Study on unconventional gas coexisted law of Jurassic coal measures in Muri Coalfield

In order to explore the coal measures gas deposition features of Muri Coalfield, with the analysis and test on the gas content, organic geochemistry of th e hydrocarbon source rock and the reservoir physical properties, the paper held that there was a big variation in the gas content of the coal measures gas and the gas C ontent at the top section in Muri Formation was highest. The total organic carbon content and hydrocarbon potential evaluation showed that the hydrocarbon source roc k of the coal measures in the block was excellent quality hydrocarbon source rock. Among them, the coal would be a卫type kerogen and the oil shale and mudstone W ould be I2type keroge. The Rodistribution would be 0.74% ~ 1.85% and would be in a maturing to high mature favorable gas production stage. The porosity of the coal reservoir was ranged from 2.7% ~ 13.7%, the permeability was ranged between ( 0.03 ~ 10.6) x 10-3μm2, the porosity of the shale and tight sandstone reservoir would not be over 4. 5% generally and the permeability would be lower than 0.1x10-3um2generally. In combination with the analysis on the typical boreholes, there were three coal measures unconventional gas coexisted combined models established within the block. Based on the summarization on the formation features of the coal measure s unconventional gas in Muli Coalfield, the comprehensive analysis showed that the upper section of Muli Formation, Middle Jurassic and Jiangcang Formation would b e the key floor section of the unconventional gas exploration. A proposal on the further exploration and development of the gas was provided.