Advances in NMR Logging

Robert Freedman, Schlumberger Oilfield Services

This summary of the state of the art in nuclear-magnetic-resonance (NMR) well-logging technology is aimed at nonspecialists who would like to gain some knowledge of the formation-evaluation capabilities of NMR logging tools. The objective is to explain the basic measurement principles and interpretations needed to understand NMR formation-evaluation techniques and to discuss a few examples of these methods. Introduction of pulsed-NMR logging tools in the 1990s provided the industry with unique, even revolutionary, new methods for analyzing reservoir fluids, rocks, and fluid/rock interactions. The introduction of this technology came at an opportune time. It coincided with rapidly declining production after the 1970s drilling boom and the need for new tools to evaluate the more complex reservoirs being explored and developed. Pulsed-NMR logging tools brought a wealth of new and unique formation-evaluation applications, and this technology has grown rapidly since its inception. Today, major service companies (e.g., Baker Hughes, Halliburton, and Schlumberger) offer NMR logging services.

Distinguished Author Series - 89177 as published in JPT

Robert Freedman, SPE, is a scientific adviser and project manager in the Resistivity/NMR Dept. at the Schlumberger Sugar Land Product Center. He holds a PhD degree in condensed matter physics from the U. of California at San Diego. During his 30-year career in the petroleum industry, he has contributed to the physics, mathematical modeling, and interpretation of NMR, resistivity, and dielectric tools; modeling of deep-reading resistivity tools for relief-well drilling; and development of mathematical inverse methods. Freedman has served as associate editor of the SPE Formation Evaluation Journal, as SPE Distinguished Lecturer, and is a member of the SPE Petroleum Professional Certification Subcommittee. He is a recipient of the 2004 SPE Cedric K. Ferguson Award. Freedman has authored 43 industry publications and has been awarded 21 patents on well-logging technology.