Method for correcting downhole NMR data contaminated by borehole signals

摘要

NMR measurements made in a borehole are susceptible to contamination by signals from the borehole fluid. Correction is made for this contamination by using a standoff measuring device to determine the fractional volume of the region of investigation of the NMR tool that lies within the borehole. Using known or determined characteristics of the borehole fluid, a correction is made either to the NMR signals prior to processing or to the processed results of the uncorrected signals.