Modeling of Pig Assisted Production Methods

2002 ◽  
Vol 124 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Hoi C. Yeung ◽  
Paulo C. R. Lima
Keyword(s):  
Gas Flow ◽  
Transient Flow ◽  
Fluid Model ◽  
Flow Behavior ◽  
Transient Behavior ◽  
Oil And Gas Industry ◽  
Experimental Program ◽  
Finite Difference Schemes ◽  
Two Phase ◽  
Process Gas

More and more transient gas-liquid operations in pipes have been successfully applied in the oil and gas industry. Pigging operation in two-phase pipelines to remove liquid accumulation or for cleaning purpose is an important transient operation. Another important operation is the injection of gas to transport the accumulated liquid in the pipeline to process facilities. Analysis of such transient two-phase flow in a pipeline is necessary not only for designing the liquid and gas handling facilities, but also for establishing safe operating procedures. In pipeline-riser systems, such operations cause even more severe change in flow conditions. A two-fluid model has been developed to determine the transient behavior of fluids during these operations. A one-dimensional set of equations for bubble/mist, annular and stratified flows has been derived. Slug flows were modeled as a combination of the foregoing. Semi-implicit finite difference schemes were used to solve the initial and boundary value problem for each phase of the pigging process: gas/pig injection, gas shut-in, slug production, and gas flow out of the system. An extensive experimental program was carried out to acquire two-phase transient flow and pigging data on a 69-m-long, 9.9-m-high, 50-mm-dia pipeline-riser system. A computer based data acquisition system was used to obtain rapidly changing and detailed information of the flow behavior during tests. The model compared well with the experimental data for characteristics such as inlet pressure, hold-up, and pig velocity. Liquid production efficiencies for different operations were compared.

Two-Phase Flows in Mini-/Micro-Gas Flow Channels of PEM Fuel Cells

2013 ◽  
Author(s):  
Sung Chan Cho ◽  
Yun Wang
Keyword(s):  
Pressure Drop ◽  
Gas Flow ◽  
Fluid Model ◽  
Pem Fuel Cells ◽  
Two Phase ◽  
Micro Gas Flow ◽  
Two Fluid Model ◽  
The Impact ◽  
Two Fluid ◽  
Phase Pressure

In this paper, two-phase flow dynamics in a micro channel with various wall conditions are both experimentally and theoretically investigated. Annulus, wavy and slug flow patterns are observed and location of liquid phase on different wall condition is visualized. The impact of flow structure on two-phase pressure drop is explained. Two-phase pressure drop is compared to a two-fluid model with relative permeability correlation. Optimization of correlation is conducted for each experimental case and theoretical solution for the flows in a circular channel is developed for annulus flow pattern showing a good match with experimental data in homogeneous channel case.

scholarly journals Multiphase gas-flow model of an electrical submersible pump

2018 ◽  
Vol 73 ◽  
pp. 29
Author(s):  
Diana Marcela Martinez Ricardo ◽  
German Efrain Castañeda Jiménez ◽  
Janito Vaqueiro Ferreira ◽  
Pablo Siqueira Meirelles
Keyword(s):  
Gas Flow ◽  
Oil And Gas ◽  
Learning Algorithm ◽  
Estimation Error ◽  
Oil And Gas Industry ◽  
Support Vector ◽  
System Response ◽  
Submersible Pump ◽  
Two Phase ◽  
Electrical Submersible Pump

Various artificial lifting systems are used in the oil and gas industry. An example is the Electrical Submersible Pump (ESP). When the gas flow is high, ESPs usually fail prematurely because of a lack of information about the two-phase flow during pumping operations. Here, we develop models to estimate the gas flow in a two-phase mixture being pumped through an ESP. Using these models and experimental system response data, the pump operating point can be controlled. The models are based on nonparametric identification using a support vector machine learning algorithm. The learning machine’s hidden parameters are determined with a genetic algorithm. The results obtained with each model are validated and compared in terms of estimation error. The models are able to successfully identify the gas flow in the liquid-gas mixture transported by an ESP.

Simulation of particles and gas flow behavior in a riser using a filtered two-fluid model

2011 ◽  
Vol 66 (4) ◽  
pp. 593-603 ◽  
Author(s):  
Wang Shuai ◽  
Xu Pengfei ◽  
Lu Huilin ◽  
Yang Yunchao ◽  
Yin Lijie ◽  
...  
Keyword(s):  
Gas Flow ◽  
Fluid Model ◽  
Flow Behavior ◽  
Two Fluid Model ◽  
Two Fluid

scholarly journals Experimental Study of a Cavitating Centrifugal Pump During Fast Startups

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
S. Duplaa ◽  
O. Coutier-Delgosha ◽  
A. Dazin ◽  
O. Roussette ◽  
G. Bois ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Transient Flow ◽  
Flow Behavior ◽  
Rocket Engine ◽  
Rotation Velocity ◽  
Transient Behavior ◽  
Operating Conditions ◽  
Physical Analysis ◽  
Different Types

