Radionuclide-based logging tools critical for reservoir characterization and well placement, are still under scrutiny due to their continuing security and/or safety risks. Of concern are Am-Be source tools used for neutron porosity, zonal correlation and spectroscopy-to-mineralogy, and Cs-137 source tools used for density. Acoustic and NMR porosity techniques, and radiation generator-based density, porosity and mineralogy techniques have been tested by industry as alternatives, with mixed results. Novel Alt-tech concepts are being assessed. Simultaneously, tighter regulations have been promulgated, improved source-use protocols developed, and e-tags to monitor source movement are being field-tested.
The talk first briefly reviews source use and risks. The four-component risk-mitigation approach noted is then discussed, with emphasis on Alternative Technologies. Requirements alternatives must meet to be replacement are examined, tested alternatives are mapped to these requirements, and novel concepts being assessed with the potential to allow a step change in well logging are described. The talk concludes by exploring two questions with the audience: Can the industry continue use of risky radioactive sources while searching for replacement technologies-if yes, how? If not, are alternatives wishful thinking?
Ahmed Badruzzaman is a consultant to US Department of Energy (DOE) on mitigating risks of radionuclide-based well logging tools. His 37 years on down-hole nuclear techniques includes R&D at Chevron, Sandia National Laboratories, and Schlumberger-Doll, and teaching at University of California, Berkeley. He led USDOE’s 2015 Scoping Study on Alternatives and guided their 2016/2017 initiative on source security & alternatives in Central Asia and Ukraine. He is a primary industry discussant on the topic through his own research with a patent on n-gamma density as an alternative to Cs-137-based density, technical papers on other novel nuclear-based alternatives, leadership of SPWLA’s Nuclear Logging SIG, and commentary at various forums. He helped develop Chevron’s in-house Radioactive Source Handling Guideline, prepare IAEA’s draft logging source safety guide under review, and revise Vienna-based WINS’ Best Practice Guide on security of these sources. He was an official reviewer of US National Academy of Sciences’ 2008 report to Congress, “Radiation Source Use and Replacement.” Author of over 45 papers, two US patents, and an upcoming textbook on Nuclear Logging, Ahmed is a Fellow of American Nuclear Society, a past SPE Distinguished Lecturer, and a two-time SPWLA Distinguished Speaker. He holds PhD in Nuclear Engineering and Science from Rensselaer Polytechnic Institute, Troy, NY.