Above-ground Pipeline Research Articles

Pipeline incidents and property values

The rapid expansion of pipelines during the U.S. shale oil and gas boom drew attention to the economic consequences of pipeline incidents. This study investigates the impacts of 426 gas distribution pipeline incidents on property values in the United States between 2010 and 2020. We find that only incidents that are both severe (involving explosion, ignition, or fatalities) and occurred on above-ground pipelines, which we define as high-profile incidents, have adverse effects on nearby property values, while other incidents have no measurable housing price effect. A difference-in-differences analysis finds that high-profile incidents significantly decrease property values within 1000 m by 8.2%, and the negative impact can persist for about eight years on average. Furthermore, we find a drop in transaction volume that lasts a short period after the incidents, suggesting an initial demand-side response. In contrast to the strong effects of pipeline incidents, we do not find statistically significant price effects from pipeline installation. We also demonstrate that there is substantial heterogeneity by the type of incident and that results based on studies of individual incidents should be generalized with caution.

Performance study of a compressed air energy storage system incorporating abandoned oil wells as air storage tank

With the rapid development of intermittent renewable energy, large-scale compressed air energy storage technology represented by Adiabatic Compressed Air Energy Storage (A-CAES) has attracted much attention. In order to simultaneously solve the problems of reuse of decommissioned oil wells and low efficiency of A-CAES system, a compressed air energy storage system incorporating abandoned oil wells as Air Storage Tank (AST) is proposed in this paper. The system performance of underground Oil Well CAES (OW-CAES), aboveground Steel Pipeline CAES (SP-CAES), and aboveground Storage Tank CAES (ST-CAES) is comparatively analyzed based on a thermodynamic model, focusing on the impact of heat transfer characteristic parameters of the AST wall on the system performance. The results show that recoverable heat and round-trip efficiency are significantly affected by the heat transfer characteristics of the AST wall. More recoverable heat and higher round-trip efficiency can be achieved by increasing the wall temperature and the surface area of the AST, respectively. The round-trip efficiency and energy storage density of the OW-CAES system are higher than those of the ST-CAES system, which are increased by 8.3 % and 18.45 % respectively. This study provides theoretical support for the feasibility of the OW-CAES system and has certain engineering guiding significance.

Effects of Fatigue Parameters on Fatigue Crack Growth Rate of Pipe Steels and Girth Weld

Abstract Oil and gas pipeline steels and welds are subjected to a wide variety of cyclic loadings: internal pressure variation, pulsation of gas pressure resulting from the cyclic operation of a reciprocating compressor at a gas compressor station, internal flow-induced vibration resulting from the turbulent flow within the pipe, vortex-induced vibration of a free-spanning section exposed to air (wind) for aboveground pipelines or water for water-crossing pipelines, and cyclic thermal stresses developed by significant changes in temperature due to seasonal changes or changes in operating temperatures. These cyclic loadings are very variable and complex. Considering the fatigue situations, a better understanding of the effects of fatigue test parameters on fatigue behaviors of pipeline steels and welds is required. Hence, in this study, the influences of fatigue test parameters on the Paris law coefficients were studied for pipeline steels and welds. It was analyzed for pipe steels of X65∼X100 and a girth weld of X70. Influences of material strength, crack orientation relative to the pipe axis, and frequency in the range of 1∼30 Hz were insignificant. It was found that the coefficients a1 and b2 of the m-ln(C) relationships linearly relied on the load ratio. The constants (α1, β1, α2, and β2) of these linear relationships between R-ratio and a1 (and b2) were determined for pipe steels.

Расчет времени охлаждения надземного водовода с теплоизоляцией в условиях отрицательных температур

