Appeal No. 1997-1190
Application No. 08/427,972
from each other sufficient to determine vibration waveforms in
axial, torsional and bending modes. See, Abstract. As
described by Bseisu in reference to Figure 2:
The strain gages 74 and 76 and the accelerometers
80, 82 and 84 are provided with suitable signal
conductors which are trained along a shank 83 of the sub
38 within a protective sleeve 90 and then through a
longitudinal groove 92 which extends through the kelly 34
and along the outer surface of the sub 36, protected by a
sleeve 94, and through a suitable passage in the flange
40 to a signal conditioning amplifier and radio
transmitter unit, generally designated by the numeral
100. The transmitter unit 100 is provided with one or
more FM radio transmitters 102 disposed on support means
104 and disposed for beaming output signals to a
receiving antenna 106 mounted on a support characterized
by opposed depending legs 108 and 110 which are secured
to the frame 21. The antenna 106 is connected to a
suitable signal transmitting cable 114 which transmits
the signals generated by the strain gages and
accelerometers by way of the transmitter unit 100 to a
receiver 116. The receiver 116 may include means for
converting the signals to a form which may be analysed by
digital computer. In this way, certain kinds of computer
processing may be carried out to determine particular
vibration modes of the drillstem. Spectral analysis of
the signals received by the various accelerometers and
strain gages may be carried out to identify particular
frequencies. Such analyses could also be correlated with
downhole measurements taken by conventional
measurement-while-drilling (MWD) tools. Accordingly, with
some level of interpretive skill, surface measurements
taken by the system of the present invention can be
correlated with certain formation characteristics, for
example. (Col. 5, lines 36-68).
Bseisu also discloses that:
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