江西修武盆地下寒武统黑色页岩矿物成分特征及意义

摘要

Based on the qualitative and quantitative analyses of the shale samples from the field outcrops and well cores,this paper studies the characteristics and significance of mineral compositions in the Lower Cambrian black shale gas reservoir from the Xiuwu basin,Jiangxi,China.The results show that the major components of the Lower Cambrian Wangyinpu Formation and Guanyintang Formation black shale are clay minerals and quartz,with an average content of 25.4% and 58.63%, respectively,and the minor components are feldspar and pyrite,with an average content of 2 .5% and 4.68%,respectively.In addition,the average content of the other minerals such as calcite,dolomite, gypsum,and so on is less than 5%.The mineral components characteristics of the Lower Cambrian black shale from Xiuwu basin are both similar and difference from the Barnett shale and the Longmaxi Formation shale. Furthermore, the paper discusses the sedimentary environments, the organic material evolution and the shale reservoirs according to the characteristics of the mineral components in the Lower Cambrian shale from the Xiuwu basin.The result shows that the mud shale thickness of this set of shale with quartz component >50%is almost 50 m which is an ideal horizon for exploration and exploitation.%以江西修武盆地下寒武统王音铺组、观音堂组黑色页岩为研究对象，通过对野外剖面样品和钻井取心样品定性和定量分析，研究修武盆地下寒武统页岩气储层矿物成分特征，结果表明，王音铺组、观音堂组黑色页岩矿物成分以黏土矿物和石英为主，石英的平均质量分数为58．63％，黏土矿物平均为25．4％。其次为方解石，平均为51．46％，另外还含有较高的长石和黄铁矿，平均质量分数分别为2．5％和4．68％。其余矿物如方解石、白云石、（硬）石膏等含量较少，平均质量分数＜5％。这种矿物成分组成与 Barnett 页岩及龙马溪组页岩既有相似性，又有差异性。修武盆地下寒武统页岩矿物组分所反映的沉积环境、有机质演化及黑色页岩储集意义表明，该套页岩石英的质量分数＞50％的泥（页）岩厚度接近50 m，是理想的页岩气勘探开发层位。