Evaluation Of Geothermal Resources And Construction Of Geothermal Database In Abandoned Mine Area Of Huainan Coalfield

Huainan coal field is an important coal base in China.With the exploitation of coal resources for many years and the active response to the coal de-capacity policy,many abandoned mines with backward production capacity or resource depletion have been formed.There are still a variety of rich potential energy sources such as groundwater,gas,geothermal energy and so on in the mined-out areas or strata of these abandoned mines.Among the above energy sources,geothermal resources belong to green and clean energy.Strengthening the evaluation and utilization of geothermal resources in abandoned mines is an important exploration for the construction of national ecological civilization and the development of low-carbon clean energy.It is also an important measure to accelerate the realization of the national’double carbon’goal.In this paper,through the collection and collation of the geological and geothermal data of the main abandoned mines in Huainan Coalfield,on the basis of the correction of the ground borehole temperature measurement data,the geothermal distribution law and terrestrial heat flow of the strata in the abandoned mine area of Huainan are studied by means of rock thermal test and theoretical comprehensive analysis.At the same time,the geothermal resources of the thermal reservoir of the abandoned mine are predicted.Finally,the database of geothermal data is established,which provides theoretical and data support for the subsequent demonstration project of resource development and utilization of the geothermal area of the abandoned mine.The main results achieved are as follows:（1）The distribution of abandoned mines in Huainan coalfield is collected,and the temperature measurement boreholes and geothermal data of the main abandoned mines in the area are counted.The bottom temperature and horizontal temperature correction of the simple temperature measurement boreholes are carried out,and the bottom temperature correction curve formula and horizontal temperature correction coefficient are obtained,which provides data for the later drawing of geothermal gradient and temperature contour maps.（2）According to the borehole temperature measurement data,the geothermal gradient value is calculated.It is concluded that the geothermal gradient value of the main abandoned mines in the area ranges from 0.74 to 4.3°C/hm,and the average geothermal gradient of the whole well section is 2.77°C/hm;using Arc Map 10.2software to draw the geothermal gradient contour map,it is concluded that the geothermal distribution characteristics of the abandoned mine area in Huainan coalfield are high in the north and west,low in the south and east.（3）According to the corrected horizontal temperature,the contour map of horizontal ground temperature is drawn.It is concluded that the ground temperature and mining depth of the strata in the abandoned mine area of Huainan coalfield are positively correlated.As the depth increases,the ground temperature also increases,showing the characteristics of conductive warming and having a good linear trend.（4）The variation range of the terrestrial heat flow in the main abandoned mine area of Huainan coalfield is 13.81-98.428 m W/m²,and the average terrestrial heat flow is 64.61 m W/m²,which is higher than the average terrestrial heat flow of 62 m W/m² in Anhui Province and the average terrestrial heat flow of 63.69 m W/m2 in Huainan coalfield.（5）The thermal storage method is used to calculate the thermal reserves of the Paleozoic thermal reservoirs in the main abandoned mine areas of Huainan Coalfield.The total thermal reservoirs are 6.70×10¹⁷J,and the total recoverable thermal energy reserves are 1.68×10¹⁷J.The total converted standard coal is 5.72×10⁶t.The geothermal energy of the abandoned mine thermal reservoirs is widely distributed and the reserves are large.（6）Using Anaconda software,based on My SQL database and Python programming language,a geothermal resource database is established to ensure the availability,integrity,confidentiality and scalability of geothermal information in abandoned mine areas,so as to realize rapid geothermal resource information query and evaluation,and provide reliable information service and auxiliary decision-making basis for geothermal resource exploration and development and utilization in abandoned mine areas.Figure 47 Table 28 Reference 91...