Investigation of Pump Failure-Induced Waterhammer Waves: A Case Study

2021 ◽  
Author(s):  
Ali Triki ◽  
Badreddine Essaidi
Keyword(s):  
Pressure Wave ◽  
Transient Flow ◽  
Pipe Wall ◽  
Plastic Material ◽  
Flow Behavior ◽  
Pipe Material ◽  
Transient Pressure ◽  
Pump Failure ◽  
Material Type ◽  
Numerical Solver

Abstract The present study analyzes the effect of the pipe material type on the transient flow behavior in a pumping system due to an accidental pump shutdown. The material types addressed in this study include steel and High- or Low-Density PolyEthylene (HDPE) or (LDPE); involving elastic and plastic rheological pipe-wall behavior. The numerical solution is developed basing on the Method Of Characteristics used for the discretization of the Extended One-Dimensional pressurized-pipe flow model, incorporating the Kelvin-Voigt and Vitkovsky rules. Experimental data from the literature were used to validate the numerical solver. The proposed numerical algorithm is then used to investigate the transient pressure-wave behavior induced by the power failure to a pumping station composed of an inline connection using different pipe material types. The findings show the severity of such a scenario, in terms of the magnitudes of induced up-surge and down-surge pressure-waves. Furthermore, this research demonstrates that plastic pipe-wall materials allow for substantial attenuation of surge magnitude in conjunction with the expansion of the period of pressure-wave oscillations. The observed attenuation and expansion effects are also found to be highly dependent on the plastic material type. In this respect, the findings indicate that the (LDPE-Steel) piping system's specific layout allows for the best tradeoff between the two last effects.

scholarly journals On the transient flow behavior in pressurized plastic pipe-based water supply systems

2020 ◽  
Author(s):  
Badreddine Essaidi ◽  
Ali Triki
Keyword(s):  
Water Supply ◽  
Pressure Wave ◽  
Transient Flow ◽  
Plastic Material ◽  
Flow Behavior ◽  
Oscillation Period ◽  
Water Supply Systems ◽  
Transient Pressure ◽  
Plastic Pipe ◽  
Supply Systems

Abstract Plastic material pipes such as high- or low-density polyethylene (HDPE or LDPE) are increasingly used in new or renewed water supply systems. Therefore, analysis of water hammer surge-waves initiated into such piping systems deserves investigation. The 1-D pressurized-pipe flow model embedding the Ramos formulation was used to describe the flow behavior in the elastic and plastic pipe-based hydraulic system. Numerical computations were performed using the method of characteristics. First, the numerical solver was validated against experimental data, available from the literature. Then, the proposed solver was applied to explore the transient pressure-wave behavior resulting from the power failure to a pumping station. Results evidenced the severity of such a scenario with regards to induced positive and negative pressure-wave magnitudes. Furthermore, the findings of this study suggested that plastic pipe-wall materials allowed a significant attenuation of pressure-wave magnitude in conjunction with the expansion of the pressure-wave oscillation period. It was also found that the observed attenuation and expansion effects depended strongly upon the plastic material type. In this respect, the results revealed that LDPE provided a better trade-off between the two last effects than HDPE.

Benchmarking the Dual and Compound Techniques-Based Branching Design Strategy Used for Upgrading of Pressurized Hydraulic Systems

2021 ◽  
Vol 143 (2) ◽  
Author(s):  
Waêl Ben Amira ◽  
Ali Triki
Keyword(s):  
Pressure Wave ◽  
Plastic Material ◽  
Conventional Technique ◽  
Steel Pipe ◽  
Low Density Polyethylene ◽  
Piping System ◽  
Low Density ◽  
Hydraulic Systems ◽  
Transient Pressure ◽  
Pipe Flow Model

