Abstract: A method and apparatus for measuring formation characteristics as a function of angular distance segments about the borehole is disclosed. The measurement apparatus includes a logging while drilling tool which turns in the borehole while drilling. Such characteristics as bulk density, photoelectric effect (PEF), neutron porosity and ultrasonic standoff are all measured as a function of such angular distance segments where one of such segments is defined to include that portion of a "down" or earth's gravity vector which is in a radial cross sectional plane of the tool. The measurement is accomplished with either a generally cylindrical tool which generally touches a down or bottom portion of the borehole while the tool rotates in an inclined borehole or with a tool centered by stabilizer blades in the borehole.
Type:
Grant
Filed:
January 14, 1994
Date of Patent:
December 5, 1995
Assignee:
Schlumberger Technology Corporation
Inventors:
Jacques M. Holenka, Michael L. Evans, Philip L. Kurkoski, William R. Sloan, David L. Best