Abstract:

Coal measures in Santanghu Basin mainly developed in Jurassic Xishanyao and Badaowan Formations.The test results of 30 samples collected in 4 wells indicate that the abundance and extractable contents of organic matter in the coal measures are both high,n-alkane possesses odd even predominance;the ratio of Pr/Ph is 1.25～8.17;n-sterane has evident C₂₉predominance;C₃₁hopane content is high and gammacerane content is low;kerogen carbon isotopes are-2.279% and-2.413%,the vitrinite reflectance is 0.50%～0.62% which is well in hydrocarbon generation period.The other geochemical characteristics differ clearly from the extracts of Jurassic and Permian oil bearing cores.This suggests that Jurassic coal measures generated hydrocarbon is still in the coal measures,it means the coal measures made no contribution to the area's oil and gas accumulation.It thus concludes that we should pay more attention to the expulsion conditions of coal formed hydrocarbon in the study of coal-formed hydrocarbon.

Key words: coal measures, geochemistry, characteristic, oil source correlation, hydrocarbon expressing, Santanghu Basin