Patent ID: 8636086

Claim:
A method of operating a drilling system, comprising: positioning the drilling system at a wellsite for drilling a borehole into an underground formation, the drilling system comprising: a tool body including a drilling motor; a drill bit mounted on the tool body to be rotated by the drilling motor; a mechanism for applying weight to the drill bit (“WOB”) during drilling; and a control system for controlling the rate of rotation of the drill bit (“RPM”) and the weight applied to the drill bit during drilling; wherein the control system is configurable to a first mode in which RPM and WOB are controlled to maintain power on the drill bit at a predetermined maximum; and wherein the control system is configurable to a second mode in which RPM and WOB are controlled to maintain a predetermined depth of cut (“DOC”); operating the drilling motor and mechanism for applying WOB to cause the drill bit to drill ahead; and using the control system to switch between the first mode and second mode depending on drilling conditions, wherein high frequency acquisition of drilling data allows identification of lithology and rock structure and stratigraphy through the use of downhole modeling, wherein the modeling comprises the use of neural networks and/or fuzzy logic.