METHOD OF DETERMINING ROCK-CUTTING TOOL SERVICEABILITY Russian patent published in 2002 - IPC

FIELD: control over well drilling parameters; applicable in diagnosis of state of rock-cutting tools. SUBSTANCE: method includes measurement of fluctuations of drilling mud pressure on drilling bit and variation of bit load, selection of current criteria of serviceability, setting of their reference values and determination of rock-cutting tool serviceability by comparison of criteria current values with their reference values. Novelty consists in performance of wavelet conversion of unidimensional signals P(t) and G(t) measured at the beginning and in the course of percussion with determination of their scale-time base and values of full energy. Current criteria of serviceability are taken in the form of values given in invention description. Reference criteria values are determined in the course of drilling of cluster first well with use of maximum worn tool. EFFECT: higher accuracy of evaluation of technical condition of rock-cutting tool in drilling process. 5 dwg, 1 tbl