Institute of Geology, Chinese Academy of Geological Sciences, Beijing, 100037, China.
MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing, 100037, China.
Sci Rep. 2023 Mar 17;13(1):4445. doi: 10.1038/s41598-023-31421-1.
The Li-enriched oilfield brine is a very important lithium resource. It has gained much attention and become the target of active Li surveys with the growing global demand for Li. However, only little is known about their feature and nature. In the study, hydrochemical data from 155 oil wells tapping the Eocene to Lower Oligocene Qianjiang Formation of the Jianghan Basin, central China indicate that the brines are of the Na-Cl or Na-Ca-Cl type and are characterized by highly variable Li contents of 7.56 to 150 mg/L, with Mg/Li ratios less than 11.65. High Na/Cl and Cl/Br molar ratios indicate distinct contributions from halite dissolution. The Ca excess, Na deficit and Ca/Mg and Ca/Sr molar ratios in the brines imply multiple diagenetic processes, including halite dissolution, dolomitization, albitization and calcite or anhydrite cementation. The lithium contents of these brines have a weak relationship with the salinity and a negative correlation with Cl/Br ratios, possibly indicating that these Qianjiang oilfield brines have been diluted by secondary brines derived from halite dissolution. The spatial distribution patterns for Li and B concentrations of the brines are different from those for salinity and Br contents and show a geographic pattern, indicating that Li enrichment in the Qianjiang brines is likely connected with geothermal sources associated with volcanic activity.
富含锂的油田卤水是一种非常重要的锂资源。随着全球对锂的需求不断增长，它引起了广泛关注，成为了积极进行锂调查的目标。然而，人们对它的特征和性质知之甚少。在这项研究中，来自中国中部江汉盆地始新统至下渐新统 155 口油井的水化学数据表明，这些卤水属于 Na-Cl 或 Na-Ca-Cl 型，其特征是锂含量变化范围很大，为 7.56 至 150mg/L，Mg/Li 比值小于 11.65。高 Na/Cl 和 Cl/Br 摩尔比值表明，卤化物的溶解作用有明显的贡献。卤水的 Ca 过剩、Na 亏损以及 Ca/Mg 和 Ca/Sr 摩尔比值表明存在多种成岩作用，包括卤化物的溶解、白云石化、钠长石化和方解石或硬石膏胶结。这些卤水的锂含量与盐度呈弱相关，与 Cl/Br 比值呈负相关，可能表明这些江汉油田卤水已被卤化物溶解产生的次生卤水稀释。卤水的 Li 和 B 浓度的空间分布模式与盐度和 Br 含量的分布模式不同，呈现出地理分布模式，表明 Qianjiang 卤水的锂富集可能与与火山活动有关的地热来源有关。
