Study on the Reinjection Experiment in Xiongxian of the Niutuozhen Geothermal Field, North China

Abstract

The Niutuozhen Geothermal Field located in North China was developed for space heating and balneology from 1970. Geothermal water with the temperature from 50 to 85 Ž was extracted from the dolomite geothermal reservoir through 40 wells at the end of 2009. Reservoir pressure of the Niutuozhen Geothermal Filed decreased dramatically due to extreme pumping without reinjection in 40 years. In order to maintain geothermal resources sustainable development, reinjection is necessary. The first reinjection experiment started from November 2009 in Xiongxian of the Niutuozhen Geothermal Field. The reinjection experiment indicated that the reinjection capacity of one geothermal well was 150 m3/h. The second reinjection experiment in 2010 indicated that reinjection capacity of geothermal well was not less than 180 m3/h with an injection index of 8.72iL/sj/bar. The first tracer test demonstrated that there are small scale hydraulic channel between reinjection and production geothermal wells, which indicated that current reinjection scale may not lead to reservoir cooling in a short period.