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

FIELD: control and measurement of parameters of well drilling process; applicable in diagnostication of serviceability of rock-cutting tools with the aim of their efficient use and in development of automated control system of drilling process. SUBSTANCE: method includes measurement of drilling mud pressure fluctuations and variation of axial weight on drilling bit; determination of entropy of drilling mud pressure fluctuations S_1P and entropy of variation of axial weight on drilling bit S_1Q at initial moment of drilling process with new drilling bit, and entropy of drilling mud pressure fluctuations S_2P and entropy of variation of axial weight on drilling bit S_2Q of drilling bit actual scale. Criteria of serviceability are taken in the form of values F_P=S_2P/S_1P and F_Q=S_2Q/S_1Q. Their reference are set, and degree or serviceability of rock-cutting tool is determined by moment of attaining of these reference values by criteria. EFFECT: higher accuracy of evaluation of technical conditions of rock-cutting tool in process of its operation simultaneously by two measured parameters. 1 dwg, 1 tbl