普光地区下三叠统富锂钾卤水成因与分布规律

Genesis and distribution law of rich lithium-potassium brine in the Lower Triassic of Puguang area

通过对普光地区钻孔卤水和油田水水化学分析测试,开展离子比例研究,明确嘉陵江组和飞仙关组各亚段卤水的成因机制和分布规律。研究结果表明:嘉陵江组卤水K^(+)质量浓度在4060.00~20160.00 mg/L,Li^(+)质量浓度在26.00~271.00 mg/L,整体为海水浓缩特征。嘉四段—嘉五段卤水K^(+)质量浓度在4110.00~20160.00 mg/L,Li^(+)质量浓度在76.15~271.00 mg/L,Li^(+),K^(+)富集受海水蒸发浓缩、“绿豆岩”风化作用和淋滤作用主控;嘉二段卤水K^(+)质量浓度在4060.00~4140.00 mg/L,Li^(+)质量浓度在26.00~27.80 mg/L,受海水蒸发浓缩及膏盐溶解主控。飞仙关组卤水K^(+)质量浓度在6.13~650.00 mg/L,Li^(+)质量浓度在0.02~50.60 mg/L,整体为地下溶滤特征。飞三段—飞四段卤水K^(+)质量浓度在588.00~650.00 mg/L,Li^(+)质量浓度在40.40~50.60 mg/L,Li^(+),K^(+)富集受膏岩等围岩溶滤和嘉陵江组卤水运移主控;飞一段—飞二段卤水K^(+)质量浓度在6.13~478.00 mg/L,Li^(+)质量浓度在0.02~17.90 mg/L,由地层水对碳酸盐岩溶解主控。富锂钾卤水平面上主要分布在大湾-土主构造及其构造作用中等的翼部。

Through the chemical analysis and test of borehole brine and oilfield water in Puguang area,the analysis of ion mass concentration and the research on water chemical index were carried out to clarify the genetic mechanism and distribution law of brine in each sub-Member of Jialingjiang Formation and Feixianguan Formation.The results show that the mass concentration of K^(+)in the brine of Jialingjiang Formation is 4,060-20,160 mg/L,and the mass concentration of Li^(+)is 26.00-271.00 mg/L,which is characterized by seawater concentration.The mass concentration of K^(+)in the brine of forth-fifth Member of Jialingjiang Formation(Jia 4-5 Members)is 4,110.00-20,160.00 mg/L,and the mass concentration of Li^(+)is 76.15-271.00 mg/L.The enrichment of Li^(+)and K^(+)elements are mainly controlled by seawater evaporation and concentration,"mung bean rock"weathering and leaching.The mass concentration of K^(+)and Li^(+)in the brine of Jia 2 Member are 4,060.00-4,140.00 mg/L and 26.00-27.80 mg/L respectively,which are mainly controlled by seawater evaporation and concentration and gypsum salt dissolution.The mass concentration of K^(+)in brine of Feixianguan Formation is 6.13-650.00 mg/L,and the mass concentration of Li^(+)is 0.02-50.60 mg/L,which is characteristized by underground leaching.The mass concentration of K^(+)in brine of Fei 3-4 Members is 588.00-650.00 mg/L,and the mass concentration of Li^(+)is 40.40-50.60 mg/L.The enrichment of Li and K elements are mainly controlled by the leaching of gypsum rock and the downward migration of Jialingjiang Formation brine.The mass concentration of K^(+)and Li^(+)in brine of Fei 1-2 Members are 6.13-478.00 mg/L and 0.02-17.90 mg/L respectively,which are mainly controlled by the dissolution of carbonate rocks by formation water.Rich lithium-potassium brine is mainly distributed in the Dawan-Tuzhu structure and its moderate wings on the plane.