根据高分辨率电阻率成像测井解释 ,结合岩心观察及薄片资料 ,探讨了塔里木盆地塔中X井下奥陶统灰岩段内罕见的萤石脉—油气叠合成藏现象。萤石脉侵位于二叠纪塔里木盆地中西部区域性火山活动时期 ,由上侵至地层浅部的低温岩浆热液沿断层、裂隙发育带充填而成。萤石脉及其附近灰岩围岩中溶洞的形成为后期油气聚集提供了良好的储集条件 ,它与充足的油气来源及上覆巨厚中、上奥陶统泥质岩有利的封盖条件配合 ,促成了油气在萤石脉基础上的叠合成藏。该油气藏的发现为塔里木盆地油气勘探开辟了一个新领域 ,并丰富了传统的油气成藏理论 Based on the interpretation of high-resolution resistivity imaging logs and the core observation and thin-slice data, the rare fluorite vein-hydrocarbon accumulation in the Lower Ordovician limestone section of the Tazhong X Tarim, Tarim Basin, is discussed. Fluorite veins are located in the Permian during the regional volcanic activities in the central and western Tarim Basin. Low-temperature magmatic hydrothermal fluids that invaded the shallow parts of the strata were filled along faults and fissures. The formation of karst caves in fluorite veins and limestone rocks provides good reservoir conditions for later hydrocarbon accumulation. It is associated with abundant oil and gas sources and a favorable cover of upper and middle Ordovician muddy rocks With the conditions, contributed to the oil and gas fluorite vein superimposed on the basis of accumulation. The discovery of this reservoir opens up a new field for oil and gas exploration in the Tarim Basin and enriches the traditional theory of hydrocarbon accumulation