| CPC E21B 41/0021 (2013.01) | 23 Claims |

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1. A device for covering an opening of a wellbore, the device comprising:
a housing having a central opening, the housing configured to be secured within a well center opening;
a plurality of covers arranged around the central opening, the plurality of covers configured to: (a) move to an open-cover position, a partially-closed-cover position, or a closed-cover position; and (b) cover at least a portion of the central opening when the plurality of covers is in the partially-closed-cover position or the closed-cover position;
at least one actuator configured to extend and retract the plurality of covers; and
a controller configured to send signals to the at least one actuator to extend the plurality of covers and to retract the plurality of covers;
wherein the controller is further configured to use motion data and diameter data of a tubular to determine the partially-closed-cover position for a cover opening time, the partially-closed-cover position being based on the motion data and diameter data of the tubular, and the controller sends signals to extend and retract the plurality of covers to the partially-closed-cover position for the cover opening time.
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