Patent ID: 7809508

Claim:
A method for correcting logging while drilling formation density measurements affected by tool standoff comprising the steps of: determining an initial formation density measurement at a defined formation depth, the initial formation density measurement being equal to an apparent formation density, wherein determining the initial formation density measurement comprises identifying from collected formation data at least one primary density quadrant of a formation at the defined formation depth; calculating, by a computer, a tool standoff measurement; after calculating the tool standoff measurement: computing, by the computer, an initial formation density and photo electric factor (PEF) histogram of the collected formation data, wherein PEF is the photo-electric factor; identifying at least one good density quadrant from the collected formation data; and building up a correction database with primary quadrant density measurements, apparent density measurements and standoff estimations from other formation quadrants; calculating, by the computer, a density correction term from the apparent formation density and the tool standoff measurement; and computing, by the computer, a corrected formation density using the density correction term and the apparent formation density.