METHOD OF DETERMINING FRICTION COEFFICIENTS BY THE "BIT-BOTTOM" SYSTEM DURING WELL DRILLING Russian patent published in 2016 - IPC E21B45/00 E21B44/00 

FIELD: mining.

SUBSTANCE: invention relates to drilling wells by means of reller-type bits and can be used for improvement of drilling conditions. Result is achieved by processes presentation, realized in the “bit-bottom“ system, by transducers characterized by generalized parameters - transmission coefficients: coefficient of speed transmission - instantaneous speed of drilling to peripheral speed of the bit periphery, coefficient of the broken rock volume transmission to the flow rate of flushing fluid. Check values of these coefficients determine coefficients of friction respectively to the rock face destruction and its cleaning of the broken rock. Summation of destruction friction coefficients and cleaning determines the friction coefficient of the “bit-bottom“ system linear movement. Cotangent of the ratio of the friction coefficient of rotational movement to the friction coefficient of linear movement determines the bit rotation attack angle, which in turn determines the pitch of the bit movement helical curve, that in turn promotes increase in mechanical drilling speed. Practical value of the knowledge of the attack angle is predicting mechanical drilling speed by selected parameters: diameter of the bit, number of its revolution, flushing fluid flow rate.

EFFECT: technical result is obtaining of friction coefficients of the bit rotational and linear movements at interaction of its drilling with rock face, that is “bit-bottom” system.

5 cl, 2 dwg