Figure - available from: Mathematical Problems in Engineering
This content is subject to copyright. Terms and conditions apply.
Source publication
Pigging is a common operation in the oil and gas industry. Because of the compressibility of the gas, starting up a pipeline inspection gauge (pig) from a stoppage can generate a very high speed of the pig, which is dangerous to the pipe and the pig itself. Understanding the maximum speed a pig achieves in the restarting process would contribute to...
Similar publications
This work involved experimental investigation for impressed current cathodic protection. The work involve site reading for the soil resistivity and potential difference between pipe and soil in four sites (AL-Zubair1, AL-dawajin, Sport city and Hamdan) along oil exporting pipeline in Basra /Iraq. Simulated cathodic system has been installed in Labo...
![Corrosion defects in Pipeline B [254 mm (10 in.) liner]](profile/Imad-Barsoum/publication/333043310/figure/tbl1/AS:927831961923585@1598223786093/Corrosion-defects-in-Pipeline-B-254-mm-10-in-liner_Q320.jpg)
Internal corrosion in carbon steel pipelines is a serious challenge in the oil and gas industry. Conventional rehabilitation techniques used to stop corrosion losses and prolong the life of pipelines use an internal lining system to isolate the corrosive medium from the inner surface of the host pipe. A recent lining technology based on an aramid-r...
Detection bands of the laser fluorosensor to detect oil pipeline leaks have been studied at the fluorescence excitation wavelength 355 nm. It is shown that a diversity of the fluorescence spectra of different oils and plant species leads to the need to adapt the number and position of spectral detection bands of the laser fluorosensor for the speci...
Gas pipelines are an integral part of each stage across several industries, including steel, oil, chemical, and pharmaceutics. Deposit of sediments causes blockages in pipelines, which leads to abrupt failure and functional impairment. Failure of gas pipelines due to blockages is a serious threat as it is catastrophic in terms of safety and economi...
Specimens of pipe steel of increased strength grade type K56-K60, with different values of impact toughness (KCV) were investigated: a metallographic examination of the specimens’ structure was carried out by optical and electron scanning microscopy methods. The interrelation of the microstructure with mechanical properties, in particular with impa...
Citations
... Then the differential equation of the PIG's motion was solved to obtain the speed and position of the PIG in the pipeline. He et al. [6] carried out the restart process of the PIG stuck in the gas pipeline and used the response surface method to calculate the maximum speed of the PIG after it was started. It was found that the maximum running speed of the PIG was related to the internal pressure and the change value of unblocking, and the calculation method of the maximum speed of the PIG unblocking and starting was obtained. ...
... A literature survey [18][19][20] shows that very few papers deal with the design and simulation of passive speed control systems for wheel suspension assembly-based next-generation pipe health monitoring robots. Numerical simulation of bypass speed control system designed for sealing cups or disc-based design of conventional PIG has been discussed in detail by various authors in an open literature. ...
... 28,29 The Runge-Kutta method is used to solve the dynamic equation of the in-pipe inspection robot. 30,31 The°uid continuity and momentum equations are solved in a vector form, which can be formulated as ...
A fluid drive in-pipe inspection robot is an essential device for the inner inspection of long-distance oil and gas pipelines. Obstacles such as dents and welds can significantly affect the operation stability of the robot as well as the accuracy of inspection. In this paper, a dynamic model is created to investigate the vibrational response of an in-pipe inspection robot moving through a dented pipe. A mechanical model of the polyurethane sealing disc is established based on the Kelvin spring damping model to simulate its bending deformation. Using the simplified model of the in-pipe inspection robot, the axial vibration equation of the robot is analyzed in detail. Furthermore, a dynamic simulation of the virtual prototype of the in-pipe inspection robot is conducted using the MSC/ADAMS software, considering the interaction between the fluid and the structure. Then, the effects of the robot’s speed, sealing disc interval, and dent height on the vibration response during the pigging are examined. The results indicate that the faster the in-pipe inspection robot passes over the pipe dents, the higher the axial vibration generated by the robot, while the time needed for returning to the stable state is shorter. The pitch vibration caused by the dent substantially intensifies with an increase in the sealing disc interval. The axial and pitch vibration caused by the dent intensify significantly with increasing the dent height. The results obtained herein should prove useful to the optimization of the structural design and precise positioning of the in-pipe inspection robot.
... For modeling pig dynamics in natural gas pipelines, the method of characteristics (MOC) has been proposed for solving the transient gas flow equations, and the Runge-Kuta method has been proposed for the dynamic equations of PIGs (Nguten et al., 2001a(Nguten et al., , 2001b. Based on their proposed MOC model, additional numerical studies related to pigging simulations have been performed (Zhang and Zhou, 2020;He and Liang, 2019a;He and Liang, 2019b;Esmaeilzadeh et al., 2009;Botros and Golshan, 2010). In addition, various numerical models for pigging simulations have been developed. ...
... In most of the existing pigging simulation studies, the friction was assumed to be constant, and the previous studies did not focus on speed excursion due to friction variation (Mirshamsi and Rafeeyan, 2015;Kim and Seo, 2020;Esmaeilzadeh et al., 2009;Zhang and Zhou, 2020;He and Liang, 2019a;He and Liang, 2019b;Lesani and Rafeeyan, 2012;Hosseinalipour et al., 2007;Liang and He, 2017). A literature survey reveals very few papers that address the speed excursion of pig that occurs when a pig passes through bends or wall thickness changes. ...
