Geological characteristics of the main aquifer coal seam in the Ordos Basin coalfield, China
- PDF / 3,060,530 Bytes
- 10 Pages / 595.276 x 790.866 pts Page_size
- 95 Downloads / 255 Views
TECHNICAL NOTE
Geological characteristics of the main aquifer coal seam in the Ordos Basin coalfield, China Feng Ju 1 & Meng Xiao 1 & Shuai Guo 1 & Baiyi Li 1 Received: 23 March 2018 / Accepted: 15 October 2018 # Saudi Society for Geosciences 2018
Abstract The main aquifer coal seam within the Ordos Basin (OB) coalfield, China, is an extremely rare example of a hydrogeological feature that is found relatively recently during basin development. Mine water gushed from this coal seam during the construction and production phases of the coalfield. However, because this seam has traditionally been considered as an aquifuge, the special geological conditions it creates have led to a range of new challenges in mine water disaster prevention, control, and management as characteristics of both confined and unconfined aquifers are evident. The aim of this paper is to reveal the causes underlying the formation of this main aquifer coal seam by analyzing hydrodynamic conditions, hydrogeological structures, and the surrounding lithological association. In addition, the particular geological conditions created by the presence of this feature are discussed, with emphasis on their influences on mine construction and production. This study provides an important theoretical basis for the future study of mine water disaster prevention as well as a potential method for disaster control that can be applied in the case of particular hydrogeological conditions. Keywords Geologic origin . Permeability . Hydrology . Hydrodynamic condition . NW China
Introduction The Ordos Basin (OB) is one of the most important fossil-fuel energy provinces in western-central China as it contains large reserves of coal, oil, natural gas, and coalbed methane (Yao et al. 2014). The Yuheng mining area (YMA) is located within the southern OB, China, and comprises part of the northern Shanxi Province Jurassic coalfield. A total of 19 mines are scheduled for construction within an area encompassing about 4900 km2. Among these, the Xiaojihan coal mine, located in the northern YMA, was the first to be constructed (Fig. 1) and has a designed capacity of 10 million tons per year. As the OB is an arid and semi-arid region subject to water shortages, encompassing the loess layer and the Maosuwu desert, hydrogeological conditions for mining are assessed as relatively straightforward (Gao et al. 2017; Huang et al. 2012;
* Meng Xiao [email protected] 1
State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221116, China
Li 2012). However, during the development phase of the Xiaojihan coal mine, water pressure in coal seam number 2 increased to 2.6 MPa, submerging the air intake shaft and the return air roadway (inclined shaft) (Fig. 2). The process of sealing these shafts by borehole grouting led to a significant construction delay. Given typical mining geological conditions, and because a coal seam is considered to be an aquifuge, the key to controlling flooding is to understand the fracture wat
Data Loading...
