A new neutron-gamma density measurement method using mass attenuation coefficient function
A new neutron-gamma density measurement method using mass attenuation coefficient function
Jun-Yan Chen 1Qiong Zhang1
作者信息
- 1. University of Electronic Science and Technology of China
- 折叠
摘要
While traditional gamma-gamma density (GGD) logging technology is widely utilized, its potential environmental risks have prompted the development of more environmentally friendly neutron-gamma density (NGD) logging technology. However, NGD measurements are influenced by both neutron and gamma radiation. In the logging environment, variations in formation composition indicate different elemental compositions, which affect neutron-gamma reaction cross-sections and gamma generation. Compared to traditional gamma sources such as Cs-137, these changes can significantly impact the generation and transport of neutron-induced inelastic gamma rays, posing challenges for accurate measurements. To address this, a novel method is proposed, the method incorporates the mass attenuation coefficient function to account for the effects of various lithologies and pore contents on gamma-ray attenuation and therefore can achieve more accurate density measurements by clarifying the transport processes of inelastic gamma rays with varying energy and spatial distributions in varied logging environments. The method avoids the complex correction of the neutron transport and is verified through Monte Carlo simulations for its applicability across various lithologies and pore contents. showing thatthe absolute density errors are less than 0.02 g/cm3 in clean formations and demonstrating good accuracy. The research not only clarifies the NGD mechanism but also provides theoretical guidance for the application of NGD logging methods. Further research will be conducted regarding extreme environmental conditions and tool calibration.Abstract
While traditional gamma-gamma density (GGD) logging technology is widely utilized, its potential environmental risks have prompted the development of more environmentally friendly neutron-gamma density (NGD) logging technology. However, NGD measurements are influenced by both neutron and gamma radiation. In the logging environment, variations in formation composition indicate different elemental compositions, which affect neutron-gamma reaction cross-sections and gamma generation. Compared to traditional gamma sources such as Cs-137, these changes can significantly impact the generation and transport of neutron-induced inelastic gamma rays, posing challenges for accurate measurements. To address this, a novel method is proposed, the method incorporates the mass attenuation coefficient function to account for the effects of various lithologies and pore contents on gamma-ray attenuation and therefore can achieve more accurate density measurements by clarifying the transport processes of inelastic gamma rays with varying energy and spatial distributions in varied logging environments. The method avoids the complex correction of the neutron transport and is verified through Monte Carlo simulations for its applicability across various lithologies and pore contents. showing that the absolute density errors are less than 0.02 g/cm3 in clean formations and demonstrating good accuracy. The research not only clarifies the NGD mechanism but also provides theoretical guidance for the application of NGD logging methods. Further research will be conducted regarding extreme environmental conditions and tool calibration. 关键词
Neutron-gamma density/Mass attenuation coefficient/Monte Carlo simulationKey words
Neutron-gamma density/Mass attenuation coefficient/Monte Carlo simulation引用本文复制引用
Jun-Yan Chen,Qiong Zhang.A new neutron-gamma density measurement method using mass attenuation coefficient function[EB/OL].(2025-06-12)[2025-12-13].https://chinaxiv.org/abs/202506.00065.学科分类
地球物理学/石油天然气地质、石油天然气勘探
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