The startup of rocket engine turbopumps is generally performed only in a few seconds. It implies that these pumps reach their nominal operating conditions after only a few rotations. During these first rotations of the blades, the flow evolution in the pump is governed by transient phenomena, based mainly on the flow rate and rotation speed evolution. These phenomena progressively become negligible when the steady behavior is reached. The pump transient behavior induces significant pressure fluctuations, which may result in partial flow vaporization, i.e., cavitation. An existing experimental test rig has been updated in the LML Laboratory (Lille, France) for the startups of a centrifugal pump. The study focuses on the cavitation induced during the pump startup. Instantaneous measurement of torque, flow rate, inlet and outlet unsteady pressures, and pump rotation velocity enable to characterize the pump behavior during rapid starting periods. Three different types of fast startup behaviors have been identified. According to the final operating point, the startup is characterized either by a single drop of the delivery static pressure, by several low-frequency drops, or by a water hammer phenomenon that can be observed in both the inlet and outlet of the pump. A physical analysis is proposed to explain these three different types of transient flow behavior.

A Two-Fluid Model for Slug Flow Initiation Based on a Lagrangian Scheme

2014 ◽  
Author(s):  
Marco Germano Conte ◽  
Cristiane Cozin ◽  
Fausto Arinos Barbuto ◽  
Rigoberto E. M. Morales
Keyword(s):  
Shallow Water ◽  
Shallow Water Equations ◽  
Slug Flow ◽  
Gas Flow ◽  
Fluid Model ◽  
Dynamic Pressure ◽  
Two Phase ◽  
Drift Flux ◽  
Two Fluid Model ◽  
Two Fluid

Two-phase slug flow is present in many industrial processes, such as the exploitation and transportation of hydrocarbon mixtures from oil wells. This kind of flow is characterized by two distinct structures which repeat intermittently: a liquid slug with a large amount of momentum followed by a compressible gas bubble. In recent decades, a few models for simulating such complex flows were developed, as the eulerian two-fluid model and drift flux, and the lagrangian slug tracking. The aim of this work is to present a detailed study on the numerical implementation of the hybrid model proposed by Fabien Renault and Nydal which is able to track down waves that arise in the gas-liquid interface and possible slugs generated by them. This model was developed from the two-fluid model equations in which the motion generated by the dynamic pressure of the gas on the slugs is decoupled from the slow movement of the liquid below the gas. The movement of the bubbles in the liquid is then modeled similarly to shallow-water equations. The solution of the equation set is achieved in two steps. The first step provides the pressure field and the gas flow through the numerical solution of the equations for the gas, using the finite difference method. The second step solves the adapted shallow-water equations analytically. The model was coded in object-oriented Intel Visual Fortran95. Simulations to analyze the ability of the code to generate slugs for some pairs of water-air superficial velocities at atmospheric pressure were carried out. The results, as the distribution of the slug length, frequency and average values were compared to experimental results reported in the literature.

A Multiscale Mechanistic Model for Slow Transient Two-Phase Gas Condensate Flows in Pipelines

2015 ◽  
Author(s):  
Khalid Kamhawi ◽  
Yabin Zhao ◽  
Liam Finch
Keyword(s):  
Oil And Gas ◽  
Fluid Model ◽  
Mechanistic Model ◽  
Oil And Gas Industry ◽  
Gas Condensate ◽  
Two Phase Flows ◽  
Two Phase ◽  
Transient Model ◽  
Operational Conditions ◽  
Simplified Approach

Various technical, commercial and operational requirements and conditions warrant the modelling of gas condensate pipelines as two-phase flows. Although phenomenological descriptions of two-phase flows are commonly used in the Oil and Gas Industry, the thermal-hydraulic complexities of such systems mean that a number of mechanistic formulations are available, some emphasising accuracy at the expense of computational efficiency, others preferring a more simplified approach. This article proposes a fully mechanistic slow transient model of two-phase condensate gas flows in pipelines, where the slip relation is derived from first principles using a mutliscale expansion method. Representative steady state and transient case studies for different operational conditions are simulated and solved numerically. Results are analysed and validated against an industry standard Two-Fluid Model based software.

scholarly journals Design and Optimization of Chemical Mixing System for Vacuum Chambers: Simulation Results

2014 ◽  
Vol 5 ◽  
Author(s):  
Faruk Unker ◽  
Erdar Kaplan ◽  
Olkan Cuvalci
Keyword(s):  
Gas Flow ◽  
Flow Behavior ◽  
Atomic Layer ◽  
Flow Patterns ◽  
Operating Conditions ◽  
Tantalum Nitride ◽  
Ansys Fluent ◽  
Design And Optimization ◽  
Parametric Investigation ◽  
Process Gas

