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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
221

Kick circulation analysis for extended reach and horizontal wells

Long, Maximilian Mark 17 February 2005 (has links)
Well control is of the utmost importance during drilling operations. Numerous well control incidents occur on land and offshore rigs. The consequences of a loss in well control can be devastating. Hydrocarbon reservoirs and facilities may be damaged, costing millions of dollars. Substantial damage to the environment may also result. The greatest risk, however, is the threat to human life. As technology advances, wells are drilled to greater distances with more complex geometries. This includes multilateral and extended-reach horizontal wells. In wells with inclinations greater than horizontal or horizontal wells with washouts, buoyancy forces may trap kick gas in the wellbore. The trapped gas creates a greater degree of uncertainty regarding well control procedures, which if not handled correctly can result in a greater kick influx or loss of well control. For this study, a three-phase multiphase flow simulator was used to evaluate the interaction between a gas kick and circulating fluid. An extensive simulation study covering a wide range of variables led to the development of a best-practice kick circulation procedure for multilateral and extended-reach horizontal wells. The simulation runs showed that for inclinations greater than horizontal, removing the gas influx from the wellbore became increasingly difficult and impractical for some geometries. The higher the inclination, the more pronounced this effect. The study also showed the effect of annular area on influx removal. As annular area increased, higher circulation rates are needed to obtain the needed annular velocity for efficient kick removal. For water as a circulating fluid, an annular velocity of 3.4 ft/sec is recommended. Fluids with higher effective viscosities provided more efficient kick displacement. For a given geometry, a viscous fluid could remove a gas influx at a lower rate than water. Increased fluid density slightly increases kick removal, but higher effective viscosity was the overriding parameter. Bubble, slug, and stratified flow are all present in the kick-removal process. Bubble and slug flow proved to be the most efficient at displacing the kick.
222

Glucocorticoid access to the brain : involvement of the efflux transporter P-glycoprotein /

Karssen, Adriaan Martijn, January 2003 (has links)
Proefschrift--Universiteit Leiden, 2003. / Bibliogr.
223

La liberté de circulation des travailleurs en question : réflexion à partir des nouveaux États adhérents à l'Union européenne /

Tonev Stratula, Victoria. January 1900 (has links)
Texte remanié de: Mémoire de DEA--Droit--Dijon--Université de Bourgogne. / En appendice, choix de textes législatifs et réglementaires. Bibliogr. et webliogr. p. 171-178. Index.
224

Étude et parallélisation d'un code d'éléments finis pour la modélisation quasi-géostrophique des circulations océaniques

Bernier, Christine. Baras, Pierre. January 2008 (has links)
Reproduction de : Thèse de doctorat : mathématiques appliquées : Grenoble, INPG : 1990. / Titre provenant de l'écran-titre. Bibliogr. p. 157-161.
225

The influence of chronic hypoxia on the responses to endothelin of the pulmonary circulation of rats /

Das, Rapti. January 2001 (has links)
Thesis (Ph. D.)--University of Hong Kong, 2001. / Includes bibliographical references.
226

High arctic observations of strato-mesospheric temperatures and gravity wave activity

Duck, Thomas James. January 1999 (has links)
Thesis (Ph. D.)--York University, 1999. Graduate Programme in Physics and Astronomy. / Typescript. Includes bibliographical references (leaves 166-174). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL:http://gateway.proquest.com/openurl?url_ver=Z39.88-2004 & res_dat=xri:pqdiss & rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation & rft_dat=xri:pqdiss:NQ39262.
227

Simulation of the Bohai Sea circulation and theromohaline structure using COHERENS model /

Obino, Rodrigo S. January 2002 (has links) (PDF)
Thesis (M.S.)--Naval Postgraduate School, 2002. / Thesis advisor(s): Peter C. Chu, Steven D. Haeger. Includes bibliographical references (p. 117-119). Also available online.
228

Intraseasonal, large-scale circulations and tropical cylcome activity over the Western North Pacific during Boreal summer /

Delk, Tracey Lee. January 2004 (has links) (PDF)
Thesis (M.S. in Meteorology and Physical Oceanography)--Naval Postgraduate School, June 2004. / Thesis advisor(s): Patrick Harr. Includes bibliographical references (p. 73-75). Also available online.
229

Quantification of pulmonary gas exchange : combined effects of gas solubility and transport mechanisms /

Anderson, Joseph Clark. January 2001 (has links)
Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (p. 112-122).
230

The nature of the propagation of sea breeze fronts in Central California

Yetter, Joseph A. January 1990 (has links) (PDF)
Thesis (M.S. in Meteorology and Oceanography)--Naval Postgraduate School, September 1990. / Thesis Advisor(s): Shaw, William J. Second Reader: Durkee, Philip A. "September 1990." Description based on title screen as viewed on December 15, 2009. DTIC Identifier(s): Fronts (Meteorology), Atmosphere Models, Wave Propagation, LASBEX (Land Sea Breeze Experiment), Meteorological Data, Circulation, Directional, Atmospheric Motion. Author(s) subject terms: LASBEX, Lidar, Sodar. Includes bibliographical references (p. 64-65). Also available in print.

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