Tests have shown that even over short distances injecting air into a borehole moves existing mine atmospheres rather than replacing them. ... The coal mining report had indicated that shallow coal ...
Permission to enter or disturb Coal Authority mining interests Express applications. ... Digital Opencast (Surface Mining) borehole data (per borehole, with scientific data) £2.50:
Effect of Deformation Instability of Gas Drainage Borehole in Deep Mining of Soft Coal Seams 4.1. Engineering Background and Establishment of Physical Model. The simulated mine is located in the eastern part of the Pingdingshan mining area. The designed production capacity of the mine is 3 million tons per year, and the mineable …
Coalbed methane (CBM) extraction is an important method for coal mine gas disaster management, natural gas utilization and environmental protection (Kurlenya et al., 2014; Tao et al., 2019; Liu et al., 2020a; Wang et al., 2015; Xi et al., 2023).Surface well extraction and underground borehole extraction are two synergistic methods of CBM …
A high-resolution three-dimensional (3-D) seismic survey was conducted in advance of coal mine development in the Illinois basin in May 1989 to better define a geologic structure with the ...
Introduction. The development of innovative technologies of bituminous coal excavation is still important, especially in the light of increasingly challenging mining conditions 1 – 3.The studies of cutting rocks using a high velocity jet of water (i.e. water jet) date from the 1960s 4 – 7, when the mechanism and threshold conditions required to …
The surface borehole mine gas drainage technology in coal mining-influenced region is a technology that the construction of borehole is implemented on the ground prior to stopping of coal seam, thus draining the methane emission from pressure relief area of coal seam mining and the methane emission from subsequent gobs with …
The tectonic coal seams are mainly distributed in most parts in Southwest and Northeast in China, such as Henan, Anhui, Guizhou, Sichuan, Yunnan and Hunan provinces (Fig. 1), the coal-bed methane (CBM) reserve of which is 5.6073 trillion cubic meters in total, accounting for 39.2% of that of the whole country. 1, 2 Although the …
Therefore, this study focuses on the actual situation of the 10# coal seam in Pingdingshan coal mine, using numerical simulation software to determine the range of high-level borehole arrangement ...
Tree-type boreholes drilling (TTBD) is a novel method of stress relief methane drainage and has become an attractive option because it improves coal mine …
The geological transparency of working face is the premise and guarantee to realize the intelligent and accurate mining for coal resources.A large number of gas drainage holes, water exploration holes and other boreholes are constructed before and during coal mining. In this paper, the borehole radar (BHR) is used to detect the coal …
Safety in coal mining is greatly increased by the drainage of the methane content of coal seams through boreholes, simultaneously producing significant energy. The design of suitable drainage technology is based on the mathematical modeling of methane flow in coal seams. In the calculation of the methane pressure, the new mathematical model …
Qu et al. [23] found that the stability of coal seam borehole was affected by the time lag effect based on field tests and numerical simulation; they found that the change of pore pressure was the ...
Due to severe harms of goaf collapse, the goaf exploration and governance has become an urgent issue for protecting the normal life of local people. According to the coal mine geology, different geo-electrical model s have been employed for the purpose of discovering the goaf s . However, most existing methods require a large amount of …
Extensive coal mining activity took place at Queenslie and the surrounding areas of Shettleston and Garthamlock in the East End of Glasgow through the nineteenth century and into the early twentieth century. ... By determining the chronology of historical mining in each borehole locality, the influence of mine workings on subsurface temperature ...
Design of gas pre-extraction borehole. Prior to mining that affected the M18 coal seam of the Qinglong Coal Mine, coal bed gas from this seam was pumped 20–210 m backward based on one control ...
Acoustic scanner data indicate the breakout at the depth 283.2-283.9 m (a) along N110° and caving of clay at the depth 284.37-285.55 m of the Barren Measures from Adriyala borehole 1199.
the borehole through cracks in the coal seam, which leads to the leakage of the borehole. In addition, the con- nections between the extraction pipes are not close, which results in low extraction ...
The ideal jet of the monitor in the borehole hydraulic coal-mining system is a nonsubmergible free jet. Through air lift, the nonsubmergible free jet can be set up in the mining hole. References [1] Dibble M F. Borehole mining: improved technology expands horizon. Mining Engineering, 1991, 290(3): 313–318. [2]
The methane drainage can be done by drilling boreholes in coal layers, drilling boreholes from the ground surface to gobs or from the inside of the mine, and …
Since their introduction to the coal mining industries of the United Kingdom and West Germany in the 1970s, geophysical methods are now utilised in coal mining around the world. ... As shown by the density log from the borehole, there are 8 coal seams present. High quality reflections are obtained from the coal seams closest to the …
Accurate evaluation of the influence range of borehole hydraulic fracturing (HF) in coal seam is crucial for optimizing the design scheme of HF. In this study, we adopted the microseismic (MS) monitoring technology to monitor and characterize the spatial shape of cracks caused by borehole HF in coal seam in an underground coal …
The emission of gas from the coal seams is one of the most important issues during the underground coal mining operation. Each year, coal gas emission from the underground stopes leads to the death of a large number of miners and is one of the biggest threats to workplace safety. In addition, ventilating and releasing coal gas …
Before hydraulic fracturing in the coal seam, the background field is simulated and analyzed to facilitate the analysis of the BHR response characteristics of the cracks. The BHR central frequency is 200 MHz, the BHR response in the coal mine borehole along the coal seam is shown in Figure 7.
Gas drainage through boreholes can effectively reduce gas disasters and significantly promote the efficient drainage and clean utilization of gas during mining activities. Gas drainage boreholes will deform and fail as the mining proceeds, but there is a lack of effective measures for real-time monitoring of borehole stability currently. …
Gamma logs are the most widely used geophysical borehole method by the coal mining industry. Gamma logging records the gamma radiation naturally occurring from a rock. Natural gamma is used to detect the presence of potassium-40, …
1. Introduction. The permeability of coal seam is low in most areas in China, and coalbed methane exploration on the ground and through underground mine gas extraction becomes difficult [1], [2].China is one of the biggest coal-producing countries in the world, but the efficiency of its coal gas extraction process is low, causing much …
In addition, the low-amplitudes are normally associated with fractures. The usefulness of the acoustic scanner data can be easily demonstrated by the scanner amplitude image from Kakatiya Khani …
