Based on the geological surveys in the field, core observation, historical well re-examination, analysis and testing, simulation experiment etc. , this paper analyses the organic geochemistry characteristics, reservoir characteristics and gas-bearing features of the rich-organic matter shale in Lower Cambrian Mufushan Formation of northern Jiangsu. The rich-in organic matter shale develops in the lower part of Mufushan Formation and is shelf-basin facies with a cumulative thickness generally of 50～200 m. The top depth is generally 2. 5～4 km. The main kerogen types are Ⅰ and Ⅱ1. The shale has a high organic matter abundance. The an average of TOC is 3. 32% and the maximum TOC is 12. 1%. In the high heat evolutionary stage, the equivalent vitrinite reflectance is 0. 73% ～3. 01% and averages 2. 83%. The shale contains abundant clay minerals and quartz and a small amount of K-feldspar and gypsum. The main compositions of clay minerals are illite and I/S mixed layer, but the clay minerals do not contain smectite. Micropores and microcracks develop well in the shale reservoir. The isothermal adsorption simulating experiment shows that the shale has good gas absorbed capacity. It is estimated that the average shale-gas (free and absorbed gas) content of Mufushan Formation in the northern Jiangsu is 1. 4 m3/t, and the shale-gas resources amount is 1. 8× 108m3/km2, which indicates a great shale-gas resources potential. According to the preliminary prediction, the favorable areas for shale-gas exploration of Mufushan Formation in northern Jiangsu are mainly distributed from Quanjiao in Anhui Province to Liuhe in Jiangsu Province and over the Yangzhou-Gaoyou-Xinghua area in Jiangsu Province.%通过野外地质调查、岩心观察、老井复查、分析测试及模拟实验等方法,研究苏北地区下寒武统幕府山组富有机质泥页岩的有机地球化学特征、储层特征及含气性等,并探讨其页岩气勘探前景.幕府山组富有机质泥页岩发育于该组下部,为陆棚-盆地相沉积,厚度一般在50～200m之间,顶界埋深一般为2.5～4.0 km,干酪根类型主要为Ⅰ型和Ⅱ1型；有机质丰度高,TOC平均值为3.32％,最高可达12.1％.有机质热演化程度普遍较高,等效镜质体反射率为0.73％～3.01％,平均为2.83％,多处于高成熟—过成熟阶段.矿物成分以黏土和石英为主,含有少量钾长石、石膏等,黏土矿物主要成分为伊利石和伊/蒙混层,不合蒙脱石.泥页岩储层微孔隙及微裂缝发育,等温吸附模拟实验表明其具有较好的天然气吸附能力.推算苏北地区幕府山组页岩气(吸附气和游离气)的含气量平均为1.4m3/t,页岩气资源量可达0.18×109 m3/km2,具有良好的资源潜力.初步预测安徽省全椒县—江苏省六合县一带、江苏省扬州—高邮—兴化一带是幕府山组页岩气有利勘探区.
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