Numerical modeling in reinjection of geothermal sandstone reservoir : a case study in North Shandong, China
Author: Zichun Zhang
Year: 2022
Supervisors: Juliet Ann Newson, Li Shengtao
Abstract:
The Neogene sandstone geothermal reservoir is widely distributed in the North China Plain and has rich geothermal potential. Pumping without reinjection has been the major form of geothermal utilization for years in space heating. However, due to the drawdown of water level, pollution of the subsurface environment, and difficulty of reinjection have become a problem that restricts geothermal resource sustainable development and utilization for space heating in winter. Geothermal Sandstone Reinjection Research Demonstration Project (GSRRDP) in sandstone reservoir reinjection in North Shandong Plain has been conducted for four years since 2016. To solve the scaling problem in local reinjection, this project analyzed the characteristics of the sandstone reservoir in the study area, tested and improved different reinjection and well-completion methods. In this thesis, the author established a numerical model based on the data from GSRRDP to simulate the temperature field and hydrodynamic field changes after long-term geothermal wastewater reinjection. After the model was built up and calibrated, the thermal breakthrough occurrence was estimated, the potential breakthrough-prevent method was simulated, and rational well spacing was calculated. Finally, with its results, this model can be a good reference for local geothermal sandstone reservoir reinjection work on thermal breakthrough aspects.