Visual analysis of geothermal numerical simulation technology based on bibliometrics: Advances and trends

The numerical simulation method is an important method to meet the needs of large time-scale research in geothermal systems, and bibliometric analysis of relevant literature can provide a reference for understanding the current research progress and trends in this field. Based on 899 and 686 relevant literature in the field of geothermal numerical simulation published in the Web of Science core database and CNKI database from 2000 to 2022, Citespace and VOSviewer software were used for bibliometric analysis to explore the development trend, key research fields, and hot issues of geothermal numerical simulation research. The results show that the number of publications in the field of geothermal numerical simulation exponentially increased, and it entered a period of rapid development after 2014, with China accounting for the highest number of articles. The key research directions of keyword co-occurrence and clustering timeline maps show that the key research directions are enhanced geothermal systems, ground source heat pumps, heat transfer performance, and multi-field coupling. Here, the multi-field coupling process is summarized. Hydraulic-thermal coupling is the earliest and most researched issue, which acts as the core of multi-field coupling. The parameters can be determined from the two aspects of reservoir physical properties and mining methods. Hydraulic-Thermal-Mechanical is the current research hotspot, which is mainly Hydraulic-Thermal-Mechanical coupling and Hydraulic-Thermal-Chemical coupling. Mechanical deformation and geochemical reaction sedimentation and dissolution process are added on the basis of two-field coupling, respectively. Hydraulic-thermal-mechanical-chemical coupling with less attention at present needs to consider the time scale effect of the heat extraction process. The advantages and limitations of mainstream methods for characterizing fractures are summarized, and the discrete fracture network model is the research focus and hotspot to be tackled at present. This study shows that the numerical simulation method is in a period of rapid development in geothermal research, and is an important means for industry-university-research applications at present and in the future.