Abstract: The Yuqia coalfield Jurassic abundant coal resources, had great potential for the formation of coalbed methane reservoirs..In order to study the controlling role of sedimentation to the CBM reservoir in Yuqia coalfield,according to the research on the Yuqia Jurassic sedimentary system, sedimentary facies and sedimentary microfacies,this paper discussed the control of different sedimentary systems and sedimentary microfacies on coal roof and floor closure performance and the effects of different depositional systemthe on the spatial distribution of coal reservoirs.The results showed that: in different depositional systems, coal reservoirs and roof and floor constituted different combinations relations with different capping performance for the CBM reservoir;the lower delta plain facies in meandering river delta sedimentary system and shallow lacustrine facies in lacustrine depositional system were the most favorable coal-forming environment and beneficial to accumulation of coalbed methane reservoirs;the capping layer formed in bay marsh microfacies was more conducive to preservation of coalbed methane reservoirs than in between bay marsh.

Key words: Yuqia Coalfield, coalbed methane, sedimentary system, sedimentary facies, sedimentary microfacies