The Genesis Discussion of Dongying Geothermal Resources in Tanggu District, Binhai New Area, Tianjin

Abstract

There are abundant geothermal resources in Tanggu—the core area of Tianjin Binhai New Area. Tanggu district has the layered reservoir which belongs to sedimentary basin type, and Dongying formation is one of layers of porous type with lower reseach level. In order to exploitation the geothermal resources more scientific and rational, The genesis discussion of geothermal resources with comprehensive analysis of the structure setting, reservoir characteristics, sedimentary surrounding, chemical characteristics, etc, is necessary. The results show that the formation of Dongying reservoir is quite different from Neogene reservoir. For Dongying reservoir, the thickness is 100 to 660m, the rate of sand and mud is 35 to 38%, the porosity is 20 to 35%, the permeability is 200 to 1000mD, the temperature of the fluids is 73 to 85℃. The hydraulic connection between the geothermal fluid and its overlying, underlying reservoir is very limit. There is also no obvious hydraulic connection between the reservoirs in the west of Cangdong Fault and Dongying reservoir in this area. The genesis of the geothermal fluid is not seawater but the meteoric water from the northern mountains.