油层物理课件 chap1.3

• gas formation volume factor (体积系数) and expansion factor
• viscosity of natural gas (粘度) •Other equations of state for real gases
•Gas hydrate
Provincial Bilingual Teaching Demonstration Course
Benzene (C6H6), others
Nitrogen (N2) Carbon dioxide (CO2) Hydrogen sulfide (H2S) Helium (He) Other sulfur and nitrogen compounds Water (H20)
Traces
Trace –15 Trace – 1 Trace occasionally Trace – 5 Trace occasionally Trace - 5
• Composition(组成), Apparent Molecular Weight (视相对分子质
量)and Specific Gravity (相对密度)of Natural Gas
• equation of state (状态方程) • the coefficient of isothermal compressibility (等温压缩系数) of gas
i 1
k
Kay mixing rule
Mg= apparent molecular weight of gas mixture, g/mol; Mi= molecular weight of the ith component, g/mol; yi= mole fraction of the ith component. Provincial Bilingual Teaching Demonstration Course
Cyclopropane (C3H6) Cyclohexane (C6H12)
Amount (%)
70 - 98 1 - 10 Trace - 5 Trace – 2 Trace – 1 Trace – 0.5 None - trace
Traces Traces
Paraffinic
Cyclic
Aromatic
Solution:
M g yi M i yO M O y N M N y A M A
i 1
k
0.21* 32.0 0.78* 28.01 0.01* 39.94 28.97g / m ol 29g / m ol
Provincial Bilingual Teaching Demonstration Course
1.3 Specific gravity (相对密度) The ratio of the density of a gas to the density of dry air when both are measured at standard conditions.
g
g a
Mg Ma Mg 29
vi
:
ni yi ni Vi vi yi Vi
Wi wi Wi
Molecular weight
wi:
yi M i wi yi M i
wi / M i yi wi / M i
Βιβλιοθήκη Baidu
Provincial Bilingual Teaching Demonstration Course
1.2 Apparent Molecular Weight of Natural Gas (视相对分子 质量)
Example: Calculation of the apparent molecular weight of dry air Component mole fraction Nitrogen 0.78 Oxygen 0.21 Argon 0.01 1.0
Nonhydrocarbon
1.1 Composition of natural gases
Definition: the components and their relative quantities of a natural gas.
Mole fraction, yi : Volume fraction, mass fraction,
1.2 Apparent Molecular Weight of Natural Gas (视相对分子质量) Definition:
The weight of 1 mole natural gas at standard conditions (0℃, 0.101MPa).
M g yi M i
1 Composition, Apparent Molecular Weight and Specific Gravity of Natural Gas
Category Component
Methane (CH4) Ethane (C2H6) Propane (C3H8) Butane (C4H10) Pentane (C5H12) Hexane (C6H14) Heptane and higher (C7+)
1.3 Properties of Natural Gas (天然气的性质)
SUN Ren-yuan School of Petroleum Engineering Sep., 2009
Provincial Bilingual Teaching Demonstration Course
Contents
g
Provincial Bilingual Teaching Demonstration Course
2 Equation of state (状态方程)
Equation of state: an equation which relates volume to pressure and temperature. 2.1 Behavior of ideal gas 1) The volume occupied by the molecules is insignificant with respect to the volume occupied by the gas. 2) There are no attractive or repulsive forces between the molecules or between the molecules and the walls of the container. 3) All collisions of molecules are perfectly elastic, that is, there is no loss of internal energy upon collision. Provincial Bilingual Teaching Demonstration Course