METHOD FOR INITIAL AZIMUTHAL ADJUSTMENT OF BORE-HOLE INSTRUMENT OF HYGROSCOPIC INCLINOMETRE, AND AZIMUTHAL MODULE Russian patent published in 2013 - IPC E21B47/02 

FIELD: oil and gas industry.

SUBSTANCE: method for determining initial azimuth involves measurement of acceleration of gravity force relative to two mutually perpendicular axes, and based on the above measurements levelling of sensitivity axes of a two-channel angular speed metre (TCASM) is performed; then, rotation of TCASM sensitivity axes relative to a vertical axis is performed. Turning angle of those axes relative to the instrument housing and projections of a horizontal component of the Earth angular rotation speed is measured based on TCASM sensitivity axis. A residual function, which represents a sum of squares of difference of reference and measured angular speeds on two sets of measurements, and its minimisation as to azimuth of the housing, is calculated. At adjustment, a bore-hole instrument (BI) is placed into an azimuthal module (AM) and rotated about vertical axis till it is aligned as to angular position with AM housing. The proposed method is implemented by means of the azimuthal module containing turning platform (19), on which two acceleration metres (25, 26) and TCASM (20) is fixed. Axes of acceleration metres are mutually perpendicular to each other and perpendicular to a platform suspension axis, and TCASM sensitivity axes coincide with sensitivity axes of acceleration metres. Besides, the device includes rotor (18) of a mining engine, which is kinematically connected to the platform suspension axis, on which rotor (21) of outlet angle transmitter, which is made in the form of sine-cosine transformer, is fixed, and digital processing unit (23). Platform suspension axis (19) is parallel to symmetry axis of a vertical hole of the housing, on the flange of which assembly (6) for attachment of bore-hole instrument (7) is installed. Bore-hole instrument attachment assembly (6) is replaceable for the purpose of possible adjustment of bore-hole instruments of different diameters. Besides, in housing (4) there are two coaxial holes (44, 45), the symmetry axis Z_Am of which is perpendicular to and crosses the symmetry axis of the vertical hole and coincides with reference plane of azimuthal angle of AM housing. Azimuthal connection assembly (3) of BI housing to AM housing is installed into one coaxial hole (44), and retractable guide (40) of the same assembly enters the second hole (45).

EFFECT: improving accuracy of determination of initial azimuth of a bore-hole instrument.

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