研究桂中盆地页岩气发育的地质条件并分析其勘探潜力。对桂中盆地近期一口页岩气钻井的产气特征和岩心开展了T O C、Ro 等测试分析。该井位于柳城县白芒村附近，钻进过程中在井深为248．33 m的下石炭统寺门组泥页岩层系砂岩夹层中出现井涌及天然气喷漏，日产气量3000～4000 m3，持续几天后无明显衰减迹象，揭示了良好的页岩气潜力。该井寺门组泥页岩TOC的质量分数为0．54％～1．59％，平均值为1．07％，为较好的烃源岩层；砂岩夹层中见丰富的沥青，其反射率Rb 为1．64％～2．1％。寺门组泥页岩烃源岩和沥青热裂解生气保证了泥页岩层系充足的气源供应。桂中盆地中下泥盆统和下石炭统深灰色或黑色泥页岩层系广泛发育，为高演化的优质烃源岩层并且具有较大的厚度，构成页岩气大规模赋存的基础地质条件。经过长期的油气勘探，已在不少钻井揭示页岩气的显示，展示了较好的页岩气勘探前景。%The purpose of this study is concentrated on the geological conditions forming shale gas and the analysis of exploration potential in Central Guangxi basin.The authors investigated the shale gas producing characteristics from a well in Central Guangxi basin and analyzed TOC and Ro of shale cores from this well.The well lies near Baimang of Liucheng County,Guangxi.The gas comes from a silt sand interlayer in the Lower Carboniferous Simen Formation (C1s)at a depth of about 248.33 m.The amount of gas released from the well is estimated at 3000 ~4000 m3 per day. This further demonstrates that there is good shale gas potential.The TOC mass fraction of the shale samples from this well is 0.54%~1.59%with the average 1.07%.The reflection of bitumen (Rb)in the sandstone samples is 1.64%~2.10%.The mud shale hydrocarbon source rocks and the thermal crack of bitumen in sandstones ensure the supply of gases from the mud shale sequences.The Devonian and Carboniferous dark mud shale sequences are extensively developed with relatively big thickness.They are high quality hydrocarbon source rocks.After a long-term hydrocarbon exploration,many wells discover the existence of shale gas,demonstrating a good prospect for shale gas exploration.The thick mud shale and sandstone interlayers with high porosity contribute to the reservoirs of shale gas.
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