四川盆地自流井构造深层地下卤水的富集和资源特征

发布时间：2018-05-18 17:45

本文选题：自流井构造 + 卤水　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：深层地下卤水是一种液体矿床,具有极高的工业价值,可以用来制盐,还可以提取溴、钾、锂、锶、钡等微量元素。本文针对开采历史比较悠久的四川盆地自流井构造,对其深层地下卤水的储集富集条件以及水化学特征进行分析,同时计算深层卤水的资源量。分布在自流井背斜构造的地下卤水分为两类,第一类储卤层为以长石石英砂岩等碎屑岩为主的上三叠统须家河组储卤层系,埋深大约50-500 m左右赋存黄卤,第二类岩性以灰岩、白云岩等碳酸盐岩为主的下中三叠统嘉陵江-雷口坡组储卤层系,埋深在920-1030 m左右赋存黑卤。碎屑岩孔隙度8.1%-10.92%,碳酸盐岩储卤层孔隙度6.33%~12.98%,为低孔隙含卤层。在背斜褶皱及断裂发育处裂隙发育,增大储卤空间,连通性提高,储卤范围主要受背斜范围控制,卤水的富集主要受断裂控制,主要分布在黄葛坡和东南翼两大断裂带。黄葛坡断裂带开采卤水占整个构造的74%。采用常规组分分析卤水的水化学特征,自流井构造卤水矿化度171.73-238.48g/L,水化学类型均为Cl-Na型。阳离子主要以Na+为主,阴离子中Cl-为主。通过离子比例系数分析与海水蒸发浓缩曲线对比方法分析,黄卤中相对富集Ca2+、Mg2+、Ba2+、Sr2+,黑卤中富集K+、Na+、Li+,微量元素Br-、Li+、Sr2+已超过单独工业开采标准,K+在黑卤中超过单独工业开采标准。通过δ2H、δ18O同位素分析以及与蒸发海水曲线对比,黑卤起源于古海水,经过白云石化、盐类沉淀、脱硫酸等过程而形成;结合Br×103/Cl等离子比例系数的分析结果,黄卤成因与沉积水有关,可能起源于海源陆相同生沉积水或古大气降水,经过隔膜渗滤、阳离子交换吸附、斜长石钠长石化等作用而形成。采用容积法估算本区黄卤天然资源量,结果为20.7×108 m3,与实际开采量1.6626×108 m3对比得到开采系数0.0803。黑卤资源量采用三维非稳定流数学模型运用Modflow软件进行计算,根据卤水产区产量分布抽水井,确定开采量。利用储卤层参数初值进行调参模拟,与实际水头进行拟合。水头降至储卤层顶板确定为可开采量,计算得到可开采量为1.28×108 m3,实际开采量为1.12×108 m3,但实际水头低于计算水头值,认为实际水文地质参数略偏小,且储卤层卤水可开采量已经开采殆尽。
[Abstract]:Deep underground brine is a kind of liquid deposit with high industrial value. It can be used to make salt and to extract trace elements such as bromine, potassium, lithium, strontium, barium and so on. In this paper, aiming at the artesian well structure of Sichuan Basin with a long history of exploitation, the reservoir and enrichment conditions and hydrochemical characteristics of deep layer underground brine are analyzed, and the resources of deep brine are calculated at the same time. There are two types of underground brine distributed in the anticline structure of Ziliujing. The first type is the upper Triassic Xujiahe formation, which is dominated by clastic rocks such as feldspar quartz sandstone. The buried depth is about 50-500 m, and the second type of lithology is limestone. The lower Triassic Jialingjiang-Leikoupo formation, dominated by dolomite and other carbonate rocks, is a halogen reservoir with a buried depth of 920-1030 m. The porosity of clastic rocks ranged from 8.1 to 10.92, and the porosity of carbonate reservoir and halogen layer was 6.33 and 12.98, which was low porosity halogenated layer. In the anticline fold and fault development, the fissure develops, increases the storage halogen space, enhances the connectivity, the storage range is mainly controlled by the anticline range, and the enrichment of brine is mainly controlled by the fault, mainly distributed in the Huanggepo and southeast wing fault zones. Exploitation of brine in Huanggepo fault zone accounts for 74% of the whole structure. The hydrochemical characteristics of the brine were analyzed by conventional components. The salinity of the structural brine in the self-flowing well was 171.73-238.48g / L, and the hydrochemical types were all of Cl-Na type. The cations mainly consist of Na and Cl- in anions. By comparing the ion ratio coefficient analysis with the evaporation and concentration curve of seawater, the results show that the relative enrichment of Ca2 _ (2) mg _ (2) O _ (2) Ba _ (2) O _ (2) Sr _ (2) in yellow halogen, and the enrichment of K _ (2) Na _ The trace element Br-Li Li Sr 2 has exceeded the standard of industrial exploitation in black brine. By means of 未 _ 2H, 未 _ 18O isotopic analysis and comparing with the curve of evaporative seawater, the black halogen originated from the ancient seawater and was formed through dolomitization, salt precipitation, desulfurization and so on, and combined with the results of Br 脳 103/Cl plasma ratio coefficient analysis. The origin of yellow halogen is related to sedimentary water, which may originate from the same sedimentary water or paleo-atmospheric precipitation from sea source and land, and may be formed by membrane filtration, cation exchange adsorption, plagioclase albite formation and so on. The volume method is used to estimate the natural resources of yellow halogen in this area. The result is 20.7 脳 108m3.Compared with the actual mining capacity of 1.6626 脳 108m3, the mining coefficient is 0.0803. The resource quantity of black brine is calculated by using Modflow software by using three-dimensional unstable flow mathematical model. According to the production distribution of pumping well in brine producing area, the extraction rate is determined. The initial parameters of the halogen reservoir are simulated and fitted with the actual water head. When the water head drops to the roof of the halogen reservoir, it is determined that the mining capacity is 1.28 脳 10 ~ 8 m ~ 3, and the actual mining capacity is 1.12 脳 10 ~ 8 m ~ 3, but the actual water head is lower than the calculated water head, and the actual hydrogeological parameters are slightly smaller. Moreover, the recoverable amount of brine in the halogen reservoir has been exhausted.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P619.211

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