Rotary steerable system steering pad actuator for wellbore drilling

A method of steering a drill string, the drill string including a remote steerable system (RSS), the RSS including a pad actuator and a steering collar, the pad actuator having a steering pad and a pad housing, the pad housing mounted on the steering collar, the steering pad pivotably coupled to the pad housing via a first hinge pin, the method comprising:

• receiving, at the RSS, pressure from upstream with respect to the RSS;
• directing the pressure to an actuation cylinder mounted on the steering collar;
• extending a piston along a longitudinal axis of the actuation cylinder in response to the pressure, the piston directly connected to the steering pad by, and pivoting around, a second hinge pin while pushing the steering pad to extend laterally as the steering pad pivots around the first hinge pin, the piston maintaining an approximately similar gap with the cylinder while pivoting around the second hinge pin;
• and
• applying, by the steering pad, a steering force to a wall of a wellbore.

A drill string for forming a wellbore, the drill string comprising:

• a drill bit;
• and
• a rotary steerable system (RSS) positioned upstream from the drill bit on the drill string, the RSS including:
• a steering collar, the steering collar including a plurality of pockets;
• a plurality of actuation cylinders, each actuation cylinder mounted within one of the pockets of the steering collar;
• a plurality of barrel-shaped pistons, each barrel-shaped piston positionable within one of the actuation cylinders, each piston including a piston hanger;
• and
• two or more pad actuators, each pad actuator including:
• a pad housing mounted on the steering collar;
• and
• a steering pad, wherein each steering pad is pivotably coupled to one of the pad housings via a first hinge pin and wherein each steering pad is directly connected via a second hinge pin to the piston hanger of at least one of the pistons,
• wherein each barrel-shaped piston is movable within its respective actuation cylinder such that, when extended out of the actuation cylinder, its respective steering pad pivots laterally from the steering collar on the first hinge pin to contact a side of the wellbore, urging the steering collar in a direction opposite the lateral direction.