下扬子皖南地区古生界页岩气形成条件及勘探潜力评价

为评价皖南地区古生界页岩气勘探潜力、优选勘探层系，根据钻井岩芯和露头岩样的地化、岩石学分析数据及野外调查等资料，对该地区古生界3套富有机质层系的页岩气形成地质－地球化学条件进行初步研究，结果表明：古生界上奥陶统五峰组-下志留统高家边组、二叠系(孤峰组＋龙潭组＋大隆组)富有机质泥页岩层系在区内分布广、厚度较大、有机质丰富（TOC普遍>2%）和热演化程度较高(Ro=1.3%～3.0%)，具有形成页岩气的良好物质基础；同时，其埋深适中且泥页岩与硅质岩相伴生，利于人工压裂和勘探开发，有较大勘探潜力。另一方面，古生界寒武统黄柏岭组富有机质页岩也有良好的成气潜力，但因其普遍深埋、成熟度偏高，该区后期发生的多期强烈构造运动等因素对早期形成页岩气的富集及保存可能有一定影响，其勘探潜力有待进一步深究。

Geological conditions of Paleozoic shale gas formation and its exploration potential in the South Anhui, Lower Yangtze area

In order to investigate the exploration potential of the Paleozoic shale gases in the South Anhui，Lower Yangtze area，the geochemical and reservoir petrologic analyses were made on the representative core samples from the study area.Also，a preliminary study was performed on the geological-geochemical conditions of Paleozoic shale gas formation using the combination of the data with geological and outcrop information.The findings are as follows：① Three sets of organic-rich shale strata，including the Lower Cambrian Huangpaling Formation(∈1h)，the Upper Ordovician Wufeng Formation(O3w) to the Lower Silurian Gaojiabian Formation(S1g)，and the Permian Formation(Gufeng Formation(P1g)，Longtan Formation(P2l)，Dalong Formation(P2d))，are developed within Paleozoic；② The O3w-S1g and P1g+P2l+P2d shales are widely distributed in South Anhui area，with relatively large thickness，high TOC(>2%)，high thermal maturity(Ro=1.3%-3.0%)，and high quartz contents，indicating their favorable geological conditions for forming shale gas and huge exploration potentia1.On the other hand，the ∈1h organic-rich shale has relatively great gas generation potential，while its deep burial andover-maturity，especially late multiphase tectonic movement，may have some influence on the generation，accumulation and preservation of shale gases within the strata，thus its exploration potential of shale gases needs a further investigation.