# Oil And Gas Process

1. #### Difference Between Viscosity and Density

by , 10-16-2012 at 01:50 PM
Originally Posted by Mohamed
Viscosity and density are two properties of liquids and gases (or referred as fluids). They are very useful physical quantities when it comes to describing statics and dynamics of these substances. Viscosity and density alone can describe more than half the properties of a fluid. Viscosity Viscosity is defined as a measure of the resistance of a fluid which is being deformed by either shear stress or tensile stress. In more common words, viscosity is the “internal friction” of a fluid. It’s also referred as the thickness of a fluid. Viscosity is simply the friction between two layers of a fluid when the two layers move relative to each other. Sir Isaac Newton was a pioneer in fluid mechanics. He postulated that, for a Newtonian fluid, the shear stress between layers is proportional to the velocity gradient in the direction perpendicular to the layers. The proportional constant (proportionality factor) used here is the viscosity of the fluid. The viscosity is usually denoted by the Greek letter “µ”. Viscosity of a fluid can be measured using Viscometers and Rheometers. The units of viscosity are Pascal-seconds (or Nm-2s). The cgs system uses the unit “poise”, named after Jean Louis Marie Poiseuille, to measure viscosity. Viscosity of a fluid can also be measured by several experiments. The viscosity of a fluid depends on the temperature. The viscosity decreases as the temperature is increased. Viscosity equations and models are very complex for non-Newtonian fluids. Density Density is defined as mass per unit volume. Density plays a vital role in fluid mechanics. Events such as up thrust are dependent on the density. Density is what we normally refer to as “weight” of a fluid. Density is a concept with which we are really familiar. It can be obtained from the simple equation density=mass/volume. Its units are Kgm-3. What is the difference between Viscosity and Density? While most of the people think that viscosity and density are both the same
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2. #### papers about slug flow

by , 07-09-2010 at 03:00 AM
Originally Posted by Mohamed
I will be thankful if any one can help me to get any of the following papers about slug flow

ABSTRACT · Taitel and Dukler, A model for predicting flow regime transitions in horizontal and near horizontal gas liquid flow, AIChE J. 1976, 22, 47-5
· Herm Stapleberg, H. and Mewes, D., ‘The pressure loss and slug frequency of liquid-liquid-gas slug flow in horizontal pipes’, Int. J. Multiphase Flow, 1994, 20(2), pp.185-303.
· Yocum, B.T.: “Offshore Riser Slug Flow Avoidance, Mathematical Model for Design and Optimization,” SPE 4312, presented at SPE European Meeting, London, April 1973.
· Schmidt, Z.: “Experimental Study of Two-Phase Slug Flow in a Pipeline-Riser Pipe System,” Ph.D. Dissertation, U. of Tulsa 1977.
· Schmidt, Z. et al.: “Choking Can Eliminate Severe Pipeline Slugging,” Oil and Gas J. 12, 230-8, 1979.
· Schmidt, Z. et al.: “Severe Slugging in Offshore Pipeline-Riser Pipe System,” SPEJ, 27-38, 1985.
· Farghaly, M. A.: “Study of Severe Slugging in Real Offshore Pipeline Riser-Pipe System,” SPE 15726, Presented at SPE Middle East Oil Technology Conference, Manama, Bahrain March 1987.
· Jansen, F. E.: “Elimination of Severe Slugging in a Pipeline-Riser System,” MS. Thesis, U. of Tulsa, 1990.
· Bendiksen et al.: “The Dynamic Two-Fluid Model OLGA: Theory and Application,” SPE Production Engineering, 171-180, May 1991.
· McGuinness, M., and Cooke, D.: “Partial Stabilization at St. Joseph,” 3rd International Offshore and Polar Engineering Conference, 235-241, June 6-11, Singapore 1993.
· Hill, T. J.: “Gas Injection at Riser Base Solves Slugging, Flow Problems,” Oil and Gas J., 88-92 February 26, 1990.
· Courbot, A.: “Prevention of Severe Slugging in the Dunbar 16” Multiphase Pipeline,” OTC 8196, 1996 Offshore Technology Conference, 445-452, 1996.
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