Experimental pvt analysis including flash liberation at separator conditions are carried out on gas condensate samples covering a great range of pvt properties. Pdf oil formation volume factor fvf is considered as relative change in oil volume between reservoir condition and standard surface condition. The reason of the oil formation volume factor being more than 1. Pvt properties is the oil formation volume factor fvf, which is defined as the volume of reservoir oil that would be occupied by one stock tank barrel oil plus any dissolved gas at the bubble point pressure and reservoir temperature. Formation volume factor is a measure of the ratio of the volume occupied by a fluid phase at reservoir conditions divided by the volume occupied by the fluid phase at surface conditions. Compressibility factor, z density, r g specific volume, v isothermal gas compressibility coefficient, c g gas formation volume factor, b g gas expansion factor, e g viscosity, m g the above gas properties may be obtained from direct laboratory measurements or by prediction from generalized mathematical expressions. Primarily, four volume factors are used in petroleum engineering. Calculating gas in place by the volumetric method gas in place by the volumetric method is given by. G pb g2 where g is gas initially in place, g p is cumulative gas production, and b g is the formationvolumefactor for gas.
Oil formation volume factor empirical correlations for some libyan. Presently, there is just one published correlation available to estimate the bubblepoint oil formation volume factor fvf directly in the absence of pvt analysis. As the reservoir pressure is decreased from initial reservoir pressure to bubble point pressure, there is a slight expansion of liquid in the reservoir, thus results in a. Up to now, there has not been one specific correlation published to directly estimate the bubblepoint pressure in the absence of pressurevolumetemperature pvt analysis.
Oil formation volume factor determination through a fused intelligence amin gholami a b s t r a c t volume change of oil between reservoir condition and standard surface condition is called oil formation volume factor fvf, which is very time, cost and labor intensive to determine. The volume of a fluid phase can have a sensitive dependence on. An empirical correlation for estimation of formation volume factor of gas condensate reservoirs at separator conditions article pdf available march 2018 with 241 reads how we measure reads. National assessment of geologic carbon dioxide storage. Oil compressibility volume changes of oil above the bubble point are very significant in recovering undersaturated oil. Reservoir fluid properties required for lowpermeability. Gt gas in place at time t, scf v b 43,560 a h bulk reservoir volume, ft3 43,560 ft 3acreft a area, acres. Pdf oil formation volume factor determination through a. The figure above shows how the formation volume factor changes as a function of pressure at constant reservoir temperature. Pdf oil formation volume factor determination through a fused. The oil formation volume factor, bo, is defined as the ratio of the volume of oil plus the gas in solution at the prevailing reservoir temperature and pressure to the volume of oil at standard conditions. The gas formation volume factor is used to relate the volume of gas, as measured at reservoir conditions, to the volume of the gas as measured at standard conditions, i. Formation volume factor for gas and oil viscosity for gas and oil solution gastooil ratio gor oil composition api gravity thermodynamic mmp crude oil swelling crude oil viscosity reduction singleand multiplecontact phase volumes dynamic modeling phase equilibrium modeling of the reservoir fluidc02. View notes 2014 oil formation volume factor from pte 461 at university of southern california.
Chapter pa production analysis production analysis of. The material balance equation for a closed gas reservoir is very simple. This gas property is then defined as the actual volume occupied by a certain amount of gas at a specified. An empirical correlation for estimation of formation. The units of bo are defined as reservoir barrels per stock tank barrel and account for the expansion that the hydrocarbon undergoes as a result of moving from a highpressure, high. The oil formation volume factor of saturated oils has been correlated by a number of investigators using the gas in solution rs, gas to oil ratio, gas gravity, oil. Prediction of oil formation volume factor using an. Pdf volume change of oil between reservoir condition and standard surface condition is called oil formation volume factor fvf, which is very time. Numerical prediction of oil formation volume factor at bubble point.
