State Key Lab of Coal Resources and Safe Mining, China University of Mining and Technology (Beijing) Shanxi
Institute of Energy Shaanxi Center of Geological Survey Beijing Urban Construction Exploration and Surveying
Design Research Institute Company Limited

为探索木里煤田煤系气赋存特征,通过含气性、烃源岩有机地化以及储集层物性特征的分析测试,认为煤系气含气量变化较大,以木里组上段含气量最高;总有机碳含量和生烃潜率评价均显示此组煤系烃源岩为优质烃源岩,其中煤为Ⅲ型干酪根,而油页岩、泥岩为Ⅱ2型干酪根,Ro分布在0.74%~1.85%,处于成熟-高成熟度的有利生气阶段;煤储层孔隙度为2.7%~13.7%,渗透率为(0.03~10.6)×10-3μm2,而页岩及致密砂岩储层孔隙度普遍不高于4.5%,渗透率普遍低于0.1×10-3μm2。结合典型钻孔分析建立了木里煤田内的3种煤系非常规气共存组合模式。在总结了木里煤田的煤系非常规气的成藏特征基础上,综合分析认为中侏罗统木里组上段以及江仓组是煤系非常规气勘探的重点层段,并进一步提出了勘探开发建议。

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.