Objective: transport infrastructure facilities include a variety of water supply systems. In the event of an emergency, after stopping the movement of water in the pipeline, it is cooled first, and then there is a risk of freezing and destruction of water pipelines. This work is devoted to the calculation of the cooling time of water in the above-ground water conduit with thermal insulation from the specified temperature value in the initial state to the freezing temperature. Methods: when building a mathematical model of the water cooling process, an approach is used based on averaging the equations of hydrodynamics by the volume of water in the pipeline and averaging the equations of thermal conductivity in the wall of the pipeline and in the layer of the heat insulator by the polar angle. To obtain a quasi-stationary form of equations, a comparative analysis of the rates of thermal processes in different layers of the water conduit is used. Results: a new mathematical model for cooling the water pipeline is formulated — a model of average temperatures. The applicability of the quasi-stationary form of the equations of the model is justified and its analytical solution is found. Explicit formulas are obtained for cooling time of water conduit as a function of its parameters. Cooling time was calculated in a wide range of parameters. The results of model calculations are compared with calculations according to traditional semi-empirical formulas. Practical importance: the formulas obtained in the work can be used to estimate the cooling time of water in an above-ground water pipeline with heat insulation to the freezing temperature in the case when the ambient temperature drops to negative values.

Rotating permanent magnet antenna array for directional communication in pipeline monitoring system

As a novel pipeline monitoring technology, wireless sensor networks (WSN) have the advantages of low power consumption, flexibility, and robustness in aboveground, underground, and underwater pipeline monitoring systems. Using low-frequency (LF) rotating permanent magnet antennas (RPMA) for communications from sensor nodes (SN) to autonomous unmanned vehicles (AUV) has the advantages of low attenuation, low latency, and portable size. However, the communication ranges of different SNs may overlap and information from different SNs should be distinguished. Methods like time-division multiplexing (TDM) and frequency-division multiplexing (FDM) are not suitable in this case. Another way is to form RPMAs into an array so that directional communications from SNs to AUVs can be realized and there is no overlap between SNs. Therefore, this work analyzes and enhances the directivity of linear RPMA arrays in the near-field region. Based on the designed RPMA array prototype, the directional communication is realized at a distance of 5 m across concrete walls. This work paves the way for directional communications from SNs to AUVs in underground pipeline monitoring systems.

Simulation of cooling of aboveground water pipeline with heat insulation

Aboveground water pipelines are often more preferred in the organization of water supply systems in permafrost and low ambient temperatures conditions. If the water movement in such pipeline stops, there is a risk of cooling and subsequent freezing of the liquid. The purpose of this work is to study the dynamics of the cooling process of an aboveground water pipeline with heat insulation and to calculate the cooling time of water to the freezing temperature. To build a mathematical model of the cooling process, the method of averaging the equations of hydrodynamics and thermal conductivity is used. The model equations do not contain any assumptions about the nature of the water movement in the pipeline during the cooling process. The possibility of using the equations of the model in a quasi-stationary form is justified. The range of task parameter values at which this approximation applies is determined. The possibilities of applying different boundary conditions on the surface of the water pipeline are also considered. In the quasi-stationary approximation, a dependence on the time of the average water temperature in the pipeline was found. An explicit formula is also obtained for calculating the cooling time of water to the freezing temperature. The criteria for the applicability of the obtained formulas have been established. For a wide range of parameters, water cooling time is calculated from the specified initial temperature to the freezing temperature. Ranges of values of parameters at which increase of thickness of heat insulator layer and increase of initial water temperature lead to significant increase of water cooling time in pipeline are determined.

Determination of deflections of above-ground pipelines under loads in the longitudinal and transverse directions

The most common method of construction of field pipelines in permafrost-dominated areas is above-ground laying on supports. The size of the span between bearings is determined taking into account the condition of tuning out resonance frequencies in case of vortex excitation due to wind load. For these purposes it is necessary to determine the natural frequencies of vibrations of above-ground pipeline sections. When determining the natural frequencies of pipeline sections, it is necessary to take into account the initial position caused by additional loads in longitudinal and transverse directions (pre-stressed state of pipeline sections). A differential equation for determining the position of a pipeline section under stationary loads in longitudinal and transverse directions based on the rod theory is obtained. The numerical solution of the equation is obtained using the finite difference method. The influence of longitudinal and lateral forces is evaluated. It is shown that the influence of longitudinal and lateral loads has a significant effect on the initial position of pipeline sections. Therefore, the complex influence of loads should be taken into account for the correct determination of deflections. The initial position of the pipeline under the action of various combinations of loads can be used to evaluate the preliminary stress-strain state in the design of above-ground pipelines.

