tests with exposure time up to 10,000 h. Meanwhile, the aging behavior was also evaluated for PE pipes in operation after a long-term service. To characterize the effect of thermo-oxidative aging on PE pipes, commonly used methods were performed such as tensile testing, scanning electron microscopy, differential scanning calorimetry, infrared spectroscopy, as well as a new method- nanoindentation. The results reveal that the degradation of polyethylene PE pipes under oxidative conditions possesses time-dependent properties and spatially heterogeneous oxidation profiles. Due to diffusion-limited oxidation, PE pipes shows more distinct heterogeneous oxidation process in high temperature than that in service condition. In addition, indentation depth is a useful parameter to characterize the long-term aging in samples, especial the heterogeneity. Moreover, the result also elucidates that thermal oxidation stability of PE100 high density polyethylene (HDPE) gas pipes is greater than that of PE80 medium density polyethylene (MDPE) gas pipes. Furthermore, the current engineering-based prediction of PE pipe failure or lifetime lacks consideration of diffusion-limited oxidation and in-depth discussion of degradation mechanism, which indicates it is too early to estimate the lifetime or the remaining lifetime of the PE pipes in operation.

Welding arc energy characteristic regulation

When welding pipes, due to the concentration of magnetic field lines in a ferromagnetic pipe with high magnetic permeability, the welding current magnetic field increases, magnetic blow, under. by the action of electromagnetic force, the arc length increases up to a break, the current and voltage on the arc fluctuate significantly, the seam dimensions change from a point to a large width, the process stability is disturbed, the welds formation and the welded joints impact toughness is reduced. Based on the study of the arc energy characteristics, according to which the voltage on the arc increases with increasing arc length, it was found that the arc moves along the tape end at a speed of 3.3 m/s, the electrode shape affects the welding arc. energy and voltage characteristics. In this case, the sum of near-electrode voltage drops depends on the work function of electrons from the cathode surface of the flux components and does not depend on the electrode shape, which confirms the main role of field emission in the arc and the arc concentration below. pinch-effect. To increase the welded joints impact toughness, it is necessary to reduce energy, heat input, crystal lattice microdistortions, microstresses, dislocation density, welding stresses, reduce the weld width, heat-affected zone, the deposited metal amount and refine the microstructure. An effective way to reduce energy is to increase the welding speed, which reduces the heat input, and reduce the arc length, arc voltage, which leads to an increase in the arc rotation speed, pinch effect, arc concentration and energy, heat input efficiency, reduce welding stresses, increase the crystallization rate, the microstructure refinement, the interatomic distance reduction and interatomic bonds increase. A process for one-sided high-speed welding of pipes for gas and oil pipelines with a low-energy composite electrode, which, due to low arc voltage, arc concentration, stability, energy reduction, heat input, welding stresses, microstructure refinement, interatomic distance reduction and interatomic bonds increase, provides an increase in the welded joints impact toughness 2-2.5 times has been developed. Minimum energy – maximum welded joints impact toughness

A study of CO2 two-phase flow in a near horizontal pipe

In this article, the observations from two different experimental studies on CO2 two-phase flow regimes in a near horizontal pipe are analysed. These experiments show significant bubble entrainment in a stratified flow, and the bubble entrainment in liquid is found to be a dominant mechanism for the flow regime transition between the stratified and bubbly flow. The hydrodynamic slug flow is not observed in these experimental studies. The X-ray measurement of the experimental study in a near horizontal pipe of 44 mm internal diameter is processed to obtain the bubble volume fraction in the liquid layer, which is found to be a function of two-phase Froude number. This Froude number definition takes into account gas density and pipe inclination effects. A parametric study shows that the bubble entrainment into the liquid layer decreases significantly with an increase of pipe internal diameter.

Modeling of heat transfer and Hydraulic Resistance of an intensified Turbu-lent flow of liquid or gas in pipes with annular Turbulators

Modeling of heat transfer and Hydraulic Resistance of an intensified Turbu-lent flow of liquid or gas in pipes with annular Turbulators

The Issue of Poland’s Dependence on Natural Gas Supplies from the Russian Federation in the Political Thought of Piotr Naimski: Selected Problems

The topic of the research was the political thought of Piotr Naimski in the field of reducing Poland’s dependence on natural gas supplies from the Russian Federation. The aim of the article was therefore to analyse Naimski’s views on the diversification of the sources and directions of natural gas supplies to Poland and to define the political concepts formulated by this politician. The article indicates Naimski’s views on increasing Poland’s energy security by realizing energy projects such as LNG terminal, Baltic Pipe gas pipeline, as well as activities aimed at counteracting the Russian Federation energy policy in Central Europe. Naimski was one of the staunchest opponents of the construction of Russian-German gas pipelines (Nord Stream and Nord Stream 2).

Structural Optimization of a Circular Symmetric Threaded Connection System Based on the Effect of the Upper Stabbing Flank Corner Radius

In order to boost shale gas drilling efficiency, oil and gas exploration and drilling distances have risen along with the number of horizontal definitions and directions. As a result, the joints of oil wells and core gas pipes are under continual stress and compression, internal and external pressures, and extreme bending stresses. This will negatively impact the drilling system’s sustainability and the performance requirements are therefore reinforced. Good thread design is crucial because premium threaded connections are typically employed in joints, and the construction of reliable premium connections to external limitations is closely related to the choice of pertinent parameters as optimal values. In this article, new premium connection systems will be created and constructed that can show good vibration and durability under such stressful conditions. The amount of von Mises stress that is received from the threaded connection depends on how each parameter is changed. In particular, the values of the “upper stabbing flank corner radius” were used to examine the von Mises stress variations in the entire structure. An optimized design for the premium connection system is proposed with the best value of upper stabbing flank corner radius according to minimized stress on the teeth of the premium connection against compressive forces. The study’s findings suggest that it is feasible to create a premium connection that can lower stress following the genuine demand of the industry.

A liquid loading prediction method of gas pipeline based on machine learning

The liquid loading is one of the most frequently encountered phenomena in the transportation of gas pipeline, reducing the transmission efficiency and threatening the flow assurance. However, most of the traditional mechanism models are semi-empirical models, and have to be resolved under different working conditions with complex calculation process. The development of big data technology and artificial intelligence provides the possibility to establish data-driven models. This paper aims to establish a liquid loading prediction model for natural gas pipeline with high generalization ability based on machine learning. First, according to the characteristics of actual gas pipeline, a variety of reasonable combinations of working conditions such as different gas velocity, pipe diameters, water contents and outlet pressures were set, and multiple undulating pipeline topography with different elevation differences was established. Then a large number of simulations were performed by simulator OLGA to obtain the data required for machine learning. After data preprocessing, six supervised learning algorithms, including support vector machine (SVM), decision tree (DT), random forest (RF), artificial neural network (ANN), plain Bayesian classification (NBC), and K nearest neighbor algorithm (KNN), were compared to evaluate the performance of liquid loading prediction. Finally, the RF and KNN with better performance were selected for parameter tuning and then used to the actual pipeline for liquid loading location prediction. Compared with OLGA simulation, the established data-driven model not only improves calculation efficiency and reduces workload, but also can provide technical support for gas pipeline flow assurance.