scholarly journals An analytical model for predicting transient flow into equally spaced ditch drains receiving water from a uniformly ponded field

2013 ◽  
Author(s):  
G. Barua ◽  
W. Alam
Keyword(s):  
Analytical Model ◽  
Transient Flow ◽  
Receiving Water

Generalized 3D Analytical Model for Transient Flow in Compartmentalized Reservoirs

SPE Journal ◽  
2000 ◽  
Vol 5 (03) ◽  
pp. 276-286 ◽  
Author(s):  
N.M.A. Rahman ◽  
A.K. Ambastha
Keyword(s):  
Analytical Model ◽  
Transient Flow

Probabilistic Models for Kick Tolerance

2021 ◽  
Author(s):  
Martine Kristoffersen ◽  
Dalila Gomes ◽  
Kjell Kåre Fjelde
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Analytical Model ◽  
Flow Model ◽  
Transient Flow ◽  
Simulation Framework ◽  
Gas Distribution ◽  
Fracture Pressure ◽  
Open Hole

Abstract Kick tolerance is an evaluation of how large kick sizes i.e. kick volumes an open hole section can withstand without threatening the formation integrity at the shoe. If a certain kick size cannot be handled safely, the planned open hole section must be shortened, and the casing design must be altered. Three models for calculating the kick tolerances in a well will be compared for a long and short open hole section for various lengths of bottom hole assembly (BHA). The kick tolerance will be performed probabilistically by use of Monte Carlo simulations where important input parameters are considered as distributions. The paper will focus on where the models differ in their results and discuss various opportunities and challenges with using a probabilistic approach. The models will be integrated in a Monte Carlo simulation framework where the major input uncertainties will be pore pressure, fracture pressure and initial gas distribution in the well. The output will be a distribution of the casing pressure load that has to be compared to the fracture pressure distribution which results in a certain probability for fracturing for a given kick size. Only gas kick in water-based mud will be considered. First a transient model based on the single bubble concept was considered and integrated in the Monte Carlo simulation framework. This was first compared against an analytical model which calculates the maximum casing shoe pressure at static shut in conditions. The analytical model considers uncertainty in the initial gas distribution. A transient flow model based on the drift flux model was also considered. Both short and long open hole length were considered. BHA length and kick size were varied. The results show that the transient flow model provides the least conservative results but also the analytical model reduces the probability for fracturing compared to the single bubble model. In most cases, the maximum casing shoe pressure is achieved when kick is located at the BHA. This paper extends the application of methods for reliability-based casing design to also include probabilistic kick tolerances. This is a contribution related to how the well design process can become more risk based. Some challenges related to specification of tolerance requirements, required number of Monte Carlo simulations and computing time will be discussed. It also provides an overview of the differences between the models and which parameters that are most important for the results.

Transient Hydraulic Response of a Pressurized Water Reactor Steam Generator to a Feedwater Line Break Using the Nonflashing Liquid Flow Model

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Jong Chull Jo ◽  
Jae Jun Jeong ◽  
Frederick J. Moody
Keyword(s):  
Analytical Model ◽  
Steam Generator ◽  
Liquid Flow ◽  
Transient Flow ◽  
Cfd Analysis ◽  
Simple Analytical Model ◽  
Pressurized Water ◽  
Hydraulic Loading ◽  
Transient Velocity ◽  
Secondary Side

In this study, a computational fluid dynamics (CFD) analysis of the transient flow field inside the secondary side of a nuclear reactor steam generator (SG) during blowdown following a feedwater line break (FWLB) accident is performed to evaluate the transient hydraulic loading (pressure) on the SG internals and tubes. The nonflashing liquid flow is assumed for a conservative prediction of the transient blowdown loading. The CFD analysis results are illustrated in terms of the transient velocity and pressure disturbances at some selected monitoring points inside the SG secondary side and compared with those predictions obtained from the existing simple analytical model to examine the physical validity of the CFD analysis model. As a result, the existing simple analytical model cannot yield the transient velocity and pressure disturbances and results in underestimation during blowdown as compared to the CFD calculations. Based on the present CFD analysis results, it is seen that an FWLB may result in excessive disastrous transient hydraulic loading on the SG internal structures and tubes near the feedwater inlet nozzle due to the significant pressure changes (pressure wave with very high amplitude) and abruptly increased velocity of water near the feedwater nozzle.

A semi-analytical model for transient flow to a subsurface tile drain

2006 ◽  
Vol 317 (1-2) ◽  
pp. 49-62 ◽  
Author(s):  
Jennifer S. Stillman ◽  
Nathan W. Haws ◽  
R.S. Govindaraju ◽  
P. Suresh C. Rao
Keyword(s):  
Analytical Model ◽  
Transient Flow

ANALYTICAL MODEL OF SUPEREXCHANGE

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-911-C8-912
Author(s):  
Yu. V. Rakitin ◽  
V. T. Kalinnikov
Keyword(s):  
Analytical Model
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