油层物理学课件(双语).pptVIP

Reservoir fluids refer to the crude oil, natural gas and water containing in the pores of the reservoir rocks. (3)As one constituent(组分) becomes more predominant, the phase envelope tends to shift to the vapor-pressure curve of the major pure component. (4)The critical temperature Tc of the mixture lies between the critical temperatures of the two pure components. Pc is usually high then Pc of the two components. Locus of critical points (临界点轨迹线) (5)a larger difference in molecular size of the components causes the mixtures to have very large critical pressures. 6)a small difference in molecular size of the components causes the small critical pressures. 测定原理： 3.3 Phase behavior of multi-component system (多组分相图) The shape is an envelop. (1)Characteristic 3.3 Phase behavior of multi-component system (多组分相图) Fig. 1.1.8 Phase diagram of a multi- component system C –Critical point； KC-Bubble point curve. OC-Dew point curve. Liquid region --Above the bubble point line ； Gas region -Below and to the right of the dew point line Two phase region-- The region bounded the bubble point line and dew point line. Dotted lines --the iso vol lines (quality lines) -等液量线 Liquid region Gas region Gas region Two phase region- Cricondenbar P’ (临界凝析压力）the highest pressure on the saturation envelope. Cricondentherm T’ (临界凝析温度) the highest temperature on the saturation envelope. The shaded area--Retrograde region where condensation or vaporization occurs in reverse to the conventional behavior. --isothermal retrograde condensation --isobaric retrograde condensation (2)Retrograde Condensation (反常凝析） Point A: entirely gas Point B: Upper dew point Point D: maximum amount of liquid Point E :Lower dew point Point F: entirely gas At normal condition, a decrease in pressure causes a change of phase from liquid to gas. But in condensate gas reservoir, the process is exactly the reverse of normal one, hence call it retrograde condensation. the hydrocarbon sys