Table 1 Current application status of cavitation completion technology in the Huainan mining area.
Construction time | Technology type | Construction place | Cave building well-group | Technical feature |
|---|---|---|---|---|
2011 | Mechanical cavitation; under coalmine directional drilling | Lizuizi coalmine | 5 drilling holes | Drilling per meter can complete coal extraction of 0.14 m3 Simple process; a large number of boreholes were deployed The single borehole gas extraction purity has increased from 41.82 m3/day to 54.24 m3/day (Gubei Coalmine) |
2011 | Gubei coalmine | 12 drilling holes | ||
2014 | Aerodynamic cavitation, ground directional wells | Xieyi coalmine | 2 directional wells and 1 horizontal multi-branch docking well | The cavity volume of each single well reaches 100 m3; complex process; each directional well completed one cave The highest single borehole gas extraction purity is 2591 m3/day |
2015 | 4 directional wells | |||
2018 | Hydraulic cavitation, ground multi-branch well | Pansan coalmine | 1 multi-branch well (contains 6 branches) | The volume of a single well reaches 135 m3 (contains 6 branches) Complex process Multiple holes were made in each group The highest single borehole gas extraction purity is 280 m3/day (contains 6 branches) |
2019 | Hydraulic cavitation, under coalmine directional drilling | Dingji coalmine | 35 drilling holes | The hole-making volume is generally about 1.5 m3/m; simple process; a large number of boreholes were required The highest single borehole gas extraction purity is 54.24 m3/day |
