Evaluation of Cenozoic Geothermal Resources of the Dongpu Depression, Bohai Bay Basin, China

Abstract

Geothermal energy is a green and sustainable energy source. Rational development and utilization of geothermal energy can not only improve the living environment for local residents but also reduce environmental pollution and promote sustainable economic development. Based on the thermal physical parameters and lithologic parameters, the volume method was implemented to comprehensively evaluate the thermal reservoir temperature, geothermal resource types, and resource potential of the Cenozoic Minghuazhen Formation, Guantao Formation, and Dongying Formations in the Dongpu Depression. The natural breakpoint method has been applied to categorize the resource intensity in the Dongpu Depression, thus clarifying the distribution of geothermal resources and favorable development areas in the study area. The results show that the reservoir temperature of the Minghuazhen Formation of the Dongpu Depression is 40–58°C, while the reservoir temperatures of the Guantao and Dongying Formations are 70–112°C and 70–140°C, respectively, primarily harboring medium–low‐temperature geothermal resources. Through calculation, it is found that the geothermal resources of the Cenozoic Minghuazhen, Guantao, and Dongying Formations in the Dongpu Depression are 3.70 × 1020 J, 2.23 × 1020 J, and 2.30 × 1020 J, respectively. Collectively, these amount to a total of 8.23 × 1020 J, equivalent to approximately 281.29 billion tons of standard coal. A comparative study of the calculated results of the three geothermal reservoirs in the research area reveals that the Dongying Formation exhibits the highest potential for geothermal resource exploration, particularly in the eastern Changyuan Sag and the Xuji Uplift. The Minghuazhen Formation follows closely. Notably, the geothermal resource potential is significant in the Gaopingji Slope, the East Changyuan Sag, the Xuji Uplift, and the Machang Uplift in the southwest. While the Guantao Formation has a relatively smaller potential, the eastern depression of the Changyuan and the middle section of the Xuji Fault, near the Yellow River Fault, do possess a certain degree of exploration value. The research can provide important basic support for the design of geothermal development in the Cenozoic of the Dongpu Depression.