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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Pressure loss in core-annular flow: Modeling, experimental investigation and full-scale experiments

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Rodriguez, O. M. H. [1] ; Bannwart, A. C. [2] ; de Carvalho, C. H. M.
Total Authors: 3
[1] USP, SEM EESC, Engn Sch Sao Carlos, Dept Mech Engn, BR-13566970 Sao Carlos, SP - Brazil
[2] Univ Estadual Campinas, Fac Mech Engn, Dept Petr Engn, Campinas - Brazil
Total Affiliations: 2
Document type: Journal article
Source: JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING; v. 65, n. 1-2, p. 67-75, MAR 2009.
Web of Science Citations: 35

The use of core-annular flow pattern. where a thin fluid surrounds a very viscous one, has been suggested as an attractive artificial lifting method for heavy oils in the current Brazilian ultra-deep water production scenario. This paper proposes a more refined pressure-loss prediction model for core-annular flow which includes a slip ratio term that implicitly accounts for the buoyancy of the oil core. Frictional pressure-gradient measurements in upward-vertical and horizontal core-annular flows in a 28.4-mm-i.d. 2.5-m-length glass tube (tap water and crude oil of 500 mPa s and 925 kg/m(3) at 20 degrees C) and 77-mm-i.d. 274-m-length steel pipeline conveying an ultra-viscous crude oil (36,950 mPa s and 972.1 kg/m(3) at 20 degrees C) respectively, are reported. The model shows very good agreement with the present data and data from the literature, improving some correlations previously developed. Regarding the onshore-field experiments, two pressure-gradient reduction factors are proposed. The observed improvement of oil production rates and pressure-loss reductions are remarkable. (c) 2009 Elsevier B.V. All rights reserved. (AU)