Stress Response Law Induced by Hydraulic Slotting of Deep Coal Rock Gas Reservoirs in Eastern Margin of Ordos Basin

To improve the efficiency of deep coal rock gas development, this study takes the Daning-Jixian Block in the eastern margin of the Ordos Basin as the research object. Using Flac3D numerical simulation and theoretical analysis methods, the in-situ stress response under hydraulic slotting in deep coal rock gas reservoirs was investigated. The results show that the stress relief space created by hydraulic slotting in coal rock gas reservoirs can effectively alter the in-situ stress state, reduce reservoir effective stress, and enhance reservoir conductivity. For every 1 m increase in slot length, the stress relief range expands by 4.3-4.9 m, and the degree of stress relief increases by 4.7%-21%. For every 1 m increase in slot width, the stress relief range increases by 0.3-0.7 m, while the degree of stress relief decreases by 0.7%-1.4%. Compared with a single slot, multiple sets of slots can form superimposed stress release zones, further expanding the stress relief range and enhancing the stress relief effect. Optimizing slot length and spacing can significantly increase the controlled range of coal rock gas recovery resources. Hydraulic slotting in coal rock gas reservoirs has a significant effect on in-situ stress modification. This research can provide a basis for the efficient development of coal rock gas through hydraulic slotting technology.