Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Drilling regime parameters
| Parameters | Units | Value | Value |
|---|---|---|---|
| Depth | m | 1535.15–1600.00 | 1600.00–1623.04 |
| Rotary speed | rpm | 35 | 45 |
| Load on drill bit | kN | 30 | 40 |
| Pump pressure | MPa | 5.5 | 5.5 |
| Pump capacity | m3/min | 0.845 | 0.845 |
Results of the rock properties – limestone
| Parameters | Units | Value |
|---|---|---|
| Cohesion | MPa | 5.50 |
| Elastic module | MPa | 28125 |
| Angle of internal friction | ° | 38.42 |
| Compressive strength | MPa | 75 |
The elemental composition of carbide coating material (Figure 2 – Position 1)
| Elements | Concentration | |
|---|---|---|
| at.% | wt.% | |
| W | 55.415 | 79.539 |
| Co | 42.380 | 19.500 |
| Fe | 0.807 | 0.962 |
The elemental composition of the tooth body (Figure 2 – Position 4)
| Elements | Concentration | |
|---|---|---|
| at.% | wt.% | |
| Fe | 95.427 | 95.385 |
| Ni | 3.164 | 3.323 |
| Mn | 0.660 | 0.649 |
| Mo | 0.218 | 0.375 |
| Si | 0.531 | 0.267 |
Chemical analysis of the tooth material – body
| Elements | Mas. % |
|---|---|
| Mn | 0.79 |
| Ni | 0.74 |
| Cr | 0.60 |
| Mo | 0.50 |
| Cu | 0.27 |
| Si | 0.26 |
| C | 0.17 |
| S | 0.016 |
| P | 0.011 |
The properties of drilling fluid
| Parameters | Units | Value |
|---|---|---|
| Density | kg/m3 | 1150–1170 |
| Viscosity (Fann Funnel) | s | 45–48 |
| Plastic viscosity (Fann Viscosimeter) | mPas | 16–18 |
| pH | – | 9.5 |
| Filtration | mL/30 min | 9.8–10 |
Results of the rock properties – carbonatic siltstone
| Parameters | Units | Value |
|---|---|---|
| Cohesion | MPa | 0.722 |
| Elastic module | MPa | 9375 |
| Angle of internal friction | ° | 20.94 |
| Compressive strength | MPa | 25 |
The elemental composition of the carbide coating matrix (Figure 2 – Position 2)
| Elements | Concentration | |
|---|---|---|
| at.% | wt.% | |
| Fe | 86.096 | 68.599 |
| W | 1.709 | 29.094 |
| Ni | 1.921 | 1.608 |
| Mn | 0.892 | 0.699 |
Results of the Vickers hardness test
| Diagonals (mm) | Hardness (HV0.5) | Average | Note | |
|---|---|---|---|---|
| d1 | d2 | |||
| 37.23 | 46.24 | 532.3198 | 594.5670 | Tip of the tooth |
| 36.22 | 37.55 | 681.5125 | ||
| 36.4 | 40.81 | 622.1374 | ||
| 37.99 | 41.33 | 589.4786 | ||
| 37.54 | 41.66 | 591.2662 | ||
| 37.43 | 39.54 | 626.0232 | ||
| 37.57 | 39.86 | 618.6071 | ||
| 36.33 | 42.41 | 598.1947 | ||
| 38.87 | 42.45 | 560.8396 | ||
| 38.48 | 42.45 | 566.2580 | ||
| 39.01 | 42.84 | 553.6000 | ||
| 44.99 | 47.95 | 429.3664 | 433.5184 | Tooth body |
| 44.44 | 48.37 | 430.5701 | ||
| 44.61 | 47.78 | 434.4937 | ||
| 44.09 | 47.10 | 446.0042 | ||
| 45.14 | 48.04 | 427.1575 | ||
| 33.28 | 37.13 | 748.1087 | 784.1543 | Carbide coating—matrix |
| 31.73 | 34.04 | 857.3887 | ||
| 33.64 | 36.53 | 753.2349 | ||
| 34.58 | 36.51 | 733.8654 | ||
| 30.41 | 36.51 | 828.1739 | 1458.984 | Carbide coating—base |
| 24.67 | 25.96 | 1446.830 | ||
| 24.43 | 25.78 | 1471.137 | ||
The elemental composition of the carbide coating matrix (Figure 2 – Position 3)
| Elements | Concentration | |
|---|---|---|
| at.% | wt.% | |
| Fe | 86.117 | 68.616 |
| W | 11.103 | 29.124 |
| Ni | 1.511 | 1.265 |
| Mn | 1.269 | 0.995 |