METHOD DETERMINING ZENITH ANGLE AND AZIMUTH OF PLANE OF INCLINATION OF BOREHOLE AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2001 - IPC

FIELD: geophysical borehole measurements, specifically, determination of spatial position of axis of cased boreholes. SUBSTANCE: pickups measuring clearances between body of down-hole logging instrument and wall of borehole are mounted on head and lug of down-hole logging instrument to reduce errors of measurement of zenith angle and azimuth of plane of inclination of borehole caused by angular motions of down-hole logging instrument with reference to borehole walls. Spatial angle of deviation of longitudinal axis of down-hole logging instrument from direction parallel to axis of borehole is computed with use of information from above- mentioned pickups. Then projections of apsidal angle on plane of inclination of borehole and on horizontal plane are found with use of values of present value of apsidal angle, angle of installation of pickups measuring values of clearances between walls of down-hole logging instrument and borehole. Actual values of parameters of borehole are determined by algebraic subtraction of vertical projection from zenith angle and of horizontal projection from azimuth of inclination of down-hole logging instrument. Down-hole logging instrument of inclinometer has pickups of azimuth, zenith and apsidal angles, information transmitting unit, modules of distance pickups mounted in head and lug. Diametrically positioned groups of distance pickups, differentially coupled with use of adders determine values and signs of deviation of centers of sections of head and lug from axis of borehole. Values of angles of positioning of modules of pickups - angles between sensitivity axes of specified pickups and axes of pickups of zenith and apsidal angles are entered into correction unit and ground computer of inclinometer. EFFECT: enhanced precision and productivity of inclinometer operations. 2 cl, 5 dwg