摘要
塔里木盆地哈得逊油田石炭系地层水化学分析结果表明,地层水是以阴阳离子分别为Cl-和(Na++K+)为主的CaCl2型水,具有高矿化度特征(112～291 g/L)。地层水的钠氯系数均值为0.78,脱硫酸系数均值为0.23,Schoeller碱交换指数(IBE)均值为128。地层水化学参数在平面上相对变化不大,在剖面上随深度的增加,HCO3-、SO42-含量具有减小的趋势,而其他离子变化相对较小,表明研究区内的地层水形成于深部封闭环境条件下。地层水化学分析表明,该区地层水经历了强烈的阳离子交替吸附和水岩相互作用。(铁)白云石化作用导致了Ca2+的富集和Mg2+的亏损,形成了现今的地层水离子分布特征。石炭系地层水在构造反转油气藏调整时期一直处于相对封闭的流体动力环境中,这种环境有利于油气的聚集与保存。
Based on the test of Carboniferous formation water in Hadson oil field of Tarim Basin,the geochemistry and origin of formation water were analyzed.The main chemical compositions are dominated by anion Cl-and cation(Na++K+).These waters are of CaCl2 type with high TDS(112 g/L to 291 g/L).The average sodium to chloride coefficient of formation water is 0.78,the average de-sulfate coefficient is 0.23,and the average cation exchange index(IBE)is 128.The chemical parameters of formation water vary little in the plane.Vertically,the concentrations of HCO-3 and SO2-4 have a tendency to decrease with increasing depth,but the concentrations of other ions keep constant,indicating that the formation water was formed in deep closed condition.The chemical characteristics of formation water show that the formation water experienced strong cationic alternate adsorption and water-rock interaction.The dolomitization(ferrodolomite)led to the excess of Ca2+ and the deficit of Mg2+,forming present ion distribution characteristics of formation water.The Carboniferous formation water has been in a relatively closed fluid dynamic environment during the petroleum reservoirs adjustment period,which is favorable for oil and gas accumulation and preservation.
出处
《现代地质》
CAS
CSCD
北大核心
2012年第2期377-383,共7页
Geoscience
基金
国家自然科学基金项目(41172128)
塔里木油田公司项目(041010120150)
关键词
哈得逊油田
石炭系
地层水化学特征
地层水成因
流体岩石相互作用
Hadson oil field
Carboniferous
geochemistry characteristics of formation water
origin of formation water
fluid-rock interaction