Effect of Solar Radiation and Soil Temperature on the Flow Characteristics in Above Ground and Underground Petroleum Pipelines

In this proposed study, all environmental factors affecting the aboveground and buried pipes, such as solar radiation and temperature, and soil temperature, have been studied on the characteristics of flow inside the aboveground and underground pipelines by building a mathematical model using MATLAB based on energy balance equations. From the mathematical model, the effect of solar radiation on the aboveground section of the pipeline is significate. During March and an inlet temperature of 34 °C, the pipeline outlet fluid temperature will rise to 50 °C. Other parameters affecting the aboveground section of the pipeline, such as ambient temperature and wind speed, have a much smaller effect on the fluid temperature, and the temperature difference is approximately 4 °C between the highest and lowest pipeline outlet fluid temperature. The result for the underground section of the pipeline showed that the main affecting parameter on the fluid temperature is the burry depth of the pipeline, the deeper the pipeline depth the lower the temperature variation and the lower fluid temperature can be seen, at 1 meter of bury depth the minimum and maximum fluid temperature was 18 °C and 36 °C respectively, and at 5 meters of bury depth, the minimum and maximum fluid temperature was 26 °C and 31 °C respectively. This study also checks different process parameters. Some of these are fluid flow, pipe diameter, and pipe material. The effect of the fluid flow and pipe diameter has a similar impact on the fluid temperature (while fixing all the other parameters), the higher the fluid flow or the smaller the pipe diameter resulted in a better heat transfer and more considerable temperature difference, and vice versa. The final process parameter, pipe material, had little to no effect on the fluid temperature variation.

ALGORITHM FOR DETERMINING THE VOLUME OF NATURAL GAS LOSSES UNDER CONDITIONS OF MEASURING ITS PARAMETERS AT THE GAS PIPELINE OUTLET

Gas pipeline networks are complex distributed systems consisting of hundreds of kilometers of pipelines of various configurations. Equipping all sections of the gas pipelines with gas accounting and gas parameter metering devices that would allow for the quick detection of pipeline damages and the determination of gas loss volumes requires significant funds. As a result, many transportation and distribution pipelines are not equipped with metering devices. Therefore, it is important to develop algorithms that can estimate the volume of gas losses based on information from existing metering units without the reconstruction of gas networks.The paper proposes an improved mathematical model for the stationary flow of natural gas in pipelines which considers the flow velocity changes along the pipeline. This model is supplemented with an equation for calculating the flowrate of gas flowing into the atmosphere through a hole in the damaged above-ground gas pipeline. The authors have developed an equation to determine the discharge coefficient for a pressure range in the pipeline from 0.1 to 1.2 MPa with a methodological error of no more than 1.7%. Based on the obtained mathematical models, an algorithm has been developed to calculate the gas volume lost because of damage for pipeline configurations with gas parameter metering units at the pipeline outlet. The developed algorithm has been validated, and an example of its application for analyzing the distributions of gas pressure and temperature in a pipeline with existing damage is presented. The paper presents the simulation results for gas leakage through pipeline damage and the iterative determination of gas parameters at the damage point, as well as the results of calculating the gas flowrate through the damage.The application of the developed algorithm allows for increased accuracy in determining the volume of gas losses through pipeline damage. Its hardware implementation in the future will reduce the time for damage detection, localization, and elimination.

Analytical Examination of Deformational Dynamics in Above-Ground Pipelines Compromised by Corrosion Under the Influence of Internal Pressurization

Abstract Corrosion is a major factor responsible for failures and leaks in gas pipelines. In the context of external corrosion, the internal pressure within pipes can create stress and strain concentrations in the area affected by corrosion. These phenomena, combined with the presence of cavities or cracks resulting from the corrosion process, amplify the risk of pipeline failure. As corrosion reduces the wall thickness of the pipe, its ability to withstand internal pressures decreases significantly. Consequently, a pipe affected by corrosion may collapse at a much lower pressure compared to a pipe that has not been subjected to corrosion. With a view to analyse and anticipate the behaviour of corroded pipes, finite element modelling is used, implemented through the Abaqus software. This tool allows for simulating the mechanical effects of internal pressure on the gas pipeline structure, thereby providing the ability to predict the pipeline's behaviour under various pressure conditions. This approach aids in identifying and assessing risks associated with corrosion, facilitating the implementation of suitable preventive and maintenance measures to ensure the integrity and functionality of gas pipelines.

