scholarly journals Direct Calculation of Large-Scale Properties for One-Phase Flow in Random Fractured Systems

1996 ◽  
Author(s):  
A. Ahmadi ◽  
V. Remazeilles ◽  
B. Netinger ◽  
M. Quintard
Keyword(s):  
Large Scale ◽  
Direct Calculation ◽  
Phase Flow ◽  
Scale Properties

Surveillance Models of Large-Scale ESP With High Viscosity Fluids and Gas

2012 ◽  
Author(s):  
Lissett Barrios ◽  
Stuart Scott ◽  
Charles Deuel
Keyword(s):  
Large Scale ◽  
Two Phase Flow ◽  
Electrical Current ◽  
High Viscosity ◽  
Viscous Fluids ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Operational Parameters ◽  
Two Phase ◽  
Operational Conditions

The paper reports on developmental research on the effects of viscosity and two phases, liquid–gas fluids on ESPs which are multi stage centrifugal pumps for deep bore holes. Multiphase viscous performance in a full-scale Electrical Submersible Pump (ESP) system at Shell’s Gasmer facility has been studied experimentally and theoretically. The main objectives is to predict the operational conditions that cause degradations for high viscosity fluids when operating in high Gas Liquid Radio (GLR) wells to support operation in Shell major Projects. The system studied was a 1025 series tandem WJE 1000. The test was performed using this configuration with ten or more pump stages moving fluids with viscosity from 2 to 200 cP at various speed, intake pressure and Gas Void Fractions (GVF). For safety considerations the injected gas was restricted to nitrogen or air. The ESP system is a central artificial lift method commonly used for medium to high flow rate wells. Multiphase flow and viscous fluids causes problems in pump applications. Viscous fluids and free gas inside an ESP can cause head degradation and gas locking. Substantial attempts have been made to model centrifugal pump performance under gas-liquid viscous applications, however due to the complexity this is still a uncertain problem. The determination of the two-phase flow performance in these harmful conditions in the ESP is fundamental aspects in the surveillance operation. The testing at Shell’s Gasmer facility revealed that the ESP system performed as theoretical over the range of single flowrates and light viscosity oils up to Gas Volume Fractions (GVF) around 25%. The developed correlations predict GVF at the pump intake based on the operational parameters. ESP performance degrades at viscosity higher than 100cp as compared to light oil applications, gas lock condition is observed at gas fraction higher than 45%. Pump flowrate can be obtained from electrical current and boost for all range of GVF and speed. The main technical contributions are the analysis of pump head degradation under two important variables, high viscosity and two-phase flow inside the ESP.

scholarly journals Measuring and calibrating galactic synchrotron emission

2008 ◽  
Vol 4 (S259) ◽  
pp. 603-612 ◽  
Author(s):  
Wolfgang Reich ◽  
Patricia Reich
Keyword(s):  
Large Scale ◽  
Angular Resolution ◽  
Galactic Plane ◽  
Synchrotron Emission ◽  
Diffuse Emission ◽  
Sky Surveys ◽  
Zero Level ◽  
The Galaxy ◽  
Scale Properties ◽  
Relative Measurements

AbstractOur position inside the Galaxy requires all-sky surveys to reveal its large-scale properties. The zero-level calibration of all-sky surveys differs from standard ‘relative’ measurements, where a source is measured in respect to its surroundings. All-sky surveys aim to include emission structures of all angular scales exceeding their angular resolution including isotropic emission components. Synchrotron radiation is the dominating emission process in the Galaxy up to frequencies of a few GHz, where numerous ground based surveys of the total intensity up to 1.4 GHz exist. Its polarization properties were just recently mapped for the entire sky at 1.4 GHz. All-sky total intensity and linear polarization maps from WMAP for frequencies of 23 GHz and higher became available and complement existing sky maps. Galactic plane surveys have higher angular resolution using large single-dish or synthesis telescopes. Polarized diffuse emission shows structures with no relation to total intensity emission resulting from Faraday rotation effects in the interstellar medium. The interpretation of these polarization structures critically depends on a correct setting of the absolute zero-level in Stokes U and Q.

scholarly journals Large-Scale Properties of the Tilt of Sunspot Groups and Joy’s Law Near the Solar Equator

Astrophysics ◽  
2019 ◽  
Vol 62 (2) ◽  
pp. 261-275 ◽  
Author(s):  
K. M. Kuzanyan ◽  
N. Safiullin ◽  
N. Kleeorin ◽  
I. Rogachevskii ◽  
S. Porshnev
Keyword(s):  
Large Scale ◽  
Scale Properties ◽  
Sunspot Groups
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