This study proposes two novel friction models of pipeline inspection gauges (PIGs) to simulate and predict speed excursions in long pipeline system pigging operations. Speed excursion of PIG indicates its sudden acceleration mainly caused by gas compressibility and frictional variation in low-pressure and low-flowrate gas pipelines. The first friction model adopts a dynamic friction table coupled with an exponential friction model to simulate the speed excursion caused by variations in friction. The second friction model utilizes a linear equation for friction variation caused by changes in wall thickness and pipe bends, then weight parameters are applied to determine the influence of each factor. These two friction models are tuning models based on field data to simulate speed excursions caused by frictional variation, which can be strategically selected according to the purpose of the simulation. In the numerical model, the transient gas flow equations are solved by the method of characteristics (MOC), and then the Runge–Kuta method is used to solve the dynamic equation of the PIGs. Simulation results applying the proposed friction models are compared to the field pigging data for three different routes operated by the Korea Gas Corporation (KOGAS), and the obtained simulation results are in good agreement with the field pigging data. The first model, tuned friction model, was able to simulate the average pigging velocity and speed excursions of the total distance ratio with high accuracy. The second proposed model, weighted friction model, was slightly less accurate than the first friction model, however it was able to predict the average pigging velocity and speed excursions under different operating conditions. These results mean that the speed excursion can be simulated and predicted with high accuracy using the proposed friction models through the tuning process. Therefore, these two novel friction models would provide insights for the operators to simulate and predict the unstable movement of the PIGs in their pipeline networks.
... To understand the dynamic behavior of the pig, the pig dynamic equation must be coupled with the governing equations of flows [14][15][16]. e method of characteristics (MOC) was employed to transform the partial differential equations of flows to ordinary differential equations [17][18][19]. is method is quite efficient to solve the governing equations of transient gas flows. ...
... (1) e gas is an ideal gas (2) e gas flow is quasi-steady heat flow (3) e fluid in the pipeline is a single-phase gas (4) e diameter of the pipeline is unchanged during pigging e unsteady flow dynamics can be modeled based on the fundamental fluid dynamic equations [11,17,18,23]: continuity equation, momentum equation, and energy equation, respectively, as follows: ...
The pipeline inspection gauge (PIG, lowercase pig is commonly used) with a bypass valve is widely used in pipeline inspection because it operates at a low speed without reducing the flow rate. Understanding the dynamics of a bypass pig in a gas pipeline would contribute to the design of the pig and the control of pig speed. This paper deals with the dynamic model for the process of a bypass pig travelling through a hilly gas pipeline. The method of characteristics (MOC) is used to solve the equations of unsteady gas flow. The backward flow of the gas in the bypass valve and pipe is shown by a simulation of pigging for a hilly gas pipeline. Parametric sensitivity analysis of pigging in the horizontal gas pipe using a bypass pig is then carried out. The results indicate that the speed of a bypass pig is most sensitive to the gas speed in the pipe followed by the bypass area and the friction of the pig. A formula, obtained from the results of the simulations using response surface methodology (RSM), is presented to predict the steady speed of a bypass pig in the horizontal gas pipeline.
Hydrates are easily formed at low-lying parts of high-sulfur gas-liquid mixed pipelines due to liquid accumulation. In pigging operations, the pig is often jammed. In order to avoid pig jamming, a novel foam jetting pig was designed in this study. The kinetic model of the jetting pig was established to simulate the hydrate crushing process. In addition, the foam jet flow experimental system was constructed to verify the feasibility of the pig design and the rationality of theoretical analysis results. After the stepped piston in the pig completed a stroke of 400 mm, the maximum jetting pressure reached 10.3 MPa. The diameter of the stepped piston rod and the degree of opening of the outlet valve had significant effects on the jetting pressure and the buffer piston had a significant effect on the buffering velocity. When the diameter of the buffer piston increased from 80 mm to 100 mm, the post-buffering velocity decreased from 0.63 m/s to 0.19 m/s and the buffering effect was improved by 3 times. In the experiment, ice samples were efficiently crushed and the trend of the jet pressure was well consistent with the theoretical calculation results. The study provides the basis for the design of the foam jetting pig and the scheme for improving the removal of hydrates in high-sulfur gas-liquid mixed pipelines.
To provide efficient pigging operation, a stable and moderate speed of the pig is preferred. This paper describes a brake device for controlling the speed of a pig in a gas pipeline. A pigging model of a pig with a brake unit in gas pipeline is presented. In the model, the relevant pig speed equation is combined with the gas flow equations. It is assumed that the velocity of gas at the tail and nose of the pig is equal to that of the pig. Moreover, the inlet flow rate and the outlet pressure are kept constant during the simulation. The method of characteristics (MOC) is applied to solve the transient equation of gas flow, and the Runge–Kutta method is used to solve the pig speed equation and the steady flow equations to obtain the values of initial flow. Two cases for pigging simulation were carried out to verify the performance of the brake unit. The corresponding results indicate that the brake unit can prevent undesired high speed of the pig when the pig restarts under a stoppage condition in a gas pipe. Additionally, a brake device can ensure a more stable speed of the pig. However, due to the drag force generated by the brake unit, a greater differential pressure between the tail and nose of the pig is required to drive the pig in motion.
