摘要
鄂尔多斯盆地志丹地区长2油层组油水分布关系复杂,地层水特征及其地质意义缺少系统研究。为明确鄂尔多斯盆地长2油层组地层水特征在空间上的差异,本文对寨科地区和双河地区长2油层组地层水的化学组成、分类、矿化度以及离子特征参数分布规律等进行了深入研究。结果表明,研究区长2油层组地层水的离子组成主要以Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)、Na^(+)+k^(+)、Ca^(+)、Mg^(+)为主,双河地区和寨科地区离子浓度存在明显的差异,双河地区各离子浓度均低于寨科地区,表明两地区地层水的水—岩相互作用强度以及受后期改造程度差别较大;研究区长2油层组浅湖区域的封闭性好于滨湖区域;寨科地区的矿化度、变质系数和钠氯系数高于双河地区,脱硫系数小于双河地区,说明寨科地区的封闭性好于双河地区,结合区域的地质条件,分析认为这种现象的发生,可能由于双河地区长2油层组的顶部受到河谷侵蚀而具有一定的开启性,进而导致浅表水渗入而引起的。
The distribution of oil and water in Chang 2 oil formation in Zhidan area,Ordos Basin,is complex,and the formation water characteristics and geological significance are not systematically studied.In order to clarify the spatial differences of formation water characteristics of Chang 2 oil formation in Ordos Basin,the chemical composition,classification,salinity and the distribution of ion characteristic parameters of formation water of Chang 2 oil formation in Zhaike area and Shuanghe area were studied in this paper.The results show that the ion composition of formation water of Chang 2 oil formation in the study area is mainly Cl^(-)、SO_(4)^(2-)、HCO_(3)^(-)、Na^(+)+k^(+)、Ca^(+)and Mg^(+).There are obvious differences in the ion concentration between Shuanghe area and Zhaike area,and the ion concentration in Shuanghe area is lower than that in Zhaike area.It shows that the water-rock interaction intensity and the degree of later modification of formation water in the two areas are different greatly.The sealing property of shallow lake area of Chang 2 oil formation is better than that of lakeside area.The salinity,metamorphism coefficient and sodium-chloride coefficient of Zhaike area are higher than those of Shuanghe area,and the desulfurization coefficient is lower than that of Shuanghe area,indicating that the sealing property of Zhaike area is better than that of Shuanghe area.Combined with the geological conditions of the region,it is believed that the occurrence of this phenomenon may be caused by the opening of the top of the Chang 2 oil layer group in the Shuanghe area due to the erosion of the river valley,which in turn leads to the infiltration of shallow water.
作者
强倩
李爱荣
欧明轩
QIANG Qian;LI Ai-rong;OU Ming-xuan(School of Earth Scienceand Engineering,Xi'an Shiyou University,Xi'an 710065,China;Shanxi Key Laboratory of Petroleum Accumulation Geology,Xi'an Shiyou University,Xi'an 710065,China)
出处
《地下水》
2022年第3期5-8,共4页
Ground water
基金
鄂尔多斯盆地南部长6油层组地层水特征与油气富集规律研究(41772140)。
关键词
寨科地区
双河地区
长2油层组
地层水特征
封闭条件
Zikaregion
Twin Rivers region
Chang2 oil formation
formation water characteristics
closed condition
