Compositional Simulation of Two-Phase Flows for Pipeline Depressurization

SPE Journal ◽  
2017 ◽  
Vol 22 (04) ◽  
pp. 1242-1253 ◽  
Author(s):  
Luigi Raimondi
Keyword(s):  
Numerical Solution ◽  
Mass Balance ◽  
Stokes Equations ◽  
Dynamic Pressure ◽  
Gas Production ◽  
Fluid Composition ◽  
Two Phase ◽  
Compositional Approach ◽  
Liquid Phases ◽  
System Pressure

Summary The simulation of multiphase flow, considered in the case of coexisting vapor and liquid phases, is an important topic in engineering for the design of oil-and-gas production and transportation facilities. This paper presents the development of a compositional approach for the dynamic calculation of multiphase flows in pipelines. This approach can be defined as “full compositional,” because the vapor and liquid phases are described by taking into account the chemical composition, presenting points of interest from both the theoretical and the practical points of view. Physical properties required are calculated at each integration timestep with the actual phase compositions instead of relying on property tables previously generated from a single constant fluid composition. With this approach, in the numerical solution of the conservative two-phase-flow equations, the congruency between the dynamic pressure, calculated by solving the Navier-Stokes equations at constant temperature, and the thermodynamic pressure of the system becomes a critical constraint. In the numerical solution, the overall mass balance defined by means of the vapor- and liquid-phase densities is verified with respect to the mass balance of each chemical component involved, and the system pressure obtained from the solution of the momentum equations is always compared with the thermodynamic value defined by mass balance. Of the numerous test cases created for model validation, three of them (focused on fast depressurizations) are presented and discussed. Similar examples are not available in the literature as solutions of the current “state-of-the-art” commercial pipeline simulators.

Axisymmetric Low-Reynolds Motion of Drops Through Circular Microchannels

2012 ◽  
Author(s):  
Saira F. Pineda ◽  
Arjan M. Kamp ◽  
D. Legendre ◽  
Armando J. Blanco
Keyword(s):  
Pressure Gradient ◽  
Drop Size ◽  
Viscosity Ratio ◽  
Stokes Equations ◽  
Flow Dynamics ◽  
Navier Stokes ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
System Pressure ◽  
The Continuum

Flow constituted by drops appears in a wide range of natural, biological and engineering situations. For example, liquid-liquid two phase flow inside capillaries constitutes a model commonly used to represent fluid flow in a petroleum reservoir. The typical modeling approach considers inertial forces negligible in comparison to viscous forces, allowing the use of Stokes equation to study flow dynamics. Very few numerical simulations have been made considering inertial effects. In this project, the flow of a periodic train of drops in a viscous suspending fluid, due to the influence of a fixed pressure gradient, was studied by numerical simulation considering the full Navier-Stokes equations. A numerical approach based on a Volume of Fluid (VOF) formulation was employed using JADIM software, developed by the Institut de Mécanique des Fluides de Toulouse, France. JADIM solves Navier-Stokes equations using a VOF finite volume method, second order in space and time using structured mesh. This two-fluid approach without reconstruction of the interface allows simulating two-phase flows with complex interface shapes. Densities of the drops equal to those of the suspending fluid and a constant interface tension were assumed. The effect of drop size, viscosity ratio, interfacial forces and system pressure gradient on the flow dynamics was studied. Parameters values were chosen to be representative for some particular viscous oil. The result validation shows an excellent agreement between both numerical results. However, there are relative differences between them due to the increase in flow velocity when drop relative size increase and validity of Stokes approach is questionable. Results show non-symmetric eddies in the continuum phase, in a referential frame fixed to the drop. The shape of eddies is strongly influenced by viscosity radio. Drop mobility decreases with increasing size. Additionally, drop mobility also decreases when the viscosity ratio increases. Extra pressure gradient of the system due to the presence of the drop shows a strong dependency on the size ratio between the drop and the pore. For size ratio lower than 0.5, the extra pressure gradient required to move the continuum phase is small. However, when drop to micro-channel ratio exceeds 0.5, the extra pressure gradient significantly increases when the drop size increases. Also, viscosity ratio affects on the system pressure loss, especially in cases where the viscosity ratio is high. The analysis of the capillary number effect on the dynamics of the two-phase system shows that it does not influence drop mobility for the drop sizes considered.

