川南页岩气采出水伴生锂资源评价与开发利用前景

Evaluation and development prospect of lithium resources associated with produced water of shale gas in southern Sichuan

关键词:  页岩气  采出水  锂资源  提锂技术 

Key words:  shale gas  produced water  lithium resource  lithium extraction technology

摘要:

随着中国页岩气开采量连年攀升,伴生的采出水量也在增加,采出水为压裂注入液与页岩地层滞留的地层卤水的混合产物,而采出水中富含锂钾溴硼等有价元素,尤其是采出水中的锂资源,具有广阔的开发利用前景,开发利用该锂资源可缓解国内锂的供需矛盾。总结了四川盆地页岩气资源的开发现状,列出了川南威远和长宁等地区页岩气采出水中部分离子浓度,目前,川南威远和长宁地区的每个井年采出水量分别是19 800 m³和15 293 m³,大部分页岩气采出水中的锂质量浓度为10.62~58.96 mg/L,具有很高的经济利用价值,并预测了川南页岩气采出水中锂的资源储量和前景,总结了萃取法、膜分离法和吸附法对于从页岩气采出水中提取锂的适用性,为后期川南页岩气锂资源的综合利用提供参考。 

Abstract:

With the continuous increase of shale gas production in China, the associated water production is also increasing, which is the mixture of the water used for hydraulic fracturing and the brine retained in shale formation. During the treatment of produced water, valuable elements such as lithium, potassium and bromine are further enriched and concentrated, especially lithium resources, which has broad prospects for development and utilization, and can alleviate the contradiction between supply and demand of strategic resource lithium in China. In this paper, the shale gas resources in Sichuan are introduced and summarized mainly. And the ion content in the produced water of shale gas in Weiyuan and Changning areas in southern Sichuan is listed respectively. At present, the produced water volume of each well in Weiyuan and Changning is 19 800 m³ and 15 293 m³ respectively, and the lithium content in most of the produced water is 10.62-58.96 mg/L, which has high economic utilization value. The reserves and prospects of lithium resources in the produced water of shale gas are predicted. The applicability of extraction method, membrane separation method and adsorption method to the extraction of lithium in shale gas produced water are summarized, which provides the reference for the comprehensive utilization of lithium resources from shale gas formation in southern Sichuan.