Literature review on a U-shaped closed loop geothermal energy development system

ABSTRACT

Geothermal energy is becoming more attractive nowadays. Compared with enhanced geothermal recovery method, developing geothermal energy using a closed loop heat exchanger possesses unique advantages, such as no fluid exchange with the geothermal reservoir. U-shaped closed loop geothermal energy development system was proposed in recent years with high energy efficiency. In this paper, we reviewed the U-shaped closed loop geothermal energy development system from literature and, then, conducted a case study based on previous models. It is found that: (a) the effective heating distance is an important parameter that can be used for economic analysis; (b) the effective heating distance grows with producer number; (c) the wellbore starting from the turning point to well-head should be insulated; (d) a higher temperature can be obtained not only from by increasing the effective heating distance, but also by decreasing mass flow rate to a reasonable level; (e) the turning point will come earlier when the mass flow rate is smaller, while it will come later when the mass flow rate is larger.

KEYWORDS:

• Literature review
• Geothermal energy development
• U-shaped wells
• closed loop system
• effective heating distance

Acknowledgments

The research was supported by National Science and Technology Major Projects of China (No. 2016ZX05042, No. 2017ZX05039, and 2016ZX05039) and the National Natural Science Foundation Projects of China (No. 51504269, No. 51490654 and No. 40974055). The authors also acknowledge Science Foundation of China University of Petroleum, Beijing (No. C201605), the National Basic Research Program of China (2015CB250900), the Program for New Century Excellent Talents in University (Grant no. NCET-13-1030) to support part of this work.

Additional information

Notes on contributors

Fengrui Sun

Fengrui Sun earned his Master in Oil-Gas Field Development Engineering from China University of Petroleum (Beijing) in Beijing, China, in 2013. At present, he is pursuing his PhD in Oil-Gas Field Development Engineering in China University of Petroleum (Beijing). His ares of interest include reservoir numerical simulation, production optimisation, and thermal recovery of heavy oil.

Yuedong Yao

Yuedong Yao earned his Master in Oil-Gas Field Development Engineering from China University of Petroleum in Beijing, China, in 1997. He earned his PhD in Oil-Gas Field Development Engineering from China University of Petroleum in Beijing, China, in 2000. At present, he is a Professor in China University of Petroleum, Beijing. His areas of interest include oil-gas field development engineering, seepage flowing mechanics and well testing.

Guozhen Li

Guozhen Liis a PhD at the College of Mechanical and Transportation Engineering, China University of Petroleum-Beijing. She is engaged in the study of multiphase flow, pipeline mixing and mechanical design, CO₂ sequestration, production optimization, and thermal recovery of heavy oil.