Individually variably configurable drag members in an anti-rotation device

A rotary steerable subterranean drill capable of establishing a deflection angle and azimuthal toolface direction of a drill bit, the rotary steerable subterranean drill, comprising:

• a housing;
• an anti-rotation device positioned at an exterior of the housing and comprising a plurality of differently configurable, radially deployable drag members that are peripherally spaced about the exterior of the housing;
• and
• a controller coupled to the plurality of drag members and which is configured to instruct different deployed configurations of at least two of the drag members in dependence upon a controller-determined formation force experienced on a drill bit of the rotary steerable subterranean drill.

A method for determining a configuration of an anti-rotation device of a rotary steerable subterranean drill in a drilling configuration, the method comprising:

• detecting, at a sensor, a toolface direction of a drill bit and a magnitude of a formation force acting on the drill bit of a rotary steerable subterranean drill, wherein the rotary steerable subterranean drill comprises a housing, an anti-rotation device positioned at an exterior of the housing, and the anti-rotation device comprising a plurality of differently configurable, radially deployable drag members that are peripherally spaced about the exterior of the housing;
• receiving, at a controller, from the sensor, data representative of the detected toolface direction of the drill bit and the detected magnitude of the formation force acting on the drill bit;
• determining, at the controller, in dependence upon the received data representative of the detected toolface direction of the drill bit and the detected magnitude of a formation force acting on the drill bit, an instruction that differently configures the plurality of differently configurable, radially deployable drag members;
• and
• issuing, from the controller, the instruction and thereby configuring the rotary steerable subterranean drill into a corresponding drilling configuration in which the radially deployable drag members are differently configured.