Ramsey 1960, correlation of oil formation volume factor and solution gasoil ratio, j. Formation volume factor how is formation volume factor. Maximum buoyant trapping pore volume minimum buoyant trapping pore volume residual trapping pore volume regional seal storage formation. Material balance calculations for petroleum reservoirs in 1936, schilthuis developed a general material balance equation that can be applied to all reservoir types. The units of bo are defined as reservoir barrels per stock tank barrel and account for the expansion that the hydrocarbon undergoes as a. Formation volume factor the plots in figure pa2 a through d are of the oil formation volume factor, normally represented as bo. The ratio of the resistivity of a rock filled with water r o to the resistivity of that water r w. An empirical correlation is developed to estimate oil formation volume factor b o. Reserves most of the oil stays stuck in the reservoir reserves can be produced economically varies widely depending on permeability, oil viscosity, reservoir pressure, etc. Fiddler creek presentation, wy co 2 conference, 52908 volumetric ooip.
Pvt properties include determination of saturation pressures, compositional characterizations, formation volume factors, viscosities. The oil formation volume factor can be expressed mathematically as. Gas z factor gas formation volume factor 5 gas expansion factor 6 calculated gas viscosity oilgas viscosity ratio psia gcm3 reservoir volume stock tank volume scfstb 1psi cp relative to air relative to air volume standard volume standard volume volume cp 6,015 0. Development of simple correlation to evaluate formation. Oil formation volume factor is one of the most important pressurevolume temperature properties of crude oils for reservoir evaluation and.
Therefore undersaturated oil formation volume factor and isothermal compressibility coefficient have been developed using the artificial neural networks. Mohmond et al 1992 used regression analysis to obtain correlation for bubble point. Applying the mass balance principle to a closed reservoir with 100% gas, we may derive the general eguation gb g1g. Oil formation volume factor determination through a fused. It has since been shown that f is independent of r w only for a certain class of petrophysically simple rocks archie rocks. The formation volume factor of gas is defined as the ratio of the volume of gas at the reservoir temperature and pressure to the volume at the standard or surface temperature and pressure p s and t s. Spe 7368 prediction of bubblepoint pressure and bubblepoint oil formation volume factor in the absence of pvt analysis s. Formation volume factor an overview sciencedirect topics.
Among those properties is the oil formation volume factor bo. Oil formation volume factor is defined as the ratio of the volume of oil at reservoir insitu conditions to that at stock tank surface conditions. Material balance calculations for petroleum reservoirs in 1936, schilthuis developed a general material balance equation. Information from chapter 3 of phase behavior spe monograph whitson and brule pdf of notes availa.
The prediction of bubblepoint pressure and bubblepoint. Mccain correlation for water formation volume factor, bbl. Surface conditions are typically stock tank or standard conditions. Estimating of undersaturated oil formation volume factor. The oil formation volume factor fvf parameter is a very important fluid property in reservoir engineering computations. Standing correlation for oil formation volume factor, p api gravity temperature correction online calculator. Formation volume factor change in volume from reservoir to surface conditions. The oil formation volume factor fvf relates the volume of oil at stocktank conditions to the volume of oil at elevated pressure and temperature in the reservoir. Pdf prediction of bubblepoint pressure and bubblepoint oil. Land surface probable low total dissolved solids zone thin regional seal zone fault 3,000 ft to,000 ft. Oil formation volume factor reflects these changes more fundamentally in the coefficient of compressibility of the oil. A lecture on the formation volume factor of natural gas.
Improved oil formation volume factor bo correlation for. Obomanu and okpobori 1987 in their work developed a correlation for oil formation volume factor and solution gas oil ratio for nigerian crude oil. Geological characterization of the muddynewcastle sandstone reservoir, fiddler creek field, weston county, wyoming mark tomasso and shaochang wo. It is given the symbol b g and is often expressed in either cubic feet of reservoir volume per standard cubic foot of gas or barrels of reservoir volume per standard. Archie postulated that the formation factor f was a constant independent of r w and solely a function of pore geometry the archie equation i. Oil formation volume factor an overview sciencedirect topics. Total formation volume factor, bt bt bo bg rsb rs above pb, bt bo. Oil formation volume factor an overview sciencedirect. Although it is a tank model equation, it can provide great insight for the practicing reservoir engineer. The above relationship is referred to as the material balance equation mbe. Oil formation volume factor is always greater than 1. A more convenient form of the mbe can be determined by introducing the concept of the total twophase formation volume factor b t into the equation. Pdf an empirical correlation for estimation of formation. Abstractphysical properties of reservoir fluid are necessary for different field applications.
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