Geological Significance and Behavior of Petroleum Light Hydrocarbons under Vapour-Liquid Equilibrium Mechanism in Tarim Basin

Ma Keyang; Zhou Yonghong; Sheng Jianzhong

There are a lot of gas-condensate reserviors bearing gas-caps or oil-rings found in the north of Tarim Basin. The calculated Ro data demonstrate that the natural gases possess much higher maturity (Ro2. 3%) than that of the associated oils and condensates (Ro1. 1 %),taking unfitable physical properties of the ring-oil into consideration, we concluded that the natural gas is a allochthonous one and the condensate is the product of vapor-liquid equilibrium between the all chthonous natural gas and the oils in reservior, in this physical-chemistry proccess, all light hydrocarbons, having distributed themselves according to their vepor-liquid equilibrium constants, would occur in different proportions in the vapor and liquid phases. On the basis of the above conclusion, we suggest that the separation of gas-cap from oil-ring once occured in the past geological time, there would be independent gas Condensate accumulation fromed in Tarim Basin, and meanwhile the light hydrocarbons of the primary reservior fractionated, which caused the unusual distribution of light hydrocarbons in Ordovician to Cretaceous reserviors.

1 Lanzhou Institute of Geology, Chinese Academy of Sciences, Lanzhou 730000;

2 Professional University of Sheuli Oil Field, Dongying 257004

Received Date: 1994-12-02

Publish Date: 1995-12-10

Key words:

Abstract: There are a lot of gas-condensate reserviors bearing gas-caps or oil-rings found in the north of Tarim Basin. The calculated Ro data demonstrate that the natural gases possess much higher maturity (Ro2. 3%) than that of the associated oils and condensates (Ro1. 1 %),taking unfitable physical properties of the ring-oil into consideration, we concluded that the natural gas is a allochthonous one and the condensate is the product of vapor-liquid equilibrium between the all chthonous natural gas and the oils in reservior, in this physical-chemistry proccess, all light hydrocarbons, having distributed themselves according to their vepor-liquid equilibrium constants, would occur in different proportions in the vapor and liquid phases. On the basis of the above conclusion, we suggest that the separation of gas-cap from oil-ring once occured in the past geological time, there would be independent gas Condensate accumulation fromed in Tarim Basin, and meanwhile the light hydrocarbons of the primary reservior fractionated, which caused the unusual distribution of light hydrocarbons in Ordovician to Cretaceous reserviors.

HTML

Reference (1)

[1]

1.Hunt J. M. et al.，1970, Generation of Light hydrocarbons in sedimentary basin. Nature. 288: 688-690.

2.Hunt J. M. et al.，1984, Generation and migration of light hydrocarbons. Science, 12:1265-1270.

3.Leythauerser D. et al.，1979, Generation and migration of light hydrocarbons (C₂-C₇) in sealimentary basins. Ch-ganic Geochemistry, 1:191-204.

4.Philippi G. T.，The deep subsurface temperature controlled origin of the gaseous and gasoline-range hydrocarbons ofretroleum. Geochim. Cosmochim. Acata, 39: 1353-1373.

5.Thompson K. F. M.，1983, Classification and thermal history of petroleum based on light hydrocarbons. Geochim.Cosmochim. Acta, 47, 303-316.

6.Mongo F. D.，1990, The origin of Gght hydrocarbons in petroleum; A kinetic test of the steady-state catalytic hy-pothesis, Geochim. Cosmochim. Acta, 54: 1315-1323.

7.程克明等，1987，陆相原油及凝析油的轻烃单体组成特征及地质意义，石油勘探与开发，16(1): 14-22.

8.Philippi G. T. et al.，1981，Correlation of crude oils with their oil Source Formation. use High Resolution GLC C₆-C₇ Component Analyses. C;eochimica et Cosmochimica Acta, 45(9).

9.Stahl W. J. et al. 1975, Source-rock identification by isotope analyses of natural gases, west Taxas. Chem. Geol.， (16):257-267.

10.戴金星，1992，各类烷烃气的鉴别，中国科学(B)辑,(2):183-193.

11.马柯阳、范璞，1995，塔北沙18井石炭系蒸发分馏成因凝析油确认的地球化学证据。科学通报，40(19):1785 -1787.

12.Thompson K. F. M. . 1987，Fractionated aromatic petroleums and the generation of gas condensates, Org. Geochem,11(6)，573-590.

13.Sawatzky H. et al.，1977, MaturaUOn studies of Canadian east coast oils, CANMET Kep. 15.

14.徐永昌等，凝析油的地球化学特征，中国科学(B辑),1988, 6.643-650.

15.Yong A. et al.，1977, Calculation of ages of hydrocarbons in oils-physical chemistry applied to petroleum geochem-istry, A. A. P. G.，45(4):573-600.

16.Snowdon L. R. et al.，1982, Immature oil and condensate modification of hydrocarbons generation model for terrestri--al organic matter. AAPC ,Bull.，66:6.

Geological Significance and Behavior of Petroleum Light Hydrocarbons under Vapour-Liquid Equilibrium Mechanism in Tarim Basin

Abstract

References

Proportional views

通讯作者: 陈斌, bchen63@163.com

Article Metrics

Proportional views

Related