Method and apparatus for determining depth of drill cuttings

摘要

A method and apparatus for identifying cuttings (20) from a wellbore (18) are provided. The cuttings are segregated through a screen assembly (33) where they can be identified by measuring emissions such as alfa, beta, or gamma particles which emanate from the cuttings via a collector or storage vessel (40). A continuous wellbore profile of the emissions from cuttings can be constructed by measuring the emissions taken from different locations in the wellbore, and by documenting such emissions. The effects of cutting dispersion caused by differing particle sizes can be reduced by collecting cuttings of an intermediate size (68) for analysis. The profile of the intermediate size cuttings can be compared with a well log to identify the original elevation of the cuttings within the wellbore.