Water, density

In Section 5.2.8 we shall look at pressure-depth relationships, and will see that the relationship is a linear function of the density of the fluid. Since water is the one fluid which is always associated with a petroleum reservoir, an understanding of what controls formation water density is required. Additionally, reservoir engineers need to know the fluid properties of the formation water to predict its expansion and movement, which can contribute significantly to the drive mechanism in a reservoir, especially if the volume of water surrounding the hydrocarbon accumulation is large. 

Formation water density is a function of its salinity (which ranges from 0 to 300,000 ppm), amount of dissolved gas, and the reservoir temperature and pressure. As pressure increases, so does water density, though the compressibility is small... 

The water pressure gradient is related to the water density (p, kg/m ) by the following equation ... 

The visualization of volumetric properties is more important in other scientific disciplines (e.g., computer tomography in medicine, or convection streams in geology). However, there are also some applications in chemistry (Figure 2-125d), among which only the distribution of water density in molecular dynamics simulations will be mentioned here. Computer visualization of this property is usually realized with two or three dimensional textures [203]. 

Many of the unusual properties of the perfluorinated inert fluids are the result of the extremely low intermolecular interactions. This is manifested in, for example, the very low surface tensions of the perfluorinated materials (on the order of 9-19 mN jm. = dyn/cm) at 25°C which enables these Hquids to wet any surface including polytetrafluoroethene. Their refractive indexes are lower than those of any other organic Hquids, as are theh acoustic velocities. They have isothermal compressibilities almost twice as high as water. Densities range from 1.7 to 1.9 g/cm (l )-... 

Hot-Water Process. The hot-water process is the only successflil commercial process to be appHed to bitumen recovery from mined tar sands in North America as of 1997 (2). The process utilizes linear and nonlinear variations of bitumen density and water density, respectively, with temperature so that the bitumen that is heavier than water at room temperature becomes lighter than water at 80°C. Surface-active materials in tar sand also contribute to the process (2). The essentials of the hot-water process involve conditioning, separation, and scavenging (Fig. 9). 

Compound CAS Registry Number Mp, °C Bp, °C Wate/ vK Methanol/ b water Density, g/mL... 

From Water Density at Atmospheric Pressure and Temperatures from 0 to 100°C, Tables of Standard Handbook Data, Standartov, Moscow, 1978. To conserve space, only a few tables of density values are given. The reader is reminded that density values may he found as the reciprocal of the specific volume values tabulated in the Thermodynamic Properties Tables subsection. 

Volatile content, water, density, volume and weight of surface coatings 24, 24A... 

The major difference of the water structure between the liquid/solid and the liquid/liquid interface is due to the roughness of the liquid mercury surface. The features of the water density profiles at the liquid/liquid interface are washed out considerably relative to those at the liquid/solid interface [131,132]. The differences between the liquid/solid and the liquid/liquid interface can be accounted for almost quantitatively by convoluting the water density profile from the Uquid/solid simulation with the width of the surface layer of the mercury density distribution from the liquid/liquid simulation [66]. 

However, they also predict a strong increase in local water density near the surface, whereas MD data (see above) suggest only an increase in correlation but not in overall packing density. 

Here the functions g(0) and /(0) are defined in a suitable way to produce the desired phase behavior (see Chapter 14). The amphiphile concentration does not appear expHcitly in this model, but it influences the form of g(0)— in particular, its sign. Other models work with two order parameters, one for the difference between oil and water density and one for the amphiphile density. In addition, a vector order-parameter field sometimes accounts for the orientional degrees of freedom of the amphiphiles [1]. 

In the CHS model only nearest neighbors interact, and the interactions between amphiphiles in the simplest version of the model are neglected. In the case of the oil-water symmetry only two parameters characterize the interactions b is the strength of the water-water (oil-oil) interaction, and c describes the interaction between water (oil) and an amphiphile. The interaction between amphiphiles and ordinary molecules is proportional to a scalar product between the orientation of the amphiphile and the distance between the particles. In Ref. 15 the CHS model is generalized, and M orientations of amphiphiles uniformly distributed over the sphere are considered, with M oo. Every lattice site is occupied either by an oil, water, or surfactant particle in an orientation ujf, there are thus 2 + M microscopic states at every lattice site. The microscopic density of the state i is p.(r) = 1(0) if the site r is (is not) occupied by the state i. We denote the sum and the difference of microscopic oil and water densities by and 2 respectively and the density of surfactant at a point r and an orientation by p (r) = p r,U(). The microscopic densities assume the values = 1,0, = 1,0 and 2 = ill 0- In close-packing case the total density of surfactant ps(r) is related to by p = Ylf Pi = 1 - i i. The Hamiltonian of this model has the following form [15]... 

V = liquid viscosity, centistokes = Density water/Density liquid ... 

A water inflow occurs suddenly at the rate of 1,000 bbl/day. Water heat capacity is 1 cal/g water density is 1,00 kg/m. The formation temperature is 200°F and the mud reaches the drill collars at a temperature of 160°F. Compute the annular temperature rise. 

To calculate the anode resistance a knowledge of the environmental resistivity is required. For submerged anodes the water resistivity can be obtained from graphical representations such as Fig. 10.19, provided that the temperature and water density are known. However, field data are preferable and, in the case of soils that have widely varying resistivities, they are essential. 

Water (density 1000 kg/m3, viscosity 1 mN s/m2) is pumped through a 50 mm diameter pipeline at 4 kg/s and the pressure drop is I MN/m2. What will be the pressure drop for a solution of glycerol in water (density 1050 kg/m3. viscosity 10 mN s/m2) when pumped at the same rate Assume the pipe to be smooth. 

Physical properties of water density 1000 kg/m3 viscosity 1 mN s/m2 thermal conductivity 0.6 W/m K specific heat capacity 4.2 kJ/kg K... 

Table 3.1. Water density and water cell concentration for water temperatures...

Repeat the studies, selecting intermediate temperature values using the relationships between Pq and J values for water shown in Table 3.2. For example, use Pb(WW) = 0.50 and J(WW) = 0.71 in Example 3.2. Compare the fx values with the Studies in Examples 3. land 3.2. A plot of each value from Studies in 3.1 and 3.2 will reveal the influence on these attributes with and without a density consideration. Also compare the average cluster sizes between these two groups of studies. How much difference is found in the fx values when water density is accounted for ... 

CO6-OO66. When 5.34 g of a salt dissolves in 155 mL of water (density = l.OOg /niL) in a coffee-cup calorimeter, the temperature rises from 21.6 °C to 23.8 °C. Determine q for the solution process, assuming that Ccal = Crater ... 

C12-0063. Urea, a fertilizer, has the chemical formula (NH2)2 CO. Calculate the vapor pressure of water above a fertilizer solution containing 7.50 g of urea in 15.0 mL of water (density = l.OOg/mL), at a temperature for which the vapor pressure of pure water is 33.00 torr. 

C12-0064. Ethylene glycol, an automobile coolant, has the chemical formula HOCH2 CH2 OH. Calculate the vapor pressure of water above a coolant solution containing 65.0 g of ethylene glycol dissolved in 0.500 L of water (density = 1.00 g/mL), at 100 °C, the boiling point of pure water. 

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