受多期次生烃和构造运动的影响，塔里木盆地下古生界储层的水烃来源和分布异常复杂，长期以来为人们高度关注。油田水中的碘离子可以提供油气的源区信息，而129I同位素则包含着水形成的时间信息。二者的综合分析不仅可以获得储层油田水的年龄，重建油田水的演化模式，而且可以恢复油气与水的接触历史，提供油气来源方向以及油气藏形成与改造的时间信息。因此，开展油田水的碘129定年研究十分重要。申请人对轮南地区奥陶系储层油田水开展了初步的129I定年研究，结果显示深部储层中的油田水可能是烃源岩排出水与较新古大气降水混合的产物。以此为基础，本项目拟以塔里木盆地塔中和轮南地区寒武-奥陶系储层油田水为研究对象，测定其碘离子含量和129I/I比值，采用碘离子示踪和129I定年的研究方法，确定油田水各个端员组分进入储层的时间，并刻画油气充注历史。项目预期能够重建油田水的演化历史，同时为解释油气来源提供新的依据。

As a result of multiple hydrocarbon generation events and tectonic movements, it is complicated for the source and distribution of hydrocarbon and water in the Lower Paleozoic strata of the Tarim Basin, which has drawn high attention from the geochemists for a long time. The iodine ion in oilfield water can provide the information about the oil and gas sources, while 129I isotope contains the time information on water formation. Integrated analysis of both can be used to not only provide the age of reservoir water to reconstruct the water's evolution model, but also recover the history of the contact of hydrocarbon with water to indicate the hydrocarbon source and to provide the time of the formation and adjustment of the oil and gas accumulation. Therefore, it is critical to develop the precise Iodine-129 dating research on local oilfield water. Preliminary investigations using the 129I dating method have been done on the oilfield water in the Ordovician strata from the Lunnan area. Our results have indicated that the oilfield water in deep reservoirs in the Tarim Basin could be a mixture of expelled brine from the source rocks and the meteoric water after Mesozoic. Based on these work, this study will select the oilfield water in Cambrian and Ordovician reservoirs from the Lunnan and Tazhong area of the Tarim Basin as the research object. Both the iodine concentration and 129I/I isotope ratio of the oilfield water will be measured, and the times of the entering of each end members of oilfield water into the reservoirs can be determined by using the iodine tracing and 129I/I dating methods. This project aims to reconstruct the evolution history of oilfield water and recover the charging process of oil and gas, and finally to provide new evidences to the understanding of the oil and gas sources.