Research Article
Polymer Drilling Fluid with Micron-Grade Cenosphere for Deep Coal Seam
Table 6
Results of dynamic damage experiments.
| Core |
Permeability measured with gas/10−3 μm2 |
Permeability measured with water/10−3 μm2 | Fracture width/μm |
Filter loss/mL | Natural flowback | Breakthrough pressure/MPa | Maximum recovery rate/% | Differential pressure under maximum recovery rate/MPa |
| 3 | 96.86 | 0.63 | 28.06 | 0.98 | 2.1 | 93.21 | 2.5 | 4 | 147.65 | 1.39 | 34.21 | 1.59 | 1.6 | 88.30 | 2.1 | 5 | 213.97 | 2.42 | 39.94 | 2.64 | 0.7 | 83.62 | 1.2 |
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