Volume 10: Sustainable Energy Solutions for Changing the World: Part II

Numerical simulation of closed-loop heat extraction from deviated-geothermal wells Yuncheng Gu, Xinli Lu, Jiaqi Zhang, Jiali Liu, Zhiwei Cui, Hao Yu, Changyou Geng, Yapeng Ren

Abstract

Exploiting the renewable energy rather than fossilfuels has become increasingly important. Among all types of renewable energy, geothermal energy is an ideal choice [1]. It can be used for heating and generating electricity and has advantages over wind and solar power [2, 3]. Closed-loop technology can be used to effectively extract heat from the underground formation and can avoid problems of corrosion, scaling in the wellbore, and mass flowrate loss in the reservoir [4]. Rybach and Hopkirk, firstly proposed the concept of using coaxial heat exchanger to provide heat for buildings in 1995 [5]. Alimonti et al. once set up a numerical model of a coaxial heat exchanger to maximize the extracted heat on Villafortuna Trecate oilfield [6]. Bu et al. made a study on acquiring geothermal energy from an abandoned oil and gas well using coaxial heat exchanger and verified its feasibility [7]. Noorollahi et al. carried out a numerical simulation of two vertical closed-loop heat extraction models for two oil wells in southern Iran [8].
However, few studies investigated the performance of closed-loop heat extraction from deviated-geothermal wells. In this paper, Closed-loop heat extraction models for a vertical geothermal well (Model A), a deviated geothermal well (Model B) and symmetrically arranged two deviated-geothermal wells (Model C) have been established. Their heat extraction performances were compared with respect to different inflow parameters.

Keywords closed-loop heat extraction, deviated-geothermal wells, numerical simulation