Ground Water Reinjection Water in Dongli Lake Geothermal Field of Tianjin

Abstract

Dongli Lake geothermal field is a typical low-medium temperature sedimentary basin area, by the end of 2018, there were 23 carbonate reservoir geothermal wells in this area, and static water level falls nearly 5m annually due to the intensive development and utilization. Although reinjection percentage is about 90％ annually, the falling of the water level still relatively fast. This area is abundant in ground water, which can be used for reinjection after treated. Tracer test had been done during heating period from Jan 1st to Mar 30th, the result helps delineate the anisotropy of the reservoir, based on this, three deep wells had been sited and drilled for ground water reinjection in 2018, and the total injection ability of these wells is 450m3/h proven by reinjection test. This paper briefly introduces the water treatment system, and discusses the feasibility of the ground water injection through water-rock interactions experiments.