Abstract Prior research has recognized that the compound- and dual-technique-based branching redesign measures, used as alternatives to the conventional technique-based one, were effective in upgrading steel pipe-based pressurized hydraulic systems. Principally, the compound technique used two different plastic material types for the short-penstock instead of the single material type utilized in the conventional technique. However, the dual technique is based on splitting the single penstock installed in the conventional technique into a set of dual subpenstocks placed at each connection of the main-piping system to hydraulic parts. This handling aimed at improving the conventional technique efficiency with regard to the tradeoff between the magnitude attenuation and period expansion effects of the transient pressure-wave signal. Accordingly, this study proposed a comprehensive comparison between the compound- and dual-technique-based branching strategy with particular focus on the tradeoff between the two last parameters. The plastic material types demonstrated in this study included the high- or low-density polyethylene. The application addressed a waterhammer maneuver initiated into a reservoir-steel-pipe-valve system. Numerical computations used the method of characteristics for the discretization of the 1D extended pressurized-pipe flow model, embedding the Kelvin–Voigt and Vitkovsky formulations. The finding of this study suggested that the high- or low-density polyethylene (HDPE–LDPE) setup of the compound technique is the most prominent protected system setup, providing an acceptable tradeoff between the attenuation of magnitude and the expansion of the period of pressure-wave oscillation.

Paper 1: Computer Solution of Surge Problems

1965 ◽  
Vol 180 (5) ◽  
pp. 62-82
Author(s):  
Victor L. Streeter
Keyword(s):  
Steady State ◽  
Differential Equations ◽  
High Speed ◽  
Transient Flow ◽  
Nonlinear Differential Equations ◽  
Pressure Fluctuations ◽  
Transient Pressure ◽  
Pump Failure ◽  
Flow Equations ◽  
Flow Impedance

Methods for handling the transient flow equations are developed for application of the high-speed digital computer. For incompressible flow cases ordinary nonlinear differential equations occur which are solved simultaneously by established sub-routines on the computer, such as the Runge-Kutta method. For the partial differential equations of compressible water hammer with nonlinear terms such as friction, the method of characteristics and of specified time intervals are employed for those problems in which the flow changes from one steady-state to another steady-state. For steady-oscillatory flow, impedance methods have been adapted to the computer with harmonic analysis of the exciting disturbance. Experimental evidence is presented to confirm the accuracy of the procedures for single and series pipes, for pump failures, and for reciprocating pumps. Additionally the design problem of optimum operation of a valve to minimize transient pressure fluctuations has been introduced and applied to single and series pipes, including a pump failure situation.

scholarly journals Pressure Wave Transmission in a Fluid Contained in a Plastically Deforming Pipe

1974 ◽  
Vol 96 (4) ◽  
pp. 258-262 ◽  
Author(s):  
G. L. Fox ◽  
D. D. Stepnewski
Keyword(s):  
Plastic Deformation ◽  
Pressure Wave ◽  
Pipe Wall ◽  
Experimental Tests ◽  
Elastic Wave Velocity ◽  
Wave Transmission ◽  
Pressure Waves ◽  
Transient Pressure ◽  
Cooling Systems ◽  
Wall Deformation

The transmission of high pressure pulses through piping loops such as reactor cooling systems is usually studied with water hammer analysis techniques. Conventional wave analysis includes only elastic pipe wall deformation. However, plastic deformation of the pipe wall is effective in reducing the magnitude of transmitted pressure waves if the pressure is of sufficient magnitude to cause plastic yielding. This effect can be treated using a one-dimensional dynamic analysis by noting the similarity between the equations describing pressure wave induced plastic deformation in a solid bar and wave transmission causing plastic strain in a fluid filled pipe. The results of the analysis show that at fluid pressures less than the pipe yield pressure, waves are transmitted at elastic wave velocity; however, at pressures which exceed the pipe yield point, wave velocities are substantially reduced and the waves are dispersed. These results demonstrate that plastic deformation from transient pressure loading is limited to a relatively short length of piping near the source of the pressure pulse. The significance of this behavior with respect to reactor cooling systems is that pressures above those causing yield are not transmitted to primary loop components such as pumps and heat exchangers. The theoretical results are compared with experimental tests and show reasonable agreement.

