摘要
在密度测井中利用X射线源代替传统^(137)Cs源成为新趋势。为了研究X射线管高压对探测器计数以及对密度测量精度的影响,首先利用蒙特卡罗模拟,研究了管高压与X射线能量以及强度的关系,并分析高压与计数率和统计误差的关系。然后模拟了不同密度地层的密度测井响应,计算得到不同高压对密度测量精度的影响,最终得到X射线密度测井合适的高压范围。研究表明:随着X射线管高压越大,计数率的相对标准偏差越小,当高压为340 kV时,密度的测量精度达到0.01 g·cm^(−3)。
[Background]It is a new trend to use X-ray sources instead of ^(137)Cs γ-ray source in density logging.[Purpose]This study aims to investigate the effect of X-ray tube high-voltage on the density measurement accuracy in the well logging.[Methods]Firstly,Monte Carlo(MC)simulation was used to study the X-ray tube high-voltage dependence of the energy and intensity of X-rays.Then,the relationship between the high-voltage and the count rate of X-rays as well as its statistical error was analyzed.Thereafter,the density logging response of formations with various densities was simulated by MC,and effects of the high-voltages on the accuracy of density measurements were calculated.Finally,the high-voltage range suitable for the X-ray density logging was obtained.[Results]Results from MC show that the relative standard deviation of the count rates decreases with the increase of X-ray tube high-voltages.The accuracy of the density measurements reach 0.01 g·cm^(-3) when the high-voltage is 340 kV.[Conclusion]This study provides a theoretical basis for the selection of X-ray tube high-voltages in the X-ray density logging and the design of well-logging schemes.
作者
于华伟
杨争春
刘超卓
张宇昕
祝倩
刘睿
YU Huawei;YANG Zhengchun;LIU Chaozhuo;ZHANG Yuxin;ZHU Qian;LIU Rui(School of Geosciences,China University of Petroleum(East China),Qingdao 266580,China;Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao 266580,China;College of Science,China University of Petroleum(East China),Qingdao 266580,China)
出处
《核技术》
CAS
CSCD
北大核心
2021年第11期47-52,共6页
Nuclear Techniques
基金
国家自然科学基金(No.41704113、No.41674129)
中央高校基本科研业务费(No.19CX02004A)资助。