Анализ процессов теплообмена на поверхности надземного трубопровода с теплоизоляцией

Purpose: Transport infrastructure facilities include a variety of water supply systems. In the conditions of negative ambient temperatures, there is a risk of freezing and destruction of water pipelines. In mathematical modeling of the operation of aboveground pipelines, the correct description of the heat exchange process between the outer wall of the pipeline and the surrounding atmosphere is of great importance. The boundary condition corresponding to this process traditionally includes a heat transfer coefficient depending on a number of unpredictable parameters (wind speed and direction, atmospheric pressure, air humidity). The purpose of this work is to carry out a comparative analysis of the role of free and forced convective heat exchange and to justify the possibility of setting a boundary condition that depends only on the outside air temperature. Methods: To solve this problem, the work uses numerical analysis of similarity criteria for the heat exchange process under conditions typical for the operation of an above-ground pipeline with thermal insulation. The justification of the boundary condition on the external surface of the pipeline is based on the law of energy conservation. Results: The values of the parameters of the problem are determined, in which free or forced convective heat exchange prevails. It has been shown that forced convection prevails in conditions typical for the operation of above-ground water pipelines. Under these conditions, the difference between the temperature of the external surface of the insulated pipeline and the surrounding atmosphere is small. It has been shown that in this case, it is advisable to use the equality of atmospheric air temperatures and pipeline surface temperatures as a boundary condition. Practical significance: Understanding the mechanisms of heat exchange makes it possible to create an adequate model of the operation of pipelines in conditions of negative temperatures. Setting a more accurate and simple boundary condition on the surface of the pipeline simplifies the task of mathematical modeling. The results obtained in this article can be used in mathematical modeling of any pipelines with thermal insulation.

A homogeneous sampling membrane inlet photoelectron ionization miniature time-of-flight mass spectrometer for on-line determination of ethane

Ethane is the second largest component among natural gas, and the detection of ethane is an effective method for rapid identification of the leakage of the natural gas pipelines. In this work, a homogeneous sampling membrane inlet was developed and coupled with the homemade photoelectron ionization miniature time-of-flight mass spectrometer (PEI-mini-TOFMS) for in situ, on-line and highly sensitive ethane detection. The membrane area of the homogeneous sampling membrane inlet was increased from 490 mm2 to 1256 mm2, gaseous sample is injected from the top port and flowed through the membrane surface and out of the bottom two ports, with the three ports arranged in a triangular shape. The highest average flow velocity of the gas on the surface of the membrane reached 0.4 m s−1, and the optimal gas pressure in the PEI source was enhanced from 2.2 Pa to 4.0 Pa with this new design. The new design improved the comprehensive sensitivity of ethane by a factor of 3.0 compared with that of the traditional two-hole membrane inlet with the membrane area of 490 mm2. The semiconductor cold trap controlled the sample relative humidity (RH) at 10–12%, enabling direct sampling for highly sensitive analysis with RH as high as 70% and temperature from 7 °C to 40 °C. The quantitative range was 1–50 ppmv with a limit of detection (LOD, S/N = 3) lowered to 420 ppbv within 1 min, and zero humidity quantitative calibration with cold trap further reduced the relative standard deviation (RSD) of the signal intensities to 2.84%. The performance of the novel method developed in this work demonstrated a potential application on the above-ground natural gas pipelines leakage monitoring.

Efficient qualitative risk assessment of pipelines using relative risk score based on machine learning

Pipelines are observed one of the economic modes of transport for transporting oil, gas, and water between various locations. Most of the countries in the world transport petroleum and other flammable products through underground pipelines. The underground and aboveground pipelines are facing various damages due to corrosion, dents, and ruptures due to the environment and operational fluid conditions. The danger of leaks and accidents increases as a result of these damages. Pipelines must be evaluated on a regular basis to make sure they are fit for transmission. By evaluating the effects of damages and the possibility of catastrophic failures using a variety of techniques, pipeline integrity is controlled. Applying the relative risk scoring (RRS) technique, pipeline failures are predicted. One of the probabilistic techniques used to forecast risk based on an impartial assessment is machine learning. With different parameters like corrosion, leakage, materials, atmosphere, surface, earth-movements, above-ground and underground facilities, etc., the RRS method provides an accuracy of 97.5% in identifying the risk and gives a precise classification of risk, whether the pipeline has a high, medium, or low risk without any delay on the prediction compared with Naive Bayes, decision tree, support vector machine, and graph convolutional network.

