Acoustic Standoff measurements improve density and neutron data

Many boreholes are rugose, enlarged, or both. Enlarged wells are a particular problem when a measurement-while-drilling (MWD) tool is used in an extended-reach or horizontal well. A new method to determine and reduce the impact of borehole size and standoff on the measurement of formation density and neutron porosity has been developed. ○ Use of standoff-based binning of density-tool data provides simultaneous measurement of density and compensation at several standoffs. ○ A three-axis caliper provides a robust measurement of the borehole size to calculate both the borehole-size and standoff corrections for the neutron tool.