Patent ID: 9309760
Filing Date: 2016-04-12
CPC Classification: E21B

Claim Text:
1. A method for directional drilling of a wellbore, comprising: drilling the wellbore initially substantially vertically while rotating a drill string disposed in the wellbore in a first direction; stopping rotation of the drill string in the first direction and orienting a toolface of a steerable drilling motor attached to the drill string in a selected direction; measuring a parameter related to torque exerted on the drill string to maintain the orientation of the toolface first when the steerable drilling motor exerts torque to rotate a drill bit so as to continue drilling the wellbore and second when the steerable drilling motor exerts no torque; determining a difference between the first measured parameter and the second measured parameter; setting a first torque value to correspond to the first measured parameter; setting a second torque value to correspond to the first measured parameter less a predetermined fraction of the difference, the second torque value lower than the first torque value; automatically rotating the drill string the first direction so that a measured torque related parameter thereon reaches the first torque value; automatically rotating the drill string in a second direction opposite to the first direction until the measured torque related parameter reaches the second torque value; and automatically controlling a rate of release of the drill string so that a measured pressure of drilling fluid is maintained at a selected pressure or within a selected pressure range.