Vertical Fracture Height: Effect on Transient Flow Behavior

1978 ◽  
Vol 18 (04) ◽  
pp. 265-277 ◽  
Author(s):  
R. Raghavan ◽  
A. Uraiet ◽  
G.W. Thomas
Keyword(s):  
Transient Flow ◽  
Flow Behavior ◽  
Petroleum Industry ◽  
Transient Pressure ◽  
Pressure Behavior ◽  
Constant Rate ◽  
Penetration Ratio ◽  
Fracture Height ◽  
Fractured Well ◽  
Pressure Analysis

Abstract Although a number of studies have examined the performance of vertically fractured wells, no performance of vertically fractured wells, no analytical study has examined the effect of fracture height on transient flow behavior and production capacity. The purpose of this paper is to close this gap in the knowledge about fractured well behavior. This paper presents an analytical study of the pressure behavior of a well producing at a constant pressure behavior of a well producing at a constant rate through one vertical fracture from an infinitely large reservoir with impermeable upper and lower boundaries. The fracture height is less than the formation thickness. The characteristics of the dimensionless wellbore pressure drop vs dimensionless time curves are examined for both uniform-flux and infinite-conductivity fractures. Two fracture locations (center and top) in the producing interval are considered. Curves also are presented for calculating the additional pressure drop that results because the fracture height is less than the formation thickness. Other parameters of interest examined here are (1) the ratio of vertical to horizontal permeability and (2) the ratio of fracture height to permeability and (2) the ratio of fracture height to formation thickness. The application of theoretical results to well test analysis also is discussed. Introduction Hydraulic fracturing, introduced in 1949, has provided the petroleum industry with an inexpensive provided the petroleum industry with an inexpensive way to increase the fluid production or injection capacity of wells. The success of many marginal wells can be directly attributed to hydraulic fracturing. Because of the many wells that have been hydraulically fractured, the study of the flow behavior of wells intersecting vertical, horizontal, and inclined fractures has received considerable attention. As a result of these studies, it is possible to predict and analyze pressure behavior of fractured wells and to compute production increases caused by fracture treatments. All studies on vertical and inclined fractures cited assume that the fracture extends over the entire vertical extent of the formation. Field observations, however, indicate that in Some instances this assumption is not valid. Also, the fracture height through which fluid is actually produced may not be equal to the created fracture produced may not be equal to the created fracture height. There is no discussion in the literature of the transient pressure behavior of a reservoir producing through a well with a fracture that does producing through a well with a fracture that does not extend throughout the vertical extent of the formation. This paper first examines the effect of fracture height on transient pressure behavior of a vertically fractured well producing at a constant rate. Second, we present information regarding production rate changes as a function of fracture height. Third, we delineate conditions under which it would be possible to recognize (by pressure analysis) that possible to recognize (by pressure analysis) that the thickness and fracture height are different. REMARKS ABOUT THE NOMENCLATURE In the petroleum engineering literature, the term, "a partially penetrating well," has been used to describe the situation where a well does not penetrate the entire thickness of the formation. penetrate the entire thickness of the formation. The term, "penetration ratio," has been defined as the ratio of the length of the open interval to the formation thickness. Unfortunately, this term also has been used to define the ratio of the fracture half-length to the drainage length. Among other definitions, the word "penetrate" implies "to enter or pierce; to make way into another body." In this context, using the term, "penetration ratio," to describe both situations is correct. Confusion regarding this terminology has not come up, since all studies on the pressure behavior of vertically fractured wells have assumed that the fracture extends over the entire extent of the formation. In this study, however, we need to clarify this term, even though we are examining only the pressure behavior of vertically fractured wells in an pressure behavior of vertically fractured wells in an infinite reservoir. SPEJ P. 265

New benchmark solutions for transient natural convection in partially porous annuli

2016 ◽  
Vol 26 (3/4) ◽  
pp. 1187-1225 ◽  
Author(s):  
Nicola Massarotti ◽  
Michela Ciccolella ◽  
Gino Cortellessa ◽  
Alessandro Mauro
Keyword(s):  
Natural Convection ◽  
Free Convection ◽  
Transient Flow ◽  
Flow Behavior ◽  
Outer Radius ◽  
Temperature Fields ◽  
Content Type ◽  
Transient Natural Convection ◽  
Velocity And Temperature Fields ◽  
Benchmark Solutions