Computational fluid dynamics (CFD) is widely used in device design to determine gas flow patterns and turbulence levels.  CFD is also used to simulate particles and droplets, which are subjected to various forces, turbulence and wall interactions. These studies can now be performed routinely because of the availability of commercial software containing high quality turbulence and particle models. In order to understand how the gas is brought down to wafer, it is necessary to have a knowledge of the gas flow behavior very early in the design spiral of the Tantalum nitride-Atomic layer deposition(TaN-ALD) chamber by undertaking parametric investigation of the interaction effect between gas flow and the funnel structure. This paper presents such a  parametric  investigation on a generic TaN-ALD chamber using CFD. The results presented have been analyzed for a total of 11 different cases by varying neck and nozzle angles for a process gas. The gas flow was mainly investigated for the nozzle angles of  4.5◦,  9◦,  12◦  and  20◦ and the film thickness results were compared with numerical flow patterns. CFD simulations using the turbulence model in ANSYS Fluent v.13 are undertaken. The parametric study has demonstrated that CFD is a powerful tool to study the problem of gas flow-structure interaction on funnel and is capable of providing a means of visualizing the path of the gas under different operating conditions

Evaluation of Potential to Air Ingestion From RWT Following RAS

2006 ◽  
Author(s):  
Young S. Bang ◽  
Ingoo Kim ◽  
Sweng W. Woo
Keyword(s):  
Water Level ◽  
Power Plants ◽  
Transient Flow ◽  
Cooling System ◽  
Check Valve ◽  
Transient Behavior ◽  
Piping System ◽  
Water Tank ◽  
Two Phase ◽  
Pipe Line

At the Recirculation Actuation Signal (RAS) when the Refueling Water Tank (RWT) water level decreased to a certain value following Loss-of-Coolant Accident (LOCA), the isolation valves of Containment Recirculation Sump (CRS) of the Korean Standard Nuclear Power Plants (KSNP) are open automatically while the RWT isolation valves would be closed manually. It was concerned whether the design has a potential to air ingestion to Emergency Core Cooling System (ECCS) pumps before completion of the manual action to close RWT isolation valves. To support the safety evaluation on this issue including the evaluation of design adequacy, an analysis of the hydraulic transient within the ECCS piping following the RAS in KSNP is performed. RELAP5/MOD3.3 code is used to calculate the transient behavior of the piping network. The code was known to have capability to calculate one-dimensional two-phase transient flow with noncondensible gas in the complex piping. Substantial portion of ECCS are modeled including RWT, CRS, each pipe line from RWT and CRS to connection point with its own isolation valve and check valve, a common pipe line to ECCS header, each pipe line from the header to High Pressure Safety Injection (HPSI) pump, Low Pressure Safety Injection (LPSI) pump, and Containment Spray (CS) pump. Transient hydraulic behavior in the piping system following RAS after LOCA is calculated. It is found that the RWT water level was always higher than the elevation of the check valve at the connecting point by more than 15 ft. It indicates the air intrusion to the check valve can be sufficiently prevented by this amount of water head.

Compressibility Effects in the Gas Phase for Unsteady Annular Two-Phase Flow in a Microchannel

2006 ◽  
Author(s):  
Alexandru Herescu ◽  
Jeffrey S. Allen
Keyword(s):  
Shock Wave ◽  
Gas Phase ◽  
High Speed ◽  
Gas Flow ◽  
Two Phase Flow ◽  
Flow Behavior ◽  
Flow Section ◽  
Phase Flow ◽  
Two Phase ◽  
Gas Liquid Flow

High speed microscopy experiments investigating two-phase (gas-liquid) flow behavior in capillary-scale systems, that is, systems where capillary forces are important relative to gravitational forces, have revealed a unique unsteady annular flow with periodic destabilization of the gas-liquid interface. Standing waves develop on the liquid film and grow into annular lobes similar with those observed in low-speed two-phase flow. The leading face of the lobe will decelerate and suddenly become normal to the wall of the capillary, suggesting the possibility of a shock wave in the gas phase at a downstream location from the minimum gas flow section. Visualization of the naturally occurring convergent-divergent nozzle-like structures as well as a discussion on the possibility of shock wave formation are presented.

A Numerical Study of BWR Steam Separator

2002 ◽  
Author(s):  
Haruo Terasaka ◽  
Sensuke Shimizu
Keyword(s):  
Transient Flow ◽  
Numerical Study ◽  
Fluid Model ◽  
Flow Analysis ◽  
Phase Flow ◽  
Step Size ◽  
Time Step ◽  
Two Phase ◽  
Time Step Size ◽  
Steam Separator

An advanced numerical method based on two-fluid model of two-phase flow has been developed to simulate the swirling gas-liquid flow and the phase separation process in a Boiling Water Reactor separator. The goal is to correctly predict the performance of operating steam separator as well as new designs. The solution method present here is an extension of SIMPLEST scheme, a fully implicit scheme for single-phase flow analysis. It is robust and unconditionally stable, therefore enable us to use very large time step size. This feature is suitable for steady and/or slow transient flow analyses. Furthermore, it enhances numerical stability during rapid transient calculations. By employing this method, separator hydrodynamics around swirler were calculated.

Sign in / Sign up

Export Citation Format

Share Document