Determination of the natural frequencies of the above-ground sections of pipelines transporting an incompressible fluid

Under certain conditions, above-ground sections of pipelines are subject to vibration. Increasing the vibration amplitudes beyond the limits can cause the object to fail. In order to assess the vibration resistance of pipelines and to find the most effective ways of detuning from the resonant frequencies of disturbances, it is necessary to determine the natural frequencies of oscillations and the characteristics of the oscillation processes. The authors of the article developed a mathematical model to determine the frequency of free vibrations of above-ground pipeline sections, taking into account the influence of internal pressure and the velocity of the pumped fluid. As a result, a numerical solution based on the Bubnov-Galerkin method was obtained and a sufficient number of series elements in the approximate solution was determined. The authors performed numerical experiments. These showed that the frequencies should be determined for each section under specific conditions according to the pumping mode.

Transient induced voltages on aboveground pipelines parallel to overhead transmission lines

Lightning strikes to conductors of overhead lines may cause high transient induced voltages at neighbouring pipelines. Thus, the computation of these voltages is important for the safe and reliable pipeline operation. This work investigates the effects of line parameters and soil modelling on the transient voltages induced at an aboveground pipeline due to lightning strikes to a phase conductor of a nearby overhead transmission line. Three different earth formulations are evaluated: the Carson, Wise, and the method of moments with surface operator combined with the extended transmission line approaches. Computations are performed using both frequency- and time-domain models, as well as constant and frequency-dependent soil electrical properties. CIGRE lightning current waveforms are employed in simulations derived on the basis of the statistical distributions of their parameters for negative first return-strokes. Transient induced voltage waveforms differ among the evaluated lightning currents, with higher peak values for shorter and steeper current wavefronts. Conservative results are obtained for the constant soil properties and Carson’s earth formulations, which neglect, respectively, the dispersion of soil electrical properties and displacement current.

Influence of Aboveground Pipeline and Associated Factors on Movement of Winter-Active Boreal Mammals in the Alberta In-Situ Oil Sands

Aboveground pipelines (AGP) associated with in-situ oil sands may restrict mammal movement, potentially increasing extinction probability and decreasing reproductive success. Our 12-year study used winter track count techniques to assess the response of winter-active mammals to AGP in northern Alberta, Canada. The primary questions were: which species were most prone to movement obstruction by AGP, facilities or natural factor(s)?; and which factor exerted the strongest influence on crossing likelihood? A total of 2,068 trails of 12 different species were observed. All species crossed more than half of the time. Focal species crossed on average 80% of the time. Crossing likelihood of white-tailed deer (Odocoileus virginianus), ermine (Mustela erminea), coyote (Canis latrans), lynx (Lynx canadensis), and fisher (Martes pennanti) were significantly influenced by predictors including pipeline height, pipeline corridor width, infrastructure age, vegetation type, and proximity to infrastructure. Deer and lynx crossing likelihood was positively affected by pipe height. Deer, coyote, and ermine crossing likelihood was positively affected by age of pipe. Fisher and deer crossing likelihood was negatively affected by pipeline corridor widths. Our investigations show that most species cross AGP with high crossing frequencies of pipe heights, ranging from 130 cm to 160 cm. These findings are important for impact mitigation because of the scarcity of published studies of wildlife movement responses to AGP, our inclusion of small and mid-sized carnivores, and our investigation of multiple factors. We highlight mitigation and design improvements, effects of pipeline corridor widths, and challenges posed by coupling infrastructure with pipelines, serving to reduce movement barriers and fragmentation.

