At standard conditions

Reservoir fluids are broadly cafegorised using those properties which are easy to measure in the field, namely oil and gas gravity, and the producing gasioil ratio (GOR) which is the volumetric ratio of the gas produced at standard condition of femperature and pressure (STP) fo fhe oil produced at STP. The commonly used units are shown in the following table. 

The most important use of the real gas law is to calculate the volume which a subsurface quantity of gas will occupy at surface conditions, since when gas sales contracts are negotiated and gas is subsequently sold it is referred to in volumes at standard conditions of temperature (Tsc) and pressure (Psc). 

It can be shown using the real gas law, and the knowledge that at standard conditions z = 1.0, that for a reservoir pressure (P) and temperature (T) ... 

The column (or line entry) headed a gives the volume of gas (in milliliters) measured at standard conditions (0°C and 760 mm or 101.325 kN dissolved in 1 mL of water at the temperature stated (in degrees Celsius) and when the pressure of the gas without that of the water vapor is 760 mm. The line entry A indicates the same quantity except that the gas itself is at the uniform pressure of 760 mm when in equilibrium with water. 

The oxygen transfer rate for aerators is normally reported at standard conditions. Thus, ia order to make meaningful comparisons, the ORT under working or field conditions should be adjusted to standard conditions oxygen requirement for treatment (SORT) by means of... 

Space Velocity. The space velocity is the ratio of the volumetric rate of gas at standard conditions to the volume of the catalyst. Generally, the percentage of ammonia in the existing gas decreases as space velocity increases however, the same volume of catalyst at the increased space velocities is capable of producing more ammonia (Fig. 4) (27). Normally space velocities for commercial operations are between 8,000 and 60, 000 h . ... 

Reaiianging equation 50, applying the energy balance, and assuming air at standard conditions enters the tower yield (38) ... 

Density and Relative Density. Density is mass per unit volume and in SI is normally expressed as kilograms per cubic meter (density of water = 1000 kg/m or 1 g/cm ). The term specific gravity was formerly the accepted dimensionless value describing the ratio of the density of sohds and Hquids to the density of water at 4°C or for gases to the density of ak at standard conditions. The term specific gravity is being replaced by relative mass density, a more descriptive term. 

Bromine [7726-95-6] Bi2, is the only nonmetallic element that is aUquid at standard conditions. Bromine [10097-32-2] Br, has at no. 35, at wt 79.904, and belongs to Group 17 (VIIA) of the Periodic Table, the halogens. Its electronic configuration is. The element s known isotopes... 

Corrosion occurs even if the two reactants involved are not at standard conditions. In this case the nonstandard equiUbrium potential for each reaction, often referred to as the reversible potential, can be calculated from the Nemst equation. Additional information on thermodynamic aspects of corrosion can be found in Reference 10. 

Mass concentration units for ambient measurements are mass (/xg) per unit volume (m ). Size classification involves the use of specially designed inlet configurations, e.g., PMjq sampling. To determine mass concentration, all the particles are removed from a known volume of air and their total mass is measured. This removal is accomplished by two techniques, filtration and impaction, described in Chapter 13. Mass measurements are made by pre-and postweighing of filters or impaction surfaces. To account for the absorption of water vapor, the filters are generally equilibrated at standard conditions T = 20°C and 50% relative humidity). 

Specific volume is determined by application of the ideal gas law. One pound mole of air occupies a volume of 359 cubic feet at standard conditions, hence ... 

A simplified estimate can be made by first converting the flow at actual conditions to the flow at standard conditions (i.e., at 70 F and 1 atm). The calculation basis for the linear velocity assumes a roughness coefficient of 0.0005 and a kinematic viscosity for air of 1.62 x lO fF/sec. From the ideal gas law, the following expression is developed ... 

SCFM Cubic feet of air per minute at standard conditions of temperature, pressure and humidity (0, 14.7 psi and 50% relative humidity). 

Table l.Estimated Thermodynamic Properties of Various Substances at Standard Conditions... 

For gaseous feeds, space velocity SV is normally determined in terms of volumes measured at standard conditions T = 25°C and P = 1.013 bar. 

A fireball s radiation hazard can be assessed by two factors its diameter (either as a function of time or original amount of fuel) and combustion duration. Fireball models presented by Lihou and Maund (1982), Roberts (1982), and others start with a hypothetical, premixed sphere of fuel and air (in some cases, oxidant) at ambient temperature. Because the molar volume of any gas at standard conditions... 

The Weymouth formula is also expressed (at standard conditions) as ... 

C = coefficient determined by the ratio of the specific heats of the gas at standard conditions. This can be obtained from Equation 2 [33a] in 4.3.2.1 of API Recommended Practice 520, Part I, or Figure 7-25. 

SpGr correction = (2.69) 72 = 154 Temperature correction = 0.9551 from Table 7-16 The volume at standard conditions of 14.7 psia and 60°F ... 

When it is considered that the volume of 1 km of 900 mm pipe is 636 dm, and if the pressure is allowed to fall from 42 bar to 19 bar, the equivalent volume of gas at standard conditions is 14,628 dm, then this should be compared to the capacity of a low-pressure gas holder of typically 28,320dm (1 million ft ). Two kilometers of pipeline operated under these conditions is therefore the equivalent of one gas holder. 

Gas that remains gaseous in the reservoir rock, whatever the pressure, but from which a liquid phase condenses at standard conditions. 

Gas that contains less than 0.013 volume per cent or 20 g of H2S per 1,000 m at standard conditions. 

Ratio between the volumes, measured at standard conditions, of the gas and oil produced simultaneously (units m /m or cu.ft./barrel). The English acronym GOR is also used in France. 

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