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A Method to Improve the Sensitivity of Neutron Porosity Measurement Based on D-T Source
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 78th EAGE Conference and Exhibition 2016, May 2016, Volume 2016, p.1 - 5
Abstract
Deuterium-Tritium (D-T) source shows a lower sensitivity to the variation of formation porosity when it is utilized in compensated porosity logging tools compared with Am-Be source. In order to improve the sensitivity, the factors of an infinite homogeneous formation influencing the slowing-down length and near to far counts ratio are analyzed. Then Monte Carlo simulation method is used to build well logging models to study the measurement responses of a neutron porosity logging tool to hydrogen index and density. It shows that in addition to hydrogen index, the variation of the density when formation porosity is changed also has a great impact on slowing-down length and the counts ratio which reduces the sensitivity of the ratio to porosity. A new method to improve the measurement sensitivity is proposed. The method is used to process the measured data in a test well, the ratio after processing shows improved dynamic range and sensitivity to porosity compared with the values without processing.