Development status of geothermal reinjection at home and abroad and its enlightenment

Geothermal tail water reinjection is an effective measure to maintain the sustainable production of geothermal resources and prevent the problems of geological setting (e.g. surface subsidence), is of great significance to various geothermal reservoirs in production and is the key factor to the success of geothermal development. In the process of geothermal reinjection, however, some problems may be caused, such as temperature decline of the produced fluid in the production well, scaling and corrosion of reinjection well and blockage in the wellbore of reinjection well in sandstone geothermal reservoir and its surrounding geothermal reservoir, which decrease the reinjection efficiency and impact the geothermal reservoir productivity. In order to better solve the problems in the geothermal tail water reinjection, this paper firstly investigated the common reinjection technologies by taking the status of geothermal tail water injection at home and abroad as the beginning point. Then, the main problems and influence factors of tail water reinjection were analyzed and four suggestions were proposed as follows. First, strengthen the study on geothermal reservoirs to increase the matching degree between development mode and geothermal reservoir. Second, carry out reinjection design reasonably to ensure the smooth operation of the reinjection system in the long term. Third, set the dynamic monitoring system to provide the reference for the later development. Fourth, innovatively research and develop reinjection technologies to increase the volume of reinjected tail water and maximize the economic benefit. They are of important significance to decrease the difficulty of geothermal tail water reinjection, increase the utilization rate of geothermal energy and promote the sustainable development of geothermal resources.