Drilling system utilizing downhole dysfunctions for determining corrective actions and simulating drilling conditions

A simulator for simulating drilling of a borehole having a given borehole profile and drilled by a given bottom hole assembly (BHA), said system comprising:

• (a) a computer;
• (b) a memory associated with said computer for storing therein programmed instructions;
• and
• (c) a model associated with said computer, said model having defined therein parameters relating to the BHA and the borehole profile and a functional relationship that correlates selected BHA parameters with selected drilling parameters for the given BHA and the borehole profile,
• and wherein said computer upon the input of a set of drilling parameters thereto utilizes said program and provides expected values of the selected BHA parameters and their severity levels.

A method of drilling an oilfield wellbore with a drilling system having a drilling assembly and a drill bit at an end thereof at enhanced drilling rates and with extended drilling assembly life, said drilling assembly conveyable with a tubing into the wellbore, said drilling assembly containing a plurality of downhole sensors for determining parameters relating to the formations surrounding the wellbore and the condition of the drilling assembly elements, comprising:

• (a) conveying the drilling assembly with the tubing into the wellbore for drilling the wellbore;
• (b) initiating drilling of the wellbore with the drilling assembly utilizing a plurality of known initial drilling parameters;
• (c) determining from the downhole sensors, during drilling of the wellbore, dysfunctions relating to selected drilling assembly parameters;
• (d) providing a computer at the surface and a model that correlates the drilling assembly parameters to the drilling parameters and wherein the computer utilizing said model determines specific drilling parameters that when changed for further drilling of the wellbore will alleviate dysfunctions relating to the drilling assembly;
• and
• (e) further drilling the wellbore by changing at least one of the specific drilling parameters to improve the overall drilling efficiency.

A method of drilling a wellbore utilizing a drill string having a drill bit at an end thereof, comprising:

• (a) making measurements relating to a plurality of drill string parameters during drilling of the wellbore;
• (b) determining downhole severity of the drill string parameters from the measurements;
• (c) transmitting data to the surface corresponding to the severity of the drill string parameters;
• (d) determining at the surface by a computer and by utilizing a model at least one drilling parameter which when changed will alleviate the dysfunctions relating to a drill string parameter during continued drilling of the wellbore;
• and
• (e) continuing drilling of the wellbore by changing the at least one drilling parameter.

A system for drilling wellbores in subsurface formations from the surface, comprising:

• (a) a drill string having
• (i) a drilling assembly carrying a drill bit at a bottom end of the drilling assembly for drilling a wellbore,
• (ii) a plurality of sensors carried by the drilling assembly making measurements of a plurality of drilling assembly parameters during drilling of the wellbore,
• (iii) a processor carried by the drilling assembly computing from said measurements values of drilling assembly parameters, and
• (iv) a transmitter associated with the drill string transmitting signals representative of the drilling assembly parameters to the surface;
• and
• (b) a surface computer receiving the transmitted signals, said computer determining from said received signals and a model provided thereto values of at least one drilling parameter that when utilized for continued drilling of the wellbore would improve the drilling efficiency.