METHOD FOR OPTIMIZING THE BIT DESIGN FOR A WELL BORE

摘要

A drill bit is designed to achieve optimum performance in a specified drilling application defined by the drilling system, the formation to be drilled and the configuration of the bore hole. A depth of cut versus predicted torque for a basic bit configuration is evaluated (Fig. 1) for different configurations of the drill bit. A computer modeling program is used to obtain the predicted torque for the basic bit configuration, and its modifications (Fig. 2). Features of the bit design are changed to achieve the lowest predicted torque for an optimum depth of cut. Presenting the computer analysis as depth of cut versus predicted torque for the bit design simplifies the design selection process. The formation being drilled may be evaluated by comparing actual torque with predicted torque for a given rate of penetration (Fig. 3). The evaluation can be used to confirm the computer model and determine formation properties.