Methodology for assessing pipeline failure probability due to a debris flow in the near field

Aboveground transmission oil pipelines can cross debris flow-prone areas. Currently, there are no available methodologies to assess pipeline failure status with the different pipeline arrangements (location, direction, and segment lengths) and different operating conditions. For solving the research gap, this study proposes a novel methodology to simulate the cascade processes of debris flow propagation, the impact of debris flow on pipelines, and pipeline failure. With consideration of different pipeline arrangement and operating conditions. We introduce the polar coordinate system to set up locations and directions scenarios for the first time. Also, we use the 3-D debris flow simulation model (DebrisInterMixing solver in OpenFOAM) coupled with a modified pipeline mechanical model considering operating conditions for the first time. The proposed methodology shows the different trends of pipeline failure probability with the increase of pipeline segment length for the different pipeline locations and directions. The result shows, for the pipelines of 30° the tensile stress has a more moderate increase rate with the increase of pipeline segment length, and the pipeline failure probability keeps 0 at the 5-m location. At 5 m and 15 m locations, the failure probabilities of the pipelines of 60° and 90° start to increase when the segment length is 13–14 m, while for other pipelines the segment length is 17–19 m. The findings of this study can support the decisions of government authorities, stakeholders, and operators for risk assessment, prioritization of hazard mitigation measures and emergency planning, or concerning decisions regarding pipeline siting during the design, routing, construction, operation, and maintenance stage.

Building an algorithm for calculation of distances between overground gas pipeline supports of different diameters depending on climatic characteristics

The use of averaged norms in the process of performing engineering calculations of gas distribution systems significantly reduces the design time, but does not take into account the influence of climatic operating conditions of linear sections of the aboveground gas network. The paper considers the possibility of using a tabular model of the algorithm for determining the distances between the supports of aboveground gas pipelines of various diameters depending on climatic characteristics on the example of the Samara region. Examples of visualization of the information structure of computational algorithms by means of spreadsheets are given. A block diagram of an algorithm for calculating the values of average spans between aboveground gas pipeline supports for various climatic conditions is proposed. The advantages of using the proposed tabular modeling technique in engineering calculations of gas distribution systems are shown.

Study of the Effect of Cutting Frozen Soils on the Supports of Above-Ground Trunk Pipelines

The transportation of oil and gas in Russia’s northern and Arctic regions has seen significant growth in recent years. However, the presence of permafrost in these areas can cause malfunctions in the main pipelines due to soil frost heaving. The operational pipelines also often suffer from various defects in their body and surface. To mitigate these issues, above-ground trunkline supports are utilized to protect the pipelines from cryogenic processes. Nevertheless, these supports are subjected to ground loads caused by cryogenic frost heaving, which poses a threat to the pipeline’s integrity and the environment. In response to these challenges, this study presents a design for pipeline support to maintain the pipeline’s stability in the face of soil displacement caused by unequal frost-heaving forces. A numerical model was created to evaluate the fracture of frozen rock and the resulting stresses in the soil and support structure. The input data for the model includes coefficients that describe the soil’s state during the cryogenic process and the proposed support’s parameters. The experimental results showed the proposed design to be effective in protecting the pipeline from soil frost heaving. The paper also provides the results of numerical and experimental studies on soil fracture stresses depending on the rock type and temperature. This design promises to increase both the safety of above-ground trunk pipelines and their technological efficiency.

Influence of Lossy Ground on High-Frequency Induced Voltages on Aboveground Pipelines by Nearby Overhead Transmission Lines

The electromagnetic interference (EMI) of overhead transmission lines (OHLs) to aboveground pipelines sharing the same right-of-ways has been a research topic for many years. Most studies focus on investigations of the induced currents and voltages at the mains frequency (50/60 Hz). However, significant voltage levels can also be induced, when the pipeline is subject to high-frequency excitation. The representation of earth conduction effects is very important to estimate accurately the level of the EMI. This article presents a detailed high-frequency analysis of OHL/pipeline configurations taking into consideration the frequency-dependent (FD) soil properties. Wise's earth formulation is adopted for the calculation of the earth return impedances and shunt admittances. Propagation characteristics, frequency-domain, and transient responses are calculated by using both the FD soil models and constant soil properties, as well as the classical transmission line approach of Carson. Frequency-domain responses calculated with Wise's formulation are compared against those obtained using the MoM-SO method of EMTP software.