METHOD TO MEASURE ZENITH AND AZIMUTHALANGLES Russian patent published in 2004 - IPC

FIELD: petroleum industry; boreholes deviation survey.

SUBSTANCE: the invention is pertinent to the precise instrumentation technologies and may be used at determination of drill-hole dip and direction of boreholes. The technical result of the invention is expansion of the range of application of a method and an increase of precision of definition of parameters of the borehole at effect of impacts of vibrations and availability of magnetic masses. For this purpose it is necessary to install and rigidly fix in the down-hole logging instrument housing three ferroprobes and three accelerometers. The axes of their sensitivity will form at orthogonal measuring system of coordinates. Then the housing of the down-hole logging instrument is moved down in the borehole on a fixed depth. Using the ferroprobes the builders of the full vector of the geomagnetic field are measured. Using indications of the accelerometers the builders of the full vector of a gravity are determined. On the base of the received data they calculate intermediate values of azimuth and zenith angles. Further they make matching of the current indications with a mean of indications of the four previous records, to define a tolerance. If the current indication is beyond the tolerance, then it is replaced by an average value. After that they make averaging of the fixed number of previous indications and replace the current measurements value by the averaged value. Then a filtering is conducted using an elimination filter.

EFFECT: the invention allows to expand the range of the method application to increase of precision of measurements.

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