FREMGANGSMAATER OG APPARATER FOR VURDERING AV FORMASJONSKARAKTERISTIKA VED BORING AV ET BOREHULL GJENNOM JORDFORMASJONER.

摘要

The MWD methods and MWD apparatus disclosed herein include methods and apparatus for rotating a directionally-responsive radiation sensor having an outwardly-directed response axis in a borehole. These MWD methods and MWD apparatus further includes methods and apparatus for obtaining a series of successive measurements representative of a geometrical parameter of the borehole as well as a characteristic of the adjacent earth formations as the sensor scans circumferentially-spaced locations on the walls of a borehole interval. Methods and apparatus are provided for determining the mean of the successive measurements as well as the standard deviation of the successive measurements and then combining these computations for providing output signals that are uniquely corrected in accord with variations in the transverse cross-sectional configuration of the borehole for providing indications representative of the desired formation characteristic as well as indications representative of the borehole configuration.