Table 4: Wiper trip data before and after drilling fluid improvement method no.1. Dh refers to hole diameter, Dp to outside drill-pipe diameter, Pv plastic viscosity and Ds is average cutting diameter.

Wiper Trips when the drilling fluid properties not improved on 9.12.2009
Q (gpm) Dh (in) Dp (OD) inch Pv (cps) Mw (ppg) Mws (ppg) Ds (in)
441 12 ¼`` 5 25 12 20 0.2
Wiper Trips when the drilling fluid properties not improved on 9.12.2009
368 12 ¼`` 5 34 14.5 35 0.1