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Drilling mud flow into the well, through the pipe, pipe head and back through the annulus between the bore and pipe is accompanied by
Complicated heat transfer phenomena and

displacement of chips of earth turn off by the
action ot the bit. Considerable amount of heat is
released at the drilling point and earth's

temperature also increases with depth, both of which cause changes in the physical properties of
the mud especially its viscosity. In the return path the mud must carry the soil chips with itself to the ground level. The ability to do this also depends
on the viscosity of the mud, which is a non-Newtonian fluid and the pressure changes in the flow path.
In this study mud viscosity changes due to temperature changes have been studied and by solving the mathematical equations governing the
heat transfer and dynamics of the mud, the transport of the drilling soil chips by the mud has
been investigated.