Table 1
Operational parameters and independent variables for the different phases of CBM producing process in Zhengzhuang and Sanjiao coalfields.
| Parameter | Values |
|||||||
|---|---|---|---|---|---|---|---|---|
| Zhengzhuang coalfield | Sanjiao coalfield | |||||||
| Rod diameter d (mm) | 19.0 | 19.0 | 19.0 | 19.0 | 19.0 | 19.0 | 19.0 | 19.0 |
| Tubing diameter D (mm) | 52.4 | 52.4 | 52.4 | 52.4 | 73.02 | 73.02 | 73.02 | 73.02 |
| Cross-sectional area of tubing AG (cm2) | 19.87 | 19.87 | 19.87 | 19.87 | 41.87 | 41.87 | 41.87 | 41.87 |
| Wall thickness of tubing DW (mm) | 3.96 | 3.96 | 3.96 | 3.96 | 7.82 | 7.82 | 7.82 | 7.82 |
| Plunger diameter DH (mm) | 44 | 44 | 44 | 44 | 56 | 56 | 56 | 56 |
| Dynamic fluid level H (m) | 610 | 671 | 695 | 701 | 457 | 545 | 631 | 649 |
| Density of well liquid in annular ρm (kg · m−3) | 956 | 833 | 486 | 778 | 970 | 856 | 512 | 765 |
| Density of well liquid ρw (kg · m−3) | 1016 | 1015 | 1013 | 1012 | 1016 | 1014 | 1014 | 1013 |
| Viscosity of well liquid μw (mPa · s) | 0.79 | 0.79 | 0.79 | 0.79 | 0.82 | 0.82 | 0.82 | 0.82 |
| Pumping speed n (r · min−1) | 10.0 | 7.0 | 4.5 | 2.0 | 9.0 | 6.5 | 3.8 | 2.4 |