METHOD FOR OPTIMIZING DRILL BIT AND DRILLING PARAMETER SELECTION USING ROCK STRENGTH MEASUREMENTS MADE FROM DRILL CUTTINGS

摘要

A method for selecting a drilling parameter is disclosed. The method includes determining a loading displacement relationship for samples of earth formations. The loading displacement measurements are made by an indenter. The drilling parameter is selected from the loading displacement relationship. In one embodiment of the invention, the loading displacement relationship is determined from cuttings made during drilling of a wellbore. The loading displacement relationship determined during drilling is used to select at least one drilling parameter during drilling to improve drilling performance. Drilling parameters which can be selected include mill tooth and/or insert bit type; type of gauge protection to be used on the bit; type, size and orientation of jet nozzles on the bit; and blade structure, cutter type and density as well as the cutter impact resistance for fixed cutter bits. Other drilling parameters include weight on bit, drill bit rotation rate, and drilling fluid flow rate.