Exploring hydraulic connections between brine mining wells is of great significance to the development of geological resources; however, there are still challenges to accurately identifying these connections. In this study, a combination of hydrochemical and biological analyses was used to investigate the hydraulic connections between three saltworks (Yangkou, Hanting, and Changyi) in southern Laizhou Bay, China. The results showed that the groundwater recharge sources at Yangkou saltworks, and therefore the associated salts and hydrochemical composition of the brine, were different from those of the other two saltworks. The diversity and composition of the microbial community among the three saltworks were identified based on a high-throughput DNA sequencing method. The brines of Hanting and Changyi saltworks had greater similarity in terms of microbial diversity and composition, which was consistent with the hydrochemical results. Based on microbial analysis combined with hydrochemistry, the depths of the mining wells at Hanting saltworks were identified, along with the hydraulic connection with Changyi saltworks. As a tool to judge the hydraulic connections of geological reservoirs, microbial analysis combined with hydrochemistry may be applicable to a wider range of subsurface resources, such as oil and gas, which will provide new ideas for the rational development of underground resources.
The coal-forming characteristics,as well as the similarities and differences between epicontinental sea basins and continental marginal sea basins developed during different time periods,were analyzed in this study by adopting comparative analysis thoughts and methods.The results obtained in this study revealed that epicontinental basins and marginal sea basins are both characterized by the main development of thin coal seams or extremely thin coal seams.In addition,changes in sea levels were determined to be the main controlling factors for coal formation,and there were similarities in the continent-sea interactions and coal-forming sedimentary systems of the different basins.However,there were also significant differences observed in the sea level change events,basin basement structural characteristics,coal seam stability levels,accumulation and aggregation characteristics,and the migration patterns of coal-forming materials.For example,the marginal sea basins in the South China Sea were found to be characterized by strong tectonic activities,diversity and complexity.The basin structures showed complex patterns of depressions,uplifts and concave or sag uplifts,which tended to lead to greater complexity in the paleogeographic patterns of the coal formations.This had subsequently resulted in complex coal-forming processes and paleogeographic characteristics,in which the coal-forming zones displayed bead-like distributions,and the enrichment areas and centers were scattered.The practical significance of studying the similarities and differences of the coal-forming characteristics between epicontinental basins and marginal sea basins is that the results can potentially be used to guide the predictions of coal-measure coal seam distributions in South China Sea,as well as provide valuable guidance for future explorations of natural gas reservoirs related to coal measures in the South China Sea area. 相似文献
