Better Use of Abandoned Oil/gas Wells and Small Lng Stations
Fei XIAO1+, Hezhen YANG2#
1Department of Civil Engineering, Nanjing University of Aeronautics and Astronautics, Singapore, 2Singapore Institute of Technology, Singapore

There are a huge number of abandoned oil/gas wells (AO/GW) all over the world, which can be harmful to the environment if not being treated in a proper way, while the corresponding treatment cost could be high. To address this issue in a more economical way, it is proposed to revitalize AO/GW via geothermal energy exploitation. Considering that the bottom hole temperature of AO/GW is usually low and medium, enhancement of the associate thermal performance is in need. It is known that extra heat should be added to facilitate the regasification of liquified natural gas (LNG) in small fuel stations, which could result in a waste of cold energy. Therefore, if it happens that a small LNG station is surrounded by one or several AO/GWs, geothermal energy exploitation and a small-scale gas turbine can be integrated into the regasification process through a binary cycle system, then the geothermal resources from AO/GWs can be better harvested due to larger temperature difference created, and the natural gas produced can be used to generate electricity first before going to the end users. The purpose of our work is to explore the variation patterns of regasification capacity of LNG station in terms of the characteristics of an AO/GWs, including different thermal conductivity of AO/GW structure and the surrounding formation, temperature gradient and depth of formation, and working fluids and the associated circulation velocities. Then a predictive model using system characteristic parameters will be built to evaluate the maximum regasification capacity under given working conditions.