Study on the hydrocarbon expulsion history of the coals in Qinshui Basin, North China

Wei Li

Faculty of Natural Resources & Information Technology, China University of Petroleum,

Changping, Beijing, P. R. China, 102249.

[email protected]

Qinshui basin is located in the south of Shanxi province，North China. It is a major coal-bed gas exploration region in China and its coal-bed gas resource is extremely large(about 6.85×10¹²m³ ). A great number of high-production coal-bed gas wells have been drilled in Qinshui basin. However, There is now consensus that coals can have oil potential. The main objective of the study, in virtue of geochemistry and organic petrology methods and techniques, is to search the evidence of coal-generated oils and analyze the expulsion history of liquid hydrocarbons and methane gas of the coals in the Basin.

The methods and techniques of the research are as follow:

1. Searching aqueous, gas and oil-bearing fluid inclusions in sandstone samples from the strata between or above the coals under microscope and measuring homogenization temperatures of the inclusions. Using the grains containing oil inclusions (GOI) method to characterize paleo-oil saturation. 2. Analyzing the gross and biomarker compositions of oil inclusions, coal and sandstone extracts. In this study we will follow the techniques of George (1997) to prepare the oil inclusion samples. 3. Analyzing quantitatively maceral compositions and maturity of the coals and evaluating the hydrocarbon-generating potentiality. 4. Studying the expulsion history of liquid hydrocarbons and methane gas from the analysis of fluid inclusions, combined with the thermal maturity and burial history of the coals.

The research will be helpful for us to understand the coalbed gas generation and accumulation and guide the coal-bed gas exploration of the basin.

AAPG Search and Discovery Article #90060©2006 AAPG Foundation Grants-in-Aid