B    At a given temperature, this condition occurs when an oil releases an infinitesimal bubble of gas from solution when pressure drops below the bubblepoint. Depending on reservoir temperature, this fluid would be defined as an oil or a gas. The initial distribution of phases depends on depth, temperature, pressure, composition, historical migration, type of geological trap, and reservoir heterogeneity (that is, varying rock properties). Fuel oil is commonly used in engines and industrial furnaces. H    Denoted mathematically as Rs (SCFstandard cubic feet/STBstock tank barrels). Some basic fluid property definitions are provided here: The ratio of a phase volume (water, oil, gas, or gas plus oil) at reservoir conditions, relative to the volume of a surface phase (water, oil, or gas) at standard conditions resulting when the reservoir material is brought to the surface. J    As per the formula below, the oil density can be determined by: Subscribe to our free newsletter now - The Best of Petropedia.

An alternative interpretation in some gas-oil reservoirs is that composition varies continuously with depth. F   

An oil exhibits a bubblepoint pressure at saturated conditions, while a gas condensate exhibits a dewpoint pressure at saturated conditions. Standing, M. B., 1977, Volumetric and phase behavior of oil field hydrocarbon systems: Dallas, TX, Society of Petroleum Engineers, AIME. Other PVT measurements include true boiling point (TBP) distillation of the C7+ material and multicontact gas injection experiments. As commonly done, the phase and volumetric behavior of petroleum reservoir fluids is referred to as PVT (pressure-volume-temperature). Whitson, C. H., and M. R. Brulé, 1993, Phase behavior: Society of Petroleum Engineers Monograph Series, in press. The water found in petroleum reservoirs is usually a brine consisting mostly of sodium chloride (NaCl) in quantities from 10 to 350 ppt (‰); seawater has about 35 ppt. N    Coal Seam Gas: An Unconventional Alternative? Transformer oil temperature also has an effect on the density of transformer oil. Density of Oil is the ratio of the mass of oil to its volume. Petroleum reservoirs may contain any of the three fluid phases—water (brine), oil, or gas. Gas cycling projects designed to avoid liquid loss from retrograde condensation can usually be justified for fluids with liquid content higher than about 50 to 100 STBstock tank barrels/MMSCF. However, the densities of chlorinated oils can be greater than water. density of oil, linseed is equal to 942 kg/m³. p = kg/m3 Water at a temperature of 20°C has a density of 998 kg/m3 Sometimes the term ‘Relative Density’ is used to describe the density of a fluid. Experimental PVT measurements are usually obtained for (1) large oil and gas fields, (2) volatile oil and gas condensate reservoirs, and (3) reservoirs where gas injection is a potential EOR (enhanced oil recovery) method. A condition where an oil and gas are in thermodynamic equilibrium, that is, the chemical force exerted by each component in the oil phase is equal to the chemical force exerted by the same component in the gas phase, thereby eliminating mass transfer of components from one phase to the other. Relatively accurate correlations are available for estimating the key fluid properties of reservoir systems (Table 2). Water viscosity ranges from about 0.3 cP at high temperatures (>250°F394.261 K 121.111 °C 709.67 °R) to about 1 cP at ambient temperatures, increasing with increasing salinity. It is generally assumed that reservoir fluids are in a static state when discovered or, more correctly, that fluids are moving at a very slow rate relative to the time required to extract the fluids (10 to 50 years). W    As the water is denser than oil it is found at the bottom while oil is found on the top of the water. A condition when an oil or a gas is in a single phase but not at its saturation point (bubblepoint or dewpoint), that is, the mixture is at a pressure greater than its saturation pressure. Many types of crude oil are produced around the world.

Gas condensate reservoirs exhibit producing gas-oil ratios from 2500 to 50,000 SCFstandard cubic feet/STBstock tank barrels (400 to 10 STBstock tank barrels/MMSCF). Standing[5] and McCain[6] give useful reviews of property correlations for oil and gas, and other correlations are available. It is referred to as "heavy" because its density or specific gravity is higher than that of light crude oil.Heavy crude oil has been defined as any liquid petroleum with an API gravity less than 20°. The amount of surface condensate that can be vaporized in a surface gas at a specific pressure and temperature; sometimes referred to as liquid content. Society of Petroleum Engineers, 1981, Phase behavior: Dallas, TX, SPE Reprint Series No. Volatile oil reservoirs have become the norm in the past 20 years, mainly because discoveries are at greater depths with higher initial pressures. Clearly the fluids may still be in a dynamic state in terms of geological time. Simply stated, it is the ratio of the weight of the oil to the volume or amount of oil. E    McCain, W. D., Jr., 1990, Petroleum Fluids, 2nd ed. Terms of Use - Increasing salinity decreases gas in solution. S    An oil at its bubblepoint pressure or a gas at its dewpoint pressure. Other compounds (electrolytes) found in reservoir brines include calcium (Ca), magnesium (Mg), sulfate (SO4), bicarbonate (HCO3), iodide (I), and bromide (Br). For this reason, the table lists density from lowest to highest and includes the state of matter. At reservoir conditions, the brine that is sharing pore space with hydrocarbons always contains a limited amount of solution gas (mainly methane), from about 10 SCFstandard cubic feet/STBstock tank barrels at 1000 psia to about 35 SCFstandard cubic feet/STBstock tank barrels at 10,000 psia for gas-water systems and slightly less for oil-water systems.

During the exploration and production process it is important to understand that the density of water is more than that of oil.

Two types of fluid samples can be taken during production, or when a well is shut-in: Recombined separator samples are standard for gas condensate fluids, but they may also be used for oil reservoirs. The ratio of density of any gas at standard conditions (14.7 psia and 60 °F) to the density of air at standard conditions; based on the ideal gas law (pV = nRT), gas gravity is also equal to the gas molecular weight divided by air molecular weight (Mair = 28.97). The alcohol is the least dense and floats on the oil.

Denoted mathematically as Bw(bblbarrels/STBstock tank barrels), B0 (bblbarrels/STBstock tank barrels), Bg (ft3/SCFstandard cubic feet), and Bt (bblbarrels/STBstock tank barrels). Use the online API to Specific gravity converter to find the Sp gr of an oil …