Reservoir evalutation for the Wuqing geothermal field, Tianjin, China

Abstract

The Wuqing geothermal field is a typical sedimentary basin low-temperature geothermal system, located in the middle-lower reaches of the Haihe river system on the North China plain. It is an extensive horizontal sandstone reservoir with a temperature range of 76-86°C. Hot water production started in 1994 and reached 1.18 Mm3 in 1997. The properties of the reservoir were estimated by analysing well test data and by simulating the available water level data by a simple distributed parameter model. The average permeability of the Wuqing reservoir is of the order 300-500 mD. For the next five years the production potential of the field is estimated to be 2.11 Mm3/year, assuming an allowable maximum draw-down of 100 m. The water level draw-down may be reduced, or the production increased, by reinjection. A tracer test is recommended to estimate the possible cooling due to reinjection as well as comprehensive reservoir monitoring.