1results about How to "Improve displacement efficiency" patented technology

The application discloses a thick coal seam gas extraction method applying directional multi-branch long borehole gas drive flow increasing, which comprises the following steps: A: coal seam geological condition investigation; B: completing the construction of the bedding extraction borehole and the directional multi-branch long borehole, and pre-extracting under negative pressure before mining; C: selecting a directional multi-branch long borehole as a first gas injection borehole, and implementing a long injection short extraction mode; D: after the first gas injection borehole gas injection is completed, a long extraction short extraction mode is implemented; then a second gas injection borehole is selected to implement the long injection short extraction mode; E: a third, a fourth, and so on, gas injection borehole is selected to implement the long injection short extraction mode according to the method in the step D; the first round of gas extraction is completed; F: according to the method in the step E, the second round, the third round, and so on, of gas extraction is continuously completed until the gas in the thick coal seam is fully extracted through the gas drive flow increasing mode. The application can effectively solve the problem of low gas extraction efficiency of the upper horizon of the existing thick coal seam.