SPECIFIC VISCOSITY UNITS FULL

All other fluids are then measured, calibrated, and thus compared to the viscosity of water. Water at approximately 70☏ (21☌) has an absolute viscosity of about one centipoise. Molasses and motor oil are thick or high viscosity liquids while gasoline and water are thin, low viscosity liquids. Thick liquids are said to have a high viscosity and thin liquids a low viscosity. Viscosity can also be thought of as a measure of the 'thickness' of the liquid. Thinner liquids, such as water, have lower viscosities, while thicker liquids like oil have higher viscosities. Viscosity is the measure of a fluid's resistance to flow. Viscosity measurements are used in everything from lubrication and heat transfer fluids, to adhesives and coatings to aerodynamic and hydrodynamic drag. One of the more obscure and confusing parameters is viscosity. These behaviors are defined by a collection of measurements. SPE-1340-PA.There is a branch of science called Rheology that deals with the deformation and flow of materials. Gases and Vapors At High Temperature and Pressure - Density of Hydrocarbon. Hydrocarbon Processing 51 (May): 119–122. Presented at the SPE Annual Technical Conference and Exhibition, Houston, 3–6 October.

Compressibility Factors for Naturally Occurring Petroleum Gases (1993 version). Presented at the SPE Annual Technical Conference and Exhibition, Las Vegas, Nevada, USA, 22-26 September. Compressibility Factors for High-Molecular-Weight Reservoir Gases. Viscosity of Hydrocarbon Gases Under Pressure. s by dividing by 1,000.Ĭalculate the viscosity at 150☏ (609.67°R) and 2,012 psia for the gas of the composition shown in Table 1.This viscosity unit (cp) is also easily converted to the SI unit of Pa were originally written to give the viscosity in micropoise, but the modified form above gives the viscosity in the more commonly used centipoise. In using these equations, it is important either to measure the density or to ensure that the z -factor calculation has included the effect of N 2, CO 2, and H 2S using the method of Wichert and Aziz. M g = gas molecular weight = 28.967 γ gįor the data from which the correlation was developed, the standard deviation in the calculated gas viscosity was 2.7%, and the maximum deviation was 9%.are for specific units as noted below and are as follows: The method uses the gas temperature, pressure, z factor, and molecular weight, which have to be measured or calculated the density can be measured or calculated as well.

This method lends itself for use in computer programs and spreadsheets. developed a useful analytical method that gives a good estimate of gas viscosity for most natural gases. 5 – Pseudocritical properties of methane-based natural gases (from Sutton ). 2 are corrections to be added to the atmospheric viscosity when the gas contains N 2, CO 2, and H 2S.įig. If only specific gravity is known, then the pseudocritical properties would have to be obtained from Fig.

SPECIFIC VISCOSITY UNITS FULL

However, Kay’s rules require a full gas composition. to calculate the pseudocritical properties for use with those charts. It would not be correct, then, to use the methods of Sutton or Piper et al. ) are based on pseudocritical properties determined with Kay’s rules. 4) to obtain the viscosity at reservoir temperature and pressure. This viscosity is then multiplied by the viscosity ratio (from Fig. N = number of components in the gas mixture.M gi = molecular weight of the ith component of the gas mixture.μ i = viscosity of the ith component of the gas mixture at the desired temperature and atmospheric pressure (obtained from Fig.y i = mole fraction of the ith component.μ ga = viscosity of the gas mixture at the desired temperature and atmospheric pressure.2 or determined from the gas-mixture composition with Eq. The viscosity of gas mixtures at one atmosphere and reservoir temperature can either be read from Fig.

4 – Effect of temperature and pressure on viscosity of natural gases (from Carr et al.

Specific viscosity units