US 12,129,620 B1
Method for repairing aquifer in coal mine area
Yifan Zeng, Beijing (CN); Weihong Yang, Beijing (CN); Qiang Wu, Beijing (CN); Kai Pang, Beijing (CN); Xinjiang Wei, Beijing (CN); Xue Liu, Beijing (CN); Xuan Xiao, Beijing (CN); Aoshuang Mei, Beijing (CN); Shihao Meng, Beijing (CN); and Chao Yu, Beijing (CN)
Assigned to CHINA UNIVERSITY OF MINING AND TECHNOLOGY, BEIJING, Beijing (CN)
Filed by CHINA UNIVERSITY OF MINING AND TECHNOLOGY, BEIJING, Beijing (CN)
Filed on Mar. 8, 2024, as Appl. No. 18/600,416.
Claims priority of application No. 202311774997.1 (CN), filed on Dec. 21, 2023.
Int. Cl. E21B 33/13 (2006.01); E02D 3/12 (2006.01)
CPC E02D 3/12 (2013.01) [E02D 2250/003 (2013.01); E21B 33/13 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A water retention method for repairing an aquifer by grouting in a coal mine area after mining based on a hole with multiple uses, comprising:
drilling a survey hole in a ground area corresponding to a water inflow position from ground surface to a caving zone in a goaf;
determining a target layer for grouting based on drilling data collected from the survey hole while drilling, which comprises: monitoring a drilling fluid leakage rate at each layer from the survey hole in real time during the drilling process; in response to determining the drilling fluid leakage rate corresponding to a certain layer is greater than 70% and the drilling fluid leakage rates corresponding to a previous layer and a subsequent layer of the certain layer are both less than 30%, determining that the certain layer is a layer to be grouted; monitoring a core sampling rate at each layer from the survey hole in real time during the drilling process; in response to determining the core sampling rate corresponding to a certain layer is less than 40% and the core sampling rates corresponding to a previous layer and a subsequent layer of the certain layer are both greater than 70%, determining that the certain layer is a layer to be grouted; monitoring a fracture density at each layer from the survey hole in real time during the drilling process; in response to determining the fracture density corresponding to a certain layer is greater than 40% and the fracture densities corresponding to a previous layer and a subsequent layer of the certain layer are both less than 10%, determining that the certain layer is a layer to be grouted; in response to determining a layer is determined as a layer to be grouted corresponds to at least two kinds of the drilling data, determining that the layer is the target layer;
changing the survey hole to a grouting hole; and measuring a water level before grouting from the grouting hole; wherein, changing the survey hole to the grouting hole comprises: sealing the survey hole with cement slurry; and drilling the grouting hole at the place of the survey hole to the target layer; wherein, an aperture of the grouting hole is larger than that of the survey hole;
grouting through the grouting hole; changing the grouting hole to an observation hole after grouting; measuring a water level after grouting from the observation hole;
determining a water retention level based on the water level before grouting and the water level after grouting.