Purpose – The purpose of this paper is to focus on the numerical analysis of transient free convection heat transfer in partially porous cylindrical domains. The authors analyze the dependence of velocity and temperature fields on the geometry, by analyzing transient flow behavior for different values of cavity aspect ratio and radii ratio; both inner and outer radius are assumed variable in order to not change the difference ro-ri. Moreover, several Darcy numbers have been considered. Design/methodology/approach – A dual time-stepping procedure based on the transient artificial compressibility version of the characteristic-based split algorithm has been adopted in order to solve the transient equations of the generalized model for heat and fluid flow through porous media. The present model has been validated against experimental data available in the scientific literature for two different problems, steady-state free convection in a porous annulus and transient natural convection in a porous cylinder, showing an excellent agreement. Findings – For vertically divided half porous cavities, with Rayleigh numbers equal to 3.4×106 for the 4:1 cavity and 3.4×105 for the 8:1 cavity, the numerical results show that transient oscillations tend to disappear in presence of cylindrical geometry, differently from what happens for rectangular one. The magnitude of this phenomenon increases with radii ratio; the porous layer also affects the stability of velocity and temperature fields, as oscillations tend to decrease in presence of a porous matrix with lower value of the Darcy number. Research limitations/implications – A proper analysis of partially porous annular cavities is fundamental for the correct estimation of Nusselt numbers, as the formulas provided for rectangular domains are not able to describe these problems. Practical implications – The proposed model represents a useful tool for the study of transient natural convection problems in porous and partially porous cylindrical and annular cavities, typical of many engineering applications. Moreover, a fully explicit scheme reduces the computational costs and ensures flexibility. Originality/value – This is the first time that a fully explicit finite element scheme is employed for the solution of transient natural convection in partially porous tall annular cavities.

scholarly journals FLOW BEHAVIOUR OF OIL BLOB THROUGH A CAPILLARY TUBE CONSTRICTION DURING PULSED INJECTION

2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Shiferaw Regassa Jufar ◽  
Tareq M Al-Shami ◽  
Ulugbek Djuraev ◽  
Berihun Mamo Negash ◽  
Mohammed Mahbubur Rahman
Keyword(s):  
Pressure Gradient ◽  
Transient Flow ◽  
Capillary Tube ◽  
Reverse Flow ◽  
Flow Behavior ◽  
Adverse Pressure Gradient ◽  
Gradient Zone ◽  
Pulsed Injection ◽  
Time Required ◽  
Continuous Injection

A numerical simulation of flow of oil blob through a capillary tube constriction is presented. The simulation was run in a 2D axisymmetric model. Water is injected at the inlet to mobilize oil blob placed near the capillary tube constriction. Transient flow images were used to understand the flow evolution process. Results from the study show that pulsed injection effectively assisted to squeeze out the oil blob through the capillary tube constriction with shorter time compared to continuous injection.  Pulsed injection reduced the time required for the first droplet to cross the capillary tube constriction by about 3 folds compared to continuous injection. In addition, the droplet that crossed the constriction is larger when the flow was pulsed. In both cases, there is a reverse flow in the opposite direction of the injection. However, the severity of the reverse flow is stronger in the case of continuous injection. Immediately downstream the constriction, there is an adverse pressure gradient zone during continuous injection which limits the mobility of droplet that crossed the constriction. However, in the case of pulsed injection, there is a favorable pressure gradient zone immediately downstream the constriction. This zone expedites mobility of droplets that cross the constriction by transporting them further downstream through suction effect. Apparently, pulsed injection eases off the adverse pressure gradient and allowed more volume of oil to pass through the constriction. Within about two periods of pulsation, 84% of original oil placed at the beginning crossed the constriction compared to only 35% in the case of continuous injection. Even though the same amount of water was injected in both cases, pulsed injection clearly altered the flow behavior. The observation from this study may be extended to more complex flows in order to tailor the method for certain specific applications, such as flow of residual oil through a reservoir.

scholarly journals Analysis of Flow Behavior for Acid Fracturing Wells in Fractured-Vuggy Carbonate Reservoirs