A Numerical Solution for Gas-Particle Flows at High Reynolds Numbers

1981 ◽  
Vol 48 (3) ◽  
pp. 465-471 ◽  
Author(s):  
J. A. Laitone
Keyword(s):  
Numerical Solution ◽  
Coal Gasification ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Particle Flows ◽  
Energy Conversion Systems ◽  
Successful Design ◽  
High Reynolds

Predicting the fluid mechanical characteristics of a gas-solid two-phase flow is critical for the successful design and operation of coal gasification systems, coal fired turbines, rocket nozzles, and other energy conversion systems. This work presents a general grid-free numerical solution which extends a numerical solution of the Navier-Stokes equations developed by Chorin to a solution suitable for unsteady or steady dilute gas-solid particle flows. The method is applicable to open or closed domains of arbitrary geometry. The capability of the method is illustrated by analyzing the flow of gas and particles about a cylinder. Good agreement is found between the numerical method and experiment.

Numerical Investigation of Tsunami-Like Solitary Wave Interaction with a Seawall

2017 ◽  
Vol 11 (01) ◽  
pp. 1740006 ◽  
Author(s):  
Changbo Jiang ◽  
Xiaojian Liu ◽  
Yu Yao ◽  
Bin Deng ◽  
Jie Chen
Keyword(s):  
Free Surface ◽  
Solitary Waves ◽  
Stokes Equations ◽  
Dynamic Pressure ◽  
Laboratory Data ◽  
Three Dimensional ◽  
Wave Interaction ◽  
Surface Velocity ◽  
Wave Impact ◽  
Two Phase

Seawall is a most commonly used structure in coastal areas to protect the landscape and coastal facilities. The studies of interactions between the tsunami-like solitary waves and the seawalls are relatively rare in the literature. In this study, a three-dimensional numerical model based on OpenFOAM® was developed to investigate the tsunami-like solitary waves propagating over a rectangular seawall. The Navier–Stokes equations for two-phase incompressible flow, combining with methods of [Formula: see text] for turbulence closure and Volume of Fluid (VOF) for tracking the free surface, were solved. Laboratory experiments were performed to measure some of the hydrodynamic feature associated with solitary waves. The model was then validated by the laboratory data, and good agreements were found for free surface, velocity and dynamic pressure around the seawall. Finally, a series of numerical experiments were conducted to analyze the evolution of both wave and flow fields, the overtopping discharge as well as wave pressure (force) around the seawall, special attention is given to the effects of seawall crest width. Our findings will help to improve the understanding in the occurrences of tsunami-induced damages in the vicinity of seawall such as wave impact and local scouring.

scholarly journals Numerical simulation of compressible cavitating two-phase flows with a pressure-based solver

2017 ◽  
Author(s):  
Marco Cristofaro ◽  
Wilfried Edelbauer ◽  
Manolis Gavaises ◽  
Phoevos Koukouvinis
Keyword(s):  
Stokes Equations ◽  
Navier Stokes ◽  
Test Case ◽  
Time Step ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Liquid Phases ◽  
Flow Features ◽  
Liquid Evaporation ◽  
Semi Empirical

This work intends to study the effect of compressibility on throttle flow simulations with a pressure–based solver.The simple micro throttle geometry allows easier access for obtaining experimental data compared to a real injector, but still maintaining the main flow features. For this reasons it represents a meaningful and well reported benchmark for validation of numerical methods developed for cavitating injector flows.An implicit pressure–based compressible solver is used on the filtered Navier–Stokes equations. Thus, no stability limitation is applied on the time step. A common pressure field is computed for all phases, but different velocity fields are solved for each phase, following the multi–fluid approach. The liquid evaporation rate is evaluated with a Rayleigh–Plesset equation based cavitation model and the Coherent Structure Model is adopted as closure for the sub–grid scales in the momentum equation.The aim of this study is to show the capabilities of the pressure–based solver to deal with both vapor and liquid phases considered compressible. A comparison between experimental results and compressible simulations is presented. Time–averaged vapor distribution and velocity profiles are reported and discussed.  The distribution of pressure maxima on the surface and the results from a semi–empirical erosion model are in good agreement with the erosion locations observed in the experiments. This test case aims to represent a benchmark for furtherapplication of the methodology to industrial relevant cases.DOI: http://dx.doi.org/10.4995/ILASS2017.2017.4629

On the Numerical Modeling of Slug and Intermittent Flows in Oil and Gas Production

