Geothermal Regime and Deep Temperatures of the Siberian Platform with comparison of the Baikal Rift zone

2nd International Geothermal Conference, GEOHEAT2018

Dorofeeva, Raisa P.^1

Institute of the Earth's Crust, SB RAS, Lermontov str., 128, Irkutsk

664033, Russia^1

关键词: Baikal rift zone;    Borehole temperature;    Deep temperatures;    Formation condition;    Hydrocarbon accumulation;    Metamorphic basements;    Siberian platform;    Thermal conductivity coefficient;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/249/1/012038/pdf
DOI  :  10.1088/1755-1315/249/1/012038

来源: IOP

【 摘 要 】

Based on well-understood geothermal regime of the southern East Siberia (about 200 heat-flow measurement points), the present paper deals with the study of deep temperatures of the southern Siberian platform (more than 70 boreholes, average heat flow 38±4 mW/m2) and thermal properties of core samples mostly representing the Vendian terrigenous deposits and Riphean magmatic and metamorphic basement rocks. The basement rocks, according to their thermal properties, are subdivided into two groups with thermal conductivity coefficients 3 and 2 W/mK. Higher coefficients indicate the presence of carbonate-halogen admixtures. Studies have been made of the borehole thermograms and temperatures at the bottom and top of the Moti suite, lower Cambrian ( mt3). The boreholes vary in depth from 1300 to 6000 m, and the borehole temperature attains a value as high as 70 oC. Rather intensive heat flow (45±6 mW/m2) is observed in the anticlinal domes and salt-dome crests, and low heat flow rate is typical of marginal uplifts. Geothermal peculiarity is also closely related to hydrodynamic features of the area where underground water seepage flow penetrates to depths of 3-5 km and diffusion flow prevails in deeper crust. Anomalous formation conditions exert influence on dynamics of hydrocarbon accumulation, which in turn is also predetermined by geothermal conditions.