| Title | GEOTHERMAL PROSPECTS AROUND THE BEIJING OLYMPIC PARK |
|---|---|
| Authors | BIN Dezhi, PAN Xiaoping, WANG Xiaoling, MA Jingchen |
| Year | 2002 |
| Conference | Beijing International Geothermal Symposium |
| Keywords | Geothermal resources; Structure; Geothermal reservoir; Geothermal reserve; The Olympic Park in Beijing |
| Abstract | Beijing will host the Olympic Games in 2008, and the Olympic Park will be constructed in the north part of the urban area. It has been proposed that geothermal be used for space heating and hot water supply for the Olympic Park. Therefore, the geothermal potential around the area of the Olympic Park becomes of great concern, and the way of the geothermal utilization is also of great importance for the sustainable use of the resources. This paper is to analyze the geological condition on the basis of data from the drilling of cold ground water wells and geothermal wells, as well as other geological data around the area; and to estimate the geothermal potential in the area. At last, some suggestions related to the geothermal development around the Olympic Park is put forward. An important Fault, Huangzguang-Gaoliying Fault, which is a normal fault striking in SW-NE direction and its drop is more than 1,000m, goes by the area of the Olympic Park. The fault is also the boundary of two geological units. There is great difference on the two sides of the fault: There are sediments of great depth since Jurassic Period south of the fault, and there are not any Cretaceous and Tertiary strata north of the fault zone. There are also two other large-scale faults, the Babaoshan Overthrust and Sunyi Fault. Baobaoshan Overthrust is 4-5km north of Huangzguang-Gaoliying Fault, spreading paralleled with Huangzguang-Gaoliying Fault. Its dip is less than 30? to southeast. And Sunyi Fault, also a normal fault, spreads to the east. There are two formations that constitute the geothermal reservoirs in the area around the Olympic Park: limestone aquifer of Ordovician-Cambrian Periods and dolomite aquifer of Proterozoic Era. The former spreads in the north part of the area, and the later distributes all over the area. The depth of the geothermal reservoirs is from 1250 to over 3500m. The geothermal gradient of the caprock in the area is mostly as low as 1.4-1.86?/100m, and only higher in locations closed to faults that conduct water from the deeper part of the reservoir, such as the well S6 in the north part of the area. Volumetric method was used to estimate the heat storage in the 136.5km2 area around the Olympic Park. It is calculated that the heat storage within a depth of 3500m is 19.85?1018J in the area. And the volume of the geothermal fluid stored in the reservoir is estimated as 1.06?109m3. Compared to that of the Urban Geothermal Field in Beijing, the sustainable production of geothermal fluid in the area is estimated as 3.98?106m3/a, accounting to 741.81?1012J/a of heat energy. In the 34km2 area including the Olympic Park and its surrounding, the heat storage is 4.38??1018J, and the geothermal fluid storage is 231.64?106m3. The sustainable production of geothermal fluid is estimated as 1.23?106m3/a, accounting to 240.65?1012J of heat energy. It is suggested that the geothermal around the Beijing Olympic Park be planned, developed and managed in a centralized manner. The geothermal water should be used cascadedly and the waste geothermal water should be reinjected back to the reservoir. The geothermal wells should be drilled close to the Huangzhuang-Gaoliying Fault Zone, and two wells, each on either side of the fault, should be drilled firstly to have a better understanding to the geological condition in the area. Before the drilling, careful geoghysical explorations should be carried out. |