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 1N001H well-Hole 2N002H wellN006H well

Mud typeKCL-polymerKCL-polymerSalt saturatedBH-WEI
Density (g/cm3)
Viscosity (s)51537865
Plastic viscosity (cp) 26274139
Y.P (lb/100 ft2)24263129
Gel strength 10′′/10′ (lb/100 ft2)5/85/147/95/7
API filtrate (mL)
Mud cake (mm)
Solid (%)13111317
Sand (%)
Bentonite content (g/L)272638
Potassium (mg/L)27000
Chloride (mg/L)5500011520
Ca+ (mg/L)200