塔中地区上奥陶统良里塔格组构造裂缝成岩作用研究

裂缝作为流体活动的通道,对碳酸盐岩储集体的形成、演化及分布起到非常重要的作用。选取塔里木盆地塔中上奥陶统良里塔格组碳酸盐岩构造裂缝为研究目标,开展了岩芯观测和采样工作,运用显微薄片、阴极发光、流体包裹体、荧光测试等分析方法,重点研究了裂缝的形成充填特征,识别出了方解石胶结、重晶石胶结及萤石胶结等成岩作用类型,良里塔格组构造裂缝经历了3期流体充填作用,第一期为浅埋藏大气淡水胶结;第二期为二叠纪末热流体活动的结果;第三期为中-深埋藏阶段流体的充填作用。

The diagenesis of Lianglitag Formation structural fracture of upper Ordovician in Tazhong region,Tarim basin

As the pathway for fluids, fracture plays a very important role of in the formation, evolution and distribution of carbonate reservoir. This study took the upper Ordovician carbonates as the objective rock. It is carried out core observation and sampling, rock and mineral observing, cathode luminescence, fluid inclusions testing and fluorescence observing. It is focused on filling characteristics of fracture. Calcite cement,barite cement and fluorite cement were identified.There are three periods flow filling events in structural fracture of Lianglitag formation.The first stage was atmospheric freshwater cementation while be shallow buried.The second stage was thermal fluid which was resulted from peimian volcano.The last filling stage happened when it was medium-deep buried.