2018 ◽  
Vol 2018 ◽  
pp. 1-20 ◽  
Author(s):  
Mingxian Wang ◽  
Zifei Fan ◽  
Xuyang Dong ◽  
Heng Song ◽  
Wenqi Zhao ◽  
...  
Keyword(s):  
Composite System ◽  
Numerical Solutions ◽  
Transient Flow ◽  
Flow Behavior ◽  
Outer Region ◽  
Carbonate Reservoirs ◽  
Single Fracture ◽  
Specific Flow ◽  
Type Curves ◽  
Acid Fracturing

This study develops a mathematical model for transient flow analysis of acid fracturing wells in fractured-vuggy carbonate reservoirs. This model considers a composite system with the inner region containing finite number of artificial fractures and wormholes and the outer region showing a triple-porosity medium. Both analytical and numerical solutions are derived in this work, and the comparison between two solutions verifies the model accurately. Flow behavior is analyzed thoroughly by examining the standard log-log type curves. Flow in this composite system can be divided into six or eight main flow regimes comprehensively. Three or two characteristic V-shaped segments can be observed on pressure derivative curves. Each V-shaped segment corresponds to a specific flow regime. One or two of the V-shaped segments may be absent in particular cases. Effects of interregional diffusivity ratio and interregional conductivity ratio on transient responses are strong in the early-flow period. The shape and position of type curves are also influenced by interporosity coefficients, storativity ratios, and reservoir radius significantly. Finally, we show the differences between our model and the similar model with single fracture or without acid fracturing and further investigate the pseudo-skin factor caused by acid fracturing.

A Semianalytical Model for Predicting Transient Pressure Behavior of a Hydraulically Fractured Horizontal Well in a Naturally Fractured Reservoir With Non-Darcy Flow and Stress-Sensitive Permeability Effects

SPE Journal ◽  
2019 ◽  
Vol 24 (03) ◽  
pp. 1322-1341 ◽  
Author(s):  
Liwu Jiang ◽  
Tongjing Liu ◽  
Daoyong Yang
Keyword(s):  
Mathematical Models ◽  
Horizontal Well ◽  
Flow Behavior ◽  
Stress Sensitivity ◽  
Darcy Flow ◽  
Combined Effects ◽  
Fractured Reservoir ◽  
Transient Pressure ◽  
Linear Flow ◽  
Fractured Horizontal Well

Summary Non-Darcy flow and the stress-sensitivity effect are two fundamental issues that have been widely investigated in transient pressure analysis for fractured wells. The main object of this work is to establish a semianalytical solution to quantify the combined effects of non-Darcy flow and stress sensitivity on the transient pressure behavior for a fractured horizontal well in a naturally fractured reservoir. More specifically, the Barree-Conway model is used to quantify the non-Darcy flow behavior in the hydraulic fractures (HFs), while the permeability modulus is incorporated into mathematical models to take into account the stress-sensitivity effect. In this way, the resulting nonlinearity of the mathematical models is weakened by using Pedrosa's transform formulation. Then a semianalytical method is applied to solve the coupled nonlinear mathematical models by discretizing each HF into small segments. Furthermore, the pressure response and its corresponding derivative type curve are generated to examine the combined effects of non-Darcy flow and stress sensitivity. In particular, stress sensitivity in HF and natural-fracture (NF) subsystems can be respectively analyzed, while the assumption of an equal stress-sensitivity coefficient in the two subsystems is no longer required. It is found that non-Darcy flow mainly affects the early stage bilinear and linear flow regime, leading to an increase in pressure drop and pressure derivative. The stress-sensitivity effect is found to play a significant role in those flow regimes beyond the compound-linear flow regime. The existence of non-Darcy flow makes the effect of stress sensitivity more remarkable, especially for the low-conductivity cases, while the stress sensitivity in fractures has a negligible influence on the early time period, which is dominated by non-Darcy flow behavior. Other parameters such as storage ratio and crossflow coefficient are also analyzed and discussed. It is found from field applications that the coupled model tends to obtain the most-reasonable matching results, and for that model there is an excellent agreement between the measured and simulated pressure response.

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