黄铁矿发育特征对云南省筇竹寺组页岩气调查的启示意义

IMPLICATIONS OF DEVELOPMENT CHARACTERISTICSOF PYRITE ON THE EXPLORATION OF SHALE GAS IN THE QIONGZHUSI FORMATION,YUNNAN

对云南龙马溪组优质页岩段中黄铁矿富集规律综合分析表明,黄铁矿在优质页岩段多成条带状、透镜状,矿物组分含量2.00%~7.00%,平均3.83%,镜下主要呈现草莓状,偶有串珠状,黄铁矿周边有机质富集,有机质孔及黄铁矿集合体内晶间孔发育;黄铁矿含量与有机碳含量呈明显的正相关关系,反应有机质页岩的沉积环境,对有机质的富集、孔隙分布具有一定的影响作用;综合对比筇竹寺组优质页岩黄铁矿发育情况,其与龙马溪组优质页岩黄铁矿发育特征有较高的相似性,可作为筇竹寺组页岩生烃能力评价的重要指标,对云南筇竹寺页岩气调查评价具有较高的启示意义。

A comprehensive analysis of pyrite enrichmentlaws in the high-quality shale section of the Longmaxi formation in Yunnan indicates that pyrite is mainly banded or lenticular,and predominantly strawberry-like texture,occasionally bead-like texture,with mineral content ranging from 2.00%to 7.00%,with an average of 3.83%.Organic matter is enriched around pyrite,andorganic matter pores and intergranular pores are well-developed within pyrite aggregates.There is a significant positive correlation between the content of pyrite and organic carbon,indicating that the sedimentary environment of organic shale has a certain impact on the enrichment and pore distribution of organic matters.The development of pyrite in the high-quality shalesfrom the Qiongzhusi formation shows high similarity with those from the Longmaxi formation,suggesting that pyrite characteristics can serve as an important indicator for evaluating hydrocarbon potential of the Qiongzhusi formation,which provides valuable insights for shale gas exploration and evaluation.