EVALUATION OF THE HYDROCARBON GENERATION POTENTIAL OF SOURCE ROCKS OF THE JURASSIC YAOJIE FORMATION IN MULI DEPRESSION OF QILIAN MOUNTAINS

The research results of the abundance,types and maturity of the organic matter of mudstone and coal seam of Yaojie coal-bearing formation in Muri depression of Qilian Mountains show that the mudstone of Yaojie coal-bearing formation is good hydrocarbon source rock and the organic matter type is sapropelic-humic( II1) during the mature stage in which gas generation is predominant. While the coal seams are relatively poor hydrocarbon source rocks,with the organic matter of humic type( III) at the mature stage,which have a certain hydrocarbon generating potential. Based on the analysis of hydrocarbon source rocks in others formation,it is concluded that the mudstone of Yaojie coal-bearing formation and the lacustrine mudstone of Galedesi formation in late Triassic are the main source rocks of gas hydrates in Muri depression.