脉冲中子-裂变中子铀矿测井技术的蒙特卡罗模拟  

The Monte Carlo Simulation of Pulsed Neutron-Fission Neutron Uranium Logging Technique

作　　者：王新光[1] 王国保[1] 张国光[1] 窦玉玲[1] 丰树强[1] 赵潇[1] 

机构地区：[1]中国原子能科学研究院核技术应用研究所,北京102413

出　　处：《同位素》2013年第1期48-52,共5页Journal of Isotopes

摘　　要：脉冲中子-裂变中子铀矿测井方法(PNFN)是采用脉冲式中子源,利用3 He管中子探测器记录瞬发裂变超热中子或缓发裂变热中子,得到地层中铀矿含量信息的测井方法。利用MCNP程序模拟了不同铀含量、不同地层孔隙度地层条件下PNFN的响应,分析了瞬发裂变超热中子和缓发裂变热中子与地层铀含量和孔隙度的关系。结果表明,地层孔隙度对利用PNFN确定地层铀含量有影响,孔隙度越大,利用裂变中子直接计算得到的地层铀含量比真实含量越小。利用瞬发裂变超热中子或热中子时间衰减谱计算得到地层宏观俘获截面,对裂变中子进行校正,可以有效提高地层铀含量计算结果的准确度。PNFN was a method for uranium exploration.Pulsed neutron source was used,prompt fission epithermal neutron or delayed fission thermal neutrons were detected by using 3He neutron detector.Under the condition of different uranium content and porosity,the PNFN responses were simulated by using the MCNP code.The relationship between fission neutron and formation condition was studied.The obtained results showed that the larger the formation porosity,the lower the calculated uranium content.The precision of uranium content could be increased by the correction of scattering cross-section obtained by prompt fission epithermal or thermal neutron time decay spectrum method.

关 键 词：脉冲中子 裂变中子 铀矿测井 蒙特卡罗模拟 孔隙度校正 

分 类 号：P631.8[天文地球—地质矿产勘探] TL816[天文地球—地质学]