Evaluation of Non-Nuclear Techniques for Well Logging: Technology Evaluation

Abstract

Sealed, chemical isotope radiation sources have a diverse range of industrial applications. There is concern that such sources currently used in the gas/oil well logging industry (e.g., americium-beryllium [AmBe], 252 Cf, 60 Co, and 137 Cs) can potentially be diverted and used in dirty bombs. Recent actions by the U.S. Department of Energy (DOE) have reduced the availability of these sources in the United States. Alternatives, both radiological and non-radiological methods, are actively being sought within the oilfield services community. The use of isotopic sources can potentially be further reduced, and source use reduction made more acceptable to the user community, if suitable non-nuclear or non-isotope-based well logging techniques can be developed. Data acquired with these non-nuclear techniques must be demonstrated to correlate with that acquired using isotope sources and historic records. To enable isotopic source reduction there is a need to assess technologies to determine (i) if it is technically feasible to replace isotopic sources with alternate sensing technologies and (ii) to provide independent technical data to guide DOE (and the Nuclear Regulatory Commission [NRC]) on issues relating to replacement and/or reduction of radioactive sources used in well logging.This report presents an initial review of the state-of-the-art nuclear and non-nuclear well logging methods and seeks to understand the technical and economic issues if AmBe, and potentially other isotope sources, are reduced or even eliminated in the oil-field services industry. Prior to considering alternative logging technologies, there is a definite need to open up discussions with industry regarding the feasibility and acceptability of source replacement. Industry views appear to range from those who see AmBe as vital and irreplaceable to those who believe that, with research and investment, it may be possible -to transition to electronic neutron sources and employ combinations of non-nuclear technologies to acquire the desired petro-physical parameters. In one sense, the simple answer to the question as to whether petro-physical parameters can be sensed with technologies other than AmBe is probably "Yes". The challenges come when attention turns to record interpretation. The many decades of existing records form a very valuable proprietary resource, and the interpretation of subtle features contained in these records are of significant value to the oil-gas exploration community to correctly characterize a well. The demonstration of equivalence and correspondence/correlation between established and any new sensing modality, and correlations with historic records is critical to ensuring accurate data interpretation. Establishing the technical basis for such a demonstration represents a significant effort.The focus of this study is the understanding of the technical obstacles that hinder the replacement of and the disadvantages from the loss of extensive interpretation experience based on data accumulated with AmBe. Enhanced ac...

Evaluation of Non-Nuclear Techniques for Well Logging: Final Report

“…Deliverables have included a report that provided an initial review of the state-of-the-art nuclear and non-nuclear well logging methods and seeks to understand the technical and economic issues if AmBe (and potentially other isotope sources) are reduced or even eliminated in the oil-field services industry (Bond et al 2010a). Prior to considering alternative logging technologies, it was determined that there is a definite need to open up discussions with industry regarding the feasibility and acceptability of source replacement.…”

“…Enhanced acoustic and electromagnetic sensing methods in combination with non-isotope-based well logging techniques have the potential to complement and/or replace existing isotope-based techniques, providing for the opportunity to reduce oil industry dependence on isotopic sources such as AmBe. This study provided initial insights to establish the information resources needed to provide independent technical data to guide DOE (and NRC) on issues relating to replacement and/or reduction of radioactive sources used in well logging (Bond et al 2010a). …”