Research Article
Chemical Effect on Wellbore Instability of Nahr Umr Shale
Table 1
The drilling fluid properties of three horizontal wells of Nahr Umr Formation.
| | Well no. | | N001H well-Hole 1 | N001H well-Hole 2 | N002H well | N006H well |
| Mud type | KCL-polymer | KCL-polymer | Salt saturated | BH-WEI | Density (g/cm3) | 1.25 | 1.25 | 1.28 | 1.28 | Viscosity (s) | 51 | 53 | 78 | 65 | Plastic viscosity (cp) | 26 | 27 | 41 | 39 | Y.P (lb/100 ft2) | 24 | 26 | 31 | 29 | Gel strength 10′′/10′ (lb/100 ft2) | 5/8 | 5/14 | 7/9 | 5/7 | API filtrate (mL) | 3.2 | 3.4 | 3.0 | 3 | Mud cake (mm) | 0.3 | 0.3 | 0.3 | 0.5 | PH | 9.5 | 9 | 9 | 8.5 | Solid (%) | 13 | 11 | 13 | 17 | Sand (%) | 0.3 | 0.3 | 0.2 | 0.3 | Bentonite content (g/L) | 27 | 26 | 38 | | Potassium (mg/L) | | | 27000 | | Chloride (mg/L) | | | 55000 | 11520 | Ca+ (mg/L) | | | 200 | |
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