中文摘要：

卡塔克隆起北坡的上奥陶统良里塔格组台缘带的礁滩相孔洞缝储集体是油气的重点勘探领域。中2井是卡塔克隆起南坡的第一口以查清卡塔克隆起南缘下古生界碳酸盐岩台缘结构、探索良里塔格组礁滩相孔洞缝储集体为目的区探井。对中2井良里塔格组取心段的碳酸盐岩沉积亚相分析表明：良里塔格组发育以苔藓虫、四分珊瑚格架岩及障积岩为特征的礁-滩-丘沉积组合。而对中2井的良里塔格组以及一间房组、鹰山组碳酸盐岩沉积地球化学分析及其对比研究表明：良里塔格组碳酸盐岩为正常的海水沉积环境,陆源碎屑较少（〈0.5%）,其中,稀土总量平均为8.65×10^-6,LREE/HREE平均为6.20,^87Sr/^86Sr平均值为0.70843（n=12）,变化范围是0.70800-0.70882,波动较小;纵向上,沉积水体向上变浅,为亚氧化或弱还原条件沉积环境,δEu平均为0.67、δCe平均为0.80;较好地保留了原始海水中稳定同位素特征,全岩的δ^18OPDB=-7.3‰--3.2‰（平均为-4.4‰）,δ^13CPDB=1.8‰-3.1‰（平均为2.7‰）,与全球晚奥陶世海水或碳酸盐岩对应的平均值相近,反映了后期成岩改造作用较弱。

英文摘要：

The pore,vadose and fissure reservoirs associated with epigenic Karstification of carbonate rocks of Lianglitaga Formation in northern margin of Katake uplift,Tarim basin,is one of important areas of hydrocarbon exploration.Well Zhong-2 is the first and foremost important exploring well for identification of structure of platform margin and reservoir of reef-shoal of Lianglitaga Formation of the Upper Ordovician,southern margin of Katake uplift.The carbonate rocks of Lianglitaga Formation in Well Zhong-2 were studied on the assemblage of para-facies and sedimentary geochemical characteristic with comparable data to that of Yijianfang and Yingshan formations of the Middle and Lower Ordovician,the results show Lianglitaga Formation of Well Zhong-2 consists of a serial of stacking pattern of reef,shoal and bioherm mound with predominant development of bryozoans and coralline framestone,bindstone and bafflestone.The geochemical data indicated that the carbonate of Lianglitoga Formation primarily precipitated in the normal marine with less contents of siliciclastic input.The total contents of SiO2,Al2O3,Fe2O3 are less than 0.5%,the content of MgO less than 0.40%,the contents of CaO values vary from 53.4% to 54.25%.The average total rare earth elements of Lianglitaga Formation carbonate rocks is 8.65（7.28-11.05）×10^-6 with average ratio of LREE and HREE 6.20（vary from 4.71 to 6.90）.The average value ^87Sr/ ^86 Sr is 0.708,43 with no significantly change between 0.708,00 and 0.708,82 for carbonate rocks of Lianglitaga Formation.The stable isotopic and rare earth elements suggest the precipitation is in shallowing upward succession carbonate cycles and in the sub-oxidization or weak reduction depositional environment,with the average value δEu 0.67（values vary from 0.49 to 0.75）and δCe 0.80（values vary from 0.76 to 0.84） respectively.The δ^18O and δ^13C values of carbonate rocks of Lianglitaga Formation vary from-7.3‰ to-3.2‰VPDB（the average value-4.4‰,n=13） and from ＋1.8‰ to ＋3.1‰