Effect of Temperature on Drilling Mud

The main functions of drilling fluids include providing hydrostatic pressure to prevent formation fluids from entering into the well bore, cooling drilling bit, cleaning borehole while drilling and Stability of borehole. While drilling, the drilling mud transport drilling cuttings to surface and suspending the cuttings while drilling stop. There are many factors that effect on drilling mud, including the borehole temperature. Therefore, with increasing in drilling depth the wellbore temperature increases that effect on drilling mud properties (viscosity include yield point (YP) and plastic viscosity (PV)). This experimental work conducted at rig IDC 41, NS-39 in the Nasiriyah oil field by using real field data. The devices for this work are fan V-G meter (Model 286), heat source and temperature measurement (IR Thermometer).In this experiment using two types of drilling mud density (1.35 gm/cc and 1.21 gm/cc), with increasing temperature the value of PV and YP increase. Also, YP/PV ratio increasing means more drilling cuttings transport.