A Modified Two-Phase Well-Control Model and Its Computer Applications as a Training and Educational Tool

1997 ◽  
Vol 9 (01) ◽  
pp. 14-20 ◽  
Author(s):  
Jonggeun Choe ◽  
Hans C. Juvkam-Wold
Keyword(s):  
Control Model ◽  
Computer Applications ◽  
Educational Tool ◽  
Two Phase ◽  
Well Control

Theory of Two-Phase Biofluid Flow Dynamics and Selected Applications

Volume 4 ◽  
2004 ◽  
Author(s):  
C. Kleinstreuer ◽  
P. W. Longest ◽  
Z. Zhang
Keyword(s):  
Two Phase Flow ◽  
Health Effect ◽  
Bypass Graft ◽  
Computer Applications ◽  
Phase Flow ◽  
Aerosol Delivery ◽  
Upper Airways ◽  
Two Phase ◽  
Optimal Drug ◽  
Human Airways

Examples of two-phase flows in the human body include particle-hemodynamics in branching arteries and toxic/therapeutic air-particle mixtures in the respiratory system. In this review, the fundamentals of modeling dilute particle suspensions are presented with computer applications to the geometric design of bypass graft-ends and the prediction of local aerosol depositions in the human upper airways. For the latter project, aerosols in the nano- and micro-size ranges, solid and liquid particles as well as evaporating droplets are considered. Specifically, the particle-hemodynamics project deals with the prediction of aggravating two-phase flow events leading to arterial diseases, such as atherosclerosis and hyperplasia, and subsequently the design of bypass grafts mitigating post-operative complications. The lung-aerosol project requires accurate and realistic computations of laminar-to-turbulent airflows and toxic (or therapeutic) particle depositions in the human airways for two applications: dosimetry-and-health-effect assessments of toxic particles and optimal drug aerosol delivery by inhalation. Two-phase flow results from different case studies are presented.

A Numerical and Experimental Study of Kick Dynamics at Downhole

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Rakibul Islam ◽  
Faisal Khan ◽  
Ramchandran Venkatesan
Keyword(s):  
Two Phase Flow ◽  
Drill Pipe ◽  
Management Strategies ◽  
Phase Flow ◽  
Sudden Increase ◽  
Prevention Strategies ◽  
Two Phase ◽  
Well Control ◽  
Gas Kick ◽  
Dynamic Numerical Simulation

The early detection of a kick and mitigation with appropriate well control actions can minimize the risk of a blowout. This paper proposes a downhole monitoring system, and presents a dynamic numerical simulation of a compressible two-phase flow to study the kick dynamics at downhole during drilling operation. This approach enables early kick detection and could lead to the development of potential blowout prevention strategies. A pressure cell that mimics a scaled-down version of a downhole is used to study the dynamics of a compressible two-phase flow. The setup is simulated under boundary conditions that resemble realistic scenarios; special attention is given to the transient period after injecting the influx. The main parameters studied include pressure gradient, raising speed of a gas kick, and volumetric behavior of the gas kick with respect to time. Simulation results exhibit a sudden increase of pressure while the kick enters and volumetric expansion of gas as it flows upward. This improved understanding helps to develop effective well control and blowout prevention strategies. This study confirms the feasibility and usability of an intelligent drill pipe as a tool to monitor well conditions and develop blowout risk management strategies.

ROLE-BASED SERIALIZABILITY USING ROLE ORDERING SCHEDULERS

2006 ◽  
Vol 07 (04) ◽  
pp. 437-450 ◽  
Author(s):  
TOMOYA ENOKIDO
Keyword(s):  
Access Control ◽  
Phase Locking ◽  
Control Model ◽  
Role Based Access Control ◽  
Access Control Model ◽  
Two Phase ◽  
The Subject ◽  
Locking Protocol ◽  
Access Rights ◽  
Role Based

In the role-based access control model, a role is a set of access rights. A subject doing jobs is granted roles showing the jobs in an enterprise. A transaction issued by a subject is associated with a subset of roles granted to the subject, which is named purpose. A method with a more significant purpose is performed before another method with a less significant purpose. We discuss which purpose is more significant than another purpose. We discuss two types of Role-Ordering (RO) schedulers SRO and PRO where multiple conflicting transactions are serializable in the significant order of subjects and purposes, respectively. We evaluate the RO schedulers compared with the traditional two-phase locking protocol in terms of throughput.

Use of Fiber Optic Information to Detect and Investigate the Gas-in-Riser Phenomenon

2021 ◽  
Author(s):  
Otto L. Santos ◽  
Wesley C. Williams ◽  
Jyotsna Sharma ◽  
Mauricio A. Almeida ◽  
Mahendra K. Kunju ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Fiber Optic ◽  
Control Area ◽  
State University ◽  
Two Phase ◽  
Flow Rates ◽  
Well Control ◽  
Louisiana State University ◽  
Potential Applications ◽  
Experimental Runs

Abstract Potential applications of optical fiber technologies in the well control area are to detect the presence of gas and to unfold the gas dynamics inside marine risers (gas-in-riser). These issues became even more relevant now when considering the application of managed pressure drilling (MPD) operations in deep and ultradeep waters that may allow for a controlled amount of gas inside the riser. The application of these fiber optic technologies in the well control domain is currently being evaluated at Louisiana State University (LSU) as a part of a gas-in-riser research project granted by the Gulf Research Program (GRP). To accomplish that, an actual well was recompleted and instrumented with fiber optic sensors to continuously collect data along the wellbore and with four pressure and temperature downhole gauges to record those parameters at four discrete depths. A 2-7/8 in. tubing string with its lower end at a depth of 5026 ft and a chemical line to inject nitrogen at the bottom of the hole were also installed in the well. This paper discusses the results of four out seven experimental runs that were performed in this full-scale apparatus using fresh water and nitrogen in order to calibrate the installed pieces of equipment, to train the crew of researchers to run the tests, to check experiments repeatability and to obtain experimental results under very controlled conditions since water and nitrogen have well defined and constant properties. The paper also presents a mathematical model based on the unsteady-state flow of a two-phase mixture that was developed to help design the experimental runs. The results obtained in the seven runs were used to calibrate the model that was additionally modified to read the experimental parameters. The simulated results produced a remarkable agreement with the fiber optic and pressure and temperature sensors gathered data. Finally, the paper shows and analyzes simulation results of gas-in-riser operations on an actual drilling floater unit after the mathematical model has been adapted to predict pressures and output flow rates during gas circulations out of the riser. The effects of circulation flow rate, backpressure applied at surface and amount of gas inside the riser on pressures and flow rates are displayed and analyzed.

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