2017 ◽  
Author(s):  
Angela O. Nieckele ◽  
João N. E. Carneiro
Keyword(s):  
Oil And Gas ◽  
Fluid Model ◽  
Dynamic Pressure ◽  
Time Discretization ◽  
Gas Production ◽  
Two Phase ◽  
Dynamic Simulations ◽  
Oil And Gas Production ◽  
Two Fluid Model ◽  
Two Fluid

Recent advances on the modeling of two-phase flows in pipes have shown that the accurate modeling of Two-Fluid equations allow the dynamic simulation of various regimes within a single numerical framework, diminishing the empiricism associated with the flow-pattern dependent closure relations. Such “Regime-Capturing” approaches have been traditionally called “Slug-Capturing”, as a reference to dynamic simulations of stratified-to-slug transition. In this paper, we will outline several examples of applications, ranging from horizontal stratified wavy, slug and annular flows, to vertical annular and intermittent flows. Vertical flow has been a bottleneck in Slug Capturing due to ill-posedness of the Two-Fluid Model. Ill-posedness of the model equations will be briefly addressed along with different regularization methods and stabilizing terms based on physical behavior, such as shape profile factors and dynamic pressure contributions. In order to numerically solve the governing system of equations, the finite volume method is employed with Upwind and second order TVD spatial discretization schemes, along with first order time discretization. Flow parameters such as temperature and pressure drop are determined as well as film thickness and wave characteristics of both annular and stratified flow, and slug velocity, length and frequency in slugging cases. Comparison with experimental data for annular, slug and stratified flows, with different fluids and pipeline configurations are presented, illustrating the good performance of the methodology.

Numerical solution of the reduced Navier-Stokes equations for internal incompressible flows

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1603-1614
Author(s):  
Martin Scholtysik ◽  
Bernhard Mueller ◽  
Torstein K. Fannelop
Keyword(s):  
Numerical Solution ◽  
Incompressible Flows ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Navier Stokes Equations

Numerical Modeling of Evolution of Boundary Between Incompressible Gas and Liquid in Two-Dimensional Region

2006 ◽  
Vol 4 ◽  
pp. 224-236
Author(s):  
A.S. Topolnikov
Keyword(s):  
Numerical Modeling ◽  
Interphase Boundary ◽  
Incompressible Liquid ◽  
Stokes Equations ◽  
Numerical Code ◽  
Navier Stokes ◽  
Two Phase ◽  
Navier Stokes Equations ◽  
Incompressible Media ◽  
Good Agreement

The paper is devoted to numerical modeling of Navier–Stokes equations for incompressible media in the case, when there exist gas and liquid inside the rectangular calculation region, which are separated by interphase boundary. The set of equations for incompressible liquid accounting for viscous, gravitational and surface (capillary) forces is solved by finite-difference scheme on the spaced grid, for description of interphase boundary the ideology of Level Set Method is used. By developed numerical code the set of hydrodynamic problems is solved, which describe the motion of two-phase incompressible media with interphase boundary. As a result of numerical simulation the solutions are obtained, which are in good agreement with existing analytical and experimental solutions.

scholarly journals Experimental and Numerical Study on Water Filling and Air Expelling Process in a Pipe with Multiple Air Valves under Water Slow Filling Condition

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2511
Author(s):  
Jintao Liu ◽  
Di Xu ◽  
Shaohui Zhang ◽  
Meijian Bai
Keyword(s):  
Numerical Model ◽  
Stokes Equations ◽  
Numerical Study ◽  
Practical Method ◽  
Navier Stokes ◽  
Physical Processes ◽  
Two Phase ◽  
Saint Venant Equations ◽  
Water Filling ◽  
Air Valve

This paper investigates the physical processes involved in the water filling and air expelling process of a pipe with multiple air valves under water slow filling condition, and develops a fully coupledwater–air two-phase stratified numerical model for simulating the process. In this model, the Saint-Venant equations and the Vertical Average Navier–Stokes equations (VANS) are respectively applied to describe the water and air in pipe, and the air valve model is introduced into the VANS equations of air as the source term. The finite-volume method and implicit dual time-stepping method (IDTS) with two-order accuracy are simultaneously used to solve this numerical model to realize the full coupling between water and air movement. Then, the model is validated by using the experimental data of the pressure evolution in pipe and the air velocity evolution of air valves, which respectively characterize the water filling and air expelling process. The results show that the model performs well in capturing the physical processes, and a reasonable agreement is obtained between numerical and experimental results. This agreement demonstrates that the proposed model in this paper offers a practical method for simulating water filling and air expelling process in a pipe with multiple air valves under water slow filling condition.

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