Patent ID: 6019180
Filing Date: 2000-02-01
Classification: E21B,Y10T

Abstract:
A method for determining the stall pressure of a downhole drilling motor, comprising the steps of:a) measuring a first off-bottom stand-pipe pressure and a first stall pressure for said drilling motor at a first drilling fluid flow rate, said first flow rate being less than the actual fluid flow rate during drilling;b) measuring a second off-bottom stand-pipe pressure and a second stall pressure for said drilling motor at a second drilling fluid flow rate;c) measuring a third off-bottom stand-pipe pressure at a third drilling fluid flow rate, said third flow rate being the actual flow rate used during drilling operations;d) calculating a differential pressure across said drilling motor at said actual drilling fluid flow rate and while said motor is stalled using said previously measured stand-pipe pressures and stall pressures; ande) calculating the stall pressure at said actual flow rate during drilling from said off-bottom stand-pipe pressure in step (c) and said differential pressure in step (d).