Method and system for predicting performance of a drilling system for a given formation

A method for predicting the performance of a drilling system for the drilling of a well bore in a given formation, said prediction method comprising the steps of:

• generating a geology characteristic of the formation per unit depth according to a prescribed geology model and outputting signals representative of the geology characteristic, the geology characteristic including at least rock strength;
• obtaining specifications of proposed drilling equipment for use in the drilling of the well bore, the specifications including at least a bit specification of a recommended drill bit;
• and
• determining a predicted drilling mechanics in response to the specifications of the proposed drilling equipment as a function of the geology characteristic per unit depth according to a prescribed drilling mechanics model and outputting signals representative of the predicted drilling mechanics, the predicted drilling mechanics including at least one of the following selected from the group consisting of bit wear, mechanical efficiency, power, and operating parameters.

A method for drilling a series of well bores in a given formation for a given drilling program with the use of a given drilling system and an apparatus for predicting the performance of the drilling system, the prediction apparatus having a prescribed set of geology and drilling mechanics models and further having optimization, prediction, and calibration modes of operation, the prediction apparatus further comprising a means for generating a geology characteristic of the formation per unit depth according to the prescribed geology model and outputting signals representative of the geology characteristic, the geology characteristic including at least rock strength, a means for inputting specifications of proposed drilling equipment for use in the drilling of a well bore, the specifications including at least a bit specification of a recommended drill bit, and a means for determining a predicted drilling mechanics in response to the specifications of the proposed drilling equipment as a function of the geology characteristic per unit depth according to the prescribed drilling mechanics model and outputting signals representative of the predicted drilling mechanics, the predicted drilling mechanics including at least one of the following selected from the group consisting of bit wear, mechanical efficiency, power, and operating parameters, said method comprising the steps of:

• (a) generating a predicted drilling performance for drilling of a given well bore in accordance with the prescribed set of geology and drilling mechanics prediction models using at least one of the following modes selected from the group consisting of the optimization mode and the prediction mode, the predicted drilling performance including predicted drilling mechanics measurements;
• (b) deciding whether or not to obtain actual drilling mechanics measurements during the drilling of the given well bore;
• (c) if obtaining actual drilling mechanics measurements, then drilling the given well bore with the drilling system using the predicted drilling performance as a guide and obtaining actual drilling mechanics measurements;
• (c-1) comparing the actual drilling mechanics measurements to the predicted drilling mechanics measurements using the calibration mode;
• (c-2) if the comparison of the actual drilling mechanics measurements to the predicted drilling mechanics measurements are acceptable, then advancing to step (e);
• and
• (c-3) if the comparison of the actual drilling mechanics measurements to the predicted drilling mechanics measurements are not acceptable, then fine tuning at least one of the geology and drilling mechanics models using the calibration mode and advancing to step (e);
• (d) if not obtaining actual drilling mechanics measurements, then drilling the given well bore with the drilling system using the predicted drilling performance as a guide and without obtaining actual drilling mechanics measurements;
• and
• (e) determining if any further well bores of the series of well bores remain to be drilled and if yes, then returning to step (a) with respect to the drilling of a subsequent well bore in the series of well bores, and if no, then ending the drilling of the series of well bores.

A computer program stored on a computer-readable medium for execution by a computer for predicting the performance of a drilling system in the drilling of a well bore of a given formation, said computer program comprising:

• instructions for generating a geology characteristic of the formation per unit depth according to a prescribed geology model and outputting signals representative of the geology characteristic, the geology characteristic including at least rock strength;
• instructions for obtaining specifications of proposed drilling equipment for use in the drilling of the well bore, the specifications including at least a bit specification of a recommended drill bit;
• and
• instructions for determining a predicted drilling mechanics in response to the specifications of the proposed drilling equipment as a function of the geology characteristic per unit depth according to a prescribed drilling mechanics model and outputting signals representative of the predicted drilling mechanics, the predicted drilling mechanics including at least one of the following selected from the group consisting of bit wear, mechanical efficiency, power, and operating parameters.

A display of predicted performance of a drilling system suitable for use as guidance in the drilling of a well bore in a given formation, said display comprising:

• a geology characteristic of the formation per unit depth, said geology characteristic having been obtained according to a prescribed geology model and including at least rock strength;
• specifications of proposed drilling equipment for use in the drilling of the well bore, said specifications including at least a bit specification of a recommended drill bit;
• and
• a predicted drilling mechanics, said predicted drilling mechanics having been determined in response to said specifications of the proposed drilling equipment as a function of said geology characteristic per unit depth according to a prescribed drilling mechanics model, said predicted drilling mechanics including at least one of the following selected from the group consisting of bit wear, mechanical efficiency, power, and operating parameters.