塔里木盆地北部露头区与井下古岩溶充填物包裹体特征对比研究

Comparative study about the characteristics of inclusions in the paleokarst fillings in the northern outcrop and underground areas of Tarim Basin

塔里木盆地奥陶系储层经历多期水-岩作用改造,其分布发育规律异常复杂,古岩溶充填物中包裹体特征对古岩溶作用环境和期次具有较好的指示性。本文通过对塔里木盆地北部露头区和井下古岩溶充填物中包裹体进行测试,系统总结了两个地区包裹体的物理、化学特征,从一个新的角度开展露头区和井下岩溶发育规律对比研究。结果表明,研究区以单液相、气液相的盐水包裹体为主,仅塔河主体区井下样品中含有少量烃质包裹体;包裹体的物理特征反映了埋藏期岩溶作用的环境特征;按盐度与均一温度的交互关系划分出5种包裹体类型;根据古地温梯度计算出包裹体形成于浅埋藏、中埋藏、深埋藏3种环境;奥陶系碳酸盐岩经历了风化壳期岩溶、浅埋藏期岩溶、中埋藏期岩溶(早、晚)、深埋藏期岩溶等4期岩溶作用,岩溶储层的充填主要发育在中埋藏期。

The Ordovician oil/gas reservoir in Tarim Basin had experienced multiple stages of water-rock interactions, so the distribution and development of the karstic reservoir are very complex. However, the teristics of inclusions in the paleo karst fillings can effectively s of water rock actions of the paleokarst. Based on the test of corn both outcrop area and the underground, the physical and indicate the changes in environments and the inclusions in paleokarst fillings sam chemical characteristics of the inclusions are summarized. From a new perspective, this paper will carry out a comparative study of the karst development over the outcrop area and the underground, repectively. The results show that in terms of type of the The physical characteristics of the inclusions reflect the particular environments of the buried paleo-karst. The inclusions can be divided into five combined types according to the interaction between salinity and uni form temperature. Based on the ancient geothermal gradient, the inclusions formed in three kindsof ment （i. e. , shallowly buried, medium buried, deep buried）. The Ordovician carbonate rock has exp four periods of karstification, including weathering crust karst, shallowly buried, moderately bur um burial period.