This paper is the result of geothermal exploration engineering.

Objective With the continuous improvement of the exploration level of geothermal fields in China, more and more temperature measurement data and logging data are emerging. How to retain the representativeness of individual data, adopt reasonable methods to extend the limited parameters, and reflect the continuity, gradation, and heterogeneity of geological parameters in the three-dimensional spatial distribution are urgent problems to be solved for improving the accuracy of geothermal resource evaluation. The three-dimensional geological modeling technology provides a solution for efficiently processing these data. The research on the evaluation method of geothermal resources based on distributed parameter models is of great significance for improving the automation level and accuracy of geothermal resource evaluation.

Methods The geological structure of the study area was characterized by the three-dimensional geological modeling technology. The temperature measurement data in the study area were discretized by the discrete smooth interpolation method, and the porosity data in the study area were discretized by the sequential Gaussian simulation method. The density and specific heat capacity were correlated with temperature respectively. Based on the above distributed parameter models, the geothermal resource evaluation was carried out with finite cells as evaluation units.

Results Three-dimensional geological models, temperature field models, porosity models, density models, and specific heat capacity models of the study area were constructed. The geothermal resource reserves of each cell were evaluated by the heat reservoir method, and a total of more than 6 million data were obtained. Through the data extraction function of the model, the heat stored in the heat reservoirs in different regions and at different depths was extracted, and the horizontal and vertical distribution laws of geothermal resources were obtained.

Conclusions The geothermal resource evaluation based on distributed parameter models can intuitively display the spatial distribution characteristics of resources. Compared with centralized parameters, it can significantly improve the evaluation accuracy. The model can extract the statistical laws and resource reserves of heat reservoir parameters within a specific spatial range, and can be used to guide the delineation of development zones in three-dimensional space, the positioning of main target layers, the argumentation and construction of geothermal drilling well positions, economic benefit analysis, and geothermal resource management.