Based on the transmitting theory of "smoke ring effect", the transient electromagnetism technique was used in coal mines to detect abnormal areas of aquiferous structures in both roofs and floors of coal sea...Based on the transmitting theory of "smoke ring effect", the transient electromagnetism technique was used in coal mines to detect abnormal areas of aquiferous structures in both roofs and floors of coal seams and in front of excavated roadways. Survey devices, working methods and techniques as well as data processing and interpretation are discussed systematically. In addition, the direction of mini-wireframe emission electromagnetic wave of the full space transient electromagnetism technique was verified by an underground borehole for water detection and drainage. The result indicates that this technique can detect both horizontal and vertical development rules of abnormal water bodies to a certain depth below the floor of coal seams and can also detect the abnormal, low resistance water bodies within a certain distance of roofs. Furthermore, it can detect such abnormal bodies in ahead of the excavated roadway front. Limited by the underground environment, the full space transient electromagnetism technique can detect to a depth of only 120 m or so.展开更多
Taking the Xutuan coal mine as an example, based on the temperature measurement data, combined with the geological background of the study area, this paper analyzes the distribution, thermal evolution, formation mecha...Taking the Xutuan coal mine as an example, based on the temperature measurement data, combined with the geological background of the study area, this paper analyzes the distribution, thermal evolution, formation mechanism and influencing factors of the deep geothermal field in the study area. Combined with previous research results and field temperature measurement data, the research results show that the temperature gradient of Xutuan coal mine varies in the range of 2.65<span style="white-space:nowrap;">°</span>C/hm - 3.15<span style="white-space:nowrap;">°</span>C/hm, most of which are 1.6<span style="white-space:nowrap;">°</span>C/hm - 3.0<span style="white-space:nowrap;">°</span>C/hm, which belongs to the normal area with relatively stable geothermal gradient. The northern part of the study area is more developed than the southern part. The minimum geothermal gradient is 2.65<span style="white-space:nowrap;">°</span>C/hm, and the geothermal gradient gradually increases from north to south;the geothermal gradient is negatively correlated with the buried depth within a certain depth range. Roughly taking the depth of 200 - 350 m as the dividing line, the temperature increases with the increase of depth, showing a good linear trend and the characteristics of conductive heating. The main influencing factor of the geothermal field in the study area is the geological structure, which is greatly affected by the fault structure. Followed by lithological changes and groundwater activities, the flow of the four waters has a certain control effect on the shallow geothermal field distribution.展开更多
文摘Based on the transmitting theory of "smoke ring effect", the transient electromagnetism technique was used in coal mines to detect abnormal areas of aquiferous structures in both roofs and floors of coal seams and in front of excavated roadways. Survey devices, working methods and techniques as well as data processing and interpretation are discussed systematically. In addition, the direction of mini-wireframe emission electromagnetic wave of the full space transient electromagnetism technique was verified by an underground borehole for water detection and drainage. The result indicates that this technique can detect both horizontal and vertical development rules of abnormal water bodies to a certain depth below the floor of coal seams and can also detect the abnormal, low resistance water bodies within a certain distance of roofs. Furthermore, it can detect such abnormal bodies in ahead of the excavated roadway front. Limited by the underground environment, the full space transient electromagnetism technique can detect to a depth of only 120 m or so.
文摘Taking the Xutuan coal mine as an example, based on the temperature measurement data, combined with the geological background of the study area, this paper analyzes the distribution, thermal evolution, formation mechanism and influencing factors of the deep geothermal field in the study area. Combined with previous research results and field temperature measurement data, the research results show that the temperature gradient of Xutuan coal mine varies in the range of 2.65<span style="white-space:nowrap;">°</span>C/hm - 3.15<span style="white-space:nowrap;">°</span>C/hm, most of which are 1.6<span style="white-space:nowrap;">°</span>C/hm - 3.0<span style="white-space:nowrap;">°</span>C/hm, which belongs to the normal area with relatively stable geothermal gradient. The northern part of the study area is more developed than the southern part. The minimum geothermal gradient is 2.65<span style="white-space:nowrap;">°</span>C/hm, and the geothermal gradient gradually increases from north to south;the geothermal gradient is negatively correlated with the buried depth within a certain depth range. Roughly taking the depth of 200 - 350 m as the dividing line, the temperature increases with the increase of depth, showing a good linear trend and the characteristics of conductive heating. The main influencing factor of the geothermal field in the study area is the geological structure, which is greatly affected by the fault structure. Followed by lithological changes and groundwater activities, the flow of the four waters has a certain control effect on the shallow geothermal field distribution.
