Method of automatically controlling the trajectory of a drilled well

Steering behavior model can include build rate and/or turn rate equations to modal bottom-hole assembly behavior. Build and/or turn rate equations can be calibrated by adjusting model parameters thereof to minimize any variance between actual response and estimated response produced for an interval of the well. Estimated position and orientation of a bottom-hole assembly along a subsequent interval can be generated by inputting subsequent tool settings into the calibrated steering behavior model. Estimated position and orientation can be compared to a well plan with a controller which determines a corrective action . Corrective action can be converted from a build and/or turn rate to a set of recommended tool settings by using an inverse application of the steering behavior model. As additional data becomes available, steering behavior model can